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1.
Curr Res Microb Sci ; 7: 100283, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39450392

RESUMO

The bagasse of Agave salmiana (maguey pulquero) is a residue generated during the exploitation of the plant to obtain pulque, inulin, honey, etc. Due to its chemical composition, it can be used for the cultivation of fungi of the Pleurotus genus and the subsequent use of the degraded material "degraded substrate (DS)" as a support for the germination of vegetables. The objective of the study was to characterize the bagasse of maguey pulquero biodegraded by Pleurotus djamor as a new perspective in its value chain, and subsequent use for the germination of Lycopersicon esculetum (tomato). The DS was recovered at 60 d from the P. djamor culture, characterized physicochemically and the conformation of the plant tissue was observed by scanning electron microscopy. The DS showed a decrease in protein (4.8-3.3 %) content and fibrous fraction (54-36 %), but dry matter digestibility increased from 47 to 71 %; in addition, changes in mineral composition were observed, mainly in calcium concentration (6 %). Due to its composition, it is possible to revalue DS in the germination of L. esculetum to reduce the use of peat moss (commercial peat). The results show that up to 25 % of maguey DS mixed with 75 % peat moss can be used (25:75), reaching a germination percentage of 85 % and increasing the seedling emergence speed index from 0.96 - 1.25. Concluding that it is possible to implement a circular strategy in which agave bagasse is used for mushroom cultivation and the subsequent recovery of the spent substrate for tomato germination.

2.
Rev Neurol ; 79(2): 67-70, 2024 Jul 16.
Artigo em Espanhol | MEDLINE | ID: mdl-38976585

RESUMO

INTRODUCTION: Reversible cerebral vasoconstriction syndrome is a clinicoradiological entity with a self-limiting course that manifests with recurrent episodes of thunderclap headache, and is associated with certain triggers. Recurrence is very rare, and the pathophysiology is thought to be related to altered autoregulation of the cerebrovascular tone. We present a clinical case that raises questions about possible recurrences and triggers. CASE REPORT: A 44-year-old woman with a history of multiple sclerosis treated with interferon beta-1b who had four episodes of thunderclap headache while resting, after completing a course of corticosteroids due to a flare-up of optic neuritis. Three years earlier, the patient had presented several episodes of explosive-onset headache during a self-limited period of one month, only occurring during sexual intercourse. In the year prior to our assessment, she had suffered three thunderclap headaches with similar characteristics, but they were triggered only by intense physical exercise. She had not consulted a physician about these events. A cranial computed tomography scan was performed after the administration of contrast media and a cerebral arteriography, which were consistent with cerebral vasoconstriction syndrome, and its reversibility was confirmed three months later. CONCLUSIONS: Reversible cerebral vasoconstriction syndrome shares a phenotypic expression with primary exertion headaches. It is associated with drugs with vasoactive effects, including interferons, and corticosteroids are associated with a worse prognosis, and such their administration should be avoided.


TITLE: Síndrome de vasoconstricción cerebral reversible. Recurrencia de cefaleas en trueno tras tratamiento con corticoides.Introducción. El síndrome de vasoconstricción cerebral reversible es una entidad clinicorradiológica de curso autolimitado que se manifiesta con episodios de cefalea en trueno recurrentes y que se asocia a determinados desencadenantes. La recidiva es muy poco frecuente y la fisiopatología se cree que está en relación con la alteración de la autorregulación del tono vascular cerebral. Presentamos un caso clínico que plantea cuestiones sobre posibles recurrencias y desencadenantes. Caso clínico. Mujer de 44 años con antecedente de esclerosis múltiple en tratamiento con interferón beta-1b que consultó por cuatro episodios de cefalea en trueno en reposo, tras finalizar un ciclo de corticoides por un brote de neuritis óptica. Tres años antes, la paciente había presentado varios episodios de cefalea de inicio explosivo durante un período autolimitado de un mes, únicamente producidos en el contexto de relaciones sexuales. El año previo a nuestra valoración padeció en tres ocasiones cefalea en trueno de características similares, pero exclusivamente desencadenadas con el ejercicio físico intenso. No había consultado por estos eventos. Se realizó una tomografía computarizada craneal tras la administración de contraste y una arteriografía cerebral, que fueron compatibles con síndrome de vasoconstricción cerebral, y se confirmó su reversibilidad tres meses después. Conclusiones. El síndrome de vasoconstricción cerebral reversible comparte expresión fenotípica con el grupo de cefaleas primarias por esfuerzo físico. Se asocia a fármacos con efectos vasoactivos, entre los que se encuentran los interferones, y los corticoides se asocian a un peor pronóstico, por lo que es importante evitar su administración.


Assuntos
Transtornos da Cefaleia Primários , Recidiva , Humanos , Feminino , Adulto , Transtornos da Cefaleia Primários/tratamento farmacológico , Transtornos da Cefaleia Primários/etiologia , Vasoconstrição/efeitos dos fármacos , Vasoespasmo Intracraniano/tratamento farmacológico , Vasoespasmo Intracraniano/induzido quimicamente , Vasoespasmo Intracraniano/diagnóstico por imagem , Síndrome , Corticosteroides/uso terapêutico
3.
Mult Scler Relat Disord ; 58: 103520, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35038645

RESUMO

BACKGROUND: Melatonin has been related to the pathophysiology of multiple sclerosis (MS), and its anti-inflammatory and immunomodulatory properties have been proved in numerous neurodegenerative diseases. This study aimed to find out whether a melatonin supplement in MS is able to act as a benefit to its clinical status, i.e. oxidative stress, inflammation and indirect biomarkers of bacterial dysbiosis, lipopolysaccharide (LPS) and LPS-binding protein (LBP), verifying its therapeutic potential and its possible clinical use in patients with MS. METHODS: The animal MS model, experimental autoimmune encephalomyelitis (EAE), was employed whereby 25 male Dark Agouti rats (5 animals per group) were divided into: a control group (not manipulated); a control+vehicle group; a control+melatonin group; an EAE group; an EAE+melatonin group. Melatonin was administered daily for 51 days, at a dose of 1 mg/kg body weight/i.p., once a day, five days a week. RESULTS: The results from the administration of melatonin demonstrated an improvement in clinical status, a diminution in oxidative stress and inflammation, as well as in bacterial dysbiosis. CONCLUSION: Melatonin could play an effective role against MS, either alone or as a therapy combined with traditional agents.


Assuntos
Encefalomielite Autoimune Experimental , Melatonina , Esclerose Múltipla , Animais , Biomarcadores/metabolismo , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/metabolismo , Humanos , Masculino , Melatonina/farmacologia , Melatonina/uso terapêutico , Camundongos , Camundongos Endogâmicos C57BL , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/metabolismo , Estresse Oxidativo , Ratos
4.
J Investig Allergol Clin Immunol ; 32(6): 451-459, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34213416

RESUMO

BACKGROUND AND OBJECTIVES: Although exposure to stings has been identified as the leading risk factor for anaphylaxis due to Hymenoptera venom allergy, professional beekeepers receive hundreds of stings yearly without developing systemic reactions. This study aims to analyze the mechanisms underlying bee venom tolerance in beekeepers. METHODS: A cross-sectional study was conducted. Participants were recruited and classified into 3 groups: allergic patients (APs), who experienced systemic reactions after bee stings, with a positive intradermal test and specific IgE (sIgE) to Apis mellifera venom (AmV); tolerant beekeepers (TBKs), who received ≥50 stings/year; and healthy nonexposed controls (HCs). We measured serum levels of sIgE and specific IgG4 (sIgG4) to AmV, rApi m 1, rApi m 2, rApi m 3, Api m 4, rApi m 5, and rApi m10, as well as AmV-induced basophil degranulation, percentage of T-cell subsets, regulatory T cells (Treg), and IL-10 production. RESULTS: Compared with TBKs, APs had high levels of sIgE to AmV and all its allergic components (P<.001), together with a high basophil activation rate (P<.001). Conversely, compared with APs, TBKs had higher levels of sIgG4 (P<.001) and IL-10 (P<.0001), as well as an enhanced CTLA-4+ Treg population (P=.001), expanded Helios- Treg (P<.003), and reduced type 1 helper T cells (TH1) (P=.008), TH2 (P=.004), and TH17 (P=.007) subsets. CONCLUSIONS: The profile of TBKs, which was strongly marked by Treg activity, differed from that of TBKs. This natural tolerance would be led by the expansion of inducible Helios- Treg cells at the peripheral level. The Helios- Treg population could be a novel candidate biomarker for monitoring tolerance.


Assuntos
Anafilaxia , Venenos de Abelha , Hipersensibilidade , Tolerância Imunológica , Mordeduras e Picadas de Insetos , Linfócitos T Reguladores , Humanos , Anafilaxia/diagnóstico , Anafilaxia/metabolismo , Abelhas , Estudos Transversais , Hipersensibilidade/diagnóstico , Imunoglobulina E/química , Imunoglobulina G/química , Mordeduras e Picadas de Insetos/complicações , Mordeduras e Picadas de Insetos/imunologia , Interleucina-10
5.
3 Biotech ; 11(2): 39, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33479594

RESUMO

In the present study, a sequential staining process of polyphenoloxidase and phenoloxidase enzymes was designed by the zymography technique. As a first step, electrophoresis was carried out under native conditions, and later, first staining was carried out with a revealing solution of 3-methyl-2-benzothiazoline hydrazone (MBTH)-3-dimethylamino benzoic acid (DMAB) that allowed the visualization of polyphenoloxidase enzymes, and later and using the same gel, we proceeded to the differential staining of phenoloxidase, adding a solution of H2O2. The technique was standardized using commercial enzymes of laccase (T. versicolor) and horseradish. The technique was used to identify polyphenoloxidases (laccases) and phenoloxidases (lignin peroxidase) of crude extracts obtained from the growth of the basidiomycete Lentinus strigosus on Pinus radiata. The technique showed great sensitivity to detect the different enzymatic activities (1.56 Activity Unit/mL minimum) in the same gel without interference between the enzymes and the solutions used. On the other hand, the efficiency of the technique was compared with the substrates that are commonly used for the detection of this type of activities such as 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and guaiacol, observing greater sensitivity and minimal interference, so that the present method will allow in the same gel, and visualize polyphenoloxidase and phenoloxidase activities simultaneously facilitating expression studies.

7.
Curr Microbiol ; 77(11): 3460-3472, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32797266

RESUMO

The Mezquital Valley (MV), Mexico, is a semi-arid region whose main economic activity is agriculture, this zone is characterized by the use of wastewater for crop irrigation. This condition has increased the amount nutrients in soils, organic carbon content and native microorganisms. The Streptomyces species are a group of saprophytic bacteria that represent between 20 and 60% of the total microbial population in soils, capable of producing metabolites of commercial importance. In this work, Streptomyces species were isolated from agricultural soils of the MV and was evaluated the production of endoglucanases (CMCase) and xylanases (Xyl) in Solid-State Cultivation (SSC). From soil samples, 73 possible strains of Streptomyces species were isolated for their ability to produce CMCase and Xyl in SSC. The study also included its characterization by morphological characteristics. Of the isolated microorganisms, 38 strains were selected as strong enzyme producers according to the measurement of the halo generated in plate and by growth on barley straw as only carbon source. Two different sizes of barley straw particle were tested, finding that the greatest enzymatic activity was observed in particle size 12. Three strains of Streptomyces species were chosen which presented the best catalytic capacities, a maximum of 100.69 AU Xyl/gram dry matter (gdm), 82 AU Xyl/gdm and 26.02 AU CMCase/gdm for strains 30, 28 and 12, respectively. The strains were identified by ribosomal gen16s sequence and identified as S. flavogriseus, S. virginiae and S. griseoaurantiacus. It is the first report of endogluconase and xylanolytic activity by S. virginiae isolated from a semi-arid soil.


Assuntos
Celulases , Streptomyces , Agricultura , México , Solo , Microbiologia do Solo
8.
Biotechnol Rep (Amst) ; 26: e00445, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32280603

RESUMO

In this work was to evaluate the conidiospores production of Trichoderma harzianum using barley straw as substrate. Four growth conditions were used; washed and unwashed barley straw and washed and unwashed barley straw supplemented with mineral salts. The highest spore production was observed when washed barley straw supplemented with mineral salts with 1.56 × 1010 conidiospores/gram of dry matter (gdm) at 216 h of cultivation was used. The effect of substrate moisture on spore production was studied, three initial moisture levels of the substrate were tested and it was observed that a humidity of 80 % of the substrate improves the production of conidiospores reaching a concentration of 2.35 × 1010 conidiospores/gdm at 136 h. Finally, conidiospores viability was evaluated for 12 months by keeping them on the conidia and substrate, and viability of 71 % of the conidiospores was observed, so this maintenance method is an excellent means of conserving the conidiospores viability.

11.
Heliyon ; 6(12): e05857, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33426343

RESUMO

In the present work, a strain of the basidiomycete fungus Trametes polyzona was used to decolorize the Amaranth dye. The decolorization was carried out in an Airlift reactor with three flow regimes: 1, 2, and 3 vvm. The results showed that the decolorization was a function of the flow regime. The decolorization times for the regimes of 1, 2, and 3 vvm were 30, 25, and 19 days, respectively. The COD (Chemical Oxygen Demand) decreased from 1600 to 72 mg COD/L. The enzymatic activity kinetics of laccase (Lcc), lignin peroxidase (LiP), and manganese peroxidase (MnP) were determined. In all the treatments, the enzyme LiP was expressed during the first 6 days, at which point 80% decolorization was observed, whereas Lcc and MnP enzymes were produced from day 6 until the end of the decolorization process. The effluent generated showed no inhibitory effects on the growth of the algae Nannochloropsis salina. T. polyzona showed great versatility in the decolorization of synthetic effluents containing the Amaranth dye, and the fungus was able to use this dye as its only carbon source starting at the beginning of the process. LiP was the enzyme that contributed the most to the decolorization process, and on average, 95% decreases in color and the COD were observed.

12.
Actas Urol Esp (Engl Ed) ; 43(9): 495-502, 2019 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31155375

RESUMO

INTRODUCTION AND OBJECTIVES: The objective of this study is to evaluate overall survival (OS), cancer-specific survival (CSS), relapse-free survival, local and distant (LRFS and DRFS, respectively) rates in patients with pT3a renal cell carcinoma (RCC) considering the perirenal and/or sinus fat infiltration (FI) as prognostic factors. MATERIALS AND METHODS: Retrospective cohort of patients with pT3a RCC who underwent radical or partial nephrectomy. The data were extracted from the LARCG (Latin American Renal Cancer Group) database. The demographic, clinical, pathological and surgical variables were evaluated. FI was divided into 4 groups (vein, perirenal, sinus and both fats infiltration). The Kaplan Meier and Cox regression curves were performed. RESULTS: 293 patients were included in the study. The mean age was 61.4 years. The median follow-up was 21 months (r: 1-194). CSS, RFS, LRFS and DRFS estimated at 3 years in the group of both fats' infiltration were 53.1, 45.1, 58.7 and 51.6 months, respectively, and always statistically lower than the rest (P˂0.005). In the multivariate analysis, the infiltration of both fats significantly increased specific mortality, overall and local relapse with respect to vein infiltration (HR: 4.5, 2.42 and 8.08, respectively). The Fuhrman grade and renal pelvis infiltration were independent predictors of CSS and RFS. CONCLUSIONS: Infiltration of both fats increases the risk of overall and local relapse in pT3a RCC. In the same way, it is associated with a lower cancer-specific survival and should be considered as a factor of poor prognosis.


Assuntos
Tecido Adiposo/patologia , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida
13.
Radiologia (Engl Ed) ; 61(4): 333-336, 2019.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-30772003

RESUMO

Crohn's disease is an autoimmune disease that predominantly affects the gastrointestinal tract. Crohn's disease is diagnosed at a young age and runs a chronic course with acute flare-ups. When patients with Crohn's disease present with flare-ups at the emergency department, they are usually managed in a way similar to patients with acute abdomen; there is no consensus about the most appropriate imaging work-up for patients with flare-ups of Crohn's disease. Thus, we decided to review the literature about the imaging tests indicated (whether related to their diagnostic performance or to lower exposure to ionizing radiation) for acute flare-ups in patients with Crohn's disease.


Assuntos
Abdome Agudo/diagnóstico por imagem , Doença de Crohn/diagnóstico por imagem , Abdome Agudo/etiologia , Doença de Crohn/complicações , Emergências , Humanos
14.
Rev. argent. dermatol ; Rev. argent. dermatol;99(4): 59-66, dic. 2018.
Artigo em Espanhol | LILACS | ID: biblio-985204

RESUMO

RESUMEN: El melanoma es una neoplasia que se origina de los melanocitos, células derivadas de la cresta neural. En el Ecuador, entre el 2001 y 2005 se diagnosticaron en Quito en promedio: 18 casos anuales de melanoma en hombres y 26 casos en mujeres, con una tasa de incidencia de 2.5 y 3.2 respectivamente, mientras queen Guayaquil, durante el período 2003-2006 fueron reportados 49 casos en total, con una incidencia de 0.9 por cada 100.000 habitantes en hombres y 0.1 en mujeres. Siempre que se pueda es preferible una biopsia escisional, extirpando la lesión entera. La determinación del ganglio centinela junto al nivel de Clark, el espesor de Breslow y la ulceración del tumor, son considerados los factores pronósticos más importantes del melanoma maligno.


SUMMARY: Melanoma is a neoplasm that originates from the melanocytes, cells derived from the neural crest. In Ecuador, between 2001 and 2005 an average of 18 cases in men and 26 cases in women were diagnosed in Quito, with an incidence rate of 2.5 and 3.2 respectively, while in Guayaquil, during the period 2003-2006, 49 cases were reported, with an incidence of 0.9 per 100.000 inhabitants in men and 0.1 in women. The exact etiology is not clear, it is considered a heterogeneous diseasewith multifactorial origin. Whenever possible, an excisional biopsy is preferable, removing the entire lesion. The determination of the sentinel lymph node along with the Clark level, the Breslow thickness and the ulceration of the tumor, are considered the most important prognostic factors of malignant melanoma.

15.
Sci Total Environ ; 610-611: 342-355, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28806551

RESUMO

We report a data-set of CO2, CH4, and N2O concentrations in the surface waters of the Meuse river network in Belgium, obtained during four surveys covering 50 stations (summer 2013 and late winter 2013, 2014 and 2015), from yearly cycles in four rivers of variable size and catchment land cover, and from 111 groundwater samples. Surface waters of the Meuse river network were over-saturated in CO2, CH4, N2O with respect to atmospheric equilibrium, acting as sources of these greenhouse gases to the atmosphere, although the dissolved gases also showed marked seasonal and spatial variations. Seasonal variations were related to changes in freshwater discharge following the hydrological cycle, with highest concentrations of CO2, CH4, N2O during low water owing to a longer water residence time and lower currents (i.e. lower gas transfer velocities), both contributing to the accumulation of gases in the water column, combined with higher temperatures favourable to microbial processes. Inter-annual differences of discharge also led to differences in CH4 and N2O that were higher in years with prolonged low water periods. Spatial variations were mostly due to differences in land cover over the catchments, with systems dominated by agriculture (croplands and pastures) having higher CO2, CH4, N2O levels than forested systems. This seemed to be related to higher levels of dissolved and particulate organic matter, as well as dissolved inorganic nitrogen in agriculture dominated systems compared to forested ones. Groundwater had very low CH4 concentrations in the shallow and unconfined aquifers (mostly fractured limestones) of the Meuse basin, hence, should not contribute significantly to the high CH4 levels in surface riverine waters. Owing to high dissolved concentrations, groundwater could potentially transfer important quantities of CO2 and N2O to surface waters of the Meuse basin, although this hypothesis remains to be tested.

16.
Radiologia ; 59(2): 115-127, 2017.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-27979433

RESUMO

Acute pelvic pain is a common condition in emergency. The sources of acute pelvic pain are multifactorial, so it is important to be familiar with this type of pathologies. The purpose of this article is review the main causes of gynecological acute pelvic pain and their radiologic appearances to be able to make an accurate diagnosis and provide objective criteria for patient management.


Assuntos
Dor Aguda/diagnóstico por imagem , Doenças dos Genitais Femininos/diagnóstico por imagem , Dor Pélvica/diagnóstico por imagem , Dor Aguda/etiologia , Diagnóstico Diferencial , Emergências , Endometriose/complicações , Feminino , Doenças dos Genitais Femininos/complicações , Humanos , Cistos Ovarianos/complicações , Doença Inflamatória Pélvica/complicações , Dor Pélvica/etiologia , Gravidez , Gravidez Ectópica , Anormalidade Torcional/complicações
17.
Int Rev Neurobiol ; 130: 1-40, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27678173

RESUMO

Central nervous system (CNS) diseases constitute a set of challenging pathological conditions concerning diagnosis and therapeutics. For most of these disorders, there is a lack of early diagnosis, biomarkers to allow proper follow-up of disease progression and effective therapeutic strategies to allow a persistent cure. The poor prognosis of most CNS diseases is, therefore, a global concern, especially regarding chronic age-related neurodegenerative disorders, which are already considered problems of public health due to the increasing average of life expectancy. The difficulties associated with the treatment of CNS diseases are owed, at least in part, to very specific characteristics of the brain and spinal cord, when compared to peripheral organs. In this regard, the CNS is physically and chemically protected by the blood-brain barrier (BBB), which, while maintaining essential brain homeostasis, significantly restricts the delivery of most therapeutic agents to the brain parenchyma. On the other hand, regenerative properties of the tissue are lacking, meaning that a CNS insult resulting in neuronal death is a permanent phenomenon. Approaches for transposing the BBB aiming to treat CNS diseases, relying on specific properties of nanosystems, have been reported for therapeutic delivery to CNS without interfering with the normal function of the brain. In this chapter, we address the latest advances concerning the principles of such approaches, employing lipid-based nanoparticles and cell-produced exosomes as drug and nucleic acid delivery systems, and summarize recent example of applications in the context of neurological diseases. Major achievements obtained in preclinical studies and the trends identified by these studies are emphasized to provide new prospects for further developments in this area, thus enabling us to move from the research realm to the clinical arena.


Assuntos
Doenças do Sistema Nervoso Central/tratamento farmacológico , Exossomos , Nanopartículas/uso terapêutico , Nanotecnologia/tendências , Animais , Sistemas de Liberação de Medicamentos , Humanos , Lipídeos/administração & dosagem , Nanopartículas/administração & dosagem
18.
J Mater Chem B ; 3(48): 9233-9241, 2015 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-32262922

RESUMO

Nitric oxide (NO) is a biologically-active free radical involved in numerous physiological processes such as regulation of vasodilation, promotion of cell proliferation and angiogenesis, and modulation of the inflammatory and immune responses. Furthermore, NO has demonstrated the ability to mitigate the foreign body response that often results in the failure of implanted biomedical devices. Although NO has promising therapeutic value, the short physiological half-life of exogenous NO complicates its effective delivery. For this reason, the development of NO-releasing materials that permit the localized delivery of NO is an advantageous method of utilizing this molecule for biomedical applications. Herein, we report the synthesis and characterization of biodegradable NO-releasing polyesters prepared from citric acid, maleic acid, and 1,8-octanediol. NO release was achieved by incorporation of S-nitrosothiol donor groups through conjugation of cysteamine and ethyl cysteinate to the polyesters, followed by S-nitrosation with tert-butyl nitrite. The extent of NO loading and the release properties under physiological conditions (pH 7.4 PBS, 37 °C) were determined by chemiluminesence-based NO detection. The average total NO content of poly(citric-co-maleic acid-co-1,8-octanediol)-cysteamine was determined to be 0.45 ± 0.07 mol NO g-1 polymer, while the NO content for poly(citric-co-maleic acid-co-1,8-octanediol)-ethyl cysteinate was 0.16 ± 0.04 mol NO g-1 polymer. Continuous NO release under physiological conditions was observed for at least 6 days for the cysteamine analog and 4 days for the ethyl cysteinate analog. Cell viability assays and morphological studies with human dermal fibroblasts indicated an absence of toxic leachates at a cytotoxic level, and suggested that these citrate-based polyesters may be suitable for future biomedical applications.

19.
ACS Appl Mater Interfaces ; 6(15): 12307-20, 2014 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-25026120

RESUMO

Herein, we describe the surface modification of an S-nitrosated polymer derivative via H2O plasma treatment, resulting in polymer coatings that maintained their nitric oxide (NO) releasing capabilities, but exhibited dramatic changes in surface wettability. The poly(lactic-co-glycolic acid)-based hydrophobic polymer was nitrosated to achieve a material capable of releasing the therapeutic agent NO. The NO-loaded films were subjected to low-temperature H2O plasma treatments, where the treatment power (20-50 W) and time (1-5 min) were varied. The plasma treated polymer films were superhydrophilic (water droplet spread completely in <100 ms), yet retained 90% of their initial S-nitrosothiol content. Under thermal conditions, NO release profiles were identical to controls. Under buffer soak conditions, the NO release profile was slightly lowered for the plasma-treated materials; however, they still result in physiologically relevant NO fluxes. XPS, SEM-EDS, and ATR-IR characterization suggests the plasma treatment resulted in polymer rearrangement and implantation of hydroxyl and carbonyl functional groups. Plasma treated samples maintained both hydrophilic surface properties and NO release profiles after storage at -18 °C for at least 10 days, demonstrating the surface modification and NO release capabilities are stable over time. The ability to tune polymer surface properties while maintaining bulk properties and NO release properties, and the stability of those properties under refrigerated conditions, represents a unique approach toward creating enhanced therapeutic biopolymers.


Assuntos
Interações Hidrofóbicas e Hidrofílicas , Ácido Láctico/química , Óxido Nítrico/química , Gases em Plasma/química , Ácido Poliglicólico/química , Catálise , Cisteína/química , Hidrólise , Microscopia Eletrônica de Varredura , Nitrosação , Espectroscopia Fotoeletrônica , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , S-Nitrosotióis , Espectrometria por Raios X , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Água/química , Molhabilidade
20.
Semergen ; 40(3): e57-9, 2014 Apr.
Artigo em Espanhol | MEDLINE | ID: mdl-23768570

RESUMO

The differential diagnosis and therapeutic management of wide QRS tachycardia preceded by pacemaker spike is presented. The pacemaker-mediated tachycardia, tachycardia fibrillo-flutter in patients with pacemakers, and runaway pacemakers, have a similar surface electrocardiogram, but respond to different therapeutic measures. The tachycardia response to the application of a magnet over the pacemaker could help in the differential diagnosis, and in some cases will be therapeutic, as in the case of a tachycardia-mediated pacemaker. Although these conditions are diagnosed and treated in hospitals with catheterization laboratories using the application programmer over the pacemaker, patients presenting in primary care clinic and emergency forced us to make a diagnosis and treat the haemodynamically unstable patient prior to referral.


Assuntos
Magnetismo , Marca-Passo Artificial/efeitos adversos , Taquicardia/etiologia , Idoso , Diagnóstico Diferencial , Eletrocardiografia , Falha de Equipamento , Feminino , Humanos , Taquicardia/diagnóstico , Taquicardia/terapia
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