Search results for "ototoxicity"
showing 10 items of 42 documents
Phytochemical profiles, phototoxic and antioxidant properties of eleven Hypericum species - A comparative study
2018
Hypericum is one out of the nine genera belonging to the botanical family Clusiaceae Lindl (syn. Hypericaceae Juss.; APG III, 2009). The genus contains 484 species spread worldwide, one of which, Hypericum perforatum, is largely used in folk medicine. The aim of this study was to evaluate the chemical composition, along with the antioxidant and phototoxic activity, of 11 Hypericum species grown in Sicily (H. perforatum L., H. aegypticum L., H. androsaemum L., H. calycinum L., H. hircinum L., H. hirsutum L., H. montanum L., H. patulum Thunb., H. perfoliatum L., H. pubescens Boiss., H. tetrapterum Fr.). Samples of flowering tops collected from these Hypericum species were extracted and analys…
Alternative Methods to Animal Testing in Safety Evaluation of Cosmetic Products
2018
Abstract This chapter reviews alternative methods recommended for animal testing in various toxicological areas. An alternative model to achieve complete animal replacement for acute toxicity testing is not possible. Skin corrosion/irritation alternative methods have been validated and accepted. For eye irritation testing, no single method is able to replace the Draize rabbit eye test. Skin sensitization methods imply refinement and reduction of numbers of animals. An in vitro dermal absorption test could be an alternative to in vivo testing. There are no generally accepted alternative methods to replace the usual repeated-dose toxicity in vivo assays. To determine the genotoxic and mutagen…
Albumin-Folate Conjugates for Drug-targeting in Photodynamic Therapy.
2016
Photodynamic therapy (PDT) is based on the cytotoxicity of photosensitizers in the presence of light. Increased selectivity and effectivity of the treatment is expected if a specific uptake of the photosensitizers into the target cells, often tumor cells, can be achieved. An attractive transporter for that purpose is the folic acid receptor α (FRα), which is overexpressed on the surface of many tumor cells and mediates an endocytotic uptake. Here, we describe the synthesis and photobiological characterization of polar β-carboline derivatives as photosensitizers covalently linked to folate-tagged albumin as the carrier system. The particles were taken up by KB (human carcinoma) cells within …
Pyrrolo[3',2':6,7]cyclohepta[1,2-b]pyridines with potent photo-antiproliferative activity.
2017
Abstract Pyrrolo[3′,2′:6,7]cyclohepta[1,2-b]pyridines were synthesized as a new class of tricyclic system in which the pyridine ring is annelated to a cycloheptapyrrole scaffold, with the aim of obtaining new photosensitizing agents with improved antiproliferative activity and lower undesired toxic effects. A versatile synthetic pathway was approached, which allowed the isolation of derivatives of the title ring system with a good substitution pattern on the pyrrole moiety. Photobiological studies revealed that the majority of the new compounds showed a potent cytotoxic effect upon photoactivation with light of the proper wavelength, especially when decorated with a 2-ethoxycabonyl group an…
Usefulness of current candidate genetic markers to identify childhood cancer patients at risk for platinum-induced ototoxicity: Results of the Europe…
2020
Background Irreversible sensorineural hearing loss is a common side effect of platinum treatment with the potential to significantly impair the neurocognitive, social and educational development of childhood cancer survivors. Genetic association studies suggest a genetic predisposition for cisplatin-induced ototoxicity. Among other candidate genes, thiopurine methyltransferase (TPMT) is considered a critical gene for susceptibility to cisplatin-induced hearing loss in the FDA drug label and a pharmacogenetic guideline. The aim of this cross-sectional cohort study was to confirm the genetic associations in a large pan-European population and to evaluate the diagnostic accuracy of the genetic…
Effectiveness and safety of once-daily aminoglycosides: A meta-analysis
1996
The effectiveness and safety of once-daily versus several-times-daily aminoglycosides were studied in a meta-analysis. MEDLINE for 1988 to 1995 was searched, and additional studies were identified from review articles and references in retrieved articles. Studies selected for meta-analysis were randomized controlled clinical trials in nonneutropenic adult patients comparing the clinical effectiveness or nephrotoxicity or ototoxicity of once-daily with several-times-daily aminoglycosides. Differences between groups were expressed as odds ratios. The results were combined by the procedure of Mantel and Haenszel, and 95% confidence intervals and exact confidence intervals were computed. An odd…
Impact of Undernutrition on the Pharmacokinetics and Pharmacodynamics of Anticancer Drugs: A Literature Review
2017
The etiology of undernourishment in cancer patients is multifactorial: tumor-related mechanisms (such as obstruction, metabolic abnormalities, and functionality changes) in addition to the influence of anticancer therapies, which can induce or worsen undernutrition. The evident role of undernutrition in cancer treatment outcomes suggests the need of considering nutritional status when evaluating anticancer drugs. In order to merge the available data and offer researchers and clinicians a global view of this phenomenon, the present manuscript reviews on a drug-by-drug basis the undernutrition-related pharmacokinetic and pharmacodynamic aspects of anticancer treatments. This review notes inte…
Relation of early Photofrin uptake to photodynamically induced phototoxicity and changes of cell volume in different cell lines.
1994
For efficacy of photodynamic therapy, selective uptake and retention of photoactive substances has been postulated. Therefore, measurements were performed to find out whether the photosensitiser Photofrin® is taken up differently in malignant and non-malignant cells in vitro . In addition, the sensitivity of malignant cells and nonmalignant cells to photodynamic exposure was investigated, by quantifying viability and volume alterations of the cells. Bovine aortic endothelial cells, mouse fibroblasts and amelanotic hamster melanoma cells were suspended in a specially designed incubation chamber under controlled conditions (e.g. pH, p O 2 , p CO 2 and temperature). After establishing constant…
MOLECULAR BASIS OF DRUG PHOTOTOXICITY: PHOTOSENSITIZED CELL DAMAGE BY THE MAJOR PHOTOPRODUCT OF TIAPROFENIC ACID
1994
Tiaprofenic acid is a photosensitizing nonsteroidal anti-inflammatory drug, whose major photoproduct (decarboxytiaprofenic acid) is also a potent photosensitizer. Because of the lack of the carboxylate moiety, this photoproduct is more lipophilic and might bind more efficiently to cell membranes, thereby causing phototoxic damage. To verify the feasibility of this hypothesis, we have prepared the 3H-labeled analogs of tiaprofenic acid and its photoproduct and examined the binding, persistence and phototoxicity of the photoproduct using poorly metabolizing (fibroblasts) and actively metabolizing cells (hepatocytes). The photoproduct of tiaprofenic acid accumulates in both cell types as it is…
Tierexperimentelle Untersuchungen zur Abh�ngigkeit der Ototoxicit�t von der Dosierung des Kanamycin und zur Schutzwirkung durch Vitamine
1963
Mit einer einfachen Methodik wird die durch Kanamycin bei Ratten ausgeloste Horschadigung quantitativ gemessen. Die Abhangigkeit der Schwere der Horschadigung von der Dosis und vom Dosierungsschema wird bestimmt. Der Nachweis, das die Vitamine A oder D eine protektive Wirkung gegenuber der Ototoxicitat des Kanamycin besitzen, kann nicht erbracht werden. Die Folgerungen aus diesen toxikologischen Untersuchungen fur die Anwendung von Kanamycin am Menschen werden kurz erortert.