Finding optimal photosensitisers for the decontamination of foods by the photodynamic effect.

A new method for sanitation based on the photodynamic effect is introduced. Photosensitisers are compounds that generate cytotoxic oxygen species and free radicals after excitation with appropriate visible light. The cell killing efficacy is due to their chemical structure, to the actual environment and therefore also to their degree of aggregation.

Hypericin--the facts about a controversial agent.

Hypericin is a naturally occurring substance found in the common St. John's Wort (Hypericum species) and can also be synthesized from the anthraquinone derivative emodin. As the main component of Hypericum perforatum, it has traditionally been used throughout the history of folk medicine.

Dehydroascorbic acid in urine as a possible indicator of surgical stress.

Background/aim: L-Ascorbic acid (AA) is the predominant circulating form of vitamin C found in human blood. It has been hypothesized that surgical stress increases the vitamin C metabolite dehydroascorbic acid (DHAA). Vitamin C is mainly excreted through the kidneys.

Photodynamic action of some sensitizers by photooxidation of luminol.

We report the development of a novel simple experimental method which allows the comparison of new photosensitizers based on their production of reactive oxygen species. A high-performance liquid chromatography (HPLC) assay permits the monitoring of several substances (sensitizer, reactant and oxidized end product) simultaneously on a single chromatogram. Photoreactions were monitored throughout their course by the HPLC assay surveying the sensitizers' efficiency of singlet oxygen production by the oxidative decomposition of luminol.

5-aminolevulinic acid-mediated photodynamic therapy of intraepithelial neoplasia and human papillomavirus of the uterine cervix--a new experimental approach.

The aim of this study was to treat patients for ectocervical dysplasia [cervical intraepithelial neoplasia (CIN) grades 1 and 2] and associated human papilloma virus (HPV) infections with photodynamic therapy (PDT). In 20 patients, 5-aminolevulinic acid (5-ALA, 12% w/v) was applied topically with a cervical cap 8 h prior to illumination. A thermal light source (150 W halogen lamp) emitting a broadband red light (total energy: 100 J/cm2, fluence rate: 90 mW/cm2) was used for superficial illumination of the portio.

Ambulant photodynamic therapy of superficial malignomas with 5-ALA in combination with folic acid and use of noncoherent light.

This study reports our first results of ambulant photodynamic treatment with 5-aminolevulinic acid (5-ALA) in combination with folic acid and subsequent illumination with a noncoherent light source. The compound was topically applied to avoid total body skin sensitivity which occurs in the case of systemic administration. If no therapeutic response could be proved, we added folic acid to 5-ALA for a further treatment attempt.

Antagonistic effects of combination photosensitization by hypericin, meso-tetrahydroxyphenylchlorin (mTHPC) and photofrin II on Staphylococcus aureus.

Photodynamic therapy involves the application of a photosensitizer activated by visible light to generate cytotoxic reactive oxygen. In addition to clinical investigations, in vitro studies concerning photodynamic potency of sensitizers as well as quantification of illumination procedures are necessary. In our investigation, the objective was to evaluate not only the effects of photosensitizer and light on Gram-positive Staphylococcus aureus, but also to investigate possible synergistic or antagonistic effects of these sensitizers.

Measurement of inotropic effects by a newly developed guinea pig papillary muscle bioassay.

In order to measure inotropic influences of physiologically occurring substances and drugs we used a newly developed guinea pig papillary muscle (GPPM) bioassay. GPPM were suspended in air and surface coated with buffer (Krebs-Henseleit solution). The muscles were stimulated (pulsating direct current, 1.

Experiences of photodynamic therapy in dermatology.

From March 1988 to May 1994, 15 patients underwent the treatment protocol of superficial photodynamic therapy (PDT) in dermatological localized malignancies. Two tumours (one M. Queyrat of the penis, one basalioma) were treated primarily; the other 13 patients experienced relapses of underlying disease after treatment by surgery, radiotherapy or chemotherapy.

Photodynamic therapy in gynaecologic cancer.

We started photodynamic therapy in gynaecologic tumors in 1988. Seven patients with endometrial carcinomas stage FIGO 1a (restricted to the endometrium) were treated primarily and also 4 patients with recurrences of vaginal and vault cervix carcinoma, carcinoma of the corpus uteri and the vulva. Residual tumors after conventional therapy of cervix and vulvar carcinoma were treated in 2 patients.

Determination of Photosan III in human plasma.

In order to develop an accurate and quick method for the determination of Photosan III in human plasma, we used statistically planned experiments with an aim to identify the factors that can influence the analysis. Through a series of 20 experiments based on acid extraction of the porphyrin from the plasma and subsequent fluorescence analysis a calibration was obtained between 0 and 3.3 x 10(-5) M.

Hypericin in phototherapy.

We describe the first local use of hypericin as photosensitizer for photodynamic therapy in a patient with recurrent malignant mesothelioma. Hypericin is a polycyclic quinone, which has been shown to possess in vivo and in vitro antiretroviral and photosensitizing activity; moreover, it is used in depressive disorders. The semiquinone radical, singlet oxygen, and superoxide anion radical are reported to be the toxic agents in hypericin phototherapy.

Wavelength-dependent photoresponse of biological and aqueous model systems using the photodynamic plant pigment hypericin.

Photodynamic eradication of tumour cells in vivo depends on the presence of a photosensitizer, light delivery to the cells, and an oxygen supply. Hypericin, a polycyclic quinone with absorption maxima in the ultraviolet and visible ranges, was prepared for clinical use as a photosensitizer. Due to antitumoral and antineoplastic activities as well as the generation of singlet oxygen after photoexcitation, hypericin was applied in clinical oncology and photodynamic therapy.

Natural products derived from plants as potential drugs for the photodynamic destruction of tumor cells.

Chlorophyll and some of its synthetically produced derivatives are important sensitizers in photodynamic cancer therapy. Other natural products from plants with light dependent activity include quinones like hypericin and fagopyrin. These compounds have extended pi-electron systems which upon photoexcitation with visible light are responsible for singlet oxygen production.

Endometrial cancer after tamoxifen treatment: a descriptive study of 25 breast cancer patients who subsequently developed endometrial cancer.

The aim of this study was to determine whether tamoxifen affects the histopathological features and clinical outcome of endometrial cancer occurring after breast cancer. 25 patients with a history of breast cancer who subsequently developed endometrial cancer were identified by computer assisted linkage of the Lainz Medical Center Tumor Registry with the National Austrian Cancer Registry. 8 endometrial cancers were tamoxifen-associated, whereas 17 cases were not.

Induratio penis plastica: effectivity of low-dose radiotherapy at different clinical stages.

This study describes the treatment of Peyronie's disease by means of low-dose radiotherapy. We treated 265 men aged 24.5-79.

Evaluation of Cyfra 21-1 as a marker for lung cancer.

The sensitivity and specificity of Cyfra 21-1 as marker for lung cancer was evaluated in comparison with carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC) and neuron-specific enolase (NSE). Patients with histologically verified lung cancer and different groups without lung cancer were investigated. Sensitivity of Cyfra 21-1 (cut-off level 2.

Photodynamic therapy--an alternative pathway in the treatment of recurrent breast cancer.

Purpose: Validity of photodynamic therapy for treatment of recurrent breast cancer.

Methods And Materials: Patients were intravenously administered with a metal-free haematoporphyrine derivative for tumor sensibilization. For irradiation both monochromatic and white light was used.

A quantitative determination of singlet oxygen with horseradish peroxidase.

A singlet oxygen determination method based on the formation of dimethyl-(2,5)-2-methoxy-5-hydroperoxydihydrofuran (DMFO2) followed by acid hydrolysis with 0.1 N H2SO4 is described. Hydrogen peroxide is formed thereby as a product of hydrolysis which is then determined by the horseradish peroxidase-catalyzed formation of the homovanillic acid dimer.

Serum urate level and cancer.

Histograms of the serum uric acid level of cancer patients (n = 501) and healthy controls (n = 15150) are compared. The statistical evaluation of the data yields significantly lower uric acid levels for cancer patients than for healthy persons (P less than 0.0001 for males, P less than 0.

Interstitial pneumonia as a cause of early mortality in allogeneic bone marrow transplantation: the Viennese experience.

A uniquely low incidence and death rate of interstitial pneumonia after allogeneic bone marrow transplantation for haemopoietic malignancy is described. Deduced from the comparison with results from a multicenter study, we conclude, that a) reduction of the dose rate to less than 5 rad/min, b) exclusion of CMV pos platelet donors and c) application of a CMV hyperimmune globulin are effectful means to reduce this most often deathly complication after BMT for haemopoietic malignancy.