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1.
Cell Mol Life Sci ; 79(1): 35, 2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-34989866

RESUMEN

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.


Asunto(s)
Analgesia/métodos , Hipocinesia/fisiopatología , Musarañas/metabolismo , Toxinas Biológicas/metabolismo , Ponzoñas/metabolismo , Adulto , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Presión Sanguínea/efectos de los fármacos , Femenino , Miembro Posterior/efectos de los fármacos , Miembro Posterior/fisiopatología , Humanos , Macaca mulatta , Masculino , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Dolor/inducido químicamente , Dolor/fisiopatología , Dolor/prevención & control , Homología de Secuencia de Aminoácido , Musarañas/genética , Trombina/antagonistas & inhibidores , Trombina/metabolismo , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/genética , Ponzoñas/genética
2.
Artículo en Inglés | MEDLINE | ID: mdl-32109507

RESUMEN

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.


Asunto(s)
Hipertensión/metabolismo , Neuronas/metabolismo , Orexinas/metabolismo , Trastornos del Sueño-Vigilia/metabolismo , Animales , Hipertensión/fisiopatología , Masculino , Microinyecciones , Neuronas/efectos de los fármacos , Neuropéptidos/administración & dosificación , Neuropéptidos/toxicidad , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Saporinas/administración & dosificación , Saporinas/toxicidad , Trastornos del Sueño-Vigilia/fisiopatología , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/toxicidad
3.
J. venom. anim. toxins incl. trop. dis ; 26: e20190070, 2020. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1484764

RESUMEN

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.


Asunto(s)
Masculino , Animales , Ratas , Analgésicos , Neuropatía Ciática/terapia , Paclitaxel , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/efectos adversos , Venenos de Araña/química , Administración Intravenosa , Ratones Endogámicos BALB C , Ratas Wistar
4.
Eur J Pharm Biopharm ; 132: 211-221, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30223028

RESUMEN

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.


Asunto(s)
Antineoplásicos Fitogénicos/administración & dosificación , Neoplasias del Colon/tratamiento farmacológico , Lípidos/química , Proteínas Inactivadoras de Ribosomas Tipo 2/administración & dosificación , Toxinas Biológicas/administración & dosificación , Albúminas/química , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/farmacología , Línea Celular Tumoral , Química Farmacéutica/métodos , Neoplasias del Colon/patología , Dextranos/química , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Calor , Liposomas , Ratones , Peso Molecular , Proteínas Inactivadoras de Ribosomas Tipo 2/química , Proteínas Inactivadoras de Ribosomas Tipo 2/farmacología , Temperatura , Toxinas Biológicas/química , Toxinas Biológicas/farmacología
5.
Viral Immunol ; 31(3): 233-241, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29185875

RESUMEN

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.


Asunto(s)
Antígenos Virales/inmunología , Proteínas de la Cápside/inmunología , Glicoproteínas/inmunología , Proteínas Recombinantes de Fusión/inmunología , Vacunas contra Rotavirus/inmunología , Rotavirus/inmunología , Toxinas Biológicas/inmunología , Proteínas no Estructurales Virales/inmunología , Adyuvantes Inmunológicos/administración & dosificación , Animales , Anticuerpos Antivirales/sangre , Antígenos Virales/administración & dosificación , Antígenos Virales/genética , Proteínas de la Cápside/administración & dosificación , Proteínas de la Cápside/genética , Glicoproteínas/administración & dosificación , Glicoproteínas/genética , Inmunoglobulina A/sangre , Inmunoglobulina G/sangre , Interferón gamma/metabolismo , Leucocitos Mononucleares/inmunología , Ratones Endogámicos BALB C , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/genética , Vacunas contra Rotavirus/administración & dosificación , Vacunas contra Rotavirus/genética , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/genética , Proteínas no Estructurales Virales/administración & dosificación , Proteínas no Estructurales Virales/genética
6.
Nat Commun ; 8(1): 1495, 2017 11 14.
Artículo en Inglés | MEDLINE | ID: mdl-29138448

RESUMEN

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.


Asunto(s)
Anuros/inmunología , Péptidos/toxicidad , Conducta Predatoria , Toxinas Biológicas/toxicidad , Animales , Antiinfecciosos , Células CACO-2 , Humanos , Péptidos/metabolismo , Piel/metabolismo , Absorción Cutánea , Toxinas Biológicas/administración & dosificación
8.
Rev Esp Med Nucl Imagen Mol ; 36(2): 110-112, 2017.
Artículo en Inglés, Español | MEDLINE | ID: mdl-27637868

RESUMEN

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.


Asunto(s)
Antineoplásicos Fitogénicos/efectos adversos , Radioisótopos de Flúor/análisis , Fluorodesoxiglucosa F18/análisis , Enfermedad de Hodgkin/diagnóstico por imagen , Ganglios Linfáticos/diagnóstico por imagen , Materia Medica/efectos adversos , Fitoterapia/efectos adversos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos/análisis , Proteínas Inactivadoras de Ribosomas Tipo 2/efectos adversos , Toxinas Biológicas/efectos adversos , Viscum album/efectos adversos , Adulto , Antineoplásicos Fitogénicos/administración & dosificación , Antineoplásicos Fitogénicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bleomicina/administración & dosificación , Dacarbazina/administración & dosificación , Doxorrubicina/administración & dosificación , Femenino , Enfermedad de Hodgkin/tratamiento farmacológico , Humanos , Inyecciones Subcutáneas , Ganglios Linfáticos/efectos de los fármacos , Estadificación de Neoplasias , Proteínas Inactivadoras de Ribosomas Tipo 2/administración & dosificación , Proteínas Inactivadoras de Ribosomas Tipo 2/uso terapéutico , Automedicación , Grasa Subcutánea/diagnóstico por imagen , Grasa Subcutánea/metabolismo , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/uso terapéutico , Vinblastina/administración & dosificación
9.
Toxicon ; 118: 129-33, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27058514

RESUMEN

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.


Asunto(s)
Encéfalo/metabolismo , Contaminantes Ambientales/toxicidad , Furanos/toxicidad , Lactonas/toxicidad , Neuronas/metabolismo , Toxinas Biológicas/toxicidad , Administración Oral , Animales , Biotransformación , Barrera Hematoencefálica/efectos de los fármacos , Barrera Hematoencefálica/metabolismo , Cromatografía Líquida de Alta Presión , Relación Dosis-Respuesta a Droga , Complejo I de Transporte de Electrón/antagonistas & inhibidores , Complejo I de Transporte de Electrón/metabolismo , Contaminantes Ambientales/administración & dosificación , Contaminantes Ambientales/análisis , Inhibidores Enzimáticos/administración & dosificación , Inhibidores Enzimáticos/análisis , Inhibidores Enzimáticos/toxicidad , Furanos/administración & dosificación , Furanos/análisis , Inyecciones Intravenosas , Lactonas/administración & dosificación , Lactonas/análisis , Masculino , Neuronas/química , Ratas Wistar , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masas en Tándem , Distribución Tisular , Toxicocinética , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/análisis
10.
J Am Soc Nephrol ; 26(2): 281-90, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25012179

RESUMEN

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.


Asunto(s)
Cresoles/farmacología , Receptores ErbB/efectos de los fármacos , Indicán/farmacología , Riñón/efectos de los fármacos , Riñón/patología , Toxinas Biológicas/farmacología , Animales , Células Cultivadas , Cresoles/administración & dosificación , Humanos , Técnicas In Vitro , Indicán/administración & dosificación , Inyecciones Intraperitoneales , Riñón/cirugía , Túbulos Renales Proximales/efectos de los fármacos , Túbulos Renales Proximales/metabolismo , Túbulos Renales Proximales/patología , Metaloproteinasa 2 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Endogámicos , Modelos Animales , Nefrectomía , Transducción de Señal/efectos de los fármacos , Toxinas Biológicas/administración & dosificación
11.
Am J Physiol Gastrointest Liver Physiol ; 307(2): G233-40, 2014 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-24875101

RESUMEN

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.


Asunto(s)
Conductos Biliares Extrahepáticos/inmunología , Atresia Biliar/inmunología , Linfocitos T CD8-positivos/inmunología , Epítopos de Linfocito T , Glicoproteínas/inmunología , Fragmentos de Péptidos/inmunología , Infecciones por Rotavirus/inmunología , Vacunas contra Rotavirus/inmunología , Toxinas Biológicas/inmunología , Proteínas no Estructurales Virales/inmunología , Animales , Conductos Biliares Extrahepáticos/patología , Conductos Biliares Extrahepáticos/virología , Atresia Biliar/patología , Atresia Biliar/prevención & control , Atresia Biliar/virología , Linfocitos T CD8-positivos/virología , Modelos Animales de Enfermedad , Femenino , Glicoproteínas/administración & dosificación , Inmunización Pasiva , Memoria Inmunológica , Inyecciones Intraperitoneales , Interferón gamma/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Fragmentos de Péptidos/administración & dosificación , Embarazo , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/inmunología , Infecciones por Rotavirus/patología , Infecciones por Rotavirus/prevención & control , Infecciones por Rotavirus/virología , Vacunas contra Rotavirus/administración & dosificación , Linfocitos T Citotóxicos/inmunología , Toxinas Biológicas/administración & dosificación , Proteínas no Estructurales Virales/administración & dosificación
12.
J Pharm Pharm Sci ; 17(4): 475-84, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25579430

RESUMEN

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.


Asunto(s)
Hígado/metabolismo , Transportadores de Anión Orgánico Sodio-Independiente/metabolismo , Transportadores de Anión Orgánico/metabolismo , Toxinas Biológicas/farmacología , Transporte Biológico , Relación Dosis-Respuesta a Droga , Células HEK293 , Humanos , Concentración 50 Inhibidora , Transportador 1 de Anión Orgánico Específico del Hígado , Transportadores de Anión Orgánico/antagonistas & inhibidores , Transportadores de Anión Orgánico Sodio-Independiente/antagonistas & inhibidores , Miembro 1B3 de la Familia de los Transportadores de Solutos de Aniones Orgánicos , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/metabolismo , Uremia/etiología
13.
Stat Med ; 32(30): 5430-47, 2013 Dec 30.
Artículo en Inglés | MEDLINE | ID: mdl-24018535

RESUMEN

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.


Asunto(s)
Antineoplásicos/administración & dosificación , Ensayos Clínicos Fase I como Asunto/métodos , Funciones de Verosimilitud , Estudios Longitudinales , Dosis Máxima Tolerada , Modelos Estadísticos , Adulto , Antineoplásicos/toxicidad , Simulación por Computador , Humanos , Neoplasias/tratamiento farmacológico , Preparaciones de Plantas/administración & dosificación , Preparaciones de Plantas/efectos adversos , Proteínas Inactivadoras de Ribosomas Tipo 2/administración & dosificación , Proteínas Inactivadoras de Ribosomas Tipo 2/efectos adversos , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/efectos adversos
14.
Toxicol Appl Pharmacol ; 268(1): 79-89, 2013 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-23360887

RESUMEN

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.


Asunto(s)
Ácidos y Sales Biliares/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Estrés Oxidativo/fisiología , Toxinas Biológicas/toxicidad , Animales , Ácidos y Sales Biliares/sangre , Ácidos y Sales Biliares/orina , Biomarcadores/sangre , Biomarcadores/metabolismo , Biomarcadores/orina , Cromatografía Líquida de Alta Presión , Cromatografía de Gases y Espectrometría de Masas , Hepatocitos/metabolismo , Masculino , Metabolómica/métodos , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley , Espectrometría de Masas en Tándem , Toxinas Biológicas/administración & dosificación
15.
Ther Deliv ; 3(3): 405-14, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22833997

RESUMEN

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.


Asunto(s)
Productos Biológicos/administración & dosificación , Enzimas/administración & dosificación , Eritrocitos/fisiología , Ácidos Nucleicos/administración & dosificación , Vehículos Farmacéuticos , Antígenos/administración & dosificación , Portadores de Fármacos , Humanos , Péptidos/administración & dosificación , Toxinas Biológicas/administración & dosificación
16.
Biosens Bioelectron ; 35(1): 503-506, 2012 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-22498641

RESUMEN

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.


Asunto(s)
Técnicas Biosensibles/métodos , Supervivencia Celular/efectos de los fármacos , Saponinas/administración & dosificación , Toxinas Biológicas/administración & dosificación , Antineoplásicos/administración & dosificación , Sistemas de Computación , Sinergismo Farmacológico , Impedancia Eléctrica , Receptores ErbB/antagonistas & inhibidores , Células HeLa , Humanos
17.
PLoS One ; 7(3): e33432, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22438929

RESUMEN

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.


Asunto(s)
Hormesis , Modelos Biológicos , Plantas/efectos de los fármacos , Amaranthus/efectos de los fármacos , Amaranthus/crecimiento & desarrollo , Bases de Datos Factuales , Relación Dosis-Respuesta a Droga , Germinación/efectos de los fármacos , Hordeum/efectos de los fármacos , Hordeum/crecimiento & desarrollo , Lactuca/efectos de los fármacos , Lactuca/crecimiento & desarrollo , Conceptos Matemáticos , Medicago sativa/efectos de los fármacos , Medicago sativa/crecimiento & desarrollo , Desarrollo de la Planta , Sinapis/efectos de los fármacos , Sinapis/crecimiento & desarrollo , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/toxicidad , Triticum/efectos de los fármacos , Triticum/crecimiento & desarrollo
18.
Leukemia ; 26(8): 1786-96, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22373785

RESUMEN

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.


Asunto(s)
Antineoplásicos/uso terapéutico , Factor Activador de Células B/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Proteínas Recombinantes de Fusión/uso terapéutico , Proteínas Inactivadoras de Ribosomas Tipo 1/uso terapéutico , Animales , Antineoplásicos/administración & dosificación , Antineoplásicos/metabolismo , Apoptosis/efectos de los fármacos , Factor Activador de Células B/administración & dosificación , Factor Activador de Células B/genética , Factor Activador de Células B/metabolismo , Bencilaminas , Médula Ósea/patología , Línea Celular Tumoral , Ciclamas , Sinergismo Farmacológico , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Compuestos Heterocíclicos/farmacología , Humanos , Ratones , Ratones Desnudos , Ratones SCID , FN-kappa B/antagonistas & inhibidores , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Proteínas Recombinantes de Fusión/administración & dosificación , Proteínas Recombinantes de Fusión/metabolismo , Proteínas Inactivadoras de Ribosomas Tipo 1/administración & dosificación , Proteínas Inactivadoras de Ribosomas Tipo 1/genética , Proteínas Inactivadoras de Ribosomas Tipo 1/metabolismo , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/metabolismo , Toxinas Biológicas/uso terapéutico , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto
19.
Toxicol Sci ; 126(1): 72-83, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21987460

RESUMEN

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.


Asunto(s)
Subunidades de Proteína/antagonistas & inhibidores , Ricina/antagonistas & inhibidores , Toxinas Biológicas/antagonistas & inhibidores , Vacunas de Subunidad/uso terapéutico , Administración por Inhalación , Animales , Armas Biológicas , Codón , Escherichia coli/genética , Escherichia coli/metabolismo , Femenino , Pulmón/efectos de los fármacos , Pulmón/inmunología , Pulmón/patología , Masculino , Subunidades de Proteína/administración & dosificación , Subunidades de Proteína/genética , Conejos , Distribución Aleatoria , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/antagonistas & inhibidores , Proteínas Recombinantes/genética , Ricina/administración & dosificación , Ricina/genética , Ricina/toxicidad , Organismos Libres de Patógenos Específicos , Toxinas Biológicas/administración & dosificación , Toxinas Biológicas/genética , Toxinas Biológicas/toxicidad , Vacunas de Subunidad/efectos adversos , Vacunas de Subunidad/inmunología , Vacunas Sintéticas/efectos adversos , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/uso terapéutico , Levaduras/genética , Levaduras/metabolismo
20.
Neoplasia ; 12(5): 366-75, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20454508

RESUMEN

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.


Asunto(s)
Antineoplásicos/administración & dosificación , Factor Activador de Células B/administración & dosificación , Sistemas de Liberación de Medicamentos/métodos , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Proteínas Recombinantes de Fusión/administración & dosificación , Toxinas Biológicas/administración & dosificación , Animales , Apoptosis/efectos de los fármacos , Factor Activador de Células B/genética , Western Blotting , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Separación Celular , Ensayo de Cambio de Movilidad Electroforética , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Humanos , Proteínas I-kappa B/efectos de los fármacos , Proteínas I-kappa B/metabolismo , Etiquetado Corte-Fin in Situ , Linfoma de Células B Grandes Difuso/metabolismo , Masculino , Ratones , Ratones SCID , FN-kappa B/efectos de los fármacos , FN-kappa B/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Inactivadoras de Ribosomas Tipo 1/administración & dosificación , Proteínas Inactivadoras de Ribosomas Tipo 1/genética , Toxinas Biológicas/genética , Ensayos Antitumor por Modelo de Xenoinjerto
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