Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this study, the effectiveness and mechanism of combination therapy of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) with simultaneous hyperthermia (HT) on human-derived osteosarcoma in vivo were examined. A tumor model was prepared by subcutaneously implanting human osteosarcoma into nude mice and local injection of ALA was selected as the administration route. This study demonstrated that both ALA-PDT and the combination of ALA-PDT with HT exhibited significant inhibitory effects on tumor growth. In the group with high total energy, the growth inhibition rates of tumor were 52.3% in ALA-PDT, and 27.3% in ALA-PDT with simultaneous HT (PDT+HT), and the synergetic index was 1.76, demonstrating that the inhibitory effect on tumor growth in ALA-PDT was significantly increased by simultaneous use of HT. In the histological findings, after ALA-PDT, necrosis was observed in the area from the surface to a depth of 2 mm, and only a slight effect was confirmed in deeper layers. On the other hand, after PDT+HT, necrosis was observed in layers even deeper than 2 mm below the surface. Furthermore, based on the immunohistochemical findings of the expression of carbonic anhydrase IX, while weak expression of CAIX was observed after ALA-PDT in an area relatively close to the surface, a positive area extended to the deeper layers after PDT+HT compared with ALA-PDT. In conclusion, PDT+HT demonstrated a significant inhibitory effect on tumor growth of human-derived osteosarcoma, and a synergistic interaction of simultaneous HT. This suggests the possibility that ALA-PDT is useful, not only for the treatment of superficial tumors but also for deep-seated mesenchymal tumors, such as osteosarcoma. Furthermore, the mechanism of the synergistic interaction suggested that ALA-PDT was effective in the deep area of tumors due to the increase of blood flow by mild hyperthermia.
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PMID:Synergistic interaction of 5-aminolevulinic acid-based photodynamic therapy with simultaneous hyperthermia in an osteosarcoma tumor model. 1682 Aug 78

5-Aminolevulinic acid (ALA) or its derivative methyl 5-aminolevulinate (MAL) combined with folic acid was applied in nude mice bearing human colon adenocarcinoma. The aim of the study is to see whether folic acid may increase biosynthesis of porphyrins in tumor tissue after systemic or topical administration of ALA or MAL. The production of porphyrins was determined by spectrofluorometric measurements with an optical fibre probe. It was found that the porphyrin production after i.p injection of 200 mg kg(-1) ALA or MAL was significantly increased by i.p injection of 100 mg kg(-1) folic acid. However, in the case of topically applied 20% ALA, folic acid had no effect. In the case of topically applied 20% MAL, folic acid (i.p or topically applied) reduced the porphyrin synthesis. This might be used for the protection of normal skin against photosensitization. The effects of folic acid were similar in tumors and normal skin. Two mechanisms may explain the results: enhancement of the efficiency of the rate-limiting enzyme porphobilinogen deaminase by folic acid or interference of folic acid with the transport of ALA and MAL to and into the cells synthesizing porphyrins in the tissues. The present data seem to favour the latter mechanism. Folic acid may have a role as an adjuvant in photodynamic therapy with systemically administered ALA and its derivatives.
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PMID:The effect of folic acid on porphyrin synthesis in tumors and normal skin of mice treated with 5-aminolevulinic acid or methyl 5-aminolevulinate. 1688 91

Tumors synthesize fluorescent and photosensitizing endogenous protoporphyrin after administrations of 5-aminolevulinic acid (5-ALA). Localization of tumors and tumor-like lesions in various organs that are labeled with fluorescing porphyrins has thus developed into a diagnostic method. Intraoperative photodynamic detection of malignant gliomas is the most common application, and has been widely performed since 1998. Although several methods to identify parathyroid glands have been employed, photodynamic methods have not yet been used for this application. In 2004, Shimizu et al. showed that human parathyroid glands could be identified photodynamically with 5-ALA. We have performed photodynamic identification of human parathyroid glands in an additional 19 cases. In hyperparathyroidism, detection of morbid parathyroid glands is extremely important. On the other hand, the identification and preservation of normal parathyroid glands is important for preventing hypoparathyroidism after thyroid surgery. Our method allows the visualization of both morbid and normal parathyroid glands. We believe that intraoperative photodynamic identification of human parathyroid glands is feasible and practical, allowing less-invasive, more-precise neck surgery.
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PMID:Photodynamic identification of human parathyroid glands with 5-aminolevulinic acid. 1710 74

The fluorescence of protoporphyrin IX (PpIX) induced endogenously by 5-aminolevulinic acid (5-ALA) administration has recently been used for the intraoperative visualization of glioma tissues. To increase the sensitivity of photodetection, the emission spectra of 5-ALA-induced PpIX fluorescence was quantitatively measured in tissues taken from six cases of en bloc resected diffusely infiltrating astrocytomas (2 diffuse astrocytomas, 2 anaplastic astrocytomas, and 2 glioblastomas), and the correlation assessed between the fluorescence intensity and histological features. A total of 65 slices were analyzed by ex vivo spectroscopy. The ratio of the peak emission intensity to reflected excitation intensity or fluorescence intensity ratio was less than 0.001 for all 36 non-tumor tissues. The tissues with glioblastoma morphology had a fluorescence intensity ratio in excess of 0.090. The spectroscopic fluorescence intensity was positively correlated with the MIB-1 labeling index as an indicator of proliferation activity, the CD31-microvessel density as a pan-endothelial marker, and the vascular endothelial growth factor expression as an angiogenetic factor. The MIB-1 proliferation index was the most powerful determinant, suggesting that higher cell proliferation may govern preferential PpIX accumulation in glioma cells. This preliminary study suggests that spectroscopic analysis may be useful for optimizing the removal of diffuse gliomas.
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PMID:Quantitative spectroscopic analysis of 5-aminolevulinic acid-induced protoporphyrin IX fluorescence intensity in diffusely infiltrating astrocytomas. 1731 41

We developed a combined system of tumor detection by 5-ALA-induced PpIX fluorescence and precise ablation by micro laser for the first time, with an automatic focusing and robotic scanning mechanism for the brain surface. 5-ALA accumulates on tumors to be metabolized to become PpIX that is a fluorescent. Intra-operative detection of 5-ALA induced PpIX fluorescence provides useful information for tumor detection. The wavelength of the micro laser is 2.8 microm close to the absorption band of water. This laser is effective only on the surface of brain tissue, enabling precise ablation at the boundary between tumor and normal tissue identified by intra-operative 5-ALA induced fluorescence. Combination tests of the fluorescence measurement and the laser ablation were performed, and it was possible to extract the area with fluorescence appropriately from the measurement data, and the micro laser with automatically scanning selectively ablated the extracted area.
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PMID:A novel robotic laser ablation system for precision neurosurgery with intraoperative 5-ALA-induced PpIX fluorescence detection. 1735 33

Several neurosurgical studies have provided descriptions of the utility of fluorescence-guided tumor resection using a microscope. However, fluorescence-guided endoscopic detection of a deep-seated brain tumor has not yet been reported. The authors report their experience with an endoscopic biopsy procedure for a malignant glioma within the third ventricle using a 5-aminolevulinic acid (5-ALA)-induced protoporphyrin IX fluorescence imaging system. A 5-ALA-induced fluorescence image of an intraventricular tumor is barely visible with the typical fluorescence endoscopic system used in other clinical fields because the intensity of excitation light at wavelengths of 390 to 405 nm through a cut-off filter is too weak to delineate a brain tumor. The technique described in this study made use of a laser illumination system with a high-powered output that delivered a violet-blue light at wavelengths of 405 nm. In addition, a common ultraviolet cutoff filter was fitted between the endoscope and the high-sensitivity camera to block the backscattered excitation light. A 5-ALA-induced fluorescence endoscopy performed using this system allowed the intraventricular tumor to be clearly visualized as a red fluorescent lesion. Several biopsy specimens obtained from the fluorescent lesion provided a definitive histological diagnosis. The results indicate that this endoscopic system is useful in detecting an intraventricular fluorescent tumor.
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PMID:Endoscopic identification and biopsy sampling of an intraventricular malignant glioma using a 5-aminolevulinic acid-induced protoporphyrin IX fluorescence imaging system. Technical note. 1736 78

Intraoperative 5-aminolevulinic acid (5-ALA)-induced fluorescence guidance for resection of malignant brain tumors was correlated with histological examination to investigate false positive findings in 42 patients with malignant glioma and six patients with metastatic brain tumor. Patients received a single 1 g oral dose of 5-ALA 2 hours before surgery. The tumor site was illuminated with a laser with a peak wavelength of 405 +/- 1 nm and output of 40 mW. Samples with strong fluorescence were obtained from the tumor bulk and samples with weak fluorescence from the tumor cavity. Fluorescence was observed in 36 of the 42 malignant gliomas and four of the six metastatic brain tumors. No tumor cells were found in fluorescent samples from six of the 36 malignant gliomas and all four metastatic brain tumors. Five of the six malignant gliomas were recurrent cases. Fluorescence was found in areas of peritumoral edema or inflammatory cell and reactive astrocyte infiltration. Intraoperative 5-ALA-induced fluorescence guidance is useful for the resection of initial malignant glioma since false positive results are rare, but only non-eloquent weak positive areas should be resected. In contrast, all weak positive areas of recurrent malignant gliomas must be resected. Weak positive areas of the peritumoral edema surrounding metastatic brain tumors should be removed carefully as false positive results are common.
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PMID:Histological examination of false positive tissue resection using 5-aminolevulinic acid-induced fluorescence guidance. 1752 47

It has been established that fluorescence-guided resection using 5-aminolevulinic acid (5-ALA) is useful in glioma surgery. The authors report on a 65-year-old woman who had a huge atypical left-hemisphere meningioma, which extended into the skull and to the superior sagittal sinus and demonstrated fluorescence in response to administration of 5-ALA. After the tumor was removed, the operative field was observed under the fluorescent mode of a fluorescence surgical microscopy system. Several minute areas of residual tumor tissue were visualized as strong fluorescence behind the vein and sinus, in a part of the hypertrophic dura, and along the edge of the skull. These remnants were completely removed. The authors concluded that fluorescence-guided resection using 5-ALA is useful in cases of atypical meningiomas with a high risk of recurrence.
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PMID:Use of 5-aminolevulinic acid in fluorescence-guided resection of meningioma with high risk of recurrence. Case report. 1756 81

Long chain omega 3 (n-3) fatty acids, eicosapentaenoic (EPA) and/or docosahexaenoic acid (DHA), have been shown to suppress growth of most cancer cells. In vivo, alpha linolenic acid (ALA, 18:3n-3) can be converted to EPA or DHA. We hypothesized that substituting canola oil (10% ALA) for the corn oil (1% ALA) in the diet of cancer bearing mice would slow tumor growth by increasing n-3 fatty acids in the diet. Sixty nude mice received MDA-MB 231 human breast cancer cells and were fed a diet containing 8% w/w corn oil until the mean tumor volume was 60 mm3. The dietary fat of half of the tumor bearing mice was then changed to 8% w/w canola oil. Compared to mice that consumed the corn oil containing diet, the mice that consumed the canola oil containing diet had significantly more EPA and DHA in both tumors and livers, and the mean tumor growth rate and cell proliferation in the tumor were significantly slower (P<0.05). About 25 days after diet change, mice that consumed the corn oil diet stopped gaining weight, whereas the mice that consumed the canola oil diet continued normal weight gain. Use of canola oil instead of corn oil in the diet may be a reasonable means to increase consumption of n-3 fatty acids with potential significance for slowing growth of residual cancer cells in cancer survivors.
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PMID:Dietary canola oil suppressed growth of implanted MDA-MB 231 human breast tumors in nude mice. 1757 51

Aminolevulinic acid photodynamic therapy (ALA-PDT) is a cancer therapy that combines the selective accumulation of a photosensitizer in tumor tissue with visible light (and tissue oxygen) to produce reactive oxygen species. This results in cellular damage and ablation of tumor tissue. The use of iron chelators in combination with ALA has the potential to increase the accumulation of the photosensitizer protoporphyrin IX (PpIX) by reducing its bioconversion to heme. This study compares directly for the first time the effects of the novel hydroxypyridinone iron chelating agent CP94 and the more clinically established iron chelator desferrioxamine (DFO) on the enhancement of ALA and methyl-aminolevulinate (MAL)-induced PpIX accumulations in cultured human cells. Cultured human cells were incubated with a combination of ALA, MAL, CP94 and DFO concentrations; the resulting PpIX accumulations being quantified fluorometrically. The use of iron chelators in combination with ALA or MAL was shown to significantly increase the amount of PpIX accumulating in the fetal lung fibroblasts and epidermal carcinoma cells; while minimal enhancement was observed in the normal skin cells investigated (fibroblasts and keratinocytes). Where enhancement was observed CP94 was shown to be significantly superior to DFO in the enhancement of PpIX accumulation.
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PMID:Direct comparison of delta-aminolevulinic acid and methyl-aminolevulinate-derived protoporphyrin IX accumulations potentiated by desferrioxamine or the novel hydroxypyridinone iron chelator CP94 in cultured human cells. 1757 85


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