Topic
Protoporphyrin IX
About: Protoporphyrin IX is a research topic. Over the lifetime, 2250 publications have been published within this topic receiving 65544 citations. The topic is also known as: PpIX.
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TL;DR: Structural perturbations at the peroxid enzyme site (MnPGHS-1) or at the cyclooxygenase site (inhibitor-treated PGHS- 1) thus can influence markedly the kinetics and the chemistry of PG HS-1 peroxIDase inactivation.
32 citations
TL;DR: Evidence of the damage effects of sonodynamic therapy (SDT) on a novel intracellular target, cytoskeletal F-actin, and the observed effect on F- actin and the subsequent bleb formation mainly due to apoptosis formation due to the treatment were reported.
32 citations
TL;DR: It is suggested that the intensity of tumor surface fluorescence correlates with the tumor PP concentration and fluorescence measurements in situ are best adapted to the measurement of changes in the porphyrin levels in tissues rather than the absolute concentrations.
Abstract: It is important to have a frame of reference for the timing of photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA) so that PDT can occur when the tissue levels of protoporphyrin IX (PP) are at a maximum. This study describes a non-invasive fluorescence technique for detecting tissue PP levels after systemic ALA administration in patients with gastrointestinal cancer. The data suggest that the intensity of tumor surface fluorescence correlates with the tumor PP concentration. Spectrophotofluorometric measurements of skin and buccal mucosa also offer an easily acquired and rapid means for determining changes in plasma concentrations of PP. A number of potential variables, including blood flow, affect the intensity of fluorescence. We report that fluorescence measurements in situ are best adapted to the measurement of changes in the porphyrin levels in tissues rather than the absolute concentrations.
32 citations
TL;DR: It is suggested that endo- and ex-PpIX in S180 cells differ not only in pharmacokinetics but also in sub-cellular localizations, which may affect their sonodynamic efficacy and mechanisms of inducing cell death.
31 citations
TL;DR: Results suggested that multi‑dose ionizing irradiation with 5‑ALA induced not only a direct cytotoxic effect but also enhanced the host antitumor immune response and thus caused high inhibition of tumor growth in experimental glioma.
Abstract: Ionizing irradiation is a well‑established therapeutic modality for malignant gliomas. Due to its high cellular uptake, 5‑aminolevulinic acid (ALA) is used for fluorescence‑guided resection of malignant gliomas. We have previously shown that 5‑ALA sensitizes glioma cells to irradiation in vitro. The aim of the present study was to assess whether 5‑ALA acts as a radiosensitizer in experimental glioma in vivo. Rats were subcutaneously injected with 9L gliosarcoma cells and administered 5‑ALA. The accumulation of 5‑ALA‑induced protoporphyrin IX was confirmed by high‑performance liquid chromatography (HPLC) analysis. Subcutaneous (s.c.) tumors were subsequently irradiated with 2 Gy/day for five consecutive days. In the experimental glioma model, high‑performance liquid chromatography analysis revealed a high level of accumulation of 5‑ALA‑induced protoporphyrin IX in s.c. tumors 3 h after 5‑ALA administration. Multi‑dose ionizing irradiation induced greater inhibition of tumor growth in rats that were administered 5‑ALA than in the non‑5‑ALA‑treated animals. Immunohistochemical analysis of the s.c. tumors revealed that numerous ionized calcium‑binding adapter molecule 1 (Iba1)‑positive macrophages gathered at the surface of and within the s.c. tumors following multi‑dose ionizing irradiation in combination with 5‑ALA administration. By contrast, the s.c. tumors in the control group scarcely showed aggregation of Iba1‑positive macrophages. These results suggested that multi‑dose ionizing irradiation with 5‑ALA induced not only a direct cytotoxic effect but also enhanced the host antitumor immune response and thus caused high inhibition of tumor growth in experimental glioma.
31 citations