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1.
J Cell Mol Med ; 24(7): 3779-3794, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32154648

RESUMEN

Gadolinium-containing carbon nanomaterials are a new class of contrast agent for magnetic resonance imaging. They are characterized by a superior proton relaxivity to any current commercial gadolinium contrast agent and offer the possibility to design multifunctional contrasts. Intense efforts have been made to develop these nanomaterials because of their potential for better results than the available gadolinium contrast agents. The aim of the present work is to provide a review of the advances in research on gadolinium-containing carbon nanomaterials and their advantages over conventional gadolinium contrast agents. Due to their enhanced proton relaxivity, they can provide a reliable imaging contrast for cells, tissues or organs with much smaller doses than currently used in clinical practice, thus leading to reduced toxicity (as shown by cytotoxicity and biodistribution studies). Their active targeting capability allows for improved MRI of molecular or cellular targets, overcoming the limited labelling capability of available contrast agents (restricted to physiological irregularities during pathological conditions). Their potential of multifunctionality encompasses multimodal imaging and the combination of imaging and therapy.


Asunto(s)
Medios de Contraste/uso terapéutico , Gadolinio/uso terapéutico , Imagen por Resonancia Magnética/tendencias , Nanoestructuras/uso terapéutico , Carbono/química , Carbono/uso terapéutico , Medios de Contraste/química , Humanos , Imagen Multimodal/métodos , Nanoestructuras/química , Distribución Tisular
2.
AIDS Res Ther ; 17(1): 6, 2020 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-32041622

RESUMEN

BACKGROUND: In resource-limited settings, multi-experienced HIV infected patients are often prescribed raltegravir for salvage therapy. Patients failing raltegravir-containing regimens require other drugs including other integrase inhibitors. In this context, real-life data about the resistance and cross-resistance pathways between integrase inhibitors is limited. The aim of this study was to investigate integrase resistance pathways in a cohort of Mexican multi-experienced patients failing of a raltegravir-containing salvage regimen. METHODS: Twenty-five plasma samples from subjects failing antiretroviral regimens which included raltegravir were obtained from various healthcare centres from 2009 to 2017 in Mexico. Antiretroviral history and demographics were collected. Samples were processed for integrase resistance genotyping testing by sequencing. The viral sequences were analysed with the Stanford HIV drug resistance database algorithm. Data was analysed with SPSS Statistics software. RESULTS: We found a mean viral load of 4.17 log10 c/mL (SD 1.11) at the time of virologic failure. Forty-eight percent of the samples were raltegravir resistant. The Y143R/H/C substitutions were the most prevalent, followed by the N155H, and both Q148H/K and G140S/A in the same proportion. The Q148 + G140 combination was found in (12%) of the samples. Cross-resistance to elvitegravir was found in 83.3% and in 18.2% for both dolutegravir and bictegravir. Thirteen samples (52%) were susceptible to the four integrase strand-transfer inhibitors. CONCLUSIONS: Our findings suggest a high occurrence of resistance and cross-resistance to other integrase inhibitors among multi-experienced subjects failing raltegravir. We found a modestly lower proportion of cross-resistance to dolutegravir than data from clinical trials. Likely this drug could be used for salvage therapy. Explanations for the absence of mutations in half of the samples, other than reduced adherence, should be further investigated. Close surveillance is needed.


Asunto(s)
Farmacorresistencia Viral/genética , Infecciones por VIH/tratamiento farmacológico , Inhibidores de Integrasa VIH/uso terapéutico , VIH-1/efectos de los fármacos , VIH-1/genética , Estudios de Cohortes , Estudios Transversales , Femenino , Infecciones por VIH/virología , Integrasa de VIH/genética , Seropositividad para VIH , Humanos , Masculino , México , Raltegravir Potásico/uso terapéutico , Análisis de Secuencia de ADN , Insuficiencia del Tratamiento , Carga Viral/efectos de los fármacos
3.
J Therm Biol ; 89: 102541, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32364969

RESUMEN

Though social insects generally seem to have a reduced individual immunoresponse compared to solitary species, the impact of heat stress on that response has not been studied. In the honey bee, the effect of heat stress on reproductives (queens and males/drones) may also vary compared to workers, but this is currently unknown. Here, we quantified the activity of an enzyme linked to the immune response in insects and known to be affected by heat stress in solitary species: phenoloxidase (PO), in workers, queens and drones of Africanized honey bees (AHBs) experimentally subjected to elevated temperatures during the pupal stage. Additionally, we evaluated this marker in individuals experimentally infected with the entomopathogenic fungus Metarhizium anisopliae. Differences in PO activity were found between sexes and castes, with PO activity generally higher in workers and lower in reproductives. Such differences are associated with the likelihood of exposure to infection and the role of different individuals in the colony. Contrary to our expectation, heat stress did not cause an increase in PO activity equally in all classes of individual. Heat stress during the pupal stage significantly decreased the PO activity of AHB queens, but not that of workers or drones, which more frequently engage in extranidal activity. Experimental infection with Metarhizium anisopliae reduced PO activity in queens and workers, but increased it in drones. Notably, heat stressed workers lived significantly shorter after infection despite exhibiting greater PO activity than queens or drones. We suggest that this discrepancy may be related to trade-offs among immune response cascades in honey bees such as between heat shock proteins and defensin peptides used in microbial defence. Our results provide evidence for complex relationships among humoral immune responses in AHBs and suggest that heat stress could result in a reduced life expectancy of individuals.


Asunto(s)
Abejas/fisiología , Resistencia a la Enfermedad , Respuesta al Choque Térmico , Longevidad , Animales , Abejas/crecimiento & desarrollo , Abejas/inmunología , Abejas/microbiología , Proteínas de Insectos/metabolismo , Metarhizium/patogenicidad , Monofenol Monooxigenasa/metabolismo , Conducta Social
4.
Molecules ; 25(8)2020 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-32340310

RESUMEN

Gold nanoparticles (AuNPs) are considered valuable nanomaterials for the design of radiolabeled nanoprobes for single-photon emission computed tomography (SPECT) imaging. Radiolabeled and functionalized AuNPs could improve lymphatic mapping by enhancing the radioactive signaling of individual particles in the sentinel node. In this study, an alternative method for functionalizing commercial AuNps with mannose is described. The chemical derivatization and biofunctionalization of AuNPs were performed with lipoic acid and mannose, respectively. Several levels of mannose were tested; the thiolate hydrazinonicotinamide-glycine-glycine-cysteine (HYNIC) molecule was also used for 99mTc radiolabeling. Physicochemical characterization of this system includes U-V spectroscopy, dynamic light scattering, Fourier-transform infrared spectroscopy, and transmission electron microscopy. The most stable nanoprobe, in terms of the aggregation, radiolabeling efficiency, and purity, was tested in a sentinel lymph node model in a rat by microSPECT/computed tomography (CT) imaging. The SPECT images revealed that 99mTc-radiolabeled AuNPs functionalized with mannose can track and accumulate in lymph nodes in a similar way to the commercial 99mTc-Sulfur colloid, commonly used in clinical practice for sentinel lymph node detection. These promising results support the idea that 99mTc-AuNPs-mannose could be used as a SPECT contrast agent for lymphatic mapping.


Asunto(s)
Oro , Manosa , Nanopartículas del Metal , Neoplasias/diagnóstico por imagen , Neoplasias/patología , Ganglio Linfático Centinela/patología , Tecnecio , Animales , Humanos , Masculino , Radiofármacos , Ratas , Tomografía Computarizada de Emisión de Fotón Único , Tomografía Computarizada por Rayos X , Microtomografía por Rayos X
5.
Neuroradiology ; 61(3): 323-330, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30693408

RESUMEN

PURPOSE: The spinal subarachnoid space (SSAS) is vital for neural performance. Although models of spinal diseases and trauma are used frequently, no methods exist to obtain high-resolution myelograms in rodents. Thereby, our aim was to explore the feasibility of obtaining high-resolution micro-CT myelograms of rats by contrast-enhanced dual-energy (DE) and single-energy (SE) digital subtraction. METHODS: Micro-CT contrast-enhanced DE and SE imaging protocols were implemented with live adult rats (total of 18 animals). For each protocol, contrast agents based on iodine (Iomeron® 400 and Fenestra® VC) and gold nanoparticles (AuroVist™ 15 nm) were tested. For DE, images at low- and high-energy settings were acquired after contrast injection; for SE, one image was acquired before and the other after contrast injection. Post-processing consisted of region of interest selection, image registration, weighted subtraction, and longitudinal alignment. RESULTS: High-resolution myelograms were obtained with contrast-enhanced digital subtraction protocols. After qualitative and quantitative (contrast-to-noise ratio) analyses, we found that the SE acquisition protocol with Iomeron® 400 provides the best images. 3D contour renderings allowed visualization of SSAS and identification of some anatomical structures within it. CONCLUSION: This in vivo study shows the potential of SE contrast-enhanced myelography for imaging SSAS in rat. This approach yields high-resolution 3D images without interference from adjacent anatomical structures, providing an innovative tool for further assessment of studies involving rat SSAS.


Asunto(s)
Medios de Contraste , Nanopartículas del Metal , Mielografía/métodos , Microtomografía por Rayos X/métodos , Animales , Estudios de Factibilidad , Oro , Yopamidol/análogos & derivados , Ratas
6.
J Therm Biol ; 74: 214-225, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29801630

RESUMEN

Beekeeping with the western honey bee (Apis mellifera) is important in tropical regions but scant information is available on the possible consequences of global warming for tropical beekeeping. We evaluated the effect of heat stress on developmental stability, the age at onset of foraging (AOF) and longevity in Africanized honey bees (AHBs) in the Yucatan Peninsula of Mexico, one of the main honey producing areas in the Neotropics, where high temperatures occur in spring and summer. To do so, we reared worker AHB pupae under a fluctuating temperature regime, simulating current tropical heatwaves, with a high temperature peak of 40.0 °C for 1 h daily across six days, and compared them to control pupae reared at stable temperatures of 34.0-35.5 °C. Heat stress did not markedly affect overall body size, though the forewing of heat-stressed bees was slightly shorter than controls. However, bees reared under heat stress showed significantly greater fluctuating asymmetry (FA) in forewing shape. Heat stress also decreased AOF and reduced longevity. Our results show that changes occur in the phenotype and behavior of honey bees under heat stress, with potential consequences for colony fitness.


Asunto(s)
Abejas , Conducta Animal , Respuesta al Choque Térmico , Animales , Abejas/crecimiento & desarrollo , Tamaño Corporal , Calor
7.
Molecules ; 23(9)2018 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-30200551

RESUMEN

With the aim improving drug delivery, liposomes have been employed as carriers for chemotherapeutics achieving promising results; their co-encapsulation with magnetic nanoparticles is evaluated in this work. The objective of this study was to examine the physicochemical characteristics, the pharmacokinetic behaviour, and the efficacy of pegylated liposomes loaded with cisplatin and magnetic nanoparticles (magnetite) (Cis-MLs). Cis-MLs were prepared by a modified reverse-phase evaporation method. To characterize their physicochemical properties, an evaluation was made of particle size, ζ-potential, phospholipid and cholesterol concentration, phase transition temperature (Tm), the encapsulation efficiency of cisplatin and magnetite, and drug release profiles. Additionally, pharmacokinetic studies were conducted on normal Wistar rats, while apoptosis and the cytotoxic effect were assessed with HeLa cells. We present a method for simultaneously encapsulating cisplatin at the core and also embedding magnetite nanoparticles on the membrane of liposomes with a mean vesicular size of 104.4 ± 11.5 nm and a ζ-potential of -40.5 ± 0.8 mV, affording a stable formulation with a safe pharmacokinetic profile. These liposomes elicited a significant effect on cell viability and triggered apoptosis in HeLa cells.


Asunto(s)
Cisplatino/farmacología , Sistemas de Liberación de Medicamentos , Nanopartículas de Magnetita/química , Neoplasias/tratamiento farmacológico , Animales , Supervivencia Celular/efectos de los fármacos , Cisplatino/química , Cisplatino/farmacocinética , Liberación de Fármacos , Células HeLa , Humanos , Liposomas/química , Liposomas/farmacología , Neoplasias/patología , Polietilenglicoles/química , Polietilenglicoles/farmacología , Ratas , Ratas Wistar
8.
Drug Dev Res ; 78(5): 173-183, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28593649

RESUMEN

Preclinical Research The presence of pain as part of the cancer process is variable. Glioblastoma multiform (GBM) can produce bone metastasis, a condition that involves other pathological phenotypes including neuropathic and inflammatory pain. Tramadol and gabapentin are drugs used in the treatment of neuropathic pain. However, there are no studies evaluating their analgesic effects in bone metastasis. We produced a pain model induced by the inoculation of glioma cells (105 ) into the rat femur, by perforating the intercodiloid fossa. Painful behavior was evaluated by measuring mechanical allodynia using the Von Frey test while thermal hyperalgesia was assessed in the plantar test. Histopathological features were evaluated and antinociceptive responses were compared using tramadol and gabapentin. The inoculation of cells inside the right femur produced nociceptive behaviors. Tramadol and gabapentin produced an anti-allodynic effect in this condition, but tramadol did not produce an anti-hyperalgesic response. The development of this model will allow us to perform tests to elucidate the pathology of bone metastasis, cancer pain, and in particular the pain produced by glioma. Drug Dev Res 78 : 173-183, 2017. © 2017 Wiley Periodicals, Inc.


Asunto(s)
Aminas/administración & dosificación , Analgésicos/administración & dosificación , Neoplasias Óseas/secundario , Dolor en Cáncer/tratamiento farmacológico , Ácidos Ciclohexanocarboxílicos/administración & dosificación , Fémur/patología , Tramadol/administración & dosificación , Ácido gamma-Aminobutírico/administración & dosificación , Aminas/farmacología , Analgésicos/farmacología , Animales , Neoplasias Óseas/complicaciones , Neoplasias Óseas/patología , Neoplasias Encefálicas/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Ácidos Ciclohexanocarboxílicos/farmacología , Gabapentina , Glioblastoma/patología , Hiperalgesia/tratamiento farmacológico , Hiperalgesia/etiología , Trasplante de Neoplasias , Dimensión del Dolor , Ratas , Tramadol/farmacología , Resultado del Tratamiento , Ácido gamma-Aminobutírico/farmacología
9.
BMC Cancer ; 15: 21, 2015 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-25622528

RESUMEN

BACKGROUND: Over the past few years, the concurrent use of cisplatin-based chemotherapy and radiation therapy has dramatically improved the local response and increased overall survival in early-stage cervical cancer. However, for the advanced stages of the disease this standard treatment has proved insufficient. We investigated the capacity of Mifepristone and ICI 182,780, which are anti-progestin and anti-estrogen drugs, respectively, to act as chemo-radiosensitizing agents in cervical cancer cells and cervix xenografts. METHODS: The effect of chemo-radiation alone or combined with Mifepristone or ICI 182,780 was evaluated in HeLa cells and with tumor growth in cervix xenografts. After concomitant chemo-radiotherapy, the effect of each of these antihormonal agents on apoptosis (determined by Annexing V assay) and the cell cycle phases were determined by flow cytometry. The expression of angiogenic factor VEGF in tumor samples was determined using quantitative RT-PCR analysis of VEGF gene expression. RESULTS: Compared to radiation alone or radiation/cisplatin therapy, there was significantly higher cytotoxicity and a greater antitumoral effect with the combined application of radiation/cisplatin and Mifepristone or ICI 182,780. Analyses of the apoptosis and cell cycle demonstrated changes only with ICI, not with Mifepristone, when was applied in combination with radiation/cisplatin. The analysis of VEGF mRNA expression levels in tumors at the end of the study demonstrated a significant inhibition, compared to radiation only or the radiation/cisplatin treatment, after concurrent chemo-radiotherapy and each one of the antihormonal drugs. CONCLUSION: Mifepristone and ICI 182,780 may be potentially promising chemo-radiosensitizing compounds to be used in combination with ionizing irradiation and cisplatin in the treatment of patients with advanced cervical cancer.


Asunto(s)
Antineoplásicos Hormonales/farmacología , Radiación Ionizante , Neoplasias del Cuello Uterino/patología , Animales , Antineoplásicos/farmacología , Antineoplásicos Hormonales/administración & dosificación , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Ciclo Celular/efectos de los fármacos , Ciclo Celular/efectos de la radiación , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Cisplatino/administración & dosificación , Cisplatino/farmacología , Modelos Animales de Enfermedad , Femenino , Expresión Génica , Células HeLa , Humanos , Ratones , Carga Tumoral/efectos de los fármacos , Carga Tumoral/efectos de la radiación , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/radioterapia , Factores de Crecimiento Endotelial Vascular/genética , Factores de Crecimiento Endotelial Vascular/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
10.
Invest Clin ; 54(1): 90-108, 2013 Mar.
Artículo en Español | MEDLINE | ID: mdl-23781716

RESUMEN

Gastrointestinal disorders or GID are debilitating conditions common in individuals infected by the human immunodeficiency virus (HIV), capable of leading to death. Numerous etiological agents and pathophysiological mechanisms have been involved in this status. Although the use of highly active antiretroviral therapy (HAART) in many countries has greatly reduced the prevalence of gastrointestinal infections, enteric pathogens such as bacteria, parasites, fungi and viruses may still act as opportunist agents in these patients. Cytomegalovirus, adenovirus, calicivirus, astrovirus, rotavirus, enterovirus, picobirnavirus and some more recently described, like bocavirus and Aichi virus, have been detected in HIV patients. However, except for cytomegalovirus, which is an established etiological agent of GID in these patients, the role of the other viruses remains unclear. Several species of Cryptosporidium, microsporidia, Salmonella, atipical mycobacteria and Campylobacter jejuni, have also been recognized as important causes of GID in HIV patients. The progressive incorporation of increasingly sensitive immunological and molecular assays for antigen, antibody and pathogens detection from faeces, has improved the diagnosis of diarrhea and contributed to clarify the etiological significance of some microorganisms in immunocompetent patients. In Venezuela, some information is available about the prevalence of enteric pathogens in immunocompromised patients infected with HIV. The identification of the etiologic agent responsible for this condition may be useful for the management and treatment of these patients, for whom viral enteritis is a disease, which reduces their quality of life and causes a high public health spending.


Asunto(s)
Enfermedades Gastrointestinales/microbiología , Enfermedades Gastrointestinales/parasitología , Enfermedades Gastrointestinales/virología , Infecciones por VIH/complicaciones , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Infecciones Oportunistas Relacionadas con el SIDA/parasitología , Infecciones Oportunistas Relacionadas con el SIDA/virología , Infecciones Bacterianas/complicaciones , Infecciones Bacterianas/microbiología , Recuento de Linfocito CD4 , Diarrea/microbiología , Diarrea/parasitología , Diarrea/virología , Enfermedades Gastrointestinales/complicaciones , Enfermedades Gastrointestinales/diagnóstico , Humanos , Huésped Inmunocomprometido , Parasitosis Intestinales/complicaciones , Parasitosis Intestinales/parasitología , Micosis/complicaciones , Micosis/microbiología , Virosis/complicaciones , Virosis/microbiología
11.
Bioconjug Chem ; 22(5): 913-22, 2011 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-21513349

RESUMEN

Integrin α(V)ß(3) plays a critical role in tumor angiogenesis and metastasis. Suitably radiolabeled cyclic RGD peptides can be used for noninvasive imaging of α(V)ß(3) expression. The aim of this research was to prepare a multimeric system of technetium-99m-labeled gold nanoparticles conjugated to c[RGDfK(C)] and to evaluate its biological behavior as a potential radiopharmaceutical for molecular imaging of tumor angiogenesis. Hydrazinonicotinamide-GGC (HYNIC-GGC) and c[RGDfK(C)] peptides were synthesized and conjugated to gold nanoparticles (AuNP, 20 nm) by means of spontaneous reaction of the thiol groups of cysteine. The nanoconjugate was characterized by TEM, FT-IR, UV-vis, XPS, and Raman spectroscopy. To obtain (99m)Tc-HYNIC-GGC-AuNP-c[RGDfK(C)] ((99m)Tc-AuNP-RGD), the (99m)Tc-HYNIC-GGC radiopeptide was first prepared and added to 1.5 mL of AuNP solution (1 nM) followed by c[RGDfK(C)] (10 µL, 50 µM) at 18 °C with stirring for 15 min. Radiochemical purity (RP) was determined by size-exclusion HPLC and ITLC-SG analyses. In vitro binding studies were carried out in α(V)ß(3) receptor-positive C6 glioma cancer cells. Biodistribution studies were accomplished in athymic mice with C6-induced tumors with blocked and nonblocked receptors, and images were obtained using a micro-SPECT/CT. TEM and spectroscopy techniques demonstrated that AuNPs were functionalized with peptides. RP was 96 ± 2% without postlabeling purification. (99m)Tc-AuNP-RGD showed specific recognition for α(V)ß(3) integrins expressed in C6 cells, and 3 h after i.p. administration in mice, the tumor uptake was 8.18 ± 0.57% ID/g. Micro-SPECT/CT images showed evident tumor uptake. (99m)Tc-AuNP-RGD demonstrates properties suitable for use as a target-specific agent for molecular imaging of tumor α(V)ß(3) expression.


Asunto(s)
Glioma/metabolismo , Oro , Integrina alfaVbeta3/análisis , Nanopartículas del Metal , Imagen Molecular , Compuestos de Organotecnecio , Péptidos Cíclicos , Animales , Línea Celular Tumoral , Femenino , Glioma/patología , Oro/química , Oro/farmacocinética , Humanos , Integrina alfaVbeta3/biosíntesis , Marcaje Isotópico , Nanopartículas del Metal/química , Ratones , Ratones Desnudos , Estructura Molecular , Compuestos de Organotecnecio/química , Compuestos de Organotecnecio/farmacocinética , Péptidos Cíclicos/química , Péptidos Cíclicos/farmacocinética , Distribución Tisular
13.
J Neuroimaging ; 31(1): 79-89, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33244842

RESUMEN

BACKGROUND AND PURPOSE: The spinal subarachnoid space (SSAS) is vital for neurologic function. Although SSAS alterations are known to occur after spinal cord injury (SCI), there is a lack of high-resolution imaging studies of the SSAS after SCI in rodents. Therefore, the aim here was to assess changes in the SSAS of rats subjected to graded SCI, using high-resolution micro-CT myelography. METHODS: Long-Evans adult rats were subjected to mild or severe spinal cord contusion at T9. Imaging studies of SSAS features were carried out in injured rats at acute (day 1) and subacute (day 15) stages postinjury, as well as in control rats, using high-resolution micro-CT myelography with a contrast-enhanced digital subtraction protocol. We studied a total of 33 rats randomly allocated into five experimental groups. Micro-CT myelograms were assessed by expert observers using both qualitative and quantitative criteria. RESULTS: Qualitative and quantitative analyses showed that SCI induces changes in the SSAS that vary as a function of both injury severity and time elapsed after injury. SSAS blockage was the main alteration detected. Moreover, the method used here allowed fine details to be observed in small animals, such as variations in the preferential pathways for contrast medium flow, neuroimaging nerve root enhancement, and leakage of contrast medium due to tearing of the dural sac. CONCLUSION: Micro-CT myelography provides high-resolution images of changes in the SSAS after SCI in rats and is a useful tool for further experimental studies involving rat SCI in vivo.


Asunto(s)
Mielografía , Relación Señal-Ruido , Traumatismos de la Médula Espinal/diagnóstico por imagen , Médula Espinal/diagnóstico por imagen , Espacio Subaracnoideo/diagnóstico por imagen , Microtomografía por Rayos X , Animales , Masculino , Ratas , Ratas Long-Evans , Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Espacio Subaracnoideo/fisiopatología
14.
Biomedicines ; 9(8)2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-34440140

RESUMEN

The FDA's approval of peptide drugs such as Ziconotide or Exendin for pain relief and diabetes treatment, respectively, enhanced the interest to explore novel conotoxins from Conus species venom. In general, conotoxins can be used in pathologies where voltage-gated channels, membrane receptors, or ligands alter normal physiological functions, as in metabolic diseases such as Type 2 diabetes. In this study, the synthetic cal14.2b (s-cal14.2b) from the unusual Californiconus californicus demonstrated bioactivity on NIT-1 insulinoma cell lines stimulating insulin secretion detecting by high performance liquid chromatography (HPLC). Accordingly, s-cal14.2b increased the CaV1.2/1.3 channel-current by 35 ± 4% with a recovery τ of 10.3 ± 4 s in primary cell culture of rat pancreatic ß-cells. The in vivo results indicated a similar effect of insulin secretion on mice in the glucose tolerance curve model by reducing the glucose from 500 mg/dL to 106 mg/dL in 60 min, compared to the negative control of 325 mg/dL at the same time. The PET-SCAN with radiolabeling 99mTc-s-cal14.2b demonstrated biodistribution and accumulation in rat pancreas with complete depuration in 24 h. These findings show the potential therapeutic use of s-cal14.2b in endocrinal pathologies such as early stages of Type 2 Diabetes where the pancreas's capability to produce insulin is still effective.

15.
PeerJ ; 9: e12164, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34721958

RESUMEN

Nutrition is vital for health and immune function in honey bees (Apis mellifera). The effect of diets enriched with bee-associated yeasts and essential oils of Mexican oregano (Lippia graveolens) was tested on survival, food intake, accumulated fat body tissue, and gene expression of vitellogenin (Vg), prophenoloxidase (proPO) and glucose oxidase (GOx) in newly emerged worker bees. The enriched diets were provided to bees under the premise that supplementation with yeasts or essential oils can enhance health variables and the expression of genes related to immune function in worker bees. Based on a standard pollen substitute, used as a control diet, enriched diets were formulated, five with added bee-associated yeasts (Starmerella bombicola, Starmerella etchellsii, Starmerella bombicola 2, Zygosaccharomyces mellis, and the brewers' yeast Saccharomyces cerevisiae) and three with added essential oils from L. graveolens (carvacrol, thymol, and sesquiterpenes). Groups of bees were fed one of the diets for 9 or 12 days. Survival probability was similar in the yeast and essential oils treatments in relation to the control, but median survival was lower in the carvacrol and sesquiterpenes treatments. Food intake was higher in all the yeast treatments than in the control. Fat body percentage in individual bees was slightly lower in all treatments than in the control, with significant decreases in the thymol and carvacrol treatments. Expression of the genes Vg, proPO, and GOx was minimally affected by the yeast treatments but was adversely affected by the carvacrol and thymol treatments.

16.
Front Oncol ; 10: 581814, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33123485

RESUMEN

Glioblastoma, the most common primary central nervous system tumor, is characterized by extensive vascular neoformation and an area of necrosis generated by rapid proliferation. The standard treatment for this type of tumor is surgery followed by chemotherapy based on temozolomide and radiotherapy, resulting in poor patient survival. Glioblastoma is known for strong resistance to treatment, frequent recurrence and rapid progression. The aim of this study was to evaluate whether mifepristone, an antihormonal agent, can enhance the effect of temozolomide on C6 glioma cells orthotopically implanted in Wistar rats. The levels of the vascular endothelial growth factor (VEGF), and P-glycoprotein (P-gp) were examined, the former a promoter of angiogenesis that facilitates proliferation, and the latter an efflux pump transporter linked to drug resistance. After a 3-week treatment, the mifepristone/temozolomide regimen had decreased the level of VEGF and P-gp and significantly reduced tumor proliferation (detected by PET/CT images based on 18F-fluorothymidine uptake). Additionally, mifepristone proved to increase the intracerebral concentration of temozolomide. The lower level of O6-methylguanine-DNA-methyltransferase (MGMT) (related to DNA repair in tumors) previously reported for this combined treatment was herein confirmed. After the mifepristone/temozolomide treatment ended, however, the values of VEGF, P-gp, and MGMT increased and reached control levels by 14 weeks post-treatment. There was also tumor recurrence, as occurred when administering temozolomide alone. On the other hand, temozolomide led to 100% mortality within 26 days after beginning the drug treatment, while mifepristone/temozolomide enabled 70% survival 60-70 days and 30% survived over 100 days, suggesting that mifepristone could possibly act as a chemo-sensitizing agent for temozolomide.

17.
Nanoscale ; 11(2): 541-551, 2019 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-30543234

RESUMEN

Despite the widespread use of nanotechnology in radio-imaging applications, lipoprotein based delivery systems have received only limited attention so far. These studies involve the synthesis of a novel hydrophobic radio-imaging tracer consisting of a hydrazinonicotinic acid (HYNIC)-N-dodecylamide and 99mTc conjugate that can be encapsulated into rHDL nanoparticles (NPs). These rHDL NPs can selectively target the Scavenger Receptor type B1 (SR-B1) that is overexpressed on most cancer cells due to excess demand for cholesterol for membrane biogenesis and thus can target tumors in vivo. We provide details of the tracer synthesis, characterization of the rHDL/tracer complex, in vitro uptake, stability studies and in vivo application of this new radio-imaging approach.


Asunto(s)
Lipoproteínas HDL/química , Nanopartículas/metabolismo , Ácidos Nicotínicos/química , Trazadores Radiactivos , Cintigrafía/métodos , Tecnecio/química , Animales , Sistemas de Liberación de Medicamentos , Humanos , Lipoproteínas HDL/administración & dosificación , Lipoproteínas HDL/metabolismo , Liposomas/administración & dosificación , Liposomas/química , Liposomas/metabolismo , Ratones Endogámicos BALB C , Ratones Desnudos , Nanopartículas/administración & dosificación , Nanopartículas/química , Células PC-3 , Receptores Depuradores de Clase B/metabolismo , Distribución Tisular
18.
Cancers (Basel) ; 11(1)2018 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-30583528

RESUMEN

The standard treatment for glioblastoma multiforme (GBM) is surgery followed by chemo/radiotherapy. A major limitation on patient improvement is the high resistance of tumors to drug treatment, likely responsible for their subsequent recurrence and rapid progression. Therefore, alternatives to the standard therapy are necessary. The aim of the present study was to evaluate whether mifepristone, an antihormonal agent, has a synergistic effect with temozolomide (used in standard therapy for gliomas). Whereas the mechanism of temozolomide involves damage to tumor DNA leading to apoptosis, tumor resistance is associated with DNA damage repair through the O6-methylguanine-DNA-methyltransferase (MGMT) enzyme. Temozolomide/mifepristone treatment, herein examined in Wistar rats after orthotopically implanting C6 glioma cells, markedly reduced proliferation. This was evidenced by a decreased level of the following parameters: a proliferation marker (Ki-67), a tumor growth marker (18F-fluorothymidine uptake, determined by PET/CT images), and the MGMT enzyme. Increased apoptosis was detected by the relative expression of related proteins, (e.g. Bcl-2 (B-cell lymphoma 2), Bax (bcl-2-like protein 4) and caspase-3). Thus, greater apoptosis of tumor cells caused by their diminished capacity to repair DNA probably contributed significantly to the enhanced activity of temozolomide. The results suggest that mifepristone could possibly act as a chemo-sensitizing agent for temozolomide during chemotherapy for GBM.

19.
Sci Adv ; 3(3): e1600513, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28435856

RESUMEN

The highly social (eusocial) corbiculate bees, comprising the honey bees, bumble bees, and stingless bees, are ubiquitous insect pollinators that fulfill critical roles in ecosystem services and human agriculture. Here, we conduct wide sampling across the phylogeny of these corbiculate bees and reveal a dynamic evolutionary history behind their microbiota, marked by multiple gains and losses of gut associates, the presence of generalist as well as host-specific strains, and patterns of diversification driven, in part, by host ecology (for example, colony size). Across four continents, we found that different host species have distinct gut communities, largely independent of geography or sympatry. Nonetheless, their microbiota has a shared heritage: The emergence of the eusocial corbiculate bees from solitary ancestors appears to coincide with the acquisition of five core gut bacterial lineages, supporting the hypothesis that host sociality facilitates the development and maintenance of specialized microbiomes.


Asunto(s)
Abejas/microbiología , Microbioma Gastrointestinal/fisiología , Animales , Especificidad de la Especie
20.
J Pharm Sci ; 95(1): 207-24, 2006 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16315246

RESUMEN

A method for delivering drugs to sites of disease extension in mediastinal nodes is described. Mediastinal node and lymphatic distributions were determined after intracavitary injection of the avidin/biotin-liposome system in normal rats. The effect of the injected dose on lymphatic targeting of liposomes after intraperitoneal injection of (99m)Tc-blue-biotin-liposomes and intrapleural injection of avidin, and vice versa, is presented. Scintigraphic imaging was used to follow the movement of (99m)Tc-blue-biotin-liposomes to determine the pharmacokinetics and organ uptake. Tissue biodistribution studies were performed 22 h after injection of the (99m)Tc-blue-biotin-liposomes. Results indicated that independent of the cavity in which each agent was injected, a dose of 5.0 mg of each agent results in higher mediastinal node targeting (8%-10% ID/Organ) as compared with the injection of a 0.5 mg dose (2%-5% ID/Organ, p < 0.05). Targeting of diaphragm and associated lymphatics was observed when (99m)Tc-blue-biotin-liposomes were injected in peritoneum and avidin in pleural space. In contrast, pleural, and pericardial lymphatic targeting was observed when (99m)Tc-blue-biotin-liposomes were injected in pleural space and avidin in peritoneum. Intracavitary injection of the avidin/biotin-liposome system could potentially be used for the delivery of prophylactic drugs that could reduce tumor metastasis and infection spread to mediastinal nodes.


Asunto(s)
Avidina/farmacocinética , Biotina/farmacocinética , Liposomas/farmacocinética , Animales , Avidina/administración & dosificación , Biotina/administración & dosificación , Diafragma/metabolismo , Inyecciones , Inyecciones Intraperitoneales , Liposomas/administración & dosificación , Ganglios Linfáticos/metabolismo , Vasos Linfáticos/metabolismo , Masculino , Mediastino , Cavidad Pleural , Ratas , Ratas Sprague-Dawley , Tecnecio
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