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1.
Lett Appl Microbiol ; 67(2): 168-174, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29740840

RESUMO

Plant proteases play a fundamental role in several processes like growth, development and in response to biotic and abiotic stress. In particular, aspartic proteases (AP) are expressed in different plant organs and have antimicrobial activity. Previously, we purified an AP from Salpichroa origanifolia fruits called salpichroin. The aim of this work was to determine the cytotoxic activity of this enzyme on selected plant and human pathogens. For this purpose, the growth of the selected pathogens was analysed after exposure to different concentrations of salpichroin. The results showed that the enzyme was capable of inhibiting Fusarium solani and Staphylococcus aureus in a dose-dependent manner. It was determined that 1·2 µmol l-1 of salpichroin was necessary to inhibit 50% of conidial germination, and the minimal bactericidal concentration was between 1·9 and 2·5 µmol l-1 . Using SYTOX Green dye we were able to demonstrate that salpichroin cause membrane permeabilization. Moreover, the enzyme treated with its specific inhibitor pepstatin A did not lose its antibacterial activity. This finding demonstrates that the cytotoxic activity of salpichroin is due to the alteration of the cell plasma membrane barrier but not due to its proteolytic activity. Antimicrobial activity of the AP could represent a potential alternative for the control of pathogens that affect humans or crops of economic interest. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides insights into the antimicrobial activity of an aspartic protease isolated from Salpichroa origanifolia fruits on plant and human pathogens. The proteinase inhibited Fusarium solani and Staphylococcus aureus in a dose-dependent manner due to the alteration of the cell plasma membrane barrier but not due to its proteolytic activity. Antimicrobial activity of salpichroin suggests its potential applications as an important tool for the control of pathogenic micro-organisms affecting humans and crops of economic interest. Therefore, it would represent a new alternative to avoid the problems of environmental pollution and antimicrobial resistance.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Ácido Aspártico Proteases/farmacologia , Fusarium/crescimento & desenvolvimento , Solanaceae/química , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/metabolismo , Antifúngicos/metabolismo , Ácido Aspártico Proteases/isolamento & purificação , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Frutas , Humanos , Testes de Sensibilidade Microbiana , Permeabilidade/efeitos dos fármacos
2.
J Water Health ; 12(1): 69-80, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24642434

RESUMO

Cyanobacteria are able to produce several metabolites that have toxic effects on humans and animals. Among these cyanotoxins, the hepatotoxic microcystins (MC) occur frequently. The intracellular MC content produced by two strains of Microcystis aeruginosa, PCC7806 and PCC7820, and its production kinetics during the culture time were studied in order to elucidate the conditions that favour the growth and proliferation of these toxic strains. Intracellular MC concentrations measured by liquid chromatography (LC) coupled to electrospray ionization mass spectrometer (MS) were compared with those obtained by enzyme-linked immunosorbent assay (ELISA) anti-Adda and protein phosphatase 2A (PP2A) inhibition assays. It has been demonstrated there are discrepancies in the quantification of MC content when comparing ELISA and LC-MS results. However, a good correlation has been obtained between PP2A inhibition assay and LC-MS. Three MC were identified using LC-MS in the PCC7806 strain: MC-LR, demethylated MC-LR and a new variant detected for the first time in this strain, [L-MeSer(7)] MC-LR. In PCC7820, MC-LR, D-Asp(3)-MCLR, Dglu(OCH3)-MCLR, MC-LY, MC-LW and MC-LF were identificated. The major one was MC-LR in both strains, representing 81 and 79% of total MC, respectively. The total MC content in M. aeruginosa PCC7820 was almost three-fold higher than in PCC7806 extracts.


Assuntos
Microcistinas/metabolismo , Microcystis/crescimento & desenvolvimento , Microcystis/metabolismo , Bioensaio/métodos , Calcineurina/análise , Técnicas de Cultura de Células , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática , Espectrometria de Massas por Ionização por Electrospray
3.
Mol Plant Microbe Interact ; 26(4): 451-60, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23216086

RESUMO

The nodulation (nod) genes of Rhizobium tropici CIAT899 can be induced by very low concentrations (micromolar to nanomolar range) of several flavonoid molecules secreted by the roots of leguminous plants under a number of different conditions. Some of these conditions have been investigated and appear to have a great influence on the concentration and the number of different Nod factors, which can induce root nodule primordia and pseudonodules in several leguminous plant roots. In one such condition, we added up to 300 mM NaCl to the induction medium of R. tropici CIAT899 containing the nod gene inducer apigenin. At the higher concentrations of NaCl, larger amounts and more different Nod factors were produced than in the absence of extra NaCl. To our surprise, under control conditions (300 mM NaCl without apigenin), some Nod-factor-like spots were also observed on the thin-layer plates used to detect incorporation of radiolabeled glucosamine into newly synthesized Nod factors. This phenomenon was further investigated with thin-layer plates, fusions of nod genes to the lacZ gene, high-performance liquid chromatography, mass spectrometry, and the formation of pseudonodules on bean roots. Here, we report that, in the absence of flavonoid inducers, high concentrations of NaCl induced nod genes and the production of Nod factors.


Assuntos
Flavonoides/farmacologia , Lipopolissacarídeos/metabolismo , Rhizobium tropici/efeitos dos fármacos , Rhizobium tropici/metabolismo , Cloreto de Sódio/farmacologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/genética , Lipopolissacarídeos/genética
4.
Neurologia ; 28(2): 95-102, 2013 Mar.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-22986093

RESUMO

INTRODUCTION: Informal caregivers provide care to dementia patients, and this service prolongs their stay at home. OBJECTIVES: To describe characteristics of dementia patients in the province of Alicante, as well as the profiles and roles of caregivers who assist them. PATIENTS AND METHODS: Multi-centre prospective study carried out in 4 neurology departments in Alicante (June 2009 to January 2010). Dementia patients' relatives/caregivers were included in sequential order. The following variables were analysed: a) Demographic information pertaining to the patient and caregivers (age, sex, marital and employment status, educational level, relationship to patient); b) patient's family unit; c) motivating factor for primary caregiver (PC); d) secondary caregiver (SC) roles; e) country of citizenship of formal caregiver (FC) and source of remuneration (private/public); f) caregivers' knowledge of dementia. RESULTS: Most of our patients live at home (74.8%), and are female (69%) with Alzheimer's disease (78.4%) in a moderately severe stage (GDS level 4-5, 71.6%). PCs and SCs are mainly women (72.1% and 60.5% respectively), middle-aged and directly related to the patient (sons/daughters account for 64.3% of the PCs and 54.4% of the SCs); most are homemakers with a low educational level. Caregivers in the first category (PC) provide care due to moral obligation (75%), while those in the second (SC) involve patients in leisure or other stimulating activities (82.3%). Absent caregivers tend to be males (73.3%) residing long distances from the relative (52.4%). The FC tends to be female (91.7%), Spanish (81.8%) and privately remunerated. CONCLUSIONS: Women dominate the network of caregivers for dementia patients, whether as principal caregivers, supporting caregivers or formal caregivers (in all cases, they have only limited training in dementia management). Males are largely absent. Better knowledge of the care structure supporting dementia patients may be helpful in the overall management of these patients.


Assuntos
Cuidadores/estatística & dados numéricos , Demência/terapia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/economia , Doença de Alzheimer/terapia , Cuidadores/economia , Efeitos Psicossociais da Doença , Demência/economia , Família , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Serviços de Assistência Domiciliar , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Remuneração , Fatores Socioeconômicos , Espanha
5.
Heliyon ; 6(6): e04162, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32577560

RESUMO

BACKGROUND: Psoriasis is a pro-inflammatory disease with unknown etiology, that is characterized by skin inflammation and keratinocytes hyperproliferation. Specific inhibition of inflammation has shown positive effects avoiding the progression of the psoriatic lesions in different animal models of the disease, turning this strategy as a remarkable therapeutic alternative. OBJECTIVE: To screen the effectiveness of a novel IFN-α/ß signalling inhibitor in the development reduction of skin lesions in IMQ and TPA mice models of psoriasis. METHODS: We used a Phage-peptide library for the screening of a peptide with inhibitory effects on the development of psoriasis-like lesions in mice. To evaluate the in vivo effect of the phage-peptides (Phpep3D) and the derived peptide (Pep3D), we administered Phpep3D or Pep3D intradermally in mice with imiquimod (IMQ)-induced psoriasis and 12-O-tetradecanoyl phorbol-13-acetate (TPA)-induced psoriasis. We scored the lesions, and we determined the number of neutrophils and the production of some pro-inflammatory cytokines in the lesions. RESULTS: In this work, we describe how the Ph3pepD and Pep3D reduced skin thickness, redness, and acanthosis despite the presence of the psoriasis inducers, IMQ or TPA. We also found that Pep3D reduced the number of GR1+ infiltrated cells and decreased the production of IL-17A and TNFα in the psoriatic skin of mice. In-silico, docking analysis showed that Pep3D may interact with the interferon-alpha receptor, but further analyses should be performed to uncover the mechanism of action of this peptide. CONCLUSION: Our results suggest that Pep3D could be used as a new treatment for psoriasis.

6.
Neuron ; 21(1): 111-22, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9697856

RESUMO

The mouse mutant mocha, a model for the Hermansky-Pudlak storage pool deficiency syndrome, is characterized by defective platelets, coat and eye color dilution, lysosomal abnormalities, inner ear degeneration, and neurological deficits. Here, we show that mocha is a null allele of the delta subunit of the adaptor-like protein complex AP-3, which is associated with coated vesicles budding from the trans-Golgi network, and that AP-3 is missing in mocha tissues. In mocha brain, the ZnT-3 transporter is reduced, resulting in a lack of zinc-associated Timm historeactivity in hippocampal mossy fibers. Our results demonstrate that the AP-3 complex is responsible for cargo selection to lysosome-related organelles such as melanosomes and platelet dense granules as well as to neurotransmitter vesicles.


Assuntos
Plaquetas/metabolismo , Endossomos/metabolismo , Melanócitos/metabolismo , Mutação/genética , Deficiência do Pool Plaquetário/genética , Vesículas Sinápticas/metabolismo , Fatores de Transcrição/genética , Complexo 3 de Proteínas Adaptadoras , Subunidades beta do Complexo de Proteínas Adaptadoras , Alelos , Animais , Sequência de Bases , Transporte Biológico/fisiologia , Sistema Nervoso Central/metabolismo , Mapeamento Cromossômico , Rearranjo Gênico , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Deficiência do Pool Plaquetário/metabolismo , RNA Mensageiro/metabolismo , Transcrição Gênica , Zinco/metabolismo
7.
Circ Res ; 98(10): 1299-305, 2006 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-16614307

RESUMO

The aim of this work was to investigate whether it is possible to remove arrhythmogenic Ca2+ release from the sarcoplasmic reticulum that occurs in calcium overload without compromising normal systolic release. Exposure of rat ventricular myocytes to isoproterenol (1 micromol/L) resulted in an increased amplitude of the systolic Ca2+ transient and the appearance of waves of diastolic Ca2+ release. Application of tetracaine (25 to 50 micromol/L) decreased the frequency or abolished the diastolic Ca2+ release. This was accompanied by an increase in the amplitude of the systolic Ca2+ transient. Cellular Ca2+ flux balance was investigated by integrating Ca2+ entry (on the L-type Ca2+ current) and efflux (on Na-Ca2+ exchange). Isoproterenol increased Ca2+ influx but failed to increase Ca2+ efflux during systole (because of the abbreviation of the duration of the Ca2+ transient). To match this increased influx the bulk of Ca2+ efflux occurred via Na-Ca2+ exchange during a diastolic Ca2+ wave. Subsequent application of tetracaine increased systolic Ca2+ efflux and abolished the diastolic efflux. The increase of systolic efflux in tetracaine resulted from both increased amplitude and duration of the systolic Ca2+ transient. In the presence of isoproterenol, those Ca2+ transients preceded by diastolic release were smaller than those where no diastolic release had occurred. When tetracaine was added, the amplitude of the Ca2+ transient was similar to those in isoproterenol with no diastolic release and larger than those preceded by diastolic release. We conclude that tetracaine increases the amplitude of the systolic Ca2+ transient by removing the inhibitory effect of diastolic Ca2+ release.


Assuntos
Cálcio/metabolismo , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Animais , Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio Tipo L/fisiologia , Cardiotônicos/farmacologia , Diástole , Ventrículos do Coração , Isoproterenol/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Sarcolema/metabolismo , Sístole , Tetracaína/farmacologia
8.
Nutr Hosp ; 23(4): 348-53, 2008.
Artigo em Espanhol | MEDLINE | ID: mdl-18604321

RESUMO

INTRODUCTION: The prevalence of hyponutrition in hospitalized patients in our setting is 53%. The therapeutic approach is controversial. OBJECTIVES: To determine whether an early nutritional intervention in hospitalized patients by means of oral nutritional support can improve their prognosis regarding decreased morbimortality and hospital stay. MATERIAL AND METHODS: Randomized prospective study comprised by a treatment group and a control group of malnourished patients hospitalized at the Internal Medicine and Respiratory Medicine Departments. The nutritional diagnosis was made by using the Subjective Global Assessment. Groups B and C were assigned to receive the hospital diet according to their needs and pathology (control group) and the treatment group also received a standard nutritional supplement. We recorded the development of infections, pressure ulcers, hospitalization days, mortality, and weight. RESULTS: We performed more than 1,700 Subjective Global Assessments. Five hundred and thirty seven patients (264 treated and 273 controls) were followed-up until hospital discharge or death. We did not find statistically significant differences in mortality, hospital stay, or occurrence of complications between the treatment group and the control group. The treatment group presented statistically significant weight increase as compared with the control group. CONCLUSIONS: We could not demonstrate benefits when using the oral nutritional supplement in terms of mortality, hospital stay, infectious complications, or pressure ulcers. The significant weight increase in the treatment group allowed us concluding that the supplement effectively treated hyponutrition in this group. This new clinical status implies a better prognosis, as it has already been shown. However, this could not be observed by means of the study parameters. Long-term studies are required to determine for how long this nutritional improvement can be sustained, implying a better prognosis in the long run.


Assuntos
Hospitalização , Desnutrição/terapia , Apoio Nutricional , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo
9.
Comput Biol Med ; 37(3): 364-75, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16793033

RESUMO

Specular microscopy is widely used to study the human corneal endothelium status in vivo. In this paper, the corneal endothelium is represented as a binary image composed of the cell inscribed circles. The granulometric distribution function of the complement of this image is used as a functional descriptor, which provides information about the shape, size and spatial arrangement of cells. Experimental evaluation using bootstrap techniques shows its ability to discriminate between controls and pathological cases. It represents a reliable and graphical alternative to the classical indices (cell density, hexagonality and coefficient of variation of cell areas), which behave poorly when detecting subtle abnormalities.


Assuntos
Simulação por Computador , Endotélio Corneano/anatomia & histologia , Processamento de Imagem Assistida por Computador , Microscopia , Análise Numérica Assistida por Computador , Oftalmoscopia , Contagem de Células , Tamanho Celular , Análise de Fourier , Humanos , Software
11.
Cell Calcium ; 39(5): 417-23, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16563501

RESUMO

The aim of this paper was to characterize the pathways that allow Ca(2+) ions to enter the cell at rest. Under control conditions depolarization produced an increase of intracellular Ca concentration ([Ca(2+)](i)) that increased with depolarization up to about 0 mV and then declined. During prolonged depolarization the increase of [Ca(2+)](i) decayed. This increase of [Ca(2+)](i) was inhibited by nifedipine and the calculated rate of entry of Ca increased on depolarization and then declined with a similar time course to the inactivation of the L-type Ca current. We conclude that this component of change of [Ca(2+)](i) is due to the L-type Ca current. If intracellular Na was elevated then only part of the change of [Ca(2+)](i) was inhibited by nifedipine. The nifedipine-insensitive component increased monotonically with depolarization and showed no relaxation on prolonged depolarization. This component appears to result from Na-Ca exchange (NCX). When the L-type current and NCX were both inhibited (nifedipine and Na-free solution) then depolarization decreased and hyperpolarization increased [Ca(2+)](i). These changes of [Ca(2+)](i) were unaffected by modifiers of B-type Ca channels such as chlorpromazine and AlF(3) but were abolished by gadolinium ions. We conclude that, in addition to L-type Ca channels and NCX, there is another pathway for entry of Ca(2+) into the ventricular myocyte but this is distinct from the previously reported B-type channel.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Canais de Cálcio/metabolismo , Cálcio/metabolismo , Miócitos Cardíacos/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Animais , Cálcio/farmacologia , Sinalização do Cálcio , Ventrículos do Coração/citologia , Potenciais da Membrana/efeitos dos fármacos , Potenciais da Membrana/fisiologia , Miócitos Cardíacos/citologia , Ratos , Sarcolema/fisiologia , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/metabolismo
12.
Circ Res ; 88(2): 195-201, 2001 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-11157672

RESUMO

The aim of this study was to investigate how sarcoplasmic reticulum (SR) Ca(2+) content and systolic Ca(2+) are controlled when Ca(2+) entry into the cell is varied. Experiments were performed on voltage-clamped rat and ferret ventricular myocytes loaded with fluo-3 to measure intracellular Ca(2+) concentration ([Ca(2+)](i)). Increasing external Ca(2+) concentration ([Ca(2+)](o)) from 1 to 2 mmol/L increased the amplitude of the systolic Ca(2+) transient with no effect on SR Ca(2+) content. This constancy of SR content is shown to result because the larger Ca(2+) transient activates a larger Ca(2+) efflux from the cell that balances the increased influx. Decreasing [Ca(2+)](o) to 0.2 mmol/L decreased systolic Ca(2+) but produced a small increase of SR Ca(2+) content. This increase of SR Ca(2+) content is due to a decreased release of Ca(2+) from the SR resulting in decreased loss of Ca(2+) from the cell. An increase of [Ca(2+)](o) has two effects: (1) increasing the fraction of SR Ca(2+) content, which is released on depolarization and (2) increasing Ca(2+) entry into the cell. The results of this study show that the combination of these effects results in rapid changes in the amplitude of the systolic Ca(2+) transient. In support of this, the changes of amplitude of the transient occur more quickly following changes of [Ca(2+)](o) than following refilling of the SR after depletion with caffeine. We conclude that the coordinated control of increased Ca(2+) entry and greater fractional release of Ca(2+) is an important factor in regulating excitation-contraction coupling.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Cálcio/metabolismo , Contração Miocárdica/fisiologia , Retículo Sarcoplasmático/metabolismo , 4-Aminopiridina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Compostos de Anilina , Animais , Bário/farmacologia , Cafeína/farmacologia , Células Cultivadas , Estimulação Elétrica , Furões , Corantes Fluorescentes , Líquido Intracelular/metabolismo , Contração Miocárdica/efeitos dos fármacos , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio , Ratos , Retículo Sarcoplasmático/efeitos dos fármacos , Trocador de Sódio e Cálcio/metabolismo , Sístole/fisiologia , Xantenos
13.
Circ Res ; 91(7): 585-93, 2002 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-12364386

RESUMO

Sarcoplasmic reticulum (SR) Ca2+ release, through the ryanodine receptor (RyR), is essential for the systolic Ca2+ transient and thus the cardiac contractile function. The aim of this study was to examine the effects on the spatial organization of the systolic Ca2+ transient of depressing RyR open probability (P(o)) with tetracaine or intracellular acidification. Voltage-clamped, fluo-3-loaded myocytes were studied using confocal microscopy. Depressing RyR P(o) increased the variability of the Ca2+ transient amplitude between different regions of the cell. This variability often produced alternans with a region producing large and small transients alternately. In addition, the raising phase of the Ca2+ transient became biphasic. The initial phase was constant but the second was variable and propagated as a wave through part of the cell. That both phases involved SR Ca2+ release was shown by their reduction by caffeine. Regional [Ca2+]i alternans was accompanied by a much smaller degree of alternans at the whole cell level. We suggest that, in tetracaine or acidosis, the initial phase of the Ca2+ transient results from Ca2+ release via RyRs directly activated by adjacent L-type Ca2+ channels. At some sites, this will activate neighboring RyRs and a Ca2+ wave will propagate via activation of other RyRs. This work is the first demonstration that decreased RyR P(o) alone can produce disarray of the Ca2+ release process and initiate alternans.


Assuntos
Sinalização do Cálcio , Ventrículos do Coração/metabolismo , Contração Miocárdica , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Animais , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , Ventrículos do Coração/citologia , Concentração de Íons de Hidrogênio , Cinética , Microscopia Confocal , Técnicas de Patch-Clamp , Ratos , Ratos Wistar , Retículo Sarcoplasmático/metabolismo , Sístole , Tetracaína/farmacologia , Função Ventricular
14.
Circ Res ; 87(12): 1087-94, 2000 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-11110764

RESUMO

The control of intracellular calcium is central to regulation of contractile force in cardiac muscle. This review illustrates how analysis of the control of calcium requires an integrated approach in which several systems are considered. Thus, the calcium content of the sarcoplasmic reticulum (SR) is a major determinant of the amount of Ca(2+) released from the SR and the amplitude of the Ca(2+) transient. The amplitude of the transient, in turn, controls Ca(2+) fluxes across the sarcolemma and thence SR content. This control of SR content influences the response to maneuvers that modify, for example, the properties of the SR Ca(2+) release channel or ryanodine receptor. Specifically, modulation of the open probability of the ryanodine receptor produces only transient effects on the Ca(2+) transient as a result of changes of SR content. These interactions between various Ca(2+) fluxes are modified by the Ca(2+) buffering properties of the cell. Finally, we predict that, under some conditions, the above interactions can result in instability (such as alternans) rather than ordered control of contractility.


Assuntos
Cálcio/metabolismo , Contração Miocárdica/fisiologia , Miocárdio/metabolismo , Retículo Sarcoplasmático/metabolismo , Transporte Biológico , Humanos , Bombas de Íon/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Retículo Sarcoplasmático/fisiologia
15.
Br J Ophthalmol ; 90(3): 378-82, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16488966

RESUMO

AIMS: To search for the induction of the expression of antimicrobial peptides in corneal fibroblasts treated with bacterial components. METHODS: RT-PCR was performed to search for mRNAs expression of antimicrobial peptides and toll-like receptors (TLRs) in murine primary cultures of corneal fibroblast (PCCF) treated with lipopolysaccharide (LPS) from Escherichia coli, peptidoglycan from Staphylococcus aureus, and cytosine-phosphorous-guanine oligonucleotide (CpG-ODN). Cellular activation was blocked with anti-TRL antibodies. RESULTS: LPS did not induce expression of antimicrobial peptide in corneal fibroblasts. Cathelin related antimicrobial peptide (CRAMP) and alpha-defensin 3 were overexpressed in a time and dose dependent manner in corneal fibroblasts treated with peptidoglycan and with CpG-ODN, respectively. CRAMP expression was blocked when PCCF were treated with anti-TLR-2 antibodies. alpha-Defensin 3 was not expressed in NIH murine corneal fibroblasts (which do not express the TLR-9 molecule) treated with CpG-ODN. CONCLUSION: Results suggest that corneal fibroblasts, which are the second cellular barrier of the cornea, can play an important part in the innate immunity of the eye via TLR stimulation.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Córnea/imunologia , Fibroblastos/imunologia , alfa-Defensinas/metabolismo , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Catelicidinas , Células Cultivadas , Imunidade Celular , Lipopolissacarídeos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos , Oligodesoxirribonucleotídeos/imunologia , Peptidoglicano/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Receptor 2 Toll-Like/imunologia , Receptor Toll-Like 9/imunologia
16.
Clin Rheumatol ; 35(5): 1353-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26198586

RESUMO

The objective of this study is to evaluate inter-reader entheses ultrasound (US) reliability and the influence of the type of image or degree of sonographer experience on US reliability in patients with spondyloarthritis (SpA). Eighteen Latin American ultrasonographers with different experience took part in an US reading exercise evaluating 60 entheseal images (50 % static images and 50 % videos) from healthy controls and SpA patients. The following sonographic lesions were assessed: structure, thickness, bone proliferation/tendon calcification, erosions, bursitis, and Doppler signal. Another group of three experts with significant experience in entheses US read all images too. Inter-reader reliability among participants and experts was calculated by the Cohen's kappa coefficient. Thresholds for kappa values were <0.2 poor, 0.21-0.4 fair, 0.41-0.6 moderate, 0.61-0.8 good, and 0.81-1 excellent. Furthermore, the results for the expert group were stratified based on the type of image. Kappa correlation coefficients among participants, showed variability depending on the type of lesion, being fair for structure and thickness, moderate for calcifications, erosions, and bursitis, and excellent for Doppler signal. Inter-reader reliability among experts was higher, being moderate for structure and thickness, good for calcifications and bursitis, and excellent for erosions and Doppler. Inter-reader reliability for assessing calcification and structure using static images was significantly higher than for videos. Overall inter-reader reliability for assessing entheses by US in SpA is moderate to excellent for most of the lesions. However, special training seems fundamental to achieve better inter-reader reliability. Moreover, the type of image influenced these results, where evaluation of entheses by videos was more difficult than by static images.


Assuntos
Entesopatia/diagnóstico por imagem , Espondilartrite/diagnóstico por imagem , Competência Clínica , Humanos , Reprodutibilidade dos Testes , Índice de Gravidade de Doença , Ultrassonografia
17.
Cell Calcium ; 38(3-4): 391-6, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16139353

RESUMO

Most of the calcium that activates contraction in the heart comes from the sarcoplasmic reticulum (SR) and it is therefore essential to control the SR Ca content. SR Ca content reflects the balance between uptake (via the SR Ca-ATPase, SERCA) and release, largely via the ryanodine receptor (RyR). Unwanted changes of SR Ca are prevented because, for example, an increase of SR Ca content increases the amplitude of the systolic Ca transient and this, in turn, results in increased loss of Ca from and decreased Ca entry into the cell thereby restoring cell and SR Ca towards control levels. We discuss the parameters that affect the steady level of SR Ca and how these may change in heart failure. Finally, we discuss disordered Ca regulation with particular emphasis on the condition of alternans where successive heartbeats alternate in amplitude. This behaviour can be explained by excessive feedback gain in the processes controlling SR Ca.


Assuntos
Cálcio/metabolismo , Miocárdio/metabolismo , Retículo Sarcoplasmático/fisiologia , Animais , Cálcio/química , Cardiopatias/metabolismo , Cardiopatias/fisiopatologia , Humanos , Miocárdio/química , Retículo Sarcoplasmático/química
18.
J Gen Physiol ; 107(6): 743-54, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8783074

RESUMO

We have recently reported that brain sodium channels display periods with high (low-Kd) and low (high-Kd) levels of lidocaine-induced open channel block (Salazar, B.C., D.O. Flash, J.L. Walewski, and E. Recio-Pinto. 1995. Brain Res. 699:305-314). In the present study, we further characterize this phenomenon by studying the effects of the permanently charged lidocaine analogue, QX-314. We found that the detection of high- and low-Kd periods does not require the presence of the uncharged form of lidocaine. The level of block, for either period, at various QX-314 concentrations indicated the presence of a single local anesthetic binding site. Increasing the concentration of QX-314 decreased the lifetime of the high-Kd periods while it increased the lifetime of the low-Kd periods. These results could be best fitted to a model with two open channel conformations that display different local anesthetic Kd values (low and high Kd), and in which the channel area defining the local anesthetic Kd consists of multiple interacting regions. Amplitude distribution analysis showed that changes in the Kd values reflected changes in the kon rates, without changes in the koff rates. Both lidocaine and QX-314 were found to be incapable of blocking small-channel subconductance states (5-6 pS). Changes in the local anesthetic kon rates for blocking the fully open state and the lack of local anesthetic block of the small subconductance state are consistent with the presence of channel conformational changes involving the intracellular permeation pathway leading to the local anesthetic binding site.


Assuntos
Encéfalo/metabolismo , Lidocaína/análogos & derivados , Lidocaína/farmacologia , Canais de Sódio/efeitos dos fármacos , Canais de Sódio/metabolismo , Anestésicos Locais/metabolismo , Anestésicos Locais/farmacologia , Animais , Sítios de Ligação , Membrana Celular/metabolismo , Relação Dose-Resposta a Droga , Condutividade Elétrica , Eletrofisiologia , Concentração Osmolar , Ratos , Canais de Sódio/fisiologia
19.
Plant Physiol ; 110(4): 1215-1222, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12226254

RESUMO

A strain of Chlamydomonas reinhardtii, named ARF-1, which grows with the glutamine synthetase (GS) inhibitor L-methionine-S-sulfoximine (MSX), has been isolated and characterized. Mutant ARF-1 is affected at a single and dominant gene, tentatively assigned to the allele msr-1-2. Neither the uptake of ammonia nor the two GS isoenzyme activities of the mutant were affected by MSX in vivo. GS activities, however, were fully abolished in vitro, thus suggesting that neither GS isoform was an altered enzyme resistant to the inhibitor. Resistance to MSX does not seem to be due to either a defect in a permease responsible for the transport of MSX or over-expression of GS activity, nor did we find an alternative enzymatic pathway for the assimilation of ammonium. Resistance was independent of the nitrogen source used and was strongly enhanced by the addition of acetate. Unlike the parental strain, mutant ARF-1 can degrade and utilize MSX as the sole nitrogen source for growth, which could account for the observed resistance. Thus, this mutant can be classified as a novel type of MSX-resistant mutant. This mutant can also use phosphinothricin, methionine sulfone, or methionine sulfoxide as the sole sources of nitrogen. This capability cosegregated in the genetic crosses and was also observed in all the diploids isolated. An MSX/[alpha]-ketoglutarate aminotransferase activity, not present in the parental strain 305, was detected in mutant ARF-1 cells. Therefore, we propose that the locus msr-1-2 either codes for this transaminase activity or its product gene is necessary to express this transaminase activity.

20.
Br J Ophthalmol ; 89(7): 904-10, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15965176

RESUMO

AIMS: To look for TLR and NOD mRNA expression in the healthy eye and in other immune privileged and non-immune privileged mouse organs. METHODS: Semiquantitative RT-PCR was performed to look for TLR1-9 and NOD1 and NOD2 mRNA expressions in the whole eye, in the anterior (AP) and posterior (PP) portions of the eye, in corneal fibroblasts (CF) and in ovary, brain, testis, heart, lung, and spleen. RESULTS: All the TLR mRNAs were expressed in the whole eye of Balb/c mice. NIH and C57BL/6 did not express TLR9 and TLR8, respectively. NIH expressed higher levels of TLR1, 2, 3, and 6 than the other strains. C57BL/6 expressed the lowest levels of all TLRs. TLR9, 5, and 4 were the less expressed in all strains. All TLRs were expressed in Balb/c PP and TLR1 was not expressed in AP. In NIH and Balb/c CF the majority of TLRs were overexpressed with LPS. In testis, expression of most TLRs was absent. Non-immune privileged organs expressed most of the TLRs. All the organs expressed NOD1 and NOD2. In PP NOD2 was not expressed. CONCLUSION: TLRs and NODs are expressed in the eye, and could have an important role in the innate immunity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/análise , Proteínas do Olho/análise , Peptídeos e Proteínas de Sinalização Intracelular/análise , Glicoproteínas de Membrana/análise , Receptores de Superfície Celular/análise , Animais , Células Cultivadas , Olho/química , Olho/imunologia , Proteínas do Olho/imunologia , Feminino , Fibroblastos/química , Fibroblastos/imunologia , Masculino , Glicoproteínas de Membrana/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteína Adaptadora de Sinalização NOD1 , Proteína Adaptadora de Sinalização NOD2 , RNA Mensageiro/análise , Receptores de Superfície Celular/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Receptor 1 Toll-Like , Receptor 8 Toll-Like , Receptores Toll-Like
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