The insertion of hydrophobic and hydrophilic chains in the chitosan molecule can improve its antibacterial activity, expanding its range of application in several areas of medical-pharmaceutical ...sciences. Thus, this work aimed to increase the antibacterial activity of chitosan through the modification reaction with phthalic anhydride (QF) and subsequent reaction with ethylenediamine (QFE). The chitosan and derivatives obtained were characterized by elemental analysis, 13C Nuclear Magnetic Resonance (13C NMR), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetric Analysis (TG), where it was possible to prove the chemical modification. Both materials showed a greater antibacterial inhibitory effect against Gram-positive bacteria, Staphylococcus aureus, emphasizing antibacterial activity against Gram-negative bacteria, Escherichia coli, with values above 70 % of the inhibitory effect, which is a promising result. Assays with human fibroblast cells by the 3-(4,5-dimethylthiazolyl)-2,5-diphenyl tetrazolium (MTT) bromide reduction test did not indicate toxicity in the materials. Thus, the derived materials showed promise for biomedical applications since they combined excellent antibacterial activity against gram-positive and gram-negative strains and did not show cytotoxicity.
•Chitosan was modified with phthalic anhydride and ethylenediamine.•The effectiveness of the modification reactions was confirmed by elemental analysis, 13C NMR, XRD, FTIR and TG.•Chitosan derivatives showed antibacterial inhibitory effects against Staphylococcus aureus and Escherichia coli bacteria.•Chitosan derivatives did not present toxicity and showed promise for biomedical applications.
Metformin, an AMP-activated protein kinase (AMPK) activator, is an oral hypoglycemic drug widely used to treat patients with type 2 diabetes. As AMPK plays a role in the nociceptive processing, ...investigating the effects induced by metformin in experimental models of pain is warranted. In the present study, we further evaluated the effects induced by metformin in models of nociceptive and neuropathic pain and investigated mechanisms that could mediate such effects. Metformin was administered per os (p.o.) in mice. Nociceptive response induced by heat (hot-plate) and mechanical allodynia induced by chronic constriction injury (CCI) were used as pain models. Naltrexone (intraperitoneal) and glibenclamide (p.o.) were used to investigate mechanisms mediating metformin effects. A single administration of metformin (500 or 1000 mg/kg) inhibited the nociceptive response in the hot-plate model. Single and repeated administration of metformin (250, 500 or 1000 mg/kg) inhibited the mechanical allodynia induced by CCI. Metformin (250, 500 or 1000 mg/kg) did not affect the time mice spent in the rota-rod apparatus. The activity of metformin (1000 mg/kg) in both pain models was attenuated by naltrexone (10 mg/kg), but not by glibenclamide. Concluding, metformin exhibited activity in models of nociceptive and neuropathic pain. In the model of neuropathic pain, preventive and therapeutic effects were observed. Activation of opioidergic pathways partially mediates metformin antinociceptive activity. Altogether, the results indicate that metformin should be further investigated aiming its repositioning in the treatment of patients with different painful conditions.
•Phosphated cellulose was synthesized.•Adsorption experiments with amitriptyline were conducted.•Adsorbents used: pure cellulose and phosphated cellulose.•Variables used in adsorption: time, pH, ...concentration, temperature and ionic strength.•Variables used in the desorption: pH and time.
In the last years has increased the study about the using of natural biopolymers and theirs derivatives in the removal (adsorption/incorporation) of contaminats of medium aqueous, and theirs utilization in the desorption (release) de drugs. However, there not in the literature studies about the utilization of the cellulose and cellulose phosphate in the adsorption (incorporation)/desorption (release) of the drug amitriptyline (AMI). Therefore, in this study was accomplished the synthesized of the phosphated cellulose (PC) through the reaction of pure cellulose (C) with sodium trimetaphosphate (P) under-reflux, for 4h and at 393K. The efficiency of the reaction was observed by XRD, TG/DTG, 31P NMR and EDS. The adsorption study for the AMI in aqueous medium was carried out by varying the time, pH, concentration, temperature and ionic strength. The results showed that the PC showed a greater adsorption capacity of AMI than pure cellulose, presenting an increase of about 102.72% in the adsorption capacity of the drug by cellulose after the phosphating reaction. In desorption of drug from the surface of biomaterials was performed by varying the pH and time, where it was observed that PC showed a maximum release of 40.98%±0.31% at pH 7.
P01-373 - Neuroticizing MCI Roque, M; Carriço, P; Morais, I
European psychiatry,
2010, 2010-00-00, Volume:
25, Issue:
S1
Journal Article
Peer reviewed
Objectives The authors describe and compare two cases of sudden onset cognitive impairment in middle-aged women. Methods Review of clinical records, laboratorial data, neuropsychological and ...imagiological studies. Results Two women in the sixth decade of life with a similar background and pre-illness state were admitted in the Day Unit for evaluation. They both presented sudden onset of bizarre behaviours, mood swings, unspecific speech disorder, and appetite and sleep pattern deviation, accompanying mild cognitive impairment (MCI) on neuropsychological evaluation. Both cases were submitted to intensive studies. Data and long-term follow-up revealed a frontotemporal dementia in one of the cases, and the second woman was shown to have a conversive pseudodementia. Conclusion Cognition's progressive deterioration is considered a major marker of dementia, but mild cognitive impairment is a heterogeneous clinical syndrome without criteria on current classifications of disease and limited prognostic value.
•Clindamycin significantly alleviates articular hyperalgesia and edema.•A clindamycin acetylated derivative (CAD) with reduced antibacterial activity inhibited articular hyperalgesia and edema.•CAD ...significantly attenuates neutrophil recruitment, NF-κB activation and tumor necrosis factor-α production.•Both clindamycin and CAD inhibited in vitro TNF-α production by RAW264.7 macrophages.
We recently demonstrated that clindamycin exhibits activities in acute and chronic models of pain and inflammation. In the present study, we investigated the effects of clindamycin and a clindamycin acetylated derivative (CAD) in models of acute joint inflammation and in a microbiological assay. Joint inflammation was induced in mice by intraarticular (i.a.) injection of zymosan or lipopolysaccharide (LPS). Clindamycin or CAD were administered via the intraperitoneal route 1 h before zymosan or LPS. Paw withdrawal threshold, joint diameter, histological changes, neutrophil recruitment, tumor necrosis factor-α (TNF-α) production and phosphorylation of the IκBα and NF-κB/p65 were evaluated. In vitro assays were used to measure the antibacterial activity of clindamycin and CAD and also their effects on zymosan-induced TNF-α production by RAW264.7 macrophages. Clindamycin exhibited activity against Staphylococcus aureus and Salmonella Typhimurium ATCC® strains at much lower concentrations than CAD. Intraarticular injection of zymosan or LPS induced articular hyperalgesia, edema and neutrophil infiltration in the joints. Zymosan also induced histological changes, NF-κB activation and TNF-α production. Responses induced by zymosan and LPS were inhibited by clindamycin (200 and 400 mg/kg) or CAD (436 mg/kg). Both clindamycin and CAD inhibited in vitro TNF-α production by macrophages. In summary, we provided additional insights of the clindamycin immunomodulatory effects, whose mechanism was associated with NF-κB inhibition and reduced TNF-α production. Such effects were extended to a clindamycin derivative with reduced antibacterial activity, indicating that clindamycin derivatives should be investigated as candidates to drugs that could be useful in the management of inflammatory and painful conditions.
Emerging contaminants and pollution are environmental problems threatening public health. Antibiotic ciprofloxacin and methylene blue dye are pollutants frequently detected in water systems ...worldwide. Photocatalysis is a process for water treatment. TiO2-based catalysts synthesized with natural gums show improved photocatalytic properties. Here, the sol–gel method synthesized TiO2/Arabic gum for photocatalytic performance. The innovation of this work was synthesized at 400 °C and investigated their photocatalytic proprieties using methylene blue and ciprofloxacin as model pollutants. XRD showed that the photocatalyst was in the anatase phase. The result showed that TiO2 with a band gap of 3.29 eV was achieved at a calcination temperature of 400 °C. Corresponding FTIR results suggest only the existence of functional groups related to TiO2. The SEM and BET method characterization indicated that TiO2/Arabic gum were spherical-shaped nanoparticles arranged in clusters with a mesoporous structure, contributing to photocatalytic performance. In addition, photocatalytic studies showed that the methylene blue dye and ciprofloxacin antibiotic degradation rates reached 99% and 94% under UV light, respectively. The hole (h+) and OH ⦁ radicals are essential in photodegradation. The synthesized material showed excellent photostability and maintained almost the same degradation percentage in the three consecutive cycles tested on the different pollutants. The TiO2/Arabic gum is an excellent candidate for future use in treating contaminants in aqueous media using photocatalysis. Therefore, TiO2/Arabic gum nanoparticles are a promising material for wastewater treatment.
To determine the clinical phenotype of Guillain-Barré syndrome (GBS) after Zika virus (ZIKV) infection, the anti-glycolipid antibody signature, and the role of other circulating arthropod-borne ...viruses, we describe a cohort of GBS patients identified during ZIKV and chikungunya virus (CHIKV) outbreaks in Northeast Brazil.
We prospectively recruited GBS patients from a regional neurology center in Northeast Brazil between December 2014 and February 2017. Serum and CSF were tested for ZIKV, CHIKV, and dengue virus (DENV), by RT-PCR and antibodies, and serum was tested for GBS-associated antibodies to glycolipids.
Seventy-one patients were identified. Forty-eight (68%) had laboratory evidence of a recent arbovirus infection; 25 (52%) ZIKV, 8 (17%) CHIKV, 1 (2%) DENV, and 14 (29%) ZIKV and CHIKV. Most patients with a recent arbovirus infection had motor and sensory symptoms (72%), a demyelinating electrophysiological subtype (67%) and a facial palsy (58%). Patients with a recent infection with ZIKV and CHIKV had a longer hospital admission and more frequent mechanical ventilation compared to the other patients. No specific anti-glycolipid antibody signature was identified in association with arbovirus infection, although significant antibody titres to GM1, GalC, LM1, and GalNAc-GD1a were found infrequently.
A large proportion of cases had laboratory evidence of a recent infection with ZIKV or CHIKV, and recent infection with both viruses was found in almost one third of patients. Most patients with a recent arbovirus infection had a sensorimotor, demyelinating GBS. We did not find a specific anti-glycolipid antibody signature in association with arbovirus-related GBS.
•Recent infection with chikungunya virus may be associated with Guillain-Barré syndrome•Recent infection with both Zika virus and chikungunya virus was associated with a severe disease course•Patients with a preceding arbovirus infection generally had a sensorimotor demyelinating subtype of GBS•No glycolipid antibody signature was found in association with arbovirus-related GBS
The Faial earthquake (M ^sub L^ 5.8) that occurred on the 9th of July, 1998, in the Azores region (north Atlantic), caused nine casualties and severe destruction affecting more than 5,000 people. The ...main shock was located at sea, 10 km NE of the Faial Island, and triggered a seismic sequence that lasted for several weeks and was characterized by an unusual high p-value of 1.40 for the modified Omori law. We present here the results of a joint inversion of hypocenters and 1D velocity model performed on the data collected by the permanent network complemented with a temporary network installed shortly after the occurrence of the main event. The 1D velocity model shows a heterogeneous upper crust, testified by the observed differences in site effects at the stations, while the middle crust from 2.5 to 8 km in depth is quite homogeneous. The Moho is located at a depth of about 12-13 km and the Vp/Vs ratio is found to be around 1.78. The events at depth are mainly concentrated in the middle-lower crust (8-12 km), while their spatial distribution shows a main cluster, visible after relocation, SSE trending. This direction of elongation is consistent with one of the fault planes (N151°E) of the centroid moment tensor (CMT) solution for the main shock. The same plane is the preferred main shock fault plane inferred after a Coulomb failure function analysis on the aftershock distribution. The main event relocation points to a focal depth shallower than 5 km. The aftershocks pattern shows that several fault systems were reactivated by the stress perturbation induced by the main shock. Besides the two main tectonic directions, trending WNW-ESE and NNW-SSE, observed in the tectonics of Faial, Pico, and S. Jorge, there is also evidence of a new tectonic direction trending WSW-ENE.PUBLICATION ABSTRACT
Metformin is an oral hypoglycemic drug widely used in the management of type 2 diabetes mellitus. We have recently demonstrated that metformin exhibits activity in models of nociceptive and ...neuropathic pain. However, little is known about its effects in experimental models of inflammation and inflammatory pain. Thus, the present study aimed to evaluate the activity of metformin in experimental models of inflammation and inflammatory pain in mice, as well as the underlying mechanisms. Previous (1 h)
per os
(
p.o
.) administration of metformin (250, 500 or 1000 mg/kg) inhibited the mechanical allodynia and paw edema induced by intraplantar (i.pl.) injection of carrageenan (600 μg) and also the pleurisy induced by this stimulus (200 μg, intrapleural). In the model of mechanical allodynia and paw edema induced by carrageenan, metformin also exhibited activity when administered after (1 h) the inflammatory stimulus. Metformin (1000 mg/kg) reduced the production of tumor necrosis factor-α induced by i.pl. injection of carrageenan. Metformin antiallodynic effect was not affected by previous administration of naltrexone (5 or 10 mg/kg, intraperitoneal) or cyproheptadine (5 or 10 mg/kg,
p.o
). However, this effect was abolished by previous administration of glibenclamide (20 or 40 mg/kg,
p.o
). In conclusion, the results demonstrate the activity of metformin in models of inflammation and inflammatory pain. In addition, the results indicate that the activity of metformin may be mediated by activation of ATP-sensitive potassium channels and reduction of production of inflammatory mediators. Altogether, these results stimulate the conduction of studies aiming to evaluate whether metformin may be repositioned in the treatment of patients with painful and inflammatory disorders.
Some B vitamins exhibit activities in models of nociceptive pain, inflammatory pain, and neuropathic pain induced by nerve lesions and also in certain painful conditions in humans. In the present ...study, we investigated the effects of thiamine, riboflavin, and nicotinamide in a neuropathic pain model induced by the chemotherapeutic paclitaxel in mice. Four intraperitoneal (i.p.) administrations of paclitaxel (2 mg/kg day, cumulative dose 8 mg/kg) induced a long-lasting mechanical allodynia. Per os (p.o.) administration of two doses of thiamine (150, 300 and 600 mg/kg), nicotinamide (250, 500 and 1000 mg/kg) or riboflavin (125, 250 and 500 mg/kg), on the seventh day after the first administration of paclitaxel, the mechanical allodynia was attenuated. The antinociceptive activity of all B vitamins was attenuated by glibenclamide (20 and 10 mg/kg, p.o.). Naltrexone (5 and 10 mg/kg, i.p.) attenuated the antinociceptive activity of thiamine. Thiamine, riboflavin, and nicotinamide also reduced the concentrations of tumor necrosis factor-α (TNF-α) and CXCL-1 in dorsal root ganglia (DRG) and thalamus. In conclusion, thiamine, riboflavin, and nicotinamide exhibit antinociceptive activity in the neuropathic pain model induced by paclitaxel. Inhibition of TNF-α and CXCL-1 production in DRG and thalamus, as well as activation of ATP-sensitive potassium channels, underly their antinociceptive activity.
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