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1.
Cell Mol Life Sci ; 79(1): 35, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34989866

RESUMO

Multiple representatives of eulipotyphlan mammals such as shrews have oral venom systems. Venom facilitates shrews to hunt and/or hoard preys. However, little is known about their venom composition, and especially the mechanism to hoard prey in comatose states for meeting their extremely high metabolic rates. A toxin (BQTX) was identified from venomous submaxillary glands of the shrew Blarinella quadraticauda. BQTX is specifically distributed and highly concentrated (~ 1% total protein) in the organs. BQTX shares structural and functional similarities to toxins from snakes, wasps and snails, suggesting an evolutional relevancy of venoms from mammalians and non-mammalians. By potentiating thrombin and factor-XIIa and inhibiting plasmin, BQTX induces acute hypertension, blood coagulation and hypokinesia. It also shows strong analgesic function by inhibiting elastase. Notably, the toxin keeps high plasma stability with a 16-h half-life in-vivo, which likely extends intoxication to paralyze or immobilize prey hoarded fresh for later consumption and maximize foraging profit.


Assuntos
Analgesia/métodos , Hipocinesia/fisiopatologia , Musaranhos/metabolismo , Toxinas Biológicas/metabolismo , Peçonhas/metabolismo , Adulto , Sequência de Aminoácidos , Animais , Sequência de Bases , Pressão Sanguínea/efeitos dos fármacos , Feminino , Membro Posterior/efeitos dos fármacos , Membro Posterior/fisiopatologia , Humanos , Macaca mulatta , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Dor/induzido quimicamente , Dor/fisiopatologia , Dor/prevenção & controle , Homologia de Sequência de Aminoácidos , Musaranhos/genética , Trombina/antagonistas & inibidores , Trombina/metabolismo , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/genética , Peçonhas/genética
2.
Artigo em Inglês | MEDLINE | ID: mdl-32109507

RESUMO

Epidemiologic studies have shown that sleep disorders are associated with the development of hypertension. The present study investigated dynamic changes in sleep patterns during the development of hypertension across the lifespan in spontaneously hypertensive rats (SHRs) and the neural mechanism that underlies these comorbidities, with a focus on the orexinergic system. Blood pressure in rats was measured using a noninvasive blood pressure tail cuff. Sleep was monitored by electroencephalographic and electromyographic recordings. Immunohistochemistry was used to detect the density and activity of orexinergic neurons in the perifornical nucleus. Hcrt2-SAP (400 or 800 ng) was microinjected in the lateral hypothalamus to lesion orexinergic neurons. Compared with Wistar-Kyoto rats, SHRs exhibited various patterns of sleep disturbances. In SHRs, dynamic changes in hypersomnia in the rats' active phase was not synchronized with the development of hypertension, but hyperarousal in the inactive phase and difficulties in falling asleep were observed concurrently with the development of hypertension. Furthermore, the density and activity of orexinergic neurons in the perifornical nucleus were significantly higher in SHRs than in age-matched Wistar-Kyoto rats. The reduction of orexinergic neurons in the lateral hypothalamus partially ameliorated the development of hypertension and prevented difficulties in falling asleep in SHRs. These results indicate that although the correlation between sleep disturbances and hypertension is very complex, common mechanisms may underlie these comorbidities in SHRs. Overactivity of the orexin system may be one such common mechanism.


Assuntos
Hipertensão/metabolismo , Neurônios/metabolismo , Orexinas/metabolismo , Transtornos do Sono-Vigília/metabolismo , Animais , Hipertensão/fisiopatologia , Masculino , Microinjeções , Neurônios/efeitos dos fármacos , Neuropeptídeos/administração & dosagem , Neuropeptídeos/toxicidade , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY , Saporinas/administração & dosagem , Saporinas/toxicidade , Transtornos do Sono-Vigília/fisiopatologia , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/toxicidade
3.
J. venom. anim. toxins incl. trop. dis ; 26: e20190070, 2020. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1484764

RESUMO

Background: Intrathecal injection of voltage-sensitive calcium channel blocker peptide toxins exerts analgesic effect in several animal models of pain. Upon intrathecal administration, recombinant Phα1β exerts the same analgesic effects as the those of the native toxin. However, from a clinical perspective, the intrathecal administration limits the use of anesthetic drugs in patients. Therefore, this study aimed to investigate the possible antinociceptive effect of intravenous recombinant Phα1β in rat models of neuropathic pain, as well as its side effects on motor, cardiac (heart rate and blood pressure), and biochemical parameters. Methods: Male Wistar rats and male Balb-C mice were used in this study. Giotto Biotech® synthesized the recombinant version of Phα1β using Escherichia coli expression. In rats, neuropathic pain was induced by chronic constriction of the sciatic nerve and paclitaxel-induced acute and chronic pain. Mechanical sensitivity was evaluated using von Frey filaments. A radiotelemeter transmitter (TA11PA-C10; Data Sciences, St. Paul, MN, USA) was placed on the left carotid of mice for investigation of cardiovascular side effects. Locomotor activity data were evaluated using the open-field paradigm, and serum CKMB, TGO, TGP, LDH, lactate, creatinine, and urea levels were examined. Results: Intravenous administration of recombinant Phα1β toxin induced analgesia for up to 4 h, with ED50 of 0.02 (0.01-0.03) mg/kg, and reached the maximal effect (Emax = 100% antinociception) at a dose of 0.2 mg/kg. No significant changes were observed in any of the evaluated motor, cardiac or biochemical parameters. Conclusion: Our data suggest that intravenous administration of recombinant Phα1β may be feasible for drug-induced analgesia, without causing any severe side effects.


Assuntos
Masculino , Animais , Ratos , Analgésicos , Neuropatia Ciática/terapia , Paclitaxel , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/efeitos adversos , Venenos de Aranha/química , Administração Intravenosa , Camundongos Endogâmicos BALB C , Ratos Wistar
4.
Eur J Pharm Biopharm ; 132: 211-221, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30223028

RESUMO

Lysolipid-containing thermosensitive liposomes (LTSL) are clinically-relevant drug nanocarriers which have been used to deliver small molecule cytostatics to tumors in combination with local hyperthermia (42 °C) to trigger local drug release. The objective of this study was to investigate the feasibility of LTSL for encapsulation and triggered release of macromolecular drugs such as plant-derived cytotoxins. As therapeutic protein we used Mistletoe lectin-1 (ML1) - a ribosome-inactivating protein with potent cytotoxic activity in tumor cells. Model macromolecules (dextrans, albumin) and ML1 were encapsulated in small unilamellar LTSL with varying lipid compositions by the thin film hydration method and extrusion. LTSLs showed molecular weight dependent heat-triggered release of the loaded cargo. The most promising composition, ML1 formulated in LTSL composed of 86:10:4 %mol DPPC:MSPC:DSPE-PEG2000, was further studied for bioactivity against murine CT26 colon carcinoma cells. Confocal live-cell imaging showed uptake of released ML1 after mild hyperthermia at 42 °C, subsequently leading to potent cytotoxicity by LTSL-ML1. Our study shows that LTSL in combination with localized hyperthermia hold promise as local tumor delivery strategy for macromolecular cytotoxins.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Neoplasias do Colo/tratamento farmacológico , Lipídeos/química , Proteínas Inativadoras de Ribossomos Tipo 2/administração & dosagem , Toxinas Biológicas/administração & dosagem , Albuminas/química , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Química Farmacêutica/métodos , Neoplasias do Colo/patologia , Dextranos/química , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Temperatura Alta , Lipossomos , Camundongos , Peso Molecular , Proteínas Inativadoras de Ribossomos Tipo 2/química , Proteínas Inativadoras de Ribossomos Tipo 2/farmacologia , Temperatura , Toxinas Biológicas/química , Toxinas Biológicas/farmacologia
5.
Viral Immunol ; 31(3): 233-241, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29185875

RESUMO

Due to the limitations and safety issues of the two currently approved live attenuated rotavirus (RV) vaccines "RotaTeq and Rotarix," studies on nonreplicating sources of RV vaccines and search for proper RV antigens are actively carried out. The adjuvant activity of NSP4 and highly immunogenic properties of RV VP6 protein prompted us to consider the construction of a NSP4112-175-VP6 fusion protein and to assess the anti-VP6 IgG, IgA, and IgG subclass responses induced by Escherichia coli-derived NSP4-VP6 fusion protein compared to that of VP6 protein with/without formulation in Montanide ISA 50V2 (M50) in BALB/c mice. Results indicated to the proper expression of the fused NSP4-VP6 and VP6 proteins in E. coli. Intraperitoneal immunization by M50 formulated NSP4-VP6 fusion protein (M5+NSP4-VP6) induced the highest titration of VP6-specific IgG and IgA responses compared to the other groups. Indeed, the presence of NSP4 resulted to the induction of stronger humoral immune responses against the fused protein compared to that elicited by administration of VP6 protein alone (with/without M50 formulation), implying the adjuvant properties of NSP4 for the fused protein. Moreover, the "M50+NSP4-VP6" formulation induced higher serum IgG2a titers than IgG1 and increased Interferon-γ levels, despite unchanged interleukin-4 amounts compared to other groups, indicating Th1-oriented responses with a possible role of NSP4. In conclusion, this study further highlights the potentiality of NSP4-VP6 fusion protein as an efficient and cost-effective immunogen in the field of RV vaccine development.


Assuntos
Antígenos Virais/imunologia , Proteínas do Capsídeo/imunologia , Glicoproteínas/imunologia , Proteínas Recombinantes de Fusão/imunologia , Vacinas contra Rotavirus/imunologia , Rotavirus/imunologia , Toxinas Biológicas/imunologia , Proteínas não Estruturais Virais/imunologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/administração & dosagem , Antígenos Virais/genética , Proteínas do Capsídeo/administração & dosagem , Proteínas do Capsídeo/genética , Glicoproteínas/administração & dosagem , Glicoproteínas/genética , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Interferon gama/metabolismo , Leucócitos Mononucleares/imunologia , Camundongos Endogâmicos BALB C , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/genética , Vacinas contra Rotavirus/administração & dosagem , Vacinas contra Rotavirus/genética , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/genética , Proteínas não Estruturais Virais/administração & dosagem , Proteínas não Estruturais Virais/genética
6.
Nat Commun ; 8(1): 1495, 2017 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-29138448

RESUMO

Animals using toxic peptides and proteins for predation or defense typically depend on specialized morphological structures, like fangs, spines, or a stinger, for effective intoxication. Here we show that amphibian poisons instead incorporate their own molecular system for toxin delivery to attacking predators. Skin-secreted peptides, generally considered part of the amphibian immune system, permeabilize oral epithelial tissue and enable fast access of cosecreted toxins to the predator's bloodstream and organs. This absorption-enhancing system exists in at least three distantly related frog lineages and is likely to be a widespread adaptation, determining the outcome of predator-prey encounters in hundreds of species.


Assuntos
Anuros/imunologia , Peptídeos/toxicidade , Comportamento Predatório , Toxinas Biológicas/toxicidade , Animais , Anti-Infecciosos , Células CACO-2 , Humanos , Peptídeos/metabolismo , Pele/metabolismo , Absorção Cutânea , Toxinas Biológicas/administração & dosagem
8.
Rev Esp Med Nucl Imagen Mol ; 36(2): 110-112, 2017.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27637868

RESUMO

Some patients use complementary medicine. We present a patient with Hodgkin's lymphoma, scanned with 18F-FDG PET/CT for evaluation of response after chemotherapy, who was self-administering mistletoe as a homeopathic medicine product. The careful review of the images of the entire scan and patient collaboration in anamnesis were crucial to avoid a false positive result. A review of the published scientific data on the effects of mistletoe is also presented.


Assuntos
Antineoplásicos Fitogênicos/efeitos adversos , Radioisótopos de Flúor/análise , Fluordesoxiglucose F18/análise , Doença de Hodgkin/diagnóstico por imagem , Linfonodos/diagnóstico por imagem , Materia Medica/efeitos adversos , Fitoterapia/efeitos adversos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos/análise , Proteínas Inativadoras de Ribossomos Tipo 2/efeitos adversos , Toxinas Biológicas/efeitos adversos , Viscum album/efeitos adversos , Adulto , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Bleomicina/administração & dosagem , Dacarbazina/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Doença de Hodgkin/tratamento farmacológico , Humanos , Injeções Subcutâneas , Linfonodos/efeitos dos fármacos , Estadiamento de Neoplasias , Proteínas Inativadoras de Ribossomos Tipo 2/administração & dosagem , Proteínas Inativadoras de Ribossomos Tipo 2/uso terapêutico , Automedicação , Gordura Subcutânea/diagnóstico por imagem , Gordura Subcutânea/metabolismo , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/uso terapêutico , Vimblastina/administração & dosagem
9.
Toxicon ; 118: 129-33, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27058514

RESUMO

The Annonaceous acetogenin annonacin is an environmental neurotoxin identified in the pulp of several fruits of the Annonaceae family, whose consumption was linked to the occurrence of sporadic atypical Parkinsonism with dementia. A method for its quantification in Rat brain homogenates by UPLC-MS/MS in selected reaction monitoring (SRM) mode was developed and validated. This method was applied to the quantitation of annonacin in Rat brain after intravenous (0.5 mg/kg) and oral (10 mg/kg, 100 mg/kg) administration.


Assuntos
Encéfalo/metabolismo , Poluentes Ambientais/toxicidade , Furanos/toxicidade , Lactonas/toxicidade , Neurônios/metabolismo , Toxinas Biológicas/toxicidade , Administração Oral , Animais , Biotransformação , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Complexo I de Transporte de Elétrons/metabolismo , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/análise , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/análise , Inibidores Enzimáticos/toxicidade , Furanos/administração & dosagem , Furanos/análise , Injeções Intravenosas , Lactonas/administração & dosagem , Lactonas/análise , Masculino , Neurônios/química , Ratos Wistar , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Distribuição Tecidual , Toxicocinética , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/análise
10.
J Am Soc Nephrol ; 26(2): 281-90, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25012179

RESUMO

Indoxyl sulfate and p-cresol sulfate have been suggested to induce kidney tissue remodeling. This study aimed to clarify the molecular mechanisms underlying this tissue remodeling using cultured human proximal renal tubular cells and half-nephrectomized mice treated with indoxyl sulfate or p-cresol sulfate as study models. Molecular docking results suggested that indoxyl sulfate and p-cresol sulfate dock on a putative interdomain pocket of the extracellular EGF receptor. In vitro spectrophotometric analysis revealed that the presence of a synthetic EGF receptor peptide significantly decreased the spectrophotometric absorption of indoxyl sulfate and p-cresol sulfate. In cultured cells, indoxyl sulfate and p-cresol sulfate activated the EGF receptor and downstream signaling by enhancing receptor dimerization, and increased expression of matrix metalloproteinases 2 and 9 in an EGF receptor-dependent manner. Treatment of mice with indoxyl sulfate or p-cresol sulfate significantly activated the renal EGF receptor and increased the tubulointerstitial expression of matrix metalloproteinases 2 and 9. In conclusion, indoxyl sulfate and p-cresol sulfate may induce kidney tissue remodeling through direct binding and activation of the renal EGF receptor.


Assuntos
Cresóis/farmacologia , Receptores ErbB/efeitos dos fármacos , Indicã/farmacologia , Rim/efeitos dos fármacos , Rim/patologia , Toxinas Biológicas/farmacologia , Animais , Células Cultivadas , Cresóis/administração & dosagem , Humanos , Técnicas In Vitro , Indicã/administração & dosagem , Injeções Intraperitoneais , Rim/cirurgia , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos , Modelos Animais , Nefrectomia , Transdução de Sinais/efeitos dos fármacos , Toxinas Biológicas/administração & dosagem
11.
Am J Physiol Gastrointest Liver Physiol ; 307(2): G233-40, 2014 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-24875101

RESUMO

Interferon (IFN)-γ-driven and CD8+ T cell-dependent inflammatory injury to extrahepatic biliary epithelium (EHBE) is likely to be involved in the development of biliary atresia (BA). We previously showed that viral protein NSP4 is the pathogenic immunogen that causes biliary injury in BA. In this study, NSP4 or four synthetic NSP4 (NSP4(157-170), NSP4(144-152), NSP4(93-110), NSP4(24-32)) identified by computer analysis as candidate CD8+ T cell epitopes were injected into neonatal mice. The pathogenic NSP4 epitopes were confirmed by studying extrahepatic bile duct injury, IFN-γ release and CD8+ T cell response against EHBE. The results revealed, at 7 days postinjection, inoculation of glutathione S-transferase (GST)-NSP4 caused EHBE injury and BA in neonatal mice. At 7 or 14 days postinject, inoculation of GST-NSP4, NSP4(144-152), or NSP4(157-170) increased IFN-γ release by CD8+ T cells, elevated the population of hepatic memory CD8+ T cells, and augmented cytotoxicity of CD8+ T cells to rhesus rotavirus (RRV)-infected or naive EHBE cells. Furthermore, depletion of CD8+ T cells in mice abrogated the elevation of GST-NSP4-induced serum IFN-γ. Lastly, parenteral immunization of mouse dams with GST-NSP4, NSP4(144-152), or NSP4(157-170) decreased the incidence of RRV-induced BA in their offspring. Overall, this study reports the CD8+ T cell response against EHBE is activated by epitopes within rotavirus NSP4 in experimental BA. Neonatal passive immunization by maternal vaccination against NSP4(144-152) or NSP4(157-170) is effective in protecting neonates from developing RRV-related BA.


Assuntos
Ductos Biliares Extra-Hepáticos/imunologia , Atresia Biliar/imunologia , Linfócitos T CD8-Positivos/imunologia , Epitopos de Linfócito T , Glicoproteínas/imunologia , Fragmentos de Peptídeos/imunologia , Infecções por Rotavirus/imunologia , Vacinas contra Rotavirus/imunologia , Toxinas Biológicas/imunologia , Proteínas não Estruturais Virais/imunologia , Animais , Ductos Biliares Extra-Hepáticos/patologia , Ductos Biliares Extra-Hepáticos/virologia , Atresia Biliar/patologia , Atresia Biliar/prevenção & controle , Atresia Biliar/virologia , Linfócitos T CD8-Positivos/virologia , Modelos Animais de Doenças , Feminino , Glicoproteínas/administração & dosagem , Imunização Passiva , Memória Imunológica , Injeções Intraperitoneais , Interferon gama/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Fragmentos de Peptídeos/administração & dosagem , Gravidez , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/imunologia , Infecções por Rotavirus/patologia , Infecções por Rotavirus/prevenção & controle , Infecções por Rotavirus/virologia , Vacinas contra Rotavirus/administração & dosagem , Linfócitos T Citotóxicos/imunologia , Toxinas Biológicas/administração & dosagem , Proteínas não Estruturais Virais/administração & dosagem
12.
J Pharm Pharm Sci ; 17(4): 475-84, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25579430

RESUMO

PURPOSE: Organic anion-transporting polypeptide (OATP) 1B1 and OATP1B3 contribute to hepatic uptake of numerous drugs. Thus, reduced OATP1B1 and OATP1B3 activity in chronic kidney disease (CKD) may have a major impact on the hepatic clearance of drugs. The effect of drug-uremic toxin interactions on OATP1B1 and OATP1B3 has not been well studied. In the present study, we examine the inhibitory effects of uremic toxins on OATP1B1 and OATP1B3 transport activity to evaluate the interactions between drugs and uremic toxins in patients with chronic kidney disease. METHODS. [3H]Estron-3-sulfate, [3H]taurocholate uptake and [3H]methotrexate by OATP1B1 and OATP1B3 expressing HEK293 cells were performed to evaluate the inhibitory effect of uremic toxins. To clarify whether the uremic toxins that interact with OATP1B1 and/or OATP1B3 were substrates for these transporters, we performed uptake studies. RESULTS. Four uremic toxins, kynurenic acid, indole-3-acetic acid, indoxyl sulfate, and p-cresol, inhibited OATP1B1- and OATP1B3-mediated transport in a concentration-dependent manner, with IC50 values of 180, 770, 2700, and 4600 µM, respectively, for OATP1B1 and 180, 1100, 1300, and 1700 µM, respectively, for OATP1B3. [3H]Methotrexate uptake by OATPs was also inhibited by the four uremic toxins in a dose-dependent manner. Uptake studies revealed that kynurenic acid is a substrate for both the OATP1B1 and OATP1B3. Moreover, OATP1B3 was involved in the transport of indoxyl sulfate. Indole-3-acetic acid and p-cresol were not significantly transported by OATP1B1 and OATP1B3. CONCLUSIONS. We showed that some uremic toxins inhibit OATP-mediated uptake in a concentration-dependent manner, and clarified OATPs contribution to uremic toxin handling in the liver. Thus, we provided basic information to estimate the inhibitory effects of uremic toxins on OATPs in CKD patients. These data suggest that the dose of drugs excreted via renal and non-renal pathways should be carefully adjusted in CKD patients.


Assuntos
Fígado/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Toxinas Biológicas/farmacologia , Transporte Biológico , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Concentração Inibidora 50 , Transportador 1 de Ânion Orgânico Específico do Fígado , Transportadores de Ânions Orgânicos/antagonistas & inibidores , Transportadores de Ânions Orgânicos Sódio-Independentes/antagonistas & inibidores , Membro 1B3 da Família de Transportadores de Ânion Orgânico Carreador de Soluto , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/metabolismo , Uremia/etiologia
13.
Stat Med ; 32(30): 5430-47, 2013 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-24018535

RESUMO

Phase I oncology clinical trials are designed to identify the optimal dose that will be recommended for phase II trials. This dose is typically defined as the dose associated with a certain probability of severe toxicity during the first cycle of treatment, although toxicity is repeatedly measured over cycles on an ordinal scale. We propose a new adaptive dose-finding design using longitudinal measurements of ordinal toxic adverse events, with proportional odds mixed-effect models. Likelihood-based inference is implemented. The optimal dose is then the dose producing a target rate of severe toxicity per cycle. This model can also be used to identify cumulative or late toxicities. The performances of this approach were compared with those of the continual reassessment method in a simulation study. Operating characteristics were evaluated in terms of correct identification of the target dose, distribution of the doses allocated and power to detect trends in the risk of toxicities over time. This approach was also used to reanalyse data from a phase I oncology trial. Use of a proportional odds mixed-effect model appears to be feasible in phase I dose-finding trials, increases the ability of selecting the correct dose and provides a tool to detect cumulative effects.


Assuntos
Antineoplásicos/administração & dosagem , Ensaios Clínicos Fase I como Assunto/métodos , Funções Verossimilhança , Estudos Longitudinais , Dose Máxima Tolerável , Modelos Estatísticos , Adulto , Antineoplásicos/toxicidade , Simulação por Computador , Humanos , Neoplasias/tratamento farmacológico , Preparações de Plantas/administração & dosagem , Preparações de Plantas/efeitos adversos , Proteínas Inativadoras de Ribossomos Tipo 2/administração & dosagem , Proteínas Inativadoras de Ribossomos Tipo 2/efeitos adversos , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/efeitos adversos
14.
Toxicol Appl Pharmacol ; 268(1): 79-89, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-23360887

RESUMO

Drug-induced liver injury (DILI) is a significant consideration for drug development. Current preclinical DILI assessment relying on histopathology and clinical chemistry has limitations in sensitivity and discordance with human. To gain insights on DILI pathogenesis and identify potential biomarkers for improved DILI detection, we performed untargeted metabolomic analyses on rats treated with thirteen known hepatotoxins causing various types of DILI: necrosis (acetaminophen, bendazac, cyclosporine A, carbon tetrachloride, ethionine), cholestasis (methapyrilene and naphthylisothiocyanate), steatosis (tetracycline and ticlopidine), and idiosyncratic (carbamazepine, chlorzoxasone, flutamide, and nimesulide) at two doses and two time points. Statistical analysis and pathway mapping of the nearly 1900 metabolites profiled in the plasma, urine, and liver revealed diverse time and dose dependent metabolic cascades leading to DILI by the hepatotoxins. The most consistent change induced by the hepatotoxins, detectable even at the early time point/low dose, was the significant elevations of a panel of bile acids in the plasma and urine, suggesting that DILI impaired hepatic bile acid uptake from the circulation. Furthermore, bile acid amidation in the hepatocytes was altered depending on the severity of the hepatotoxin-induced oxidative stress. The alteration of the bile acids was most evident by the necrosis and cholestasis hepatotoxins, with more subtle effects by the steatosis and idiosyncratic hepatotoxins. Taking together, our data suggest that the perturbation of bile acid homeostasis is an early event of DILI. Upon further validation, selected bile acids in the circulation could be potentially used as sensitive and early DILI preclinical biomarkers.


Assuntos
Ácidos e Sais Biliares/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Estresse Oxidativo/fisiologia , Toxinas Biológicas/toxicidade , Animais , Ácidos e Sais Biliares/sangue , Ácidos e Sais Biliares/urina , Biomarcadores/sangue , Biomarcadores/metabolismo , Biomarcadores/urina , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas , Hepatócitos/metabolismo , Masculino , Metabolômica/métodos , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Espectrometria de Massas em Tandem , Toxinas Biológicas/administração & dosagem
15.
Ther Deliv ; 3(3): 405-14, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22833997

RESUMO

Biological drugs are among the most exciting drugs of the future, offering better treatment options for patients than ever before but they need an appropriate delivery vehicle. Carrier erythrocytes are one of the most promising drug-delivery systems. Application of erythrocytes as containers for various drugs minimizes toxicity, decreasing the risk of side effects and pathologic immune reactions against encapsulated agents as well as improving their efficacy, leading to better patient compliance. This review discusses the rationale for the use of erythrocytes as a vehicle for biopharmaceuticals and summarizes the categories of these new encapsulable compounds that are currently under investigation. The authors' intent is to describe the development of this delivery system to give the reader an overview of the remarkable potential of erythrocytes as naturally designed carriers and their versatility in the field of biologics for the treatment of various pathological conditions.


Assuntos
Produtos Biológicos/administração & dosagem , Enzimas/administração & dosagem , Eritrócitos/fisiologia , Ácidos Nucleicos/administração & dosagem , Veículos Farmacêuticos , Antígenos/administração & dosagem , Portadores de Fármacos , Humanos , Peptídeos/administração & dosagem , Toxinas Biológicas/administração & dosagem
16.
Biosens Bioelectron ; 35(1): 503-506, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22498641

RESUMO

This work describes the application of an impedance-based measurement for the real time evaluation of targeted tumor therapies in cell culture (HeLa cells). We used a treatment procedure that is well established in cells and mice. Therein, tumor cells are treated with a combination of an epidermal growth factor-based targeted toxin named SE and particular plant glycosides called saponins. In the present study HeLa cells were seeded in different numbers onto interdigitated electrode structures integrated into the bottom of a 96 well plate. The cells were treated with SE in the presence and absence of the saponin SpnS-1 (isolated from Saponaria officinalis roots). The impedance was directly correlated with the viability of the cells. As expected from known end point measurements, a concentration dependent enhancement of toxicity was observed; however, with the impedance measurement we were for the first time able to trace the temporal changes of cell death during the combination treatment. This substantially added to the understanding of initial cellular mechanisms in the augmentation of the toxicity of targeted toxins by saponins and indicated the superiority of real time monitoring over end point assays. The method is less labor intensive and label-free with ease of monitoring the effects at each time point.


Assuntos
Técnicas Biossensoriais/métodos , Sobrevivência Celular/efeitos dos fármacos , Saponinas/administração & dosagem , Toxinas Biológicas/administração & dosagem , Antineoplásicos/administração & dosagem , Sistemas Computacionais , Sinergismo Farmacológico , Impedância Elétrica , Receptores ErbB/antagonistas & inibidores , Células HeLa , Humanos
17.
Leukemia ; 26(8): 1786-96, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22373785

RESUMO

Acute lymphoblastic leukemia (ALL) is the most common malignancy affecting children and a major cause of mortality from hematopoietic malignancies in adults. A substantial number of patients become drug resistant during chemotherapy, necessitating the development of alternative modes of treatment. rGel (recombinant Gelonin)/BlyS (B-lymphocyte stimulator) is a toxin-cytokine fusion protein used for selective killing of malignant B-cells expressing receptors for B-cell-activating factor (BAFF/BLyS) by receptor-targeted delivery of the toxin, Gelonin. Here, we demonstrate that rGel/BLyS binds to ALL cells expressing BAFF receptor (BAFF-R) and upon internalization, it induces apoptosis of these cells and causes downregulation of survival genes even in the presence of stromal protection. Using an immunodeficient transplant model for human ALL, we show that rGel/BLyS prolongs survival of both Philadelphia chromosome-positive and negative ALL-bearing mice. Furthermore, we used AMD3100, a CXCR4 antagonist, to mobilize the leukemic cells protected in the bone marrow (BM) microenvironment and the combination with rGel/BLyS resulted in a significant reduction of the tumor load in the BM and complete eradication of ALL cells from the circulation. Thus, a combination treatment with the B-cell-specific fusion toxin rGel/BLyS and the mobilizing agent AMD3100 could be an effective alternative approach to chemotherapy for the treatment of primary and relapsed ALL.


Assuntos
Antineoplásicos/uso terapêutico , Fator Ativador de Células B/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Proteínas Recombinantes de Fusão/uso terapêutico , Proteínas Inativadoras de Ribossomos Tipo 1/uso terapêutico , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Fator Ativador de Células B/administração & dosagem , Fator Ativador de Células B/genética , Fator Ativador de Células B/metabolismo , Benzilaminas , Medula Óssea/patologia , Linhagem Celular Tumoral , Ciclamos , Sinergismo Farmacológico , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Compostos Heterocíclicos/farmacologia , Humanos , Camundongos , Camundongos Nus , Camundongos SCID , NF-kappa B/antagonistas & inibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Inativadoras de Ribossomos Tipo 1/administração & dosagem , Proteínas Inativadoras de Ribossomos Tipo 1/genética , Proteínas Inativadoras de Ribossomos Tipo 1/metabolismo , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/metabolismo , Toxinas Biológicas/uso terapêutico , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
18.
PLoS One ; 7(3): e33432, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22438929

RESUMO

BACKGROUND: Two hormetic modifications of a monotonically decreasing log-logistic dose-response function are most often used to model stimulatory effects of low dosages of a toxicant in plant biology. As just one of these empirical models is yet properly parameterized to allow inference about quantities of interest, this study contributes the parameterized functions for the second hormetic model and compares the estimates of effective dosages between both models based on 23 hormetic data sets. Based on this, the impact on effective dosage estimations was evaluated, especially in case of a substantially inferior fit by one of the two models. METHODOLOGY/PRINCIPAL FINDINGS: The data sets evaluated described the hormetic responses of four different test plant species exposed to 15 different chemical stressors in two different experimental dose-response test designs. Out of the 23 data sets, one could not be described by any of the two models, 14 could be better described by one of the two models, and eight could be equally described by both models. In cases of misspecification by any of the two models, the differences between effective dosages estimates (0-1768%) greatly exceeded the differences observed when both models provided a satisfactory fit (0-26%). This suggests that the conclusions drawn depending on the model used may diverge considerably when using an improper hormetic model especially regarding effective dosages quantifying hormesis. CONCLUSIONS/SIGNIFICANCE: The study showed that hormetic dose responses can take on many shapes and that this diversity can not be captured by a single model without risking considerable misinterpretation. However, the two empirical models considered in this paper together provide a powerful means to model, prove, and now also to quantify a wide range of hormetic responses by reparameterization. Despite this, they should not be applied uncritically, but after statistical and graphical assessment of their adequacy.


Assuntos
Hormese , Modelos Biológicos , Plantas/efeitos dos fármacos , Amaranthus/efeitos dos fármacos , Amaranthus/crescimento & desenvolvimento , Bases de Dados Factuais , Relação Dose-Resposta a Droga , Germinação/efeitos dos fármacos , Hordeum/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , /crescimento & desenvolvimento , Conceitos Matemáticos , Medicago sativa/efeitos dos fármacos , Medicago sativa/crescimento & desenvolvimento , Desenvolvimento Vegetal , Sinapis/efeitos dos fármacos , Sinapis/crescimento & desenvolvimento , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/toxicidade , Triticum/efeitos dos fármacos , Triticum/crescimento & desenvolvimento
19.
Toxicol Sci ; 126(1): 72-83, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21987460

RESUMO

Ricin, isolated from the castor bean plant Ricinus communis, is included on the Centers for Disease Control and Prevention Category B list of bioterrorism agents, indicating that the toxin is moderately easy to disseminate and could result in moderate morbidity rates. This study evaluated two promising recombinant ricin subunit vaccines, one made using an Escherichia coli codon-optimized gene and the other using a yeast codon-optimized gene in E. coli-based fermentations. Rabbits were vaccinated four times over a period of 6 months and challenged with ∼10 to 30 times the median lethal dose of aerosolized ricin. All unvaccinated control rabbits were either found dead or humanely euthanized within 30 h postchallenge, while the rabbits vaccinated with either vaccine survived the exposure without adverse clinical signs. When the protective antibody responses were analyzed, no significant difference was seen between the two vaccines. However, there was a significant difference in the immune response over time for both vaccines tested. Although clinical pathology was unremarkable, significant histological lesions in the control animals included fibrinonecrotic pneumonia, acute necrotizing lesions in the upper respiratory tract, and necrotizing lymphadenitis in the lymph nodes draining the upper and lower respiratory tract. Vaccine-treated rabbits exhibited resolving lesions associated with ricin exposure, namely chronic inflammation in the upper respiratory tract and lungs, fibrosis, type II pneumocyte hyperplasia, and bronchiolitis obliterans. This study confirmed the safety and efficacy of two recombinant ricin subunit vaccines in rabbits, offering potential protection to warfighters and select populations.


Assuntos
Subunidades Proteicas/antagonistas & inibidores , Ricina/antagonistas & inibidores , Toxinas Biológicas/antagonistas & inibidores , Vacinas de Subunidades/uso terapêutico , Administração por Inalação , Animais , Armas Biológicas , Códon , Escherichia coli/genética , Escherichia coli/metabolismo , Feminino , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Masculino , Subunidades Proteicas/administração & dosagem , Subunidades Proteicas/genética , Coelhos , Distribuição Aleatória , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/antagonistas & inibidores , Proteínas Recombinantes/genética , Ricina/administração & dosagem , Ricina/genética , Ricina/toxicidade , Organismos Livres de Patógenos Específicos , Toxinas Biológicas/administração & dosagem , Toxinas Biológicas/genética , Toxinas Biológicas/toxicidade , Vacinas de Subunidades/efeitos adversos , Vacinas de Subunidades/imunologia , Vacinas Sintéticas/efeitos adversos , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/uso terapêutico , Leveduras/genética , Leveduras/metabolismo
20.
Neoplasia ; 12(5): 366-75, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20454508

RESUMO

Diffuse large B-cell lymphoma (DLBCL) is an aggressive subtype of B-cell non-Hodgkin lymphoma (NHL) and accounts for 30%to 40%of NHL. Molecules targeting nuclear factor-kappaB (NF-kappaB) are expected to be of therapeutic value in those tumors where NF-kappaB seems to play a unique survival role such as activated B-cell (ABC)-subtype DLBCL. We previously generated a rGel/BLyS fusion toxin for receptor-mediated delivery of the rGel toxin specifically to malignant B cells. In this study, we examined this fusion toxin for its ability to suppress DLBCL growth in vitro and in vivo. rGel/BLyS was specifically cytotoxic to DLBCL lines expressing all three BLyS receptors and constitutively active NF-kappaB. Treatment with rGel/BLyS induced down-regulation of the phosphorylation of inhibitory subunit of NF-kappaB (IkappaB-alpha), inhibition of NF-kappaB DNA-binding activity, and accumulation of IkappaB-alpha. In agreement with these results, we additionally found that rGel/BLyS downregulated levels of several NF-kappaB targets including Bcl-xL, Mcl-1, survivin, and x-chromosome linked inhibitor-of-apoptosis. Treatment also induced up-regulation of Bax and apoptosis through caspase-3 activation and poly ADP-ribose polymerase cleavage. Importantly, rGel/BLyS significantly inhibited tumor growth (P < .05) in a DLBCL xenograft model. Thus, our results indicate that rGel/BLyS is an excellent candidate for the treatment of aggressive NHLs that are both dependent on NF-kappaB and are resistant to conventional chemotherapeutic regimens.


Assuntos
Antineoplásicos/administração & dosagem , Fator Ativador de Células B/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Proteínas Recombinantes de Fusão/administração & dosagem , Toxinas Biológicas/administração & dosagem , Animais , Apoptose/efeitos dos fármacos , Fator Ativador de Células B/genética , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Separação Celular , Ensaio de Desvio de Mobilidade Eletroforética , Citometria de Fluxo , Imunofluorescência , Humanos , Proteínas I-kappa B/efeitos dos fármacos , Proteínas I-kappa B/metabolismo , Marcação In Situ das Extremidades Cortadas , Linfoma Difuso de Grandes Células B/metabolismo , Masculino , Camundongos , Camundongos SCID , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Inativadoras de Ribossomos Tipo 1/administração & dosagem , Proteínas Inativadoras de Ribossomos Tipo 1/genética , Toxinas Biológicas/genética , Ensaios Antitumorais Modelo de Xenoenxerto
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