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A terapia fotodinâmica com ácido 5-aminolevulínico como modalidade de tratamento para neoplasias cutâneas não-melanoma; Topical 5-aminolevulinic acid photodynamic therapy as a treatment modality for nonmelanoma skin cancer

FELÍCIO, Lília Bernardini Antunes de; FERREIRA, Juliana; BENTLEY, Maria Vitória Badra; BAGNATO, Vanderlei Salvador; TEDESCO, Cláudio Antonio; SOUZA, Cacilda da Silva
Fonte: Sociedade Brasileira de Dermatologia Publicador: Sociedade Brasileira de Dermatologia
Tipo: Artigo de Revista Científica
POR
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FUNDAMENTOS: A terapia fotodinâmica baseia-se na associação de fonte de luz e fotossensibilizador para destruir seletivamente as células. OBJETIVO: Avaliar os efeitos imediatos e tardios, a resposta clínica e os resultados estéticos da terapia fotodinâmica com ácido 5-aminolevulínico em neoplasias cutâneas não-melanoma. MÉTODOS: Trinta e quatro lesões, sendo 19 disceratoses de Bowen e 15 carcinomas basocelulares, foram submetidas à aplicação tópica e oclusiva do ácido 5-aminolevulínico a 20%, por seis horas, e posteriormente a sessão única de laser de diodo (630nm). RESULTADOS: Foram registrados: sensação de queimação durante as sessões; eritema, edema e erosões, nas primeiras 72 horas; cicatrização em média de quatro semanas; resultados estéticos variáveis de excelentes a bons. Aos três meses, a resposta clínica foi de 91,2%, sendo reduzida, aos 18 meses, para 73,3%, de modo similar tanto para disceratose de Bowen (72,2%) quanto para carcinoma basocelular (75%). Foi evidenciada relação de tendência linear entre a redução da freqüência da resposta clínica e o aumento da dimensão das neoplasias cutâneas não-melanoma (p<0,001). CONCLUSÃO: A terapia fotodinâmica com ácido 5-aminolevulínico tópico mostrou destacadas vantagens: minimamente invasiva no tratamento de lesões múltiplas em sessão única ou em sítios de pobre cicatrização com superioridade dos resultados estéticos. O tipo/subtipo(clínico e histopatológico)...

Terapia fotodinâmica em dermatologia: princípios básicos e aplicações; Photodynamic therapy in dermatology: basic principles

TOREZAN, Luís; NIWA, Ane Beatriz Mautari; FESTA NETO, Cyro
Fonte: Sociedade Brasileira de Dermatologia Publicador: Sociedade Brasileira de Dermatologia
Tipo: Artigo de Revista Científica
POR
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A terapia fotodinâmica envolve a administração de uma droga fotossensibilizante e sua ativação subsequente pela luz de comprimento de onda correspondente ao espectro de absorção do fotossensibilizador. Atualmente, a terapia fotodinâmica tópica é aprovada para o tratamento de condições oncológicas cutâneas como queratoses actínicas, doença de Bowen e carcinoma basocelular superficial em diversos países do mundo. Estudos multicêntricos controlados e randomizados demonstram a alta eficácia e resultado cosmético final superior dessa modalidade terapêutica em relação aos tratamentos convencionais. Para condições cutâneas não oncológicas, como acne vulgar, verrugas virais e esclerodermia localizada, há também relatos e série de casos confirmando o potencial terapêutico da terapia fotodinâmica. O desenvolvimento de fotossensibilizantes tópicos, ácido 5-aminolevulínico (ALA) ou seu metiléster (MAL), frente aos derivados da hematoporfirina de aplicação sistêmica, permitiu um grande avanço na popularidade da TFD na dermatologia, uma vez que tanto ALA quanto MAL tópicos não induzem mais fotossensibilidade generalizada prolongada. A produção de intermediários reativos de oxigênio, como oxigênio singlet...

Photodynamic Effects of Curcumin Against Cariogenic Pathogens

Araujo, Natalia Costa; Fontana, Carla Raquel; Bagnato, Vanderlei Salvador; Martinez Gerbi, Marleny Elizabeth
Fonte: MARY ANN LIEBERT INC; NEW ROCHELLE Publicador: MARY ANN LIEBERT INC; NEW ROCHELLE
Tipo: Artigo de Revista Científica
ENG
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Background data: The presence of Streptococcus mutans and Lactobacillus acidophilus in dental structure is an indicator of a cariogenic biofilm. Photodynamic therapy is a technique that involves the activation of photosensitizers by light in the presence of oxygen, resulting in the production of reactive radicals capable of inducing cell death. Reduction of bacteria levels can provide additional means of preventing dental caries. Objective: The present study evaluated the susceptibility of planktonic cultures of S. mutans (ATCC 25175) and L. acidophilus (ATCC-IAL-523) from the Adolfo Lutz Institute (IAL) to photodynamic therapy after sensitization with curcumin and exposure to blue light at 450 nm. Methods: Bacterial suspensions of S. mutans and L. acidophilus isolated (as single species) and combined (multspecies) were prepared and then evaluated. Four different groups were analyzed: L-D- (control group), L-D+ (drug group), L+D- (light group), and L+D+ (photodynamic therapy group). Two different concentrations of curcumin were tested (0.75 and 1.5 g/L) associated with a 5.7 J/cm(2) light emission diode. Results: Significant decreases (p < 0.05) in the viability of S. mutans were only observed when the bacterial suspensions were exposed to both curcumin and light. Then...

Fotoinativação seletiva dos microorganismos: Escherichia coli e staphylococcus aureus; Selective photoinactivation of Escherichia coli and Staphylococcus aureus

Melo, Wanessa de Cássia Martins Antunes de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/03/2014 PT
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O aparecimento de uma grande variedade de microrganismos patogênicos resistentes aos antimicrobianos tem resultado no aumento do índice de doenças e mortalidade provocadas por infecções que eram facilmente tratadas no passado. Muitas vezes essa resistência está relacionada à formação de biofilme pelos microrganismos, que produzem substâncias poliméricas extracelulares (EPS) dificultando a penetração de agentes antimicrobianos. A Terapia Fotodinâmica antimicrobiana (aPDT, do inglês antimicrobial photodynamic therapy) é uma alternativa promissora para combater infecções microbianas, principalmente aquelas em que apresentam biofilmes. Basicamente esse mecanismo envolve a combinação sinérgica de um fotossensibilizador (FS), oxigênio molecular e luz visível de comprimento de onda adequado para produzir espécies reativas de oxigênio (EROs) que causam oxidação dos componentes da célula levando-a à morte. Devido à natureza multifacetada e não-específica das EROs produzidos na aPDT, os microrganismos têm menos chance de desenvolver mecanismos de resistência. Apesar destas vantagens, a aPDT tem enfrentando o problema da hidrofobicidade que FSs como hipericina (Hy) e ftalocianina de zinco (FcZn) apresentam. Esta hidrofobicidade promove a agregação do FS em meio biológico...

Antimicrobial Photodynamic Therapy: Photodynamic Antimicrobial Effects of Malachite Green on Staphylococcus, Enterobacteriaceae, and Candida

Junqueira, Juliana Campos; Ribeiro, M. A.; Rossoni, R. D.; Barbosa, J. O.; Querido, S. M. R.; Jorge, A. O. C.
Fonte: Mary Ann Liebert, Inc. Publicador: Mary Ann Liebert, Inc.
Tipo: Artigo de Revista Científica Formato: S67-S72
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 07/54997-5; Objective: This study investigated in vitro the photodynamic antimicrobial effects of the photosensitizer malachite green on clinical strains of Staphylococcus, Enterobacteriaceae, and Candida. Materials and Methods: Thirty-six microbial strains isolated from the oral cavity of patients undergoing prolonged antibiotic therapy, including 12 Staphylococcus, 12 Enterobacteriaceae, and 12 Candida strains, were studied. The number of cells of each microorganism was standardized to 10(6) cells/mL. Twenty-four assays were carried out for each strain according to the following experimental conditions: gallium-aluminum-arsenide laser and photosensitizer (n = 6, L+P+), laser and physiologic solution (n = 6, L+P-), photosensitizer (n = 6, L-P+), and physiologic solution (n = 6, L-P-). Next, cultures were prepared on brain-heart infusion agar for the growth of Staphylococcus and Enterobacteriaceae, and on Sabouraud dextrose agar for the growth of Candida, and incubated for 48 h at 37 degrees C. The results are reported as the number of colony-forming units (CFU/mL) and were analyzed with analysis of variance and the Tukey test. Results: The Staphylococcus...

Phototoxic effect of curcumin on methicillin-resistant Staphylococcus aureus and L929 fibroblasts

Ribeiro, Ana Paula Dias; Pavarina, Ana Cláudia; Dovigo, Livia Nordi; Brunetti, Iguatemy Lourenço; Bagnato, Vanderlei Salvador; Vergani, Carlos Eduardo; De Souza Costa, Carlos Alberto
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 391-398
ENG
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Photodynamic therapy has been investigated as an alternative method of killing pathogens in response to the multiantibiotic resistance problem. This study evaluated the photodynamic effect of curcumin on methicillin-resistant Staphylococcus aureus (MRSA) compared to susceptible S. aureus (MSSA) and L929 fibroblasts. Suspensions of MSSA and MRSA were treated with different concentrations of curcumin and exposed to light-emitting diode (LED). Serial dilutions were obtained from each sample, and colony counts were quantified. For fibroblasts, the cell viability subsequent to the curcumin-mediated photodynamic therapy was evaluated using the MTT assay and morphological changes were assessed by SEM analysis. Curcumin concentrations ranging from 5.0 to 20.0 μM in combination with any tested LED fluences resulted in photokilling of MSSA. However, only the 20.0 μM concentration in combination with highest fluence resulted in photokilling of MRSA. This combination also promoted an 80% reduction in fibroblast cell metabolism and morphological changes were present, indicating that cell membrane was the main target of this phototherapy. The combination of curcumin with LED light caused photokilling of both S. aureus strains and may represent an alternative treatment for eradicating MRSA...

Potentiation of thermal inactivation of glyceraldehyde-3-phosphate dehydrogenase by photodynamic treatment. A possible model for the synergistic interaction between photodynamic therapy and hyperthermia.

Prinsze, C; Dubbelman, T M; Van Steveninck, J
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/06/1991 EN
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Thermal inactivation of glyceraldehyde-3-phosphate dehydrogenase appeared to be caused by a conformational mechanism, without involvement of covalent reactions. On the other hand, photodynamic inactivation of the enzyme (induced by illumination in the presence of Photofrin II) was caused by photo-oxidation of the essential thiol group in the active centre. A short photodynamic treatment of the enzyme, leading to only a limited inactivation, caused a pronounced potentiation of subsequent thermal inactivation, as measured over the temperature range 40-50 degrees C. Analysis of the experimental results according to the Arrhenius equation revealed that both the activation energy of thermal inactivation and the frequency factor (the proportionality constant) were significantly decreased by the preceding photodynamic treatment. The experimental results indicate a mechanism in which limited photodynamic treatment induced a conformational change of the protein molecule. This conformational change did not contribute to photodynamic enzyme inhibition, but was responsible for the decreased frequency factor and activation energy of subsequent thermal inactivation of the enzyme. The opposing effects of decreased activation energy and decreased frequency factor resulted in potentiation of thermal inactivation of the enzyme over the temperature range 40-50 degrees C. With other proteins...

The sensitivity of normal brain and intracranially implanted VX2 tumour to interstitial photodynamic therapy.

Lilge, L.; Olivo, M. C.; Schatz, S. W.; MaGuire, J. A.; Patterson, M. S.; Wilson, B. C.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em /02/1996 EN
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The applicability and limitations of a photodynamic threshold model, used to describe quantitatively the in vivo response of tissues to photodynamic therapy, are currently being investigated in a variety of normal and malignant tumour tissues. The model states that tissue necrosis occurs when the number of photons absorbed by the photosensitiser per unit tissue volume exceeds a threshold. New Zealand White rabbits were sensitised with porphyrin-based photosensitisers. Normal brain or intracranially implanted VX2 tumours were illuminated via an optical fibre placed into the tissue at craniotomy. The light fluence distribution in the tissue was measured by multiple interstitial optical fibre detectors. The tissue concentration of the photosensitiser was determined post mortem by absorption spectroscopy. The derived photodynamic threshold values for normal brain are significantly lower than for VX2 tumour for all photosensitisers examined. Neuronal damage is evident beyond the zone of frank necrosis. For Photofrin the threshold decreases with time delay between photosensitiser administration and light treatment. No significant difference in threshold is found between Photofrin and haematoporphyrin derivative. The threshold in normal brain (grey matter) is lowest for sensitisation by 5 delta-aminolaevulinic acid. The results confirm the very high sensitivity of normal brain to porphyrin photodynamic therapy and show the importance of in situ light fluence monitoring during photodynamic irradiation.

Aminolaevulinic acid-induced photodynamic therapy: cellular responses to glucose starvation

Wyld, L; Tomlinson, M; Reed, M W R; Brown, N J
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 22/04/2002 EN
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Photodynamic therapy is a cancer treatment based on the interaction of light, oxygen and a photosensitiser. Protoporphyrin. IX is an endogenous photosensitiser derived from the pro-drug aminolaevulinic acid. Tumours contain areas of hypoxia and hypoglycaemia. Tumour cells adapt to these conditions by stress protein induction which may induce resistance to cancer therapies. The effect of chronic hypoglycaemia on sensitivity to aminolaevulinic acid-induced photodynamic therapy in vitro was studied in MCF-7, human breast cancer cells. Following chronic exposure to 0, 1 or 25 mM, glucose, cells were treated with aminolaevulinic acid and the generation of intracellular protoporphyrin. IX measured by spectrofluorimetry. Aminolaevulinic acid-induced photodynamic therapy sensitivity was compared between cells following chronic exposure to 0, 1 or 25 mM glucose. Percentage cell survival was determined by clonogenic assay. Cells cultured in low glucose generated higher levels of protoporphyrin IX compared to standard glucose medium (0 mM glucose: 0.88×10−5 ng cell−1, 1 mM: 0.86×10−5 ng cell−1, 25 mM: 0.605×10−5 ng cell−1, P<0.05). However, photodynamic therapy sensitivity was reduced in glucose deprived cells (0 mM glucose: 61% survival...

Photodynamic Therapy with ATX-S10·Na(II) Inhibits Synovial Sarcoma Cell Growth

Takeda, Ken; Kunisada, Toshiyuki; Miyazawa, Shinichi; Nakae, Yoshinori; Ozaki, Toshifumi
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
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Photodynamic therapy (PDT) is an effective cancer treatment modality that allows selective destruction of malignant tumor cells. We asked whether PDT could inhibit in vivo and in vitro growth of synovial sarcoma cells. We analyzed PDT using ATX-S10·Na(II) and a diode laser for a synovial sarcoma cell line (SYO-1). Photodynamic therapy with ATX-S10·Na(II) showed an in vitro cytotoxic effect on the cultured SYO-1 cells. The in vitro effect of PDT depended on the treatment concentration of ATX-S10·Na(II) and the laser dose of irradiation. ATX-S10·Na(II) was detected in the tumor tissue specimens that were excised from nude mice bearing SYO-1 within 6 hours after intravenous injection, but it was eliminated from the tumor 12 hours after injection. Photodynamic therapy suppressed the tumor growth of nude mice bearing SYO-1, and high-dose irradiation induced no viable tumor cells in histologic specimens. Photodynamic therapy performed after marginal resection of the tumor of nude mice bearing SYO-1 reduced the rate of local recurrence of the tumor. Our results suggest PDT using ATX-S10·Na(II) and laser irradiation may be a potentially useful treatment for synovial sarcoma, especially to reduce the surgical margin and preserve critical anatomic structures adjacent to the tumor.

Treatment of Canine Osseous Tumors with Photodynamic Therapy: A Pilot Study

Burch, S.; London, C.; Seguin, B.; Rodriguez, C.; Wilson, B. C.; Bisland, S. K.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
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Photodynamic therapy uses nonthermal coherent light delivered via fiber optic cable to locally activate a photosensitive chemotherapeutic agent that ablates tumor tissue. Owing to the limitations of light penetration, it is unknown whether photodynamic therapy can treat large osseous tumors. We determined whether photodynamic therapy can induce necrosis in large osseous tumors, and if so, to quantify the volume of treated tissue. In a pilot study we treated seven dogs with spontaneous osteosarcomas of the distal radius. Tumors were imaged with MRI before and 48 hours after treatment, and the volumes of hypointense regions were compared. The treated limbs were amputated immediately after imaging at 48 hours and sectioned corresponding to the MR axial images. We identified tumor necrosis histologically; the regions of necrosis corresponded anatomically to hypointense tissue on MRI. The mean volume of necrotic tissue seen on MRI after photodynamic therapy was 21,305 mm3 compared with a pretreatment volume of 6108 mm3. These pilot data suggest photodynamic therapy penetrates relatively large canine osseous tumors and may be a useful adjunct for treatment of bone tumors.

Basal cell carcinoma treated successfully with combined CO2 laser and photodynamic therapy in a renal transplant patient: a case report

Shokrollahi, Kayvan; Marsden, Nicholas J; Whitaker, Iain S; James, William; Murison, Maxwell SC
Fonte: Cases Network Ltd Publicador: Cases Network Ltd
Tipo: Artigo de Revista Científica
Publicado em 11/08/2009 EN
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Renal transplant recipients are at significantly greater risk of developing skin malignancies due to combination immunosuppressive therapy. A significant number of patients present with lesions needing excision at multiple outpatient follow-up visits. For basal cell carcinoma, we have recently described how combining CO2 laser with Photodynamic therapy greatly increases the efficacy of long-term tumour clearance compared with each modality alone. We present a case of a 66-year-old renal transplant therapy patient who repeatedly presents with new skin malignancies, in whom we treated successfully with Laser-Photodynamic therapy in a see-and-treat setting. This therapy offers patients the possibility of better cosmetic and functional results whilst obviating the need for repeated surgery. Other pre-cancerous lesions such as solar keratoses are prevalent in this patient group and respond extremely well to Photodynamic therapy monotherapy. We propose a regular clinic for renal transplant patients in a laser facility equipped with CO2 laser and Photodynamic therapy, histopathology and punch-biopsy materials. This strategy allows simple and effective treatment of multiple lesions simultaneously, avoidance of numerous operations, avoidance of non-essential outpatient appointments that result in booking furthers visits for treatment...

Therapeutic and Aesthetic Uses of Photodynamic Therapy Part three of a five-part series: Chemoprevention Utilizing ALA–PDT

Gold, Michael H.
Fonte: Matrix Medical Communications Publicador: Matrix Medical Communications
Tipo: Artigo de Revista Científica
Publicado em /11/2008 EN
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The use of aminolevulinic acid photodynamic therapy and methyl ester of aminolevulinic acid photodynamic therapy has become commonplace in dermatology for the treatment of actinic keratoses, among other clinical entities. An intriguing question that has arisen is whether we can utilize these medicines for a chemopreventive effect; that is, preventing or delaying the onset of actinic keratoses and perhaps nonmelanoma skin cancers. This manuscript reviews the current literature and anecdotal evidence that suggests that aminolevulinic acid photodynamic therapy and methyl ester of aminolevulinic acid photodynamic therapy may indeed be chemopreventive and thus useful in preventing and/or delaying these lesions.

Synergistic Anti-Tumor Effects of Combination of Photodynamic Therapy and Arsenic Compound in Cervical Cancer Cells: In Vivo and In Vitro Studies

Kim, Yong-Wan; Bae, Su Mi; Battogtokh, Gantumur; Bang, Hyo Joo; Ahn, Woong Shick
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 08/06/2012 EN
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The effects of As4O6 as adjuvant on photodynamic therapy (PDT) were studied. As4O6 is considered to have anticancer activity via several biological actions, such as free radical production and inhibition of VEGF expression. PDT or As4O6 significantly inhibited TC-1 cell proliferation in a dose-dependent manner (P<0.05) by MTT assay. The anti-proliferative effect of the combination treatment was significantly higher than in TC-1 cells treated with either photodynamic therapy or As4O6 alone (62.4 and 52.5% decrease compared to vehicle-only treated TC-1 cells, respectively, P<0.05). In addition, cell proliferation in combination of photodynamic therapy and As4O6 treatment significantly decreased by 77.4% (P<0.05). Cell survival pathway (Naip1, Tert and Aip1) and p53-dependent pathway (Bax, p21Cip1, Fas, Gadd45, IGFBP-3 and Mdm-2) were markedly increased by combination treatment of photodynamic therapy and As4O6. In addition, the immune response in the NEAT pathway (Ly-12, CD178 and IL-2) was also modulated after combination treatment, suggesting improved antitumor effects by controlling unwanted growth-stimulatory pathways. The combination effect apparently reflected concordance with in vitro data, in restricting tumor growth in vivo and in relation to some common signaling pathways to those observed in vitro. These findings suggest the benefit of combinatory treatment with photodynamic therapy and As4O6 for inhibition of cervical cancer cell growth.

A case of presumed choroidal metastasis from carcinoid tumor treated by photodynamic therapy with verteporfin

Kawakami, Setsuko; Wakabayashi, Yoshihiro; Goto, Hiroshi
Fonte: Dove Medical Press Publicador: Dove Medical Press
Tipo: Artigo de Revista Científica
EN
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We report a case of metastatic choroidal carcinoid tumor with favorable outcome after photodynamic therapy. A 75-year-old woman was presumptively diagnosed with bilateral choroidal metastases from carcinoid tumor. Although the tumor in the right eye showed a tendency toward rapid expansion and required aggressive treatment to preserve vision, the size was still small and we hesitated to use external-beam radiotherapy because of the risk of radiation retinopathy. Consequently, photodynamic therapy was performed on the right eye, resulting in drastic reduction of the size and height of the choroidal tumor. Good visual acuity was maintained after photodynamic therapy. Photodynamic therapy may be an effective treatment for choroidal metastasis from carcinoid tumor.

Photodynamic Therapy with Hypericin Improved by Targeting HSP90 Associated Proteins

Solár, Peter; Chytilová, Mária; Solárová, Zuzana; Mojžiš, Ján; Ferenc, Peter; Fedoročko, Peter
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 10/11/2011 EN
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In this study we have focused on the response of SKBR-3 cells to both single 17-DMAG treatment as well as its combination with photodynamic therapy with hypericin. Low concentrations of 17-DMAG without any effect on survival of SKBR-3 cells significantly reduced metabolic activity, viability and cell number when combined with photodynamic therapy with hypericin. Moreover, IC10 concentation of 17-DMAG resulted in significant increase of SKBR-3 cells in G1 phase of the cell cycle, followed by an increase of cells in G2 phase when combined with photodynamic therapy. Furthermore, 17-DMAG already decreased HER2, Akt, P-Erk1/2 and survivin protein levels in SKBR-3 cells a short time after its application. In this regard, 17-DMAG protected also SKBR-3 cells against both P-Erk1/2 as well as survivin upregulations induced by photodynamic therapy with hypericin. Interestingly, IC10 concentration of 17-DMAG led to total depletion of Akt, P-Erk1/2 proteins and to decrease of survivin level at 48 h. On the other hand, 17-DMAG did not change HER2 relative expression in SKBR-3 cells, but caused a significant decrease of HER2 mRNA in MCF-7 cells characterized by low HER2 expression. These results show that targeting HSP90 client proteins increases the efficiency of antineoplastic effect of photodynamic therapy in vitro.

Stability enhanced polyelectrolyte-coated gold nanorod-photosensitizer complexes for high/low power density photodynamic therapy

Shi, Zhenzhi; Ren, Wenzhi; Gong, An; Zhao, Xinmei; Zou, Yuehong; Brown, Eric Michael Bratsolias; Chen, Xiaoyuan; Wu, Aiguo
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
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Photodynamic therapy (PDT) is a promising treatment modality for cancer and other malignant diseases, however safety and efficacy improvements are required before it reaches its full potential and wider clinical use. Herein, we investigated a highly efficient and safe photodynamic therapy procedure by developing a high/low power density photodynamic therapy mode (high/low PDT mode) using methoxypoly(ethylene glycol) thiol (mPEG-SH) modified gold nanorod (GNR)-AlPcS4 photosensitizer complexes. mPEG-SH conjugated to the surface of simple polyelectrolyte-coated GNRs was verified using Fourier transform infrared spectroscopy; this improved stability, reduced cytotoxicity, and increased the encapsulation and loading efficiency of the nanoparticle dispersions. The GNR-photosensitizer complexes were exposed to the high/low PDT mode (high light dose = 80 mW/cm2 for 0.5 min; low light dose = 25 mW/cm2 for 1.5 min), and a high PDT efficacy leads to approximately 90% tumor cell killing. Due to synergistic plasmonic photothermal properties of the complexes, the high/low PDT mode demonstrated improved efficacy over using single wavelength continuous laser irradiation. Additionally, no significant loss in viability was observed in cells exposed to free AlPcS4 photosensitizer under the same irradiation conditions. Consequently...

Comparative study between photodynamic and antibiotic therapies for treatment of footpad dermatitis (bumblefoot) in Magellanic penguins (Spheniscus magellanicus)

Nascimento, Cristiane Lassalvia; Ribeiro, Martha Simoes; Sellera, Fabio Parra; Pereira Dutra, Gustavo Henrique; Simoes, Alyne; Teixeira, Carlos Roberto
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 36-44
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Processo FAPESP: 2012/18935-3; Background: Bumblefoot, referring to bed-sore-like foot lesions, is one of the most important clinical complications in captive birds and has a multifactorial etiology. Photodynamic therapy has been proposed as an alternative treatment for localized infections in response to the escalating problem of antibiotic resistance. The aim of this study was to compare outcomes in a group of captive Spheniscus magellanicus with bumblefoot lesions treated with photodynamic therapy (PDT) or antibiotics (ATB).Methods: Ten captive Magellanic penguins with preexisting stage III bumblefoot lesions were selected and randomly divided into one PDT and one ATB group, each including 11 pelvic-limb lesions. All animals underwent surgical debridement of lesions. In the ATB group, antibiotic ointment was applied topically three times a week, and systemic antibiotic and anti-inflammatory drugs were administered daily. In the PDT group, photodynamic therapy was applied three times a week without the use of topical or systemic medication. Lesion areas were photographed, and swabs were collected for culture and sensitivity, on the first day and every 14 days for a total of 84 days. The four species of bacteria showing the most resistance to the antibiotics screened on. the antibiogram were used to determine resistance to PDT with an in vitro test.Results: There were significant differences in healing rate and average healing time between the PDT and ATB groups (63.62% vs. 9.09% and 42 vs. 70 days...

Own Experience in Treatment of Patients with Penile Cancer Using Photodynamic Therapy

Filonenko, Elena; Kaprin, Andrey; Alekseev, Boris; Urlova, Antonina
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
EN
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Penile cancer is a rare pathology. For penile cancer surgical treatment, radiotherapy, chemotherapy, and combined modality treatment are available. Because of great importance of this organ for mental condition of patient, the development of organ-preserving methods allowing to minimize impact on patient's quality of life without compromising of oncological results is desirable. In the Center of Laser and Photodynamic diagnosis and treatment of tumors in P.A. Herzen Moscow Cancer Research Institute the methods of photodynamic therapy in patients with penile cancer have been developed. From 2011 to 2013 the treatment was conducted in 11 patients with precancer and cancer of penile. The average age was 56.6. According to morphological diagnosis photodynamic therapy (PDT) was performed using two methods. One method included topical application of agent for PDT and the second intravenous administration of photosensitizer. For topical application alasens was used and for intravenous injection we applied radachlorine. All patients had no complications. Complete regression was achieved in 9 patients, and partial regression in 2. Thus, the results showed that photodynamic therapy for penile cancer stage Tis-1N0M0 permits performing organ-preserving treatment with satisfactory oncological results and no impairment of patient's quality of life.

Metabolismo del hemo y neoplasias; Haem metabolism and malignancies

Casas, Adriana Gabriela
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //1996 SPA
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48.07911%
La Terapia Fotodinámica del cáncer (TFD) es un tratamiento que se basa en la acumulación selectiva de un fotosensibilizante en las células tumorales. Este, luego de ser excitado por acción de la luz roja, desencadena una serie de reacciones mediadas por radicales libres, que finalmente destruyen el tejido. El empleo del ácido 5-aminolevúlico (ALA) como precursor de la síntesis de porfirinas, ha cobrado especial interés en los últimos años tanto en la TFD usando las porfirinas como fotosensibilizantes, como en la fotodetección de tumores, empleando la propiedad de estos pigmentos de fluorescer con la luz UV. Por otra parte, se ha observado que algunos tejidos neoplásicos acumulan porfirinas, por lo cual se ha postulado que el camino biosintético de los tetrapirroles se encuentra alterado en los pacientes con neoplasias. En el presente trabajo se caracterizaron las actividades de algunas de las enzimas del camino biosintético del hemo en un adenocarcinoma mamario de ratón y en el hígado de los animales portadores de dicha neoplasia. Se estudió la biosíntesis de porfirinas in vitro a partir de ALA en tumor y otros tejidos, empleando para ello la técnica de explantes tisulares, y se encontró que la acumulación de porfirinas se hace más selectiva para el tumor cuando el precursor se administra encapsulado en liposomas o cuando se agrega cinc en el medio de incubación. Se desarrolló un modelo in vitro-in vivo para estudiar la efectividad de la acción fotodinámica de las porfirinas sintetizadas endógenamente a partir de ALA...