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BACKGROUND: Long-term pulmonary sequelae following hospitalization for SARS-CoV-2 pneumonia is largely unclear. The aim of this study was to identify and characterise pulmonary sequelae caused by SARS-CoV-2 pneumonia at 12-month from discharge. METHODS: In this multicentre, prospective, observational study, patients hospitalised for SARS-CoV-2 pneumonia and without prior diagnosis of structural lung diseases were stratified by maximum ventilatory support ("oxygen only", "continuous positive airway pressure (CPAP)" and "invasive mechanical ventilation (IMV)") and followed up at 12 months from discharge. Pulmonary function tests and diffusion capacity for carbon monoxide (DLCO), 6 min walking test, high resolution CT (HRCT) scan, and modified Medical Research Council (mMRC) dyspnea scale were collected. RESULTS: Out of 287 patients hospitalized with SARS-CoV-2 pneumonia and followed up at 1 year, DLCO impairment, mainly of mild entity and improved with respect to the 6-month follow-up, was observed more frequently in the "oxygen only" and "IMV" group (53% and 49% of patients, respectively), compared to 29% in the "CPAP" group. Abnormalities at chest HRCT were found in 46%, 65% and 80% of cases in the "oxygen only", "CPAP" and "IMV" group, respectively. Non-fibrotic interstitial lung abnormalities, in particular reticulations and ground-glass attenuation, were the main finding, while honeycombing was found only in 1% of cases. Older patients and those requiring IMV were at higher risk of developing radiological pulmonary sequelae. Dyspnea evaluated through mMRC scale was reported by 35% of patients with no differences between groups, compared to 29% at 6-month follow-up. CONCLUSION: DLCO alteration and non-fibrotic interstitial lung abnormalities are common after 1 year from hospitalization due to SARS-CoV-2 pneumonia, particularly in older patients requiring higher ventilatory support. Studies with longer follow-ups are needed.
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COVID-19/complicaciones , Enfermedades Pulmonares/diagnóstico , Enfermedades Pulmonares/virología , Anciano , COVID-19/diagnóstico , COVID-19/terapia , Femenino , Estudios de Seguimiento , Hospitalización , Humanos , Enfermedades Pulmonares/terapia , Masculino , Persona de Mediana Edad , Terapia por Inhalación de Oxígeno , Estudios Prospectivos , Respiración Artificial , Pruebas de Función Respiratoria , Factores de TiempoRESUMEN
Bisphenol A (BPA) is an endocrine disruptor that negatively affects spermatogenesis, a process where Sertoli cells play a central role. Thus, in the present study we sought to ascertain whether BPA could modulate the endocannabinoid (eCB) system in exposed mouse primary Sertoli cells. Under our experimental conditions, BPA turned out to be cytotoxic to Sertoli cells with an half-maximal inhibitory concentration (IC50) of ~6.0 µM. Exposure to a non-cytotoxic dose of BPA (i.e., 0.5 µM for 48 h) increased the expression levels of specific components of the eCB system, namely: type-1 cannabinoid (CB1) receptor and diacylglycerol lipase-α (DAGL-α), at mRNA level, type-2 cannabinoid (CB2) receptor, transient receptor potential vanilloid 1 (TRPV1) receptors, and DAGL-ß, at protein level. Interestingly, BPA also increased the production of inhibin B, but not that of transferrin, and blockade of either CB2 receptor or TRPV1 receptor further enhanced the BPA effect. Altogether, our study provides unprecedented evidence that BPA deranges the eCB system of Sertoli cells towards CB2- and TRPV1-dependent signal transduction, both receptors being engaged in modulating BPA effects on inhibin B production. These findings add CB2 and TRPV1 receptors, and hence the eCB signaling, to the other molecular targets of BPA already known in mammalian cells.
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Compuestos de Bencidrilo/toxicidad , Endocannabinoides/metabolismo , Inhibinas/biosíntesis , Fenoles/toxicidad , Células de Sertoli/metabolismo , Animales , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Regulación de la Expresión Génica/efectos de los fármacos , Masculino , Ratones , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Cannabinoides/genética , Receptores de Cannabinoides/metabolismo , Células de Sertoli/efectos de los fármacos , Transferrina/metabolismoRESUMEN
PURPOSE: To evaluate the image quality and radiation dose exposure of low-dose coronary CTA (cCTA) study, reconstructed with the new model-based iterative reconstruction algorithm (IMR), compared with standard hybrid-iterative reconstruction (iDose4) cCTA in patients with suspected coronary artery disease. MATERIALS AND METHODS: Ninety-eight patients with an indication for coronary CT study were prospectively enrolled. Fifty-two patients (study group) underwent 256-MDCT low-dose cCTA (80 kV; automated-mAs; 60 mL of CM, 350 mgL/mL) with prospective ECG-triggering acquisition and IMR. A control group of 46 patients underwent 256-MDCT standard prospective ECG-gated protocol (100 kV; automated-mAs; 70 mL of CM, 400 mgL/mL; iDose4). Subjective and objective image quality (attenuation value, SD, SNR and CNR) were evaluated by two radiologists subjectively. Radiation dose exposure was quantified as DLP, CTDIvol and ED. RESULTS: Mean values of mAs were significantly lower for IMR-cCTA (167 ± 62 mAs) compared to iDose-cCTA (278 ± 55 mAs), p < 0.001. With a significant reduction of 38% in radiation dose exposure (DLP: IMR-cCTA 91.7 ± 26 mGy cm vs. iDose-cCTA 148.6 ± 35 mGy cm; p value < 0.001), despite the use of different CM, we found higher mean attenuation values of the coronary arteries in IMR group compared to iDose4 (mean density in LAD: 491HU IMR-cCTA vs. 443HU iDose-cCTA; p = 0.03). We observed a significant higher value of SNR and CNR in study group due to a lower noise level. Qualitative analysis did not reveal any significant differences between the two groups (p = 0.23). CONCLUSIONS: Low-dose cCTA study combined with IMR reconstruction allows to correctly evaluate coronary arteries disease, offering high-quality images and significant radiation dose exposure reduction (38%), as compared to standard cCTA protocol.
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Algoritmos , Angiografía por Tomografía Computarizada/métodos , Angiografía Coronaria/métodos , Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Anciano , Anciano de 80 o más Años , Técnicas de Imagen Sincronizada Cardíacas , Medios de Contraste , Femenino , Humanos , Yohexol/análogos & derivados , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Dosis de Radiación , Relación Señal-RuidoRESUMEN
Endocannabinoid (eCB)-binding receptors can be modulated by several ligands and membrane environment, yet the effect of glycosylation remains to be assessed. In this study, we used human neuroblastoma SH-SY5Y cells to interrogate whether expression, cellular localization, and activity of eCB-binding receptors may depend on N-linked glycosylation. Following treatment with tunicamycin (a specific inhibitor of N-linked glycosylation) at the non-cytotoxic dose of 1 µg/mL, mRNA, protein levels and localization of eCB-binding receptors, as well as N-acetylglucosamine (GlcNAc) residues, were evaluated in SH-SY5Y cells by means of quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR), fluorescence-activated cell sorting (FACS), and confocal microscopy, respectively. In addition, the activity of type-1 and type-2 cannabinoid receptors (CB1 and CB2) was assessed by means of rapid binding assays. Significant changes in gene and protein expression were found upon tunicamycin treatment for CB1 and CB2, as well as for GPR55 receptors, but not for transient receptor potential vanilloid 1 (TRPV1). Deglycosylation experiments with N-glycosidase-F and immunoblot of cell membranes derived from SH-SY5Y cells confirmed the presence of one glycosylated form in CB1 (70 kDa), that was reduced by tunicamycin. Morphological studies demonstrated the co-localization of CB1 with GlcNAc residues, and showed that tunicamycin reduced CB1 membrane expression with a marked nuclear localization, as confirmed by immunoblotting. Cleavage of the carbohydrate side chain did not modify CB receptor binding affinity. Overall, these results support N-linked glycosylation as an unprecedented post-translational modification that may modulate eCB-binding receptors' expression and localization, in particular for CB1.
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Endocannabinoides/genética , Neuroblastoma/tratamiento farmacológico , Receptores de Cannabinoides/química , Tunicamicina/farmacología , Línea Celular Tumoral , Membrana Celular/efectos de los fármacos , Endocannabinoides/química , Endocannabinoides/farmacología , Citometría de Flujo , Glicosilación/efectos de los fármacos , Humanos , Ligandos , Microscopía Confocal , Neuroblastoma/genética , Neuroblastoma/patología , Péptido-N4-(N-acetil-beta-glucosaminil) Asparagina Amidasa/genética , Receptores de Cannabinoides/genética , Canales Catiónicos TRPV/genética , Tunicamicina/químicaRESUMEN
PURPOSE: This study evaluated the effectiveness of patient dose reduction tools on a 256-slice computed tomography scanner (Brilliance iCT, Philips). MATERIALS AND METHODS: The performance of the Brilliance iCT scanner was described in terms of cumulative dose and dose-normalised contrast-to-noise ratio (CNRD). The efficiency of automatic tube current modulation (Z-Dom and D-Dom), shaping filters (SmartShape and IntelliBeam) and asymmetric collimator (Eclipse) was evaluated using appropriate phantoms. RESULTS: The scattered radiation contribution from the peripheral regions to the cumulative dose is not negligible. The CNRD is 20 % better compared to a traditional 16-slice scanner, with a dose reduction of 40 %. The application of shaping filters decreases the dose in the peripheral regions. The application of D-Dom and Z-Dom modulations reduces the current-time product (mAs) values by 23 and 18 %, respectively, but they are not yet integrated. The over-ranging effect is not negligible, despite the use of an Eclipse asymmetric collimator. CONCLUSIONS: Brilliance iCT dose reduction tools are efficient, but should be analysed carefully and used correctly.
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Tomografía Computarizada por Rayos X/normas , Fantasmas de Imagen , RadiometríaRESUMEN
OBJECTIVE: The objective of the study was to evaluate the role of perfusion computed tomography (CT) for monitoring and predicting therapy response in patients with hepatocellular carcinoma treated with thalidomide. METHODS: Twenty-four patients with advanced hepatocellular carcinoma were treated with thalidomide. Perfusion and conventional CT were performed at baseline and every 2 months until disease progression. Baseline tumor size and enhancement characteristics, as well as baseline perfusion parameters and their changes after therapy, were explored and tested for association with therapy response. RESULTS: Perfusion CT was feasible in 18 patients. Baseline tumor size and enhancement characteristics showed no predictive value, whereas baseline blood flow and blood volume were higher in patients with progressive disease (P < 0.042), with cutoff values for blood flow (16.7 mL/100 g per minute) and blood volume (1.84 mL/100 g) predicting progressive disease in 83.3% and 77.8% of patients, respectively. Significant changes were observed after 2, 4, and 6 months in blood flow (P < 0.031), blood volume after 4 months (P = 0.018), and mean transit time after 4 and 6 months (P = 0.030) in patients with stable disease at 6 months. CONCLUSIONS: Baseline blood flow and blood volume predicted response to therapy in our cohort.
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Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/tratamiento farmacológico , Imagen de Perfusión/métodos , Talidomida/uso terapéutico , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Inhibidores de la Angiogénesis/uso terapéutico , Carcinoma Hepatocelular/secundario , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Resultado del TratamientoRESUMEN
OBJECTIVE: The aim of this study was to assess the potential of perfusion computed tomography (CTp) for monitoring induction chemotherapy in patients with squamous cell carcinoma (SCCA) of the upper aerodigestive tract. MATERIALS AND METHODS: Twenty-five patients with advanced SCCA underwent CTp and volumetric CT before and after induction chemotherapy. Perfusion CT parameters were calculated in the tumor, normal tissue, and muscles and correlated with tumor volume. RESULTS: The blood flow (BF), blood volume (BV), and permeability surface were significantly higher, and the mean transit time was significantly lower in the tumor than in the normal tissue. The tumor BF and BV significantly decreased, and the mean transit time significantly increased after the therapy; decrease in BF and BV correlated with tumor volume reduction after chemotherapy. The baseline tumor BV was significantly lower in nonresponders compared with that in responders. CONCLUSIONS: In patients with SCCA, CTp showed potential for monitoring induction chemotherapy, reduction in tumor BF and BV correlated with reduction of tumor volume after chemotherapy, and baseline tumor BV may predict response to chemotherapy.
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Carcinoma de Células Escamosas/diagnóstico por imagen , Carcinoma de Células Escamosas/tratamiento farmacológico , Tomografía Computarizada de Haz Cónico/métodos , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , Imagen de Perfusión/métodos , Carga Tumoral , Adulto , Anciano , Anciano de 80 o más Años , Volumen Sanguíneo , Permeabilidad Capilar , Carcinoma de Células Escamosas/irrigación sanguínea , Carcinoma de Células Escamosas/patología , Medios de Contraste , Neoplasias de Cabeza y Cuello/irrigación sanguínea , Neoplasias de Cabeza y Cuello/patología , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Persona de Mediana Edad , Intensificación de Imagen Radiográfica/métodos , Flujo Sanguíneo Regional , Reproducibilidad de los ResultadosRESUMEN
RATIONALE: Granulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmatic antibodies (ANCA)-associated vasculitis affecting small- and medium-sized blood vessels, mostly involving lung and kidney. PATIENT CONCERNS: We report the case of a 33-year-old man that presented with acute respiratory distress syndrome caused by alveolar hemorrhage. DIAGNOSES: Aggressive GPA presenting with diffuse alveolar hemorrhage and multiorgan involvement. INTEVENTIONS: Immunosuppressive therapy, plasma exchange, extracorporeal membrane oxygenation (ECMO). OUTCOMES: Relapse occurred very early, despite immunosuppressive treatment, with a rare involvement of genital system (epididymitis) and rapidly progressive glomerulonephritis difficult to treat. LESSONS: GPA is a challenging, multifaceted disease that can require aggressive supportive therapy and is associated with a high rate of relapse that may present with uncommon site of involvement.
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Oxigenación por Membrana Extracorpórea , Granulomatosis con Poliangitis/complicaciones , Hemoptisis/etiología , Adulto , Hemoptisis/terapia , Humanos , MasculinoAsunto(s)
Enfermedades Autoinmunes , COVID-19 , Enfermedades Pulmonares Intersticiales , Neumonía , Enfermedades Autoinmunes/complicaciones , Enfermedades Autoinmunes/diagnóstico , COVID-19/complicaciones , COVID-19/diagnóstico , Humanos , Enfermedades Pulmonares Intersticiales/diagnóstico , SARS-CoV-2RESUMEN
BACKGROUND: Interstitial pneumonia with autoimmune features (IPAF) identifies a recently recognized autoimmune syndrome characterized by interstitial lung disease and autoantibodies positivity, but absence of a specific connective tissue disease diagnosis or alternative etiology. We retrospectively reviewed the clinical presentation, diagnostic workup and management of seven critically ill patients who met diagnostic criteria for IPAF. We compared baseline characteristics and clinical outcome of IPAF patients with those of the population of ARDS patients admitted in the same period. RESULTS: Seven consecutive patients with IPAF admitted to intensive care unit for acute respiratory distress syndrome (ARDS) were compared with 78 patients with ARDS secondary to a known risk factor and with eight ARDS patients without recognized risk factors. Five IPAF patients (71%) survived and were discharged alive from ICU: Their survival rate was equal to that of patients with a known risk factor (71%), while the subgroup of patients without risk factors had a markedly lower survival (38%). According to the Berlin definition criteria, ARDS was severe in four IPAF patients and moderate in the remaining three. All had multiple organ dysfunction at presentation. The most frequent autoantibody detected was anti-SSA/Ro52. All patients required prolonged mechanical ventilation (median duration 49 days, range 10-88); four received extracorporeal membrane oxygenation and one received low-flow extracorporeal CO2 removal. All patients received immunosuppressive therapy. CONCLUSIONS: This is the first description of a cohort of critical patients meeting the diagnostic criteria for IPAF presenting with ARDS. This diagnosis should be considered in any critically ill patient with interstitial lung disease of unknown origin. While management is challenging and level of support high, survival appears to be good and comparable to that of patients with ARDS associated with a known clinical insult.
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In this study we report the effect of AZT on the whole protein expression profile both in the control and the AZT-treated K562 cells, evidenced by two-dimensional gel electrophoresis and peptide mass fingerprinting analysis. Two-dimensional gels computer digital image analysis showed two spots that appeared up-regulated in AZT-treated cells and one spot present only in the drug exposed samples. Upon extraction and analysis by peptide mass fingerprinting, the first two spots were identified as PDI-A3 and stathmin, while the third one was proved to be NDPK-A. Conversely, two protein spots were present only in the untreated K562 cells, and were identified as SOD1 and HSP-60, respectively.
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Great interest is currently centered on the biologic activities of quercetin a polyphenol belonging to the class of flavonoids, natural products well known for their beneficial effects on health, long before their biochemical characterization. In particular, quercetin is categorized as a flavonol, one of the five subclasses of flavonoid compounds. Although flavonoids occur as either glycosides (with attached glycosyl groups) or as aglycones, most altogether of the dietary intake concerning quercetin is in the glycoside form. Following chewing, digestion, and absorption sugar moieties can be released from quercetin glycosides. Several organs contribute to quercetin metabolism, including the small intestine, the kidneys, the large intestine, and the liver, giving rise to glucuronidated, methylated, and sulfated forms of quercetin; moreover, free quercetin (such as aglycone) is also found in plasma. Quercetin is now largely utilized as a nutritional supplement and as a phytochemical remedy for a variety of diseases like diabetes/obesity and circulatory dysfunction, including inflammation as well as mood disorders. Owing to its basic chemical structure themost obvious feature of quercetin is its strong antioxidant activity which potentially enables it to quench free radicals from forming resonance-stabilized phenoxyl radicals. In this review the molecular, cellular, and functional bases of therapy will be emphasized taking strictly into account data appearing in the peer-reviewed literature and summarizing the main therapeutic applications of quercetin; furthermore, the drug metabolism and the main drug interaction as well as the potential toxicity will be also spotlighted.
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Quercetina/química , Quercetina/farmacología , Animales , Antioxidantes/química , Antioxidantes/farmacología , Disponibilidad Biológica , Interacciones Farmacológicas , Frutas/química , Glicósidos/química , Humanos , Mucosa Intestinal/metabolismo , Riñón/metabolismo , Hígado/metabolismo , Estructura Molecular , Verduras/químicaRESUMEN
The role of the endocannabinoid system (ECS) in mammalian reproduction is a rather active field of research, due to its potential exploitation to combat human infertility. Available data shows that the aberrant endocannabinoid signaling negatively affects embryo development, implantation and pregnancy. Although many efforts have been devoted to a better understanding of the ECS in these steps of female reproduction, very little is known about its role in regulating ovarian follicle development and production of mature oocytes. This is the subject of the present review where we discuss current knowledge about the impact and potential exploitation of the ECS and endocannabinoid signaling in mammalian ovary and folliculogenesis.
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Endocannabinoides/fisiología , Folículo Ovárico/fisiología , Ovario/fisiología , Reproducción/fisiología , Transducción de Señal , Amidohidrolasas/metabolismo , Animales , Femenino , Humanos , Oocitos/crecimiento & desarrollo , Folículo Ovárico/efectos de los fármacos , Ovario/efectos de los fármacos , EmbarazoAsunto(s)
Anestesia Raquidea/efectos adversos , Bupivacaína/efectos adversos , Complicaciones Posoperatorias/etiología , Incontinencia Urinaria/etiología , Anciano , Bupivacaína/administración & dosificación , Femenino , Humanos , Complicaciones Posoperatorias/inducido químicamente , Complicaciones Posoperatorias/diagnóstico , Incontinencia Urinaria/inducido químicamente , Incontinencia Urinaria/diagnósticoRESUMEN
Great interest is currently centred on the biologic activities of pycnogenol a standardized plant extract obtained from the bark of the French maritime pine Pinus pinaster (formerly known as Pinus maritima), Aiton, subspecies Atlantica des Villar (Pycnogenol, Horphag Research Ltd., UK, Geneve, Switzerland), which grows in the coastal southwest France. The quality of this extract is specified in the United States Pharmacopeia (USP 28). Between 65% and 75% of Pycnogenol are procyanidins comprising of catechin and epicatechin subunits with varying chain lengths. Other constituents are polyphenolic monomers, phenolic or cinnamic acids and their glycosides. As many studies indicate, pycnogenol components are highly bioavailable. Uniquely, pycnogenol displays greater biologic effects as a mixture than its purified components do individually indicating that the components interact synergistically. Pycnogenol is now utilized throughout the world as a nutritional supplement and as a phytochemical remedy for various diseases ranging from chronic inflammation to circulatory dysfunction, including several impaired psycho-physiological functions. Owing to the basic chemical structure of its components, the most obvious feature of pycnogenol is its strong antioxidant activity. In fact, phenolic acids, polyphenols, and in particular flavonoids, are composed of one (or more) aromatic rings bearing one or more hydroxyl groups and are therefore potentially able to quench free radicals by forming resonance-stabilized phenoxyl radicals. In this review, emphasizing the molecular, cellular, and functional bases of therapy, data appearing in the peer-reviewed literature and focussing the main therapeutic applications of pycnogenol will be summarized and critically evaluated.
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Antioxidantes/uso terapéutico , Flavonoides/uso terapéutico , Fitoterapia , Pinus/química , Extractos Vegetales/uso terapéutico , Proantocianidinas/uso terapéutico , Antioxidantes/farmacología , Flavonoides/farmacología , Humanos , Fenoles , Corteza de la Planta , Extractos Vegetales/farmacología , Polifenoles , Proantocianidinas/farmacologíaRESUMEN
Resveratrol, a naturally occurring polyphenol, shows pleiotropic health beneficial effects, including anti-oxidant, anti-inflammatory, anti-aging, cardioprotective and neuroprotective activities. Due to the several protective effects and since this compound is widely distributed in the plant kingdom, resveratrol can be envisaged as a chemo-preventive/curative agent introduced almost daily with the diet. Currently, a number of preclinical findings suggest resveratrol as a promising nature's weapon for cancer prevention and treatment. A remarkable progress in elucidating the molecular mechanisms underlying anti-cancer properties of resveratrol has been achieved in the last years. Concerning the resveratrol mechanism of action as a protective (vs. normal cells and tissues) and toxic (vs. cancer cells) compound, many studies focus on its antioxidant capacity as well as on its ability to trigger and favor the apoptotic cascade in malignant cells. However, a generalized mechanism of action able to explain this dual effect of resveratrol has not yet been clearly established. In addition to these important functions, resveratrol is reported to exhibit several other biological/biochemical protective effects on heart, circulation, brain and age-related diseases which are summarized in this Review.
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Antioxidantes/química , Antioxidantes/farmacología , Estilbenos/química , Estilbenos/farmacología , Estructura Molecular , ResveratrolRESUMEN
The science of antiviral research was well advanced when HIV/AIDS appeared as a major new virus disease in the early 1980s. The first effective antiviral compound (AZT, azidothymidine, zidovudine) was already among the library of compounds screened and was promptly reported to be a specific inhibitor of retroviruses, including HIV. Due to the pivotal role of AZT in HIV treatment, this review summarizes the most known effects -some of which are toxic side effects- induced by AZT a drug which is still used in the combined therapy of HIV-infected patients. Among the toxic side effects, a severe bone marrow toxicity manifested as anemia, neutropenia and siderosis, and caused by inhibition of heme and globin synthesis together with a general derangement of iron supply, have been reported. In this regard, we proved that while AZT and its monophosphorylated derivative AZTMP were unable to chelate iron, the triphosphate form AZTTP displayed a significant capacity to remove iron from transferrin. Moreover, we have previously demonstrated that AZT-exposed K562 cells showed an increase of transferrin receptors located on the cell membrane without affecting their biosynthesis, but slowing down their endocytotic pathway. Interestingly, literature data report the impairement of glycosylation reactions by AZT. Indeed, we have shown that AZT-treated K562 cells exhibited a reduced sialylation of proteins and lipids, and a strong inhibition of alpha,(2-->8) sialyltransferase activity while beta,(1-->4)galactosyltransferase and beta-galactosidase activities were significantly increased. These latter observations could be of clinical relevance since alterations of intracellular and cell surface carbohydrate expression and composition, often are associated with several diseases. However, contrarily to previous reports by other authors on AZT as an inhibitor of plant and bacterial toxins activity, we have demonstrated that AZT not only did not inhibit saporin toxicity, but even increased the cytotoxic activity of this plant toxin on K562 cells. Furthermore, the review enlightens the potential utilization of AZT as a tool in proteomics since in the recent years several genes responding to this drug have been identified in different cell lines. We have shown, for the first time, an over-expression of two proteins (PDI-A3 and sthatmin), and a full repression of two others (HSP-60 and SOD1) in AZT-exposed K562 cells. At present, we are investigating if the above reported alterations are a general feature of AZT-treatment of cultured cells, or they represent a peculiar characteristic of a specific cell line. Finally, the paper reviews a number of novel methodologies aimed at enhancing the AZT plasma levels and its bioavailability in all human organs in order to improve its therapeutic efficacy against HIV infection. These new possibilities, namely the AZT prodrug strategy, the AZT transdermal delivery and the targeted brain delivery, are yet not in use for humans but they are under experimental studies.
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Fármacos Anti-VIH/toxicidad , Zidovudina/toxicidad , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/genética , Administración Cutánea , Anemia/inducido químicamente , Animales , Médula Ósea/efectos de los fármacos , Células Eritroides/efectos de los fármacos , Glicosilación , Humanos , Inmunotoxinas/farmacología , Hierro/metabolismo , Profármacos/farmacología , Proteómica , Zidovudina/administración & dosificación , Zidovudina/metabolismoRESUMEN
The present paper shows that human chronic myeloid (K562) cells exposed 3 h to 20 microM 3'-azido-3'-deoxythymidine (AZT) exhibit marked variations of the oligosaccharide moiety of glycoconjugates. These changes were analyzed by confocal fluorescence microscopy, upon incubation of control and AZT-treated cells with biotin-lectin conjugates to visualize cell surface glycans or total glycans after cells permeabilization. In addition, cell fluorescence distribution of the biotinylated lectins, localized with streptavidin conjugates labeled with Alexa Fluor 488, was analyzed by flow cytometry. The results obtained show significant variations on the expression/distribution of membrane surface glycans as detected by both WGA and SNA, two lectins that recognize primarily cellular internal membrane glycolipids. A further interesting result was the significant increase of N-acetylglucosamine linked glycans localized either at the cell surface or intracellularly but only in K562 cells exposed to AZT. On the whole, our data demonstrate that AZT alters both lipid and N-linked glycosylations thus confirming previous observations, from our laboratory and from other Authors, that the drug impair the nucleotide-sugar import in the Golgi's lumen. AZT does also alter the O-linked glycosylations that occur in the Golgi complex since these reactions require the incorporation of sialic acid, GlcNAc and GalNAc all of which are sensitive to the drug.
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Lectinas/metabolismo , Polisacáridos/metabolismo , Zidovudina/farmacología , Biotinilación , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Citometría de Flujo , Fluorescencia , Colorantes Fluorescentes , Histocitoquímica , Humanos , Células K562 , Microscopía Confocal , Permeabilidad/efectos de los fármacosRESUMEN
There is considerable interest in monitoring alpha,(2-->8)sialyltransferase (ST8) levels; however, there are few specific and sensitive methods to directly detect and quantitate the protein. This paper reports the development of a synthetic probe composed of oxidized colominic acid coupled to biotinyl-L-lysine hydrazide to detect and quantify ST8 with putative "initiase" activity and its use in three solid-phase applications. The detection limit observed for ST8 purified from K562 cells was approximately 2 pg by dot-blot analysis. In Western blots the probe bound and specifically recognized a protein band corresponding to ST8. In ELISA a linear dose response was obtained for pure protein in the range of 50-200 pg. Analysis of 3'-azido-3'deoxythymidine-treated cells by all three methods showed a reduction in ST8 compared to control cells; treated cells had 73% of control levels by ELISA. This probe will be useful for studies on the expression ST8 and its role in glycoconjugate biosynthesis.
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Sondas Moleculares/análisis , Proteínas/análisis , Sialiltransferasas/análisis , Línea Celular Tumoral , Humanos , Sondas Moleculares/síntesis química , Polisacáridos/análisis , Polisacáridos/síntesis químicaRESUMEN
Osteopontin, a non-collageneous bone matrix protein, is produced in several human tumors but its role in cancer progression has been only partially elucidated. In this study we investigated the potential role of osteopontin in the malignancy of prostate cancer cells. Chemotaxis and chemoinvasion analyses revealed a dose-dependent increase in PC3 cell movement induced by osteopontin and a strict dependence of cell invasion on alphavbeta3 integrin function. The pattern of protease expression was modified by osteopontin and was characterized by an upregulation of plasminogen activators. Our findings suggest that osteopontin may confer selective malignant potential to prostate cancer cells through the enhancement of their invasive and proteolytic capability.