244 research outputs found
Tailoring the chemical structure of cellulose nanocrystals by amine functionalization
The surface functionalization of cellulose nanocrystals is presently considered a useful and straightforward tool for accessing very reliable biocompatible and biodegradable nanostructures with tailored physical and chemical properties. However, to date the fine characterization of the chemical appendages introduced onto cellulose nanocrystals remains a challenge, due to the low sensitivity displayed by the most common techniques towards surface functionalization. In this paper, we demonstrate the easy functionalization of cellulose nanocrystals with aliphatic and aromatic amines, demonstrating the tunability of their properties in dependence on the selected functionality. Then, we apply to colloidal suspensions of modified nanocrystals 1H NMR analysis to elucidate their surface structure. To the best of our knowledge, this is the first report where such investigation was performed on cellulose nanocrystals presenting both surface and reducing end modification. These results involve interesting implications for the fields of cultural heritage and of materials chemistry
IDIOPATHIC PARTIAL EPILEPSY WITH AUDITORY FEATURES (IPEAF): A CLINICAL AND GENETIC STUDY OF 53 SPORADIC CASES
The purpose of our study was to describe the clinical characteristics of sporadic
(S) cases of partial epilepsy with auditory features (PEAF) and pinpoint
clinical, prognostic and genetic differences with respect to previously reported
familial (F) cases of autosomal dominant partial epilepsy with auditory features
(ADPEAF). We analysed 53 patients (24 females and 29 males) with PEAF diagnosed
according to the following criteria: partial epilepsy with auditory symptoms,
negative family history for epilepsy and absence of cerebral lesions on NMR
study. All patients underwent a full clinical, neuroradiological and
neurophysiological examination. Forty patients were screened for mutations in
LGI1/epitempin, which is involved in ADPEAF. Age at onset ranged from 6 to 39
years (average 19 years). Secondarily generalized seizures were the most common
type of seizures at onset (79%). Auditory auras occurred either in isolation
(53%) or associated with visual, psychic or aphasic symptoms. Low seizure
frequency at onset and good drug responsiveness were common, with 51% of patients
seizure-free. Seizures tended to recur after drug withdrawal. Clinically, no
major differences were found between S and F patients with respect to age at
onset, seizure frequency and response to therapy. Analysis of LGI1/epitempin
exons failed to disclose mutations. Our data support the existence of a peculiar
form of non-lesional temporal lobe epilepsy closely related to ADPEAF but without
a positive family history. This syndrome, here named IPEAF, has a benign course
in the majority of patients and could be diagnosed by the presence of auditory
aura. Although LGI1 mutations have been excluded, genetic factors may play an
aetiopathogenetic role in at least some of these S cases
Two novel precursors of the hiv-1 protease inhibitor darunavir target the UPR/proteasome system in human hepatocellular carcinoma cell line HepG2
Background: Several pre-clinical and clinical reports suggest that HIV-1 protease inhibitors, in addition to the antiretroviral properties, possess pleiotropic pharmacological effects including anti-cancer action. Therefore, we investigated the pro-apoptotic activity in tumor cells of two molecules, RDD-19 and RDD-142, which are hydroxyethylamine derivatives’ precursors of darunavir and several HIV-1 protease inhibitors. Methods: Three hepatoma cell lines and one non-pathological cell line were treated with RDD-19 and RDD-142, and cell viability was assessed. The expression levels of several markers for ER stress, autophagy, cellular ubiquitination, and Akt activation were quantified in HepG2 cells treated with RDD-19 and RDD-142 to evaluate apoptotic and non-apoptotic cell death. Results: RDD-19 and RDD-142 showed a greater dose-dependent cytotoxicity towards the hepatic tumor cell line HepG2 compared to the non-pathological hepatic cell line IHH. Both molecules caused two types of cell death, a caspase-dependent apoptosis, which was ascertained by a series of biochemical and morphological assays, and a caspase-independent death that was characterized by the induction of ER stress and autophagy. The strong increase of ubiquitinated proteins inside the cells suggested that the target of these molecules could be the proteasome and in silico molecular docking analysis that was used to support the plausibility of this hypothesis. Furthermore, cells treated with the two compounds displayed decreased levels of p-AKT, which interferes with cell survival and proliferation. Conclusions: These findings demonstrate that two compounds, RDD-19 and RDD-142, have pleiotropic effects and that they may represent promising anticancer candidates
Recommended from our members
Obstetric care models in the Southern Region of Brazil and associated factors
The study sought to identify obstetric care models for low-risk pregnancies in the Southern Region of Brazil and to estimate factors associated with these models and maternal and neonatal outcomes. This is a cross-sectional, hospital-based study using data from the Birth in Brazil survey regarding puerperae and newborns. We identified 2,668 low-risk pregnant women. We carried out an exploratory analysis using the proportion of practices per hospital, among them inducing labor, presence of a companion, cesarean section and skin-to-skin contact, in order to obtain the care models we called Best Practice, Interventionist I and Interventionist II. We then carried out an inferential analysis of the associated characteristics. Results show that access to public or private funding, cultural factors and actions taken by health professional are associated with the care models. Public care had different contexts, one based on public policies and evidence-based practices; and another, that suggests the intentionality of vaginal delivery without considering humanization principles. Private care, on the other hand, is standardized and centered on the medical professional, with higher intervention levels. We conclude there is a predominance of interventionist obstetric care models in the Southern Region of Brazil, a type of care that goes against the best evidence, and that women who receive care in public hospitals have greater chances of benefiting from good practices
Validazione di Piani di Disaster Recovery mediante Simulatore
Contribution published online at: http://www.mimos.it/nuovo/contenuto_view.asp?check=10
Recommended from our members
Prevalence of spontaneous, induced labour or planned caesarean section and factors associated with caesarean scetion and factors associated with caesarian section in low-risk women in southern Brazil
Objective
This study aimed to examine the prevalence of spontaneous labour, induced labour and planned caesarean section in low-risk women; to identify the contribution of each group to the overall caesarean section rate; and to estimate factors associated with caesarean section in low-risk women according to spontaneous labour, induced labour and planned caesarean section.
Design
Cross-sectional hospital-based study of postpartum women and newborns, using data from the survey Birth in Brazil, Southern region. In the sample of 2,668 low-risk women, a descriptive analysis was undertaken and a Multinomial Logistic Regression model was applied to verify associations among caesarean section and spontaneous labour, induced labour and planned caesarean section in comparison with vaginal birth.
Measurements and Findings
The results showed the prevalence of spontaneous labour (48.0%), induced labour (14.0%) and planned caesarean sections (38.0%); these frequencies contributed to an overall caesarean section rate of 50.5%. Obstetric characteristics like previous vaginal birth or previous caesarean section were differentially associated with caesarean section, independently of the labour. Caesarean section without labour was significantly associated with age ≥ 35 years (ORadj 5.45 95%CI 3.16-9.39), economic class A and B (ORadj 3.10 95%CI 1.92-4.99), pregnancy between 37 and 38 weeks (ORadj 1.65 95%CI 1.22-2.24), same obstetrician in prenatal and childbirth (ORadj 13.83 95%CI 8.85-21.61) and private payment source at birth (ORadj 11.50 95%CI 6.64-19.93).
Key conclusion
For low-risk women in Southern Brazil, the results identify high planned caesarean section rates, not associated with socioeconomic, obstetric, institutional or prenatal factors that justify these rates
Associated factors of depressive symptoms in the elderly: EpiFloripa study
OBJECTIVE To estimate the prevalence and associated factors of depressive symptoms in the elderly. METHODS Cross-sectional population based epidemiological study (The EpiFloripa Elderly survey) was carried out in two stage clusters, census tracts and households, with1.656 elderly individuals in Florianópolis, SC. The prevalence of depressive symptoms (outcome) was obtained using Geriatric Depression Scale (GDS-15) and its associations with socio-demographic, health, behavioral and social variables were assessed. Crude and adjusted prevalence ratios (PR) with 95% confidence intervals were calculated using Poisson regression. RESULTS Depressive symptoms were observed in 23.9% of the elderly individuals (95%CI 21.84;26.01). In the final model, depressive symptoms were associated with: 5 to 8 years of schooling (PR = 1.50, 95%CI 1.08;2.08); one to four years of schooling (PR = 1.62, 95%CI 1.18;2.23) and no schooling (PR = 2.11, 95%CI 1.46;3.05); being in a worse financial condition than at the age of 50 (PR = 1.33, 95%CI 1.02;1.74); cognitive impairment (PR = 1.45, 95%CI 1.21;1.75); perceiving their health to be regular (PR = 1.95, 95%CI 1.47;2.60) or poor (PR = 2.64, 95%CI 1.82;3.83); functional dependence (PR =1.83, 95%CI 1.43;2.33) and chronic pain (PR = 1.35, 95%CI 1.10;1.67). Factors with protective effects were: being in the 70 to 79 year old age group (PR = 0.77, 95%CI 0.64;0.93); physical activity in leisure time (PR = 0.75, 95%CI 0.59;0.94); participation in social or religious groups (PR = 0.80, 95%CI 0.64;0.99) and having sexual relations (PR = 0.70, 95%CI 0.53;0.94). CONCLUSIONS : Adverse clinical situations, being socioeconomically disadvantaged and low social and sexual activity were associated with depressive symptoms in the elderly.OBJETIVO Analizar la prevalencia y factores asociados a síntomas depresivos en ancianos. MÉTODOS Estudio epidemiológico transversal y de base domiciliar (pesquisa EpiFloripa Anciano ) con 1.656 ancianos, realizado por conglomerados en dos fases, sectores censitarios y domicilios, en Florianópolis, SC, Brasil. La prevalencia de síntomas depresivos (resultado) fue obtenida por medio de la Geriatric Depression Scale (GDS-15), y evaluadas asociaciones según variables sociodemográficas, de salud, comportamiento y sociales. Se calcularon tasas de prevalencia brutas y ajustadas con intervalo de 95% de confianza por regresión de Poisson. RESULTADOS La prevalencia de síntomas depresivos fue de 23,9% (IC95% 21,84;26,01). Los factores de riesgo asociados en el modelo final fueron: escolaridad de cinco a ocho años (RP = 1,50; IC95% 1,08; 2,08), uno a cuatro años (RP = 1,62; IC95% 1,18; 2,23) y ningún año de estudio (RP = 2,11; IC95% 1,46;3,05); situación económica peor al compararse con la que tenía a los 50 años (RP = 1,33; IC95% 1,02;1,74); déficit cognitivo (RP = 1,45; IC95% 1,21;1,75); percepción de salud regular (RP = 1,95; IC95% 1,47;2,60) y mala (RP = 2,64; IC95% 1,82;3,83); dependencia funcional (RP = 1,83; IC95% 1,43; 2,33) y dolor crónico (RP = 1,35; IC95% 1,10;1,67). Grupo etario de 70 a 79 años (RP = 0,77; IC95% 0,64;0,93); actividad física de placer (RP = 0,75; IC95% 0,59;0,94); participación en grupos de convivencia o religiosos (RP = 0,80; IC95% 0,64;0,99) y tener relación sexual (RP = 0,70; IC95% 0,53;0,94) se mostraron como factores protectores de la aparición de los síntomas depresivos. CONCLUSIONES Situación clínica adversa, desventaja socioeconómica y poca actividad social y sexual se mostraron asociados a los síntomas depresivos en ancianos
PEGylated Liposomes Loaded with Carbamate Inhibitor ANP0903 Trigger Apoptosis by Enhancing ER Stress in HepG2 Cancer Cells
Liver cancer is one of the most common causes of cancer death worldwide. In recent years, substantial progress has been made in the development of systemic therapies, but there is still the need for new drugs and technologies that can increase the survival and quality of life of patients. The present investigation reports the development of a liposomal formulation of a carbamate molecule, reported as ANP0903, previously tested as an inhibitor of HIV-1 protease and now evaluated for its ability to induce cytotoxicity in hepatocellular carcinoma cell lines. PEGylated liposomes were prepared and characterized. Small, oligolamellar vesicles were produced, as demonstrated by light scattering results and TEM images. The physical stability of the vesicles in biological fluids was demonstrated in vitro, alongside the stability during storage. An enhanced cellular uptake was verified in HepG2 cells treated with liposomal ANP0903, resulting in a greater cytotoxicity. Several biological assays were performed to elucidate the molecular mechanisms explaining the proapoptotic effect of ANP0903. Our results allow us to hypothesize that the cytotoxic action in tumor cells is probably due to the inhibition of the proteasome, resulting in an increase in the amount of ubiquitinated proteins within the cells, which in turn triggers activation of autophagy and apoptosis processes, resulting in cell death. The proposed liposomal formulation represents a promising approach to deliver a novel antitumor agent to cancer cells and enhance its activity
VST: the telescope progress toward stars
The VST telescope is in an advanced stage of integration in Chile, after a period of work spent mainly on the active optics system, started in mid-2007. We present the results of the recent work on the primary and secondary mirror support systems and on the mirror cell auxiliary units
- …