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1.
Radiat Res ; 201(3): 189-196, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38294870

RESUMEN

One of the most distinguished features in biological effects of heavy ions would be the decrease of oxygen effect in the high-LET region. This feature has been referred to as the radiobiological basis for the control of hypoxic fraction in cancer radiotherapy. However, mechanisms to explain this phenomenon have not been fully understood. One of the explanations was given by the oxygen in the track hypothesis, which proposes that oxygen is produced along ion tracks even in the hypoxic irradiation condition. In the present study, we designed an experimental approach to support this hypothesis by using 8-hydroxy-2'-deoxyguanosine (8-OHdG) as DNA damage requiring oxygen to produce. The LET dependence of 8-OHdG under hypoxic condition revealed that with increasing LET 8-OHdG yield seems to increase, despite that the yield of OH radical, which is also required for the production of 8-OHdG, decreases in the high-LET region. This result is consistent with the explanation that the local generation of oxygen along ion tracks contributes to the increase of 8-OHdG yield.


Asunto(s)
Daño del ADN , Oxígeno , Animales , 8-Hidroxi-2'-Desoxicoguanosina , Radiobiología , Desoxiguanosina , Mamíferos
2.
Ann Oncol ; 33(2): 216-226, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34843940

RESUMEN

BACKGROUND: Cancer of unknown primary (CUP) has a poor prognosis. Given the recent approval of immune checkpoint inhibitors for several cancer types, we carried out a multicenter phase II study to assess the efficacy of nivolumab for patients with CUP. PATIENTS AND METHODS: Patients with CUP who were previously treated with at least one line of systemic chemotherapy constituted the principal study population. Previously untreated patients with CUP were also enrolled for exploratory analysis. Nivolumab (240 mg/body) was administered every 2 weeks for up to 52 cycles. The primary endpoint was objective response rate in previously treated patients as determined by blinded independent central review according to RECIST version 1.1. RESULTS: Fifty-six patients with CUP were enrolled in the trial. For the 45 previously treated patients, objective response rate was 22.2% [95% confidence interval (CI), 11.2% to 37.1%], with a median progression-free survival and overall survival of 4.0 months (95% CI, 1.9-5.8 months) and 15.9 months (95% CI, 8.4-21.5 months), respectively. Similar clinical benefits were also observed in the 11 previously untreated patients. Better clinical efficacy of nivolumab was apparent for tumors with a higher programmed death-ligand 1 expression level, for those with a higher tumor mutation burden, and for microsatellite instability-high tumors. In contrast, no differences in efficacy were apparent between tumor subgroups based on estimated tissue of origin. Adverse events were consistent with the known safety profile of nivolumab. No treatment-related death was observed. CONCLUSIONS: Our results demonstrate a clinical benefit of nivolumab for patients with CUP, suggesting that nivolumab is a potential additional therapeutic option for CUP.


Asunto(s)
Neoplasias Primarias Desconocidas , Nivolumab , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Humanos , Inestabilidad de Microsatélites , Neoplasias Primarias Desconocidas/tratamiento farmacológico , Nivolumab/efectos adversos , Supervivencia sin Progresión , Criterios de Evaluación de Respuesta en Tumores Sólidos
3.
Ann ICRP ; 50(1_suppl): 74-81, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34353146

RESUMEN

After the accident at Fukushima Daiichi nuclear power plant on 11 March 2011, radioactive materials were released into the atmosphere resulting in environmental contamination. Following the implementation of environmental decontamination efforts, the Radiation Dose Registration Centre of the Radiation Effects Association established the radiation dose registration system for decontamination and related workers to consolidate and prevent the loss of radiation records. This article presents statistics on the radiation doses of decontamination and related workers using official records. Since approximately 10 years have passed since the accident in Fukushima, the types of work conducted in the affected restricted areas have changed over time. Therefore, changes in radiation dose for each type of work and comparisons with nuclear workers are presented.


Asunto(s)
Accidente Nuclear de Fukushima , Monitoreo de Radiación , Protección Radiológica , Descontaminación , Humanos , Japón , Plantas de Energía Nuclear , Dosis de Radiación
4.
Int J Oral Maxillofac Surg ; 50(11): 1413-1421, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33663900

RESUMEN

The purpose of this study was to investigate the prognostic value of prognostic nutritional index (PNI) in oral squamous cell carcinoma (OSCC) patients and to undertake a comparative evaluation of the prognostic value of comparing PNI, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) in terms of prognostic utility. A retrospective study was conducted involving 203 consecutive patients with OSCC who were treated with radical surgery with curative intent. The PNI and systemic inflammatory response were developed, and their prognostic utility was evaluated. Kaplan-Meier curve analysis and log-rank testing showed that PNI (P< 0.001), NLR (P=0.011), PLR (P=0.013), and LMR (P=0.014) were significantly associated with overall survival. Multivariate analysis identified PNI as an independent prognostic factor for OSCC patients (P=0.029). In time-dependent receiver operating characteristic curve analysis, PNI was continuously superior to that of NLR, PLR, and LMR. In conclusion, this study suggested that PNI offered an independent prognostic biomarker in OSCC patients undergoing radical surgery. However, this study was small and retrospective, thus further investigations are needed to clarify the utility of PNI for tailor-made treatments in clinical settings.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias de Cabeza y Cuello , Neoplasias de la Boca , Carcinoma de Células Escamosas/cirugía , Humanos , Neoplasias de la Boca/cirugía , Neutrófilos , Evaluación Nutricional , Pronóstico , Estudios Retrospectivos , Carcinoma de Células Escamosas de Cabeza y Cuello
6.
Eur Rev Med Pharmacol Sci ; 24(21): 11187-11191, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33215436

RESUMEN

OBJECTIVE: Systemic inflammatory response may contribute to the onset of febrile seizures (FSs). The neutrophil-to-lymphocyte ratio (NLR) has been reported to be useful for differentiating simple and complex FSs in children with a first FS. This study aimed to determine whether easily measurable inflammatory markers were useful for distinguishing between the types of FSs in children with FSs not limited to the first FS. PATIENTS AND METHODS: We conducted a retrospective study of children aged 6-60 months who were presented to the Atsugi City Hospital in Japan for the treatment of FSs between December 2018 and February 2020. A complex FS was defined as a seizure with multiple seizures during the same febrile illness, prolonged seizures and/or focal seizures. A simple FS was defined as a seizure without the characteristics of complex FS. We assessed complete blood count, C-reactive protein, and calculated osmotic pressure. RESULTS: A total of 205 children with FSs (simple, 139; complex, 66) fulfilled the inclusion criteria. None of the inflammatory markers, including NLR, could predict the FS type. The median osmotic pressure was 279.0, 278.8, 283.3, and 278.3 mOsm/kg H2O for children with simple, multiple, prolonged, and focal seizures, respectively. Children with prolonged seizures had a significantly higher calculated osmotic pressure than those with simple FSs (p<0.001) and multiple seizures during the same febrile illness (p=0.004). CONCLUSIONS: Easily measurable inflammatory markers, including NLR, were not useful for distinguishing between types of FSs in children. Large multicenter studies are needed to evaluate the association between osmotic pressure and FS.


Asunto(s)
Proteína C-Reactiva/análisis , Convulsiones Febriles/sangre , Biomarcadores/sangre , Preescolar , Femenino , Humanos , Lactante , Masculino , Presión Osmótica , Estudios Retrospectivos
7.
Public Health ; 188: 51-53, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33120232

RESUMEN

OBJECTIVES: The purpose of this study is to show that social distancing is a public good under the COVID-19 pandemic. STUDY DESIGN: We apply economic theory to analyse a cross-sectional survey. METHODS: Economic theory is complemented with empirical evidence. An online survey of those aged 30-49 years in Japan (n = 2177) was conducted between April 28 and May 7. Respondents were selected by quota sampling with regard to age group, gender and prefecture of residence. Our main figure shows the proportion of people who increased/did not change/decreased social distancing, relative to the level of altruism and sensitivity to public shaming. The results of OLS and logit models are shown in Supplementary Materials. RESULTS: Social distancing is a public good under the COVID-19 pandemic for which the free-rider problem is particularly severe. Altruism and social norms are crucial factors in overcoming this problem. Using an original survey, we show that people with higher altruistic concerns and sensitivity to shaming are more likely to follow social distancing measures. CONCLUSIONS: Altruism and social norms are important for reducing the economic cost of the pandemic.


Asunto(s)
Altruismo , Infecciones por Coronavirus/prevención & control , Pandemias/prevención & control , Neumonía Viral/prevención & control , Distancia Psicológica , Adulto , COVID-19 , Infecciones por Coronavirus/epidemiología , Estudios Transversales , Femenino , Humanos , Japón/epidemiología , Masculino , Persona de Mediana Edad , Pandemias/economía , Neumonía Viral/epidemiología , Normas Sociales , Encuestas y Cuestionarios , Adulto Joven
8.
BJS Open ; 2020 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-32894010

RESUMEN

BACKGROUND: Severe inflammation with necrosis and fibrosis of the gallbladder in acute cholecystitis increases operative difficulty during laparoscopic cholecystectomy. This study aimed to assess the use of preoperative MRI in predicting pathological changes of the gallbladder associated with surgical difficulty. METHODS: Patients who underwent both preoperative MRI and early cholecystectomy for acute cholecystitis between 2012 and 2018 were identified retrospectively. On the basis of the layered pattern of the gallbladder wall on MRI, patients were classified into three groups: high signal intensity (HSI), intermediate signal intensity (ISI), and low signal intensity (LSI). The endpoint was the presence of pathological changes of the gallbladder associated with surgical difficulty, such as necrosis, abscess formation and fibrosis. RESULTS: Of 229 eligible patients, pathological changes associated with surgical difficulty were found in 17 (27 per cent) of 62 patients in the HSI group, 84 (85 per cent) of 99 patients in the ISI group, and 66 (97 per cent) of 68 patients in the LSI group (P < 0·001). For detecting these changes, intermediate to low signal intensity of the gallbladder wall had a sensitivity of 90 (95 per cent c.i. 84 to 94) per cent, specificity of 73 (60 to 83) per cent and accuracy of 85 (80 to 90) per cent. CONCLUSION: Preoperative MRI predicted pathological changes associated with surgical difficulty during laparoscopic cholecystectomy for acute cholecystitis.


ANTECEDENTES: La inflamación grave con necrosis y fibrosis de la vesícula biliar en la colecistitis aguda aumenta la dificultad quirúrgica durante la colecistectomía laparoscópica. Este estudio tuvo como objetivo evaluar el uso de la resonancia magnética preoperatoria (magnetic resonance imaging, MRI) para predecir los cambios patológicos de la vesícula biliar asociados con la dificultad quirúrgica. MÉTODOS: Los pacientes que se sometieron tanto a MRI preoperatoria como a colecistectomía precoz por colecistitis aguda entre 2012 y 2018 fueron identificados retrospectivamente. En base a la distribución en capas de la pared de la vesícula biliar en la MRI, los pacientes se clasificaron en tres grupos: (1) intensidad de señal alta (high signal intensity, HSI), (2) intensidad de señal intermedia (intermediate signal intensity, ISI) y (3) intensidad de señal baja (low signal intensity, LSI). El objetivo final fue la presencia de cambios patológicos en la vesícula biliar asociados con la dificultad quirúrgica, tales como necrosis, formación de abscesos y fibrosis. RESULTADOS: De los 229 pacientes elegibles, se documentaron cambios patológicos asociados con dificultad quirúrgica en 17 (27,4%) de 62 pacientes en el grupo HSI, 84 (84,8%) de 99 pacientes en el grupo ISI y 66 (97,1%) de 68 pacientes en el grupo LSI (P < 0,001). Para detectar estos cambios, la intensidad de señal de intermedia a baja de la pared de la vesícula biliar tuvo una sensibilidad del 89,8% (i.c. del 95% 84,2%-94,0%), una especificidad del 72.6% (i.c. del 95% 59,8%-83,1%) y una precisión del 85,2% (i.c. del 95% 79,9%-89,5%). CONCLUSIÓN: La MRI preoperatoria predijo los cambios patológicos asociados con la dificultad quirúrgica durante la colecistectomía laparoscópica por colecistitis aguda.

9.
Acta Neuropathol ; 139(3): 565-582, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31897643

RESUMEN

Protein O-glucosyltransferase 1 (POGLUT1) activity is critical for the Notch signaling pathway, being one of the main enzymes responsible for the glycosylation of the extracellular domain of Notch receptors. A biallelic mutation in the POGLUT1 gene has been reported in one family as the cause of an adult-onset limb-girdle muscular dystrophy (LGMD R21; OMIM# 617232). As the result of a collaborative international effort, we have identified the first cohort of 15 patients with LGMD R21, from nine unrelated families coming from different countries, providing a reliable phenotype-genotype and mechanistic insight. Patients carrying novel mutations in POGLUT1 all displayed a clinical picture of limb-girdle muscle weakness. However, the age at onset was broadened from adult to congenital and infantile onset. Moreover, we now report that the unique muscle imaging pattern of "inside-to-outside" fatty degeneration observed in the original cases is indeed a defining feature of POGLUT1 muscular dystrophy. Experiments on muscle biopsies from patients revealed a remarkable and consistent decrease in the level of the NOTCH1 intracellular domain, reduction of the pool of satellite cells (SC), and evidence of α-dystroglycan hypoglycosylation. In vitro biochemical and cell-based assays suggested a pathogenic role of the novel POGLUT1 mutations, leading to reduced enzymatic activity and/or protein stability. The association between the POGLUT1 variants and the muscular phenotype was established by in vivo experiments analyzing the indirect flight muscle development in transgenic Drosophila, showing that the human POGLUT1 mutations reduced its myogenic activity. In line with the well-known role of the Notch pathway in the homeostasis of SC and muscle regeneration, SC-derived myoblasts from patients' muscle samples showed decreased proliferation and facilitated differentiation. Together, these observations suggest that alterations in SC biology caused by reduced Notch1 signaling result in muscular dystrophy in LGMD R21 patients, likely with additional contribution from α-dystroglycan hypoglycosylation. This study settles the muscular clinical phenotype linked to POGLUT1 mutations and establishes the pathogenic mechanism underlying this muscle disorder. The description of a specific imaging pattern of fatty degeneration and muscle pathology with a decrease of α-dystroglycan glycosylation provides excellent tools which will help diagnose and follow up LGMD R21 patients.


Asunto(s)
Distroglicanos/metabolismo , Glucosiltransferasas/genética , Músculo Esquelético/patología , Distrofia Muscular de Cinturas/genética , Distrofia Muscular de Cinturas/patología , Animales , Animales Modificados Genéticamente , Drosophila melanogaster , Femenino , Estudios de Asociación Genética , Glicosilación , Humanos , Masculino , Músculo Esquelético/metabolismo , Distrofia Muscular de Cinturas/metabolismo , Mutación , Linaje , Células Satélite del Músculo Esquelético/patología
10.
RSC Adv ; 10(48): 28484-28491, 2020 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-35520094

RESUMEN

Environmental conditions have a profound effect on the photophysical behavior of highly conjugated compounds, which can be exploited in a large variety of applications. In this context, we use a combination of experimental and computational methods to investigate thermal and solvatochromic effects on the fluorescence properties of a dansyl derivative bearing a thienyl substituent, namely 2-(3-thienyl)ethyl dansylglycinate (TEDG). In particular, we analyze how the solvent polarity and temperature affect the ground and excited state energies of TEDG by using time-resolved and steady-state fluorescence techniques. We determine the changes in dipole moment of the TEDG molecule upon photoexcitation, as well as the solvent polarity effects on the excited state lifetime. Besides, we provide theoretical modeling of the HOMO-LUMO orbitals and the vertical absorption and emission energies using time-dependent density functional theory (TDDFT) as well as the polarizable continuum model (PCM) to include the solvent contribution to the absorption and emission energies. Our results show that the emission mechanism of TEDG involves locally excited states derived from hybrid molecular orbitals, accompanied by a moderate variation of the molecular dipole moment upon light excitation. Our findings demonstrate that TEDG exhibits desirable fluorescence properties that make it a promising candidate for use as a photoactive material in electrochromic, optical thermometry, and thermography applications.

11.
Colloids Surf B Biointerfaces ; 181: 856-863, 2019 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-31382333

RESUMEN

Flavonoid-metal complexes are widely studied because of their interesting luminescent behavior and biological activity. Despite the extensive exploration of flavonoid-metal coordination processes in solution, the formation of complexes using the flavonoid molecule inserted in a lipid membrane has been little investigated. This effect could provide important insight into the biological activity of flavonoids at lipid membranes and could represent an attractive strategy to design supramolecular structures. Here, we studied the complexation between Sr2+ and morin inserted in an octadecylphosphonic acid (OPA) Langmuir monolayer. This is a relevant system due to the synergism imposed by the association of the Sr2+ ability to control bone formation/resorption with the morin antioxidative effect. Morin incorporation into the OPA monolayers and further Sr2+ complexation were monitored by surface pressure isotherms. Electronic absorption spectroscopy and fluorescence techniques showed Sr-morin complexation both in solution and at the air-liquid interface. Although morin complexation has been described to occur only at basic pH, the specific thermodynamic properties at the air-liquid interface drove metal complexation. LB films were deposited on Ti surfaces, and the resulting OPA/Sr-morin coatings exhibited high surface free energy and increase on its polar component. This optimized surface feature supported further serum protein adsorption and osteoblast growth and differentiation, indicating that these lipid-based coatings are promising for bioactive coating design. This study paves the way for the use of this lipid-based coating in the design of implants for faster osteointegration. Moreover, flavonoid-metal complexation at membranes could also help to shed light on the biological role played by flavonoids.


Asunto(s)
Complejos de Coordinación/farmacología , Diseño de Fármacos , Flavonoides/farmacología , Estroncio/farmacología , Adsorción , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Flavonoides/química , Humanos , Estructura Molecular , Imagen Óptica , Osteoblastos/efectos de los fármacos , Tamaño de la Partícula , Estroncio/química , Propiedades de Superficie , Termodinámica , Humectabilidad
12.
Braz J Med Biol Res ; 52(3): e8281, 2019 Mar 25.
Artículo en Inglés | MEDLINE | ID: mdl-30916221

RESUMEN

It has been hypothesized that the therapeutic effects of artepillin C, a natural compound derived from Brazilian green propolis, are likely related to its partition in the lipid bilayer component of biological membranes. To test this hypothesis, we investigated the effects of the major compound of green propolis, artepillin C, on model membranes (small and giant unilamelar vesicles) composed of ternary lipid mixtures containing cholesterol, which display liquid-ordered (lo) and liquid-disordered (ld) phase coexistence. Specifically, we explored potential changes in relevant membrane parameters upon addition of artepillin C presenting both neutral and deprotonated states by means of small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and confocal and multiphoton excitation fluorescence microscopy. Thermotropic analysis obtained from DSC experiments indicated a loss in the lipid cooperativity of lo phase at equilibrium conditions, while at similar conditions spontaneous formation of unilamellar vesicles from SAXS experiments showed that deprotonated artepillin C preferentially located at the surface of the membrane. Time-resolved experiments using fluorescence microscopy showed that at doses above 100 µM, artepillin C in its neutral state interacted with both liquid-ordered and liquid-disordered phases, inducing curvature stress and promoting dehydration at the membrane interface.


Asunto(s)
Membrana Dobles de Lípidos/química , Liposomas/química , Fenilpropionatos/química , 2-Naftilamina/análogos & derivados , Rastreo Diferencial de Calorimetría , Colesterol/química , Lauratos , Microscopía Confocal , Microscopía Fluorescente , Modelos Químicos , Valores de Referencia , Reproducibilidad de los Resultados , Dispersión del Ángulo Pequeño , Temperatura , Factores de Tiempo
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 215: 327-333, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30852279

RESUMEN

The changing of the electronic and vibronic states due to the insertion of Zn(II), Cu(II), Ni(II) or Co(II) ions in the meso-tetrakis(4-pyridyl)porphyrin ring center is investigated. The combination of absorption, photoluminescence, Raman and infrared spectroscopies with second-derivative-based spectral deconvolution analysis reveals that the structuration of both B- and Q-bands is very sensitive to the decorating ion. Similar to free base porphyrins, metal(II) meso-tetra(4-pyridyl)porphyrins also present their Q-band constituted of multiple electronic transitions, where the central ion plays an important role in the selection of vibration modes that mediate the vibronic transitions. Our novel results will expand and reinterpret current assignments for metal(II) meso-tetra(4-pyridyl)porphyrins vibrational modes available in the literature.

15.
J Helminthol ; 93(6): 681-689, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30149813

RESUMEN

As part of the international joint projects working towards the control of taeniosis/cysticercosis in Asia Pacific, epidemiological studies on Taenia solium cysticercosis have been carried out in high-incidence populations, such as minority groups in Thailand. To assess the epidemiology of cysticercotic infections in pigs in the hill-tribe minority villages (Karen) in Tak province, Thailand, we conducted serological screening and necropsies. The patterns of antibody response to T. solium antigens were then investigated using immunoblot assays. Of the 188 pig serum samples tested for antibody responses to partially purified low-molecular-weight antigens of T. solium cyst fluid, positive responses were detected in 37 samples (19.7%). Based on these results, 16 pigs (10 seropositive and 6 seronegative) were necropsied for investigation of cysticerci and intestinal parasites. All seropositive pigs were coinfected with both T. solium and Taenia hydatigena cysticerci, except one, which was infected with T. hydatigena alone. Three of the six seronegative pigs were confirmed to be infected with T. hydatigena. Pigs infected with T. solium showed much stronger antibody responses than those infected with T. hydatigena. Our results demonstrate the co-occurrence of two swine cysticercoses due to T. solium and T. hydatigena in the studied areas. This study also reveals the importance of direct confirmation of the presence of cysticerci by necropsy after serological screening. In addition to the prevalence of swine cysticercosis in these endemic areas, our findings also reveal potential implications for the development of serological diagnostic assays for swine cysticercosis.


Asunto(s)
Coinfección/veterinaria , Cisticercosis/veterinaria , Enfermedades de los Porcinos/parasitología , Taenia/aislamiento & purificación , Teniasis/veterinaria , Animales , Coinfección/epidemiología , Coinfección/parasitología , Cisticercosis/parasitología , Femenino , Humanos , Masculino , Mianmar/epidemiología , Población Rural , Porcinos , Enfermedades de los Porcinos/epidemiología , Taenia/clasificación , Taenia/genética , Taenia solium/genética , Taenia solium/aislamiento & purificación , Taenia solium/fisiología , Teniasis/parasitología , Tailandia/epidemiología
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 209: 274-279, 2019 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-30414576

RESUMEN

We present novel results on the free base 5,10,15,20-meso-tetra(pyridyl)-21H,23H-porphyrin (H2TPyP). This molecule presents complex electronic and vibrational properties and despite the vast literature reporting the transitions observed in its absorption and fluorescence spectra, a more accurate interpretation has been kept elusive. In particular, we show that the molecule's Q-band develops into many electronic and vibronic transitions, whose the well-known "four orbital model" finds it difficult to reconcile. Using distinct spectroscopy techniques, we conclude that both Qx- and Qy-bands comprise, in fact, two quasi-degenerated electronic states together with their respective vibronic progressions each. The analysis of the Huang-Rhys factors and complementary time- and polarization-resolved measurements reinforce the need for the proposed Q-band multi features remodeling.

17.
Braz. j. med. biol. res ; 52(3): e8281, 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-989461

RESUMEN

It has been hypothesized that the therapeutic effects of artepillin C, a natural compound derived from Brazilian green propolis, are likely related to its partition in the lipid bilayer component of biological membranes. To test this hypothesis, we investigated the effects of the major compound of green propolis, artepillin C, on model membranes (small and giant unilamelar vesicles) composed of ternary lipid mixtures containing cholesterol, which display liquid-ordered (lo) and liquid-disordered (ld) phase coexistence. Specifically, we explored potential changes in relevant membrane parameters upon addition of artepillin C presenting both neutral and deprotonated states by means of small angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and confocal and multiphoton excitation fluorescence microscopy. Thermotropic analysis obtained from DSC experiments indicated a loss in the lipid cooperativity of lo phase at equilibrium conditions, while at similar conditions spontaneous formation of unilamellar vesicles from SAXS experiments showed that deprotonated artepillin C preferentially located at the surface of the membrane. Time-resolved experiments using fluorescence microscopy showed that at doses above 100 µM, artepillin C in its neutral state interacted with both liquid-ordered and liquid-disordered phases, inducing curvature stress and promoting dehydration at the membrane interface.


Asunto(s)
Fenilpropionatos/química , Membrana Dobles de Lípidos/química , Liposomas/química , Valores de Referencia , Temperatura , Factores de Tiempo , Rastreo Diferencial de Calorimetría , Colesterol/química , Reproducibilidad de los Resultados , Microscopía Confocal , Dispersión del Ángulo Pequeño , Lauratos , Microscopía Fluorescente , Modelos Químicos , 2-Naftilamina/análogos & derivados
18.
Ultramicroscopy ; 194: 1-6, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30029082

RESUMEN

Soft X-ray spectromicroscopy was applied to study the quantitative distribution of DNA and protein in a mammalian chromosome at the spatial resolution of 100 nm. The quantities of DNA and protein were evaluated using 1s-π* transition in the NEXAFS spectra at the nitrogen K absorption edge. DNA was not uniformly distributed in the chromosome and DNA/protein ratio was less than 0.497. The present analysis revealed the clues to identify other molecules that contribute to the absorption spectrum of the sample. The results suggested that accumulation of the absorption spectra of relevant molecules would support the refinement of the analysis.


Asunto(s)
Cromosomas de los Mamíferos/química , Animales , Células CHO , Línea Celular , Cricetulus , ADN/química , Estudios de Evaluación como Asunto , Microscopía Electrónica de Transmisión de Rastreo/métodos , Nitrógeno/química , Proteínas/química , Rayos X
20.
Br J Surg ; 105(8): 1036-1043, 2018 07.
Artículo en Inglés | MEDLINE | ID: mdl-29617036

RESUMEN

BACKGROUND: Only a few reports exist on the use of ethanol ablation for posthepatectomy bile leakage. The aim of this study was to assess the value of ethanol ablation in refractory bile leakage. METHODS: Medical records of consecutive patients who underwent a first hepatobiliary resection with bilioenteric anastomosis between 2007 and 2016 were reviewed retrospectively, with special attention to bile leakage and ethanol ablation therapy. Bile leakage was graded as A/B1/B2 according to the International Study Group of Liver Surgery definition. Absolute ethanol was injected into the target bile duct during fistulography. RESULTS: Of the 609 study patients, 237 (38·9 per cent) had bile leakage, including grade A in 33, grade B1 in 18 and grade B2 in 186. Left trisectionectomy was more often associated with grade B2 bile leakage than other types of hepatectomy (P < 0·001). Of 186 patients with grade B2 bile leakage, 31 underwent ethanol ablation therapy. Ethanol ablation was started a median of 34 (range 15-122) days after hepatectomy. The median number of treatments was 3 (1-7), and the total amount of ethanol used was 15 (3-71) ml. Complications related to ethanol ablation included transient fever (27 patients) and mild pain (13). Following ethanol ablation, bile leakage resolved in all patients and drains were removed. The median interval between the first ablation and drain removal was 28 (1-154) days. CONCLUSION: Ethanol ablation is safe and effective, and may be a treatment option for refractory bile leakage.


Asunto(s)
Técnicas de Ablación/métodos , Anastomosis en-Y de Roux/efectos adversos , Fuga Anastomótica/cirugía , Etanol/administración & dosificación , Hepatectomía/efectos adversos , Técnicas de Ablación/efectos adversos , Adulto , Anciano , Anciano de 80 o más Años , Bilis , Conductos Biliares/cirugía , Drenaje/efectos adversos , Drenaje/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
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