Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Braz. j. biol ; Braz. j. biol;80(3): 497-505, July-Sept. 2020. graf
Artigo em Inglês | LILACS | ID: biblio-1132403

RESUMO

Abstract Little is known regarding whether photodynamic therapy (PDT)-induced cell death can substantially compromise macrophages (MΦ), which are important cells in PDT-induced immune responses. Here, parameters of PDT-mediated MΦ cytotoxicity and cytokine production in response to protoporphyrin IX (PpIX) were evaluated. Peritoneal MΦ from BALB/c mice were stimulated in vitro with PDT, light, PpIX, or lipopolysaccharide (LPS). After that, cell viability, lipid peroxidation, Nitric Oxide (NO), DNA damage, TNF-α, IL-6 and IL-10 were evaluated. Short PDT exposure reduced cell viability by 10-30%. There was a two-fold increase in NO and DNA degradation, despite the non-increase in lipoperoxidation. PDT increased TNF-α and IL-10, particularly in the presence of LPS, and decreased the production of IL-6 to 10-fold. PDT causes cellular stress, induces NO radicals and leads to DNA degradation, generating a cytotoxic microenvironment. Furthermore, PDT modulates pro- and anti-inflammatory cytokines in MΦ.


Resumo Pouco se sabe se a morte celular induzida pela terapia fotodinâmica (PDT) compromete os macrófagos (MΦ), envolvidos nas respostas imunes induzidas pela PDT. Neste estudo, foram avaliados parâmetros de citotoxicidade dos MΦ mediada pela PDT e a produção de citocinas, frente à protoporfirina IX (PpIX). MΦ peritoneais de camundongos BALB/c foram estimulados in vitro com PDT, luz, PpIX ou lipopolissacarídeo (LPS). Após isto, a viabilidade celular (VC), a lipoperoxidação, os níveis de óxido nítrico (NO), de DNA degradado, de TNF-α, IL-6 e IL-10 foram avaliados. A exposição curta à PDT reduziu a VC em 10-30%. Os níveis de NO e de DNA degradado duplicaram, sem aumento da lipoperoxidação. Houve aumento de TNF-α e IL-10, sendo maior na presença de LPS. Já a produção de IL-6 reduziu em dez vezes. A PDT induz estresse celular, gera radicais NO e causa dano ao DNA, tornando o microambiente citotóxico. Ainda, modula citocinas pró e anti-inflamatórias em MΦ.


Assuntos
Animais , Coelhos , Fotoquimioterapia , Interleucina-10 , Protoporfirinas , Citocinas , Interleucina-6 , Fator de Necrose Tumoral alfa , Macrófagos , Camundongos Endogâmicos BALB C
2.
Artigo em Inglês | MEDLINE | ID: mdl-34858795

RESUMO

This paper describes an overview of the capability of the NMIs that participated on the CCM Pilot Study measurement systems, conducted by the CIPM/CCM/Working Group on Hardness, to characterize the Rockwell hardness diamond indenter geometry, by measuring the included cone angle, the straightness of the generatrix, the spherical tip radius, the deviation of the local radius and the tilt angle. Nine NMIs took part in this study: INMETRO (Brazil); INRiM (Italy); KRISS (South Korea); NIM/PR (China); NIMT (Thailand); NIST (USA); PTB (Germany); TUBITAK UME (Turkey); VNIIFTRI (Russia), where INMETRO (Brazil) served as pilot laboratory.

3.
Braz J Biol ; 80(3): 497-505, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31576928

RESUMO

Little is known regarding whether photodynamic therapy (PDT)-induced cell death can substantially compromise macrophages (MΦ), which are important cells in PDT-induced immune responses. Here, parameters of PDT-mediated MΦ cytotoxicity and cytokine production in response to protoporphyrin IX (PpIX) were evaluated. Peritoneal MΦ from BALB/c mice were stimulated in vitro with PDT, light, PpIX, or lipopolysaccharide (LPS). After that, cell viability, lipid peroxidation, Nitric Oxide (NO), DNA damage, TNF-α, IL-6 and IL-10 were evaluated. Short PDT exposure reduced cell viability by 10-30%. There was a two-fold increase in NO and DNA degradation, despite the non-increase in lipoperoxidation. PDT increased TNF-α and IL-10, particularly in the presence of LPS, and decreased the production of IL-6 to 10-fold. PDT causes cellular stress, induces NO radicals and leads to DNA degradation, generating a cytotoxic microenvironment. Furthermore, PDT modulates pro- and anti-inflammatory cytokines in MΦ.


Assuntos
Interleucina-10 , Fotoquimioterapia , Animais , Citocinas , Interleucina-6 , Macrófagos , Camundongos , Camundongos Endogâmicos BALB C , Protoporfirinas , Fator de Necrose Tumoral alfa
4.
Braz. J. Biol. ; 80(3): 497-505, 2020. ilus, graf
Artigo em Inglês | VETINDEX | ID: vti-27988

RESUMO

Little is known regarding whether photodynamic therapy (PDT)-induced cell death can substantially compromise macrophages (M), which are important cells in PDT-induced immune responses. Here, parameters of PDT-mediated M cytotoxicity and cytokine production in response to protoporphyrin IX (PpIX) were evaluated. Peritoneal M from BALB/c mice were stimulated in vitro with PDT, light, PpIX, or lipopolysaccharide (LPS). After that, cell viability, lipid peroxidation, Nitric Oxide (NO), DNA damage, TNF-, IL-6 and IL-10 were evaluated. Short PDT exposure reduced cell viability by 1030%. There was a two-fold increase in NO and DNA degradation, despite the non-increase in lipoperoxidation. PDT increased TNF- and IL-10, particularly in the presence of LPS, and decreased the production of IL-6 to 10-fold. PDT causes cellular stress, induces NO radicals and leads to DNA degradation, generating a cytotoxic microenvironment. Furthermore, PDT modulates pro- and anti-inflammatory cytokines in M(AU)


Pouco se sabe se a morte celular induzida pela terapia fotodinâmica (PDT) compromete os macrófagos (M), envolvidos nas respostas imunes induzidas pela PDT. Neste estudo, foram avaliados parâmetros de citotoxicidade dos M mediada pela PDT e a produção de citocinas, frente à protoporfirina IX (PpIX). M peritoneais de camundongos BALB/c foram estimulados in vitro com PDT, luz, PpIX ou lipopolissacarídeo (LPS). Após isto, a viabilidade celular (VC), a lipoperoxidação, os níveis de óxido nítrico (NO), de DNA degradado, de TNF-, IL-6 e IL-10 foram avaliados. A exposição curta à PDT reduziu a VC em 10-30%. Os níveis de NO e de DNA degradado duplicaram, sem aumento da lipoperoxidação. Houve aumento de TNF- e IL-10, sendo maior na presença de LPS. Já a produção de IL-6 reduziu em dez vezes. A PDT induz estresse celular, gera radicais NO e causa dano ao DNA, tornando o microambiente citotóxico. Ainda, modula citocinas pró e anti-inflamatórias em M(AU)


Assuntos
Animais , Citocinas/análise , Fator de Necrose Tumoral alfa/análise , Interleucina-6 , Interleucina-10 , Macrófagos , Estresse Oxidativo , Fotoquimioterapia
5.
Artigo em Inglês | VETINDEX | ID: vti-743105

RESUMO

Abstract Little is known regarding whether photodynamic therapy (PDT)-induced cell death can substantially compromise macrophages (M), which are important cells in PDT-induced immune responses. Here, parameters of PDT-mediated M cytotoxicity and cytokine production in response to protoporphyrin IX (PpIX) were evaluated. Peritoneal M from BALB/c mice were stimulated in vitro with PDT, light, PpIX, or lipopolysaccharide (LPS). After that, cell viability, lipid peroxidation, Nitric Oxide (NO), DNA damage, TNF-, IL-6 and IL-10 were evaluated. Short PDT exposure reduced cell viability by 1030%. There was a two-fold increase in NO and DNA degradation, despite the non-increase in lipoperoxidation. PDT increased TNF- and IL-10, particularly in the presence of LPS, and decreased the production of IL-6 to 10-fold. PDT causes cellular stress, induces NO radicals and leads to DNA degradation, generating a cytotoxic microenvironment. Furthermore, PDT modulates pro- and anti-inflammatory cytokines in M.


Resumo Pouco se sabe se a morte celular induzida pela terapia fotodinâmica (PDT) compromete os macrófagos (M), envolvidos nas respostas imunes induzidas pela PDT. Neste estudo, foram avaliados parâmetros de citotoxicidade dos M mediada pela PDT e a produção de citocinas, frente à protoporfirina IX (PpIX). M peritoneais de camundongos BALB/c foram estimulados in vitro com PDT, luz, PpIX ou lipopolissacarídeo (LPS). Após isto, a viabilidade celular (VC), a lipoperoxidação, os níveis de óxido nítrico (NO), de DNA degradado, de TNF-, IL-6 e IL-10 foram avaliados. A exposição curta à PDT reduziu a VC em 10-30%. Os níveis de NO e de DNA degradado duplicaram, sem aumento da lipoperoxidação. Houve aumento de TNF- e IL-10, sendo maior na presença de LPS. Já a produção de IL-6 reduziu em dez vezes. A PDT induz estresse celular, gera radicais NO e causa dano ao DNA, tornando o microambiente citotóxico. Ainda, modula citocinas pró e anti-inflamatórias em M.

6.
Braz. j. biol ; Braz. j. biol;2017.
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1467317

RESUMO

Abstract Little is known regarding whether photodynamic therapy (PDT)-induced cell death can substantially compromise macrophages (M), which are important cells in PDT-induced immune responses. Here, parameters of PDT-mediated M cytotoxicity and cytokine production in response to protoporphyrin IX (PpIX) were evaluated. Peritoneal M from BALB/c mice were stimulated in vitro with PDT, light, PpIX, or lipopolysaccharide (LPS). After that, cell viability, lipid peroxidation, Nitric Oxide (NO), DNA damage, TNF-, IL-6 and IL-10 were evaluated. Short PDT exposure reduced cell viability by 1030%. There was a two-fold increase in NO and DNA degradation, despite the non-increase in lipoperoxidation. PDT increased TNF- and IL-10, particularly in the presence of LPS, and decreased the production of IL-6 to 10-fold. PDT causes cellular stress, induces NO radicals and leads to DNA degradation, generating a cytotoxic microenvironment. Furthermore, PDT modulates pro- and anti-inflammatory cytokines in M.


Resumo Pouco se sabe se a morte celular induzida pela terapia fotodinâmica (PDT) compromete os macrófagos (M), envolvidos nas respostas imunes induzidas pela PDT. Neste estudo, foram avaliados parâmetros de citotoxicidade dos M mediada pela PDT e a produção de citocinas, frente à protoporfirina IX (PpIX). M peritoneais de camundongos BALB/c foram estimulados in vitro com PDT, luz, PpIX ou lipopolissacarídeo (LPS). Após isto, a viabilidade celular (VC), a lipoperoxidação, os níveis de óxido nítrico (NO), de DNA degradado, de TNF-, IL-6 e IL-10 foram avaliados. A exposição curta à PDT reduziu a VC em 10-30%. Os níveis de NO e de DNA degradado duplicaram, sem aumento da lipoperoxidação. Houve aumento de TNF- e IL-10, sendo maior na presença de LPS. Já a produção de IL-6 reduziu em dez vezes. A PDT induz estresse celular, gera radicais NO e causa dano ao DNA, tornando o microambiente citotóxico. Ainda, modula citocinas pró e anti-inflamatórias em M.

7.
Rev. bras. plantas med ; Rev. bras. plantas med;17(4,supl.2): 891-899, 2015. tab
Artigo em Inglês | LILACS | ID: lil-771167

RESUMO

ABSTRACT The permanent investigation of new antimycobacterial drugs is necessary for the eradication programs of tuberculosis and other mycobacterium-related diseases. The aim of the present study is to search for new sources of antimycobacterial drugs using plant materials. In this study, 11 plant materials (extracts, essential oils and some fractions) obtained from 4 species of medicinal plants traditionally used as general therapeutics for different illnesses and specifically as treatment of tuberculosis, were evaluated using the microplate resazurin assay against 2 species of the Mycobacterium tuberculosis Complex and 3 nontuberculous mycobacteria. The results showed the hexane extract and the essential oil from fruits of Pterodonemarginatus (Vogel) as potential sources of antimycobacterial drugs against 4 species of tested mycobacteria. The hexane fraction of methanol extract from leaves of Centella asiatica also presented significant mycobacterial growth inhibition, but against M. chelonae only. In conclusion, it was possible to contribute to the antimycobacterial investigations by presenting three new samples of plants with significant antimicrobial activity against four Mycobacteriumspp and suggest future studies about the antimycobacterial properties of fruits from P. emarginatus.


RESUMO A investigação permanente de novas drogas antimicobacterianas é necessária no programa de erradicação da tuberculose e de outras doenças relacionadas com micobactérias. O objetivo deste estudo foi buscar novas fontes de drogas antimicobacterianas usando material vegetal. Neste estudo, 11 materiais de base vegetal (extratos, óleos essenciais e algumas frações) foram avaliados contra 5 espécies de micobactérias. Estes materiais foram obtidos a partir de 4 espécies de plantas medicinais tradicionalmente utilizadas como terapêutica geral para diferentes doenças e, especificamente, no tratamento de tuberculose (Baccharis dracunculifolia, Centella asiatica, Lantana camara, Pterodon emarginatus). Os ensaios foram realizados em microplacas com resazurina contra duas espécies do Complexo Mycobacteriumtuberculosis e 3 espécies de micobactérias não tuberculosas. Os resultados mostraram o extrato hexânico e o óleo essencial de frutos de P.emarginatus como potenciais fontes para drogas antimicobacterianas contra quatro espécies de micobactérias testadas. A fração hexânica do extrato metanólico das folhas de C. asiatica também apresentou significativa inibição do crescimento de micobactérias apenas contra M.chelonae. Em conclusão, foi possível contribuir para as investigações de antimicobacterianos por apresentar três novas amostras de plantas com atividade antimicrobiana significativa contra quatro Mycobacterium spp e sugerir a realização de estudos futuros sobre as propriedades antimicobacterianas de frutos de P. emarginatus.


Assuntos
/classificação , Baccharis/classificação , Lantana/classificação , Anti-Infecciosos/farmacologia , Plantas , Micobactérias não Tuberculosas
8.
Regul Pept ; 165(2-3): 191-9, 2010 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-20691217

RESUMO

This study compared the ability of CRF and UCN1 to induce a thermoregulatory response when centrally injected into rats. The effects of antipyretic drugs and CRF receptor antagonists (CRF1 and CRF2) on the temperature (T) changes induced by these peptides were also investigated. Rectal (rT) and tail skin (T(sk)) temperatures were measured with a thermistor probe while body (bT) temperature was measured with a battery-operated biotelemetry transmitter in male Wistar rats (200 g) every 30 min over a period of 6h, after intracerebroventricular (i.c.v.) injection of 1 nmol of either CRF or UCN1. Rats were pre-treated with indomethacin (2 mg kg⁻¹, i.p.) or celecoxib (5 mg kg⁻¹, p.o.), dexamethasone (0.5 mg kg⁻¹, s.c.), astressin (a CRF1/CRF2 antagonist, 7 nmol, i.c.v.) or antalarmin (a CRF1 antagonist, 20 mg kg⁻¹, i.p.). The increase in body temperature induced by CRF was accompanied by a reduction in T(sk) while the response induced by UCN1 was accompanied by an elevation in T(sk). Indomethacin or celecoxib did not change the increases in rT caused by either CRF or UCN1. Although dexamethasone attenuated the increase in rectal temperature in response to CRF, dexamethasone did not modify the response induced by UCN1. Astressin blocked the UCN1-induced hyperthermia and reduced CRF-induced fever. Antalarmin did not modify the hyperthermia in response to UCN1, but reduced the fever evoked by CRF. This study demonstrated that CRF by acting on the CRF1 receptor induces a prostaglandin-independent fever which seems to depend, at least in part, on the synthesis of other mediators while UCN1 acts on the CRF2 receptor, promoting a hyperthermic response which seems to be independent on synthesis/release of any mediator.


Assuntos
Temperatura Corporal/efeitos dos fármacos , Hormônio Liberador da Corticotropina/farmacologia , Urocortinas/farmacologia , Animais , Antipiréticos/farmacologia , Masculino , Ratos , Ratos Wistar , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores
9.
Clin Exp Immunol ; 154(2): 255-63, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18782329

RESUMO

Splenectomy results in an increased risk of sepsis. The autogenous transplant of the spleen is an option for preserving splenic functions after total splenectomy. In this study, the capacity of animals undergoing autogenous spleen transplantation to respond to Staphylococcus aureus infection was investigated. BALB/c mice were divided into three groups: splenectomy followed by autotransplantation in the retroperitonium (AT), splenectomized only (SP) and operated non-splenectomized sham control (CT). Thirty days after surgery the mice were infected intravenously with S. aureus. Splenectomized mice had a higher number of colony-forming units (CFU) of S. aureus in liver and lungs in comparison with either AT or with CT mice (P < 0.05). Higher CFU numbers in lung of SP mice correlated with elevated production of interleukin-10 associated with a lower production of interferon-gamma and tumour necrosis factor-alpha. However, systemically, the level of tumour necrosis factor-alpha was higher in the SP group than in CT or AT. Lower titres of specific anti-S. aureus immunoglobulin (Ig)M and IgG1 were observed 6 days after infection in SP mice in comparison either with the AT or CT groups. Thus, splenectomy is detrimental to the immune response of BALB/c mice against infection by S. aureus which can be re-established by autogenous implantation of the spleen.


Assuntos
Infecções Oportunistas/prevenção & controle , Baço/transplante , Esplenectomia , Infecções Estafilocócicas/prevenção & controle , Acetilglucosaminidase/metabolismo , Animais , Anticorpos Antibacterianos/sangue , Contagem de Colônia Microbiana , Citocinas/sangue , Feminino , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Fígado/microbiologia , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções Oportunistas/imunologia , Infecções Oportunistas/patologia , Peroxidase/metabolismo , Pneumonia Bacteriana/imunologia , Pneumonia Bacteriana/patologia , Baço/imunologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/patologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/imunologia
10.
Eur Biophys J ; 38(1): 111-9, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18661127

RESUMO

An interferometer that measures the refractive index changes due to bacterial metabolism is described. The apparatus permits simultaneous and real time measurement of bacterial growth in several samples of slowly growing mycobacteria. The error sources are discussed and the sensitivity of the apparatus is tested. For the species Mycobacterium bovis BCG and M. smegmatis, a relation between refractive index change and bacterial concentration is determined experimentally and the time constant of bacterial growth is measured.


Assuntos
Metabolismo Energético/fisiologia , Interferometria/instrumentação , Mycobacterium tuberculosis/isolamento & purificação , Mycobacterium tuberculosis/fisiologia , Refratometria/instrumentação , Calibragem , Proliferação de Células , Desenho de Equipamento , Análise de Falha de Equipamento , Interferometria/normas , Refratometria/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
Eur Biophys J ; 32(2): 159-62, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12679859

RESUMO

It is shown that bacterial activity, even of slowly growing species, can be detected by precise interferometric measurements of refractive index changes of the culture medium. The bacteria-containing sample is kept in an isothermal block together with a reference liquid without bacteria. The biological activity is obtained from the difference of the index changes of these samples. Experiments were performed with Bacilo Calmette-Guérin. The order of magnitude of the observed total refractive index change was compatible with theoretical estimates based on the amount of available oxygen. An unexpected positive index change during the lag phase was observed, which might permit fast diagnostics in medical applications. This technique may provide cheap and quick tests of bacterial susceptibility with respect to antibiotics.


Assuntos
Interferometria/métodos , Testes de Sensibilidade Microbiana/métodos , Mycobacterium bovis/isolamento & purificação , Mycobacterium bovis/metabolismo , Mycobacterium bovis/crescimento & desenvolvimento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA