Pharmacokinetics of Photogem Using Fluorescence Spectroscopy in Dimethylhydrazine-Induced Murine Colorectal Carcinoma

This study aimed to investigate the pharmacokinetics of a hematoporphyrin derivative in colonic tumors induced by dimethylhydrazine and adjacent normal colon in Wistar rats using an in vivo fluorescence spectroscopy technique. In conventional clinical application of photodynamic therapy, the interval between photosensitizer (PS) administration and lesion illumination is often standardized without taking into account variations due to the type or localization of the tumor and intrinsic differences in the microcirculation and vascular permeability of each target organ. The analysis of the fluorescence spectra was based on the intensity of porphyrin emission band centered at around 620 nm in normal colon and colon tumors. The photosensitizer fluorescence intensity rapidly grew for carcinoma and normal colon, reaching the maximum values 1 and 3 hours after PS injection, respectively. Data presented here allow us to verify that the best compromise between selectivity and drug concentration for colon carcinoma in rats took place in the interval between 1 to 4 h after PS injection

AVALIAÇÃO DA ASSOCIAÇÃO DA TERAPIA FOTODINÂMICA COM AZUL DE METILENO AO ÓLEO SAFETEAM® SOBRE CEPAS DE CANDIDA ALBICANS ISOLADAS DE CATETER

As espécies de Candida estão entre as principais causas de infecção da corrente sanguínea, promovendo elevados índices de mortalidade, sendo a Candida albicans a espécie mais frequente em infecções hospitalares. Atualmente, diversos medicamentos antifúngicos são utilizados, porém podem ser tóxicos ao hospedeiro e, com o seu uso excessivo, as leveduras têm adquirido resistência ao tratamento convencional. O objetivo do presente estudo é avaliar os efeitos da associação da Terapia Fotodinâmica (PDT) com Azul de Metileno ao óleo Safeteam® e o seu efeito na inativação sobre cepas de Candida albicans isoladas de cateter. O experimento foi realizado com a irradiação dos grupos, em placa de Kline, utilizando LED (Diodo Emissor de Luz) e densidade de energia de 15 J/cm², sendo, posteriormente, incubadas a 37ºC por 48h, e realizada análise quantitativa para avaliar o percentual de redução de Unidades Formadoras de Colônias (UFCs).  Quando analisado o efeito da associação do óleo Safeteam® à PDT, foi observada uma significativa redução de UFCs, quando comparado ao grupo controle e o grupo utilizando o óleo e a PDT isoladamente, demonstrando ser uma promissora modalidade terapêutica na inativação, in vitro, de cepas de Candida albicans isoladas de cateter

Photodynamic Therapy (PDT) using intratumoral injection of the 5-aminolevulinic acid (5-ALA) for the treatment of eye cancer in cattle - art. no. 64271C

A six-year old Holstein cow with an eye cancer (ocular squamous cell carcinoma) involving the third eyelid and conjunctiva was submitted to photodynamic therapy using intratumoral 20% aminolevulinic acid (5-ALA - Aldrich Chemical Company, Milwaukee, USA) and a light emitting diode (LED - VET LED - MMOptics (R)) with wavelength between 600 and 700 nm, 2 cm diameter circular light beam, power of 150 mW, light dose of 50 J/cm(2) as a source of irradiation. Fifteen days after the experimental procedure we observed about 50% tumor reduction and complete remission after 3 months. Relapse was not observed up to 12 months after the treatment. Although the study only includes one animal not allowing definite conclusions, it indicates that PDT represents a safe and technically feasible approach in the treatment of eye cancer in cattle.Universidade Federal de São Paulo, Operat Tech & Expt Surg Div, Dept Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Operat Tech & Expt Surg Div, Dept Surg, São Paulo, BrazilWeb of Scienc

Pharmacokinetics of Photogem Using Fluorescence Spectroscopy in Dimethylhydrazine-Induced Murine Colorectal Carcinoma

This study aimed to investigate the pharmacokinetics of a hematoporphyrin derivative in colonic tumors induced by dimethylhydrazine and adjacent normal colon in Wistar rats using an in vivo fluorescence spectroscopy technique. in conventional clinical application of photodynamic therapy, the interval between photosensitizer (PS) administration and lesion illumination is often standardized without taking into account variations due to the type or localization of the tumor and intrinsic differences in the microcirculation and vascular permeability of each target organ. the analysis of the fluorescence spectra was based on the intensity of porphyrin emission band centered at around 620nm in normal colon and colon tumors. the photosensitizer fluorescence intensity rapidly grew for carcinoma and normal colon, reaching the maximum values 1 and 3 hours after PS injection, respectively. Data presented here allow us to verify that the best compromise between selectivity and drug concentration for colon carcinoma in rats took place in the interval between 1 to 4 h after PS injection

Analysis of colon tumors in rats by near-infrared Raman spectroscopy - art. no. 642714

Biomedical applications of near-infrared Raman spectroscopy have increased their importance at the last ten years. This technique can determinate the molecular composition of materials, allowing a sensible and fast biological diagnosis. It has showed to be a promising tool for health diagnosis due to its high sensibility. Colorectal cancer (CRC) is one of the most common malignant tumors in humans beings. in the last decades many experimental models have been developed in animals based in the use of chemical composites to induce the formation and development of these tumors, many of them present similar characteristics to those of natural occurrence aiming to the attainment of information on genesis, evolution, as well as diagnosis and more efficient therapies for treating these neoplasias. Amongst the most used chemical composites is the 1,2-dimetilhydrazine (DMH) because its morphological and histological similarity to those tumors. This study aims to compare in vivo normal colon tissue and tumoral colon tissue, induced by DMH, in rats by near-infrared Raman spectroscopy to permit the use in the near future for an efficient diagnosis in real time besides being useful as an auxiliary method for several therapies, including the photodynamic therapy.Universidade Federal de São Paulo, EPM, Expt Surg Dept, São Paulo, BrazilUniversidade Federal de São Paulo, EPM, Expt Surg Dept, São Paulo, BrazilWeb of Scienc

Low-Level Laser Therapy and Calcitonin in Bone Repair: Densitometric Analysis

The aim of this work was to evaluate the association of low-level laser therapy (LLLT, 830 nm) and calcitonin in bone repair considering that bone healing remains a challenge to health professionals. Calcitonin has antiosteoclastic action and LLLT is a treatment that uses low-level lasers or light-emitting diodes to alter cellular function. Both are used to improve bone healing. Densitometry is a clinical noninvasive valuable tool used to evaluate bone mineral density (BMD). Sixty male rats were submitted to bone defect with a trephine bur, randomly divided into four groups of 15 animals each: control (C); synthetic salmon calcitonin (Ca); LLLT (La); LLLT combined with calcitonin (LaCa). Animals from Ca and LaCa received 2UI/Kg synthetic salmon calcitonin intramuscularly on alternate days after surgery. Animals from groups La and LaCa were treated with infrared LLLT (830 nm, 10mW, 20 J/cm(2), 6 s, contact mode). Five animals from each group were euthanized 7, 14, and 21 days after surgery and bone defects were analyzed by densitometry. Statistical analysis showed a significant difference in BMD values in LaCa group at 7 and 21 days (P = 0, 005). The results of the densitometric study showed that LLLT (830 nm) combined with calcitonin improved bone repair

Anti-fibrotic effects of human amniotic membrane transplantation in established biliary fibrosis induced in rats

Liver fibrosis is characterized by excessive accumulation of extracellular matrix components in the liver parenchyma that distorts the normal architecture and hepatic function. Progressive fibrosis could end in the advanced stage know as cirrhosis, resulting in the need to resort to liver transplantation. Amniotic membrane (AM) has emerged as an innovative therapeutic approach for chronic liver diseases for its antiinflammatory, antiscarring, and wound-healing effects. We have recently shown that AM used as a patch onto the liver surface at the same time of fibrosis induction significantly reduces the progression and severity of biliary fibrosis. Here, we have investigated the effects of human AM on the already established liver fibrosis induced in rats by the bile duct ligation (BDL). We also explored the action of AM on the expression of the transforming growth factor (TGF)-\u3b21, the main profibrogenic factor in hepatic fibrosis, and the pro-inflammatory cytokines, tumor necrosis factor (TNF)-\u3b1, interleukin (IL)-6 and anti-inflammatory cytokine, IL-10. After 2 weeks from BDL, the liver was covered with a fragment of AM, or left untreated. Six weeks later, the fibrosis was first assessed by the semiquantitative Knodell and the METAVIR scoring systems and, thereafter, by the CellProfiler digital image analysis to quantify the area occupied by collagen deposition, ductular reaction, activated myofibroblasts, and TGF-\u3b21. The hepatic cytokines were determined by ELISA. AM-treated rats showed a significantly lower score compared to the control BDL rats (2.5 \ub1 0.9 versus 3.5 \ub1 0.3; p<0.05), respectively. The collagen deposition, ductular reaction, number of activated myofibroblasts, and TGF-\uf0621 were all reduced to about 50% of levels observed in untreated BDL rats. These findings suggest that AM, when applied as a patch onto the liver surface is useful for treating well-established cholestatic fibrosis and the mechanism was partly by, means of downregulating the profibrotic factor TGF-\u3b21 and IL-6