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.
Papers published on a yearly basis
Papers
More filters
30 citations
TL;DR: Rapid, sensitive and specific high-performance liquid chromatographic assays are described for protoporphyrinogen oxidase and ferrochelatase in human leucocytes in humans with variegate porphyria.
30 citations
TL;DR: A dominant modifier gene, Orom, which allows oro seedlings to bypass their lesion, and several mutants of maize defective in chlorophyll synthesis are analysed.
Abstract: Several mutants of maize defective in chlorophyll synthesis are analysed. By feeding shoots of dark-grown seedlings δ-aminolevulinic acid, the regulatory step in chlorophyll biosynthesis is bypassed and chlorophyll precursors accumulate. In normal plants this results in a buildup of protoporphyrin IX and protochlorophyllide, while mutants accumulate precursors, depending on the site of the mutant-induced lesion. Mutants at three loci, l*-Blandy4, 113, and oy, are defective in conversion of protoporphyrin IX to Mg-protoporphyrin. Mutants at the oro and oro2 loci are defective in conversion of Mg-protoporphyrin monomethyl ester to protochlorophyllide. A dominant modifier gene, Orom, which allows oro seedlings to bypass their lesion is also described.
30 citations
TL;DR: In human in Situ brain tumor tissue, fluorescence after 5-ALA administration is determined to be maximal later than previously thought, with timing adjusted to internal logistical circumstances and factors related to approaching the tumor.
Abstract: Background Five-aminolevulinic acid (5-ALA) is well established for fluorescence-guided resections of malignant gliomas by eliciting the accumulation of fluorescent protoporphyrin IX (PpIX) in tumors. Because of the assumed time point of peak fluorescence, 5-ALA is recommended to be administered 3 h before surgery. However, the actual time dependency of tumor fluorescence has not yet been evaluated in humans and may have important implications. Objective To investigate the time dependency of PpIX by measuring fluorescence intensities in tumors at various time points during surgery. Methods Patients received 5-ALA (20 mg/kg b.w.) 3 to 4 h before surgery. Fluorescence intensities (FI) and estimated tumor PpIX concentrations (CPPIX) were measured in the tumors over time with a hyperspectral camera. CPPIX was assessed using hyperspectral imaging and by evaluating fluorescence phantoms with known CPPIX. Results A total of 201 samples from 68 patients were included in this study. On average, maximum values of calculated FI and CPPIX were observed between 7 and 8 h after 5-ALA administration. FI and CPPIX both reliably distinguished central strong and marginal weak fluorescence, and grade III compared to grade IV gliomas. Interestingly, marginal (weak) fluorescence was observed to peak later than strong fluorescence (8-9 vs 7-8 h). Conclusion In human in Situ brain tumor tissue, we determined fluorescence after 5-ALA administration to be maximal later than previously thought. In consequence, 5-ALA should be administered 4 to 5 h before surgery, with timing adjusted to internal logistical circumstances and factors related to approaching the tumor.
30 citations
TL;DR: It is suggested that l-CDL likely protects against nerve damage and attenuates vincristine-induced neuroinflammation by upregulating Nrf2/HO-1/CO to inhibit Cx43 expression.
30 citations