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At least 307 records · Page 17Linked to original sources
PubMed1994

[Photodynamic procedures in urology].

Photodynamic therapy (PDT) has been demonstrated to be an effective therapy for carcinoma in situ of the urinary bladder. The data recorded in the various pilot studies are not comparable, because different photosensitizers, various irradiation modalities and different doses of photosensitizers have been used. Present activities include basic research on principles of action of PDT, the development of photosensitizers with better tumor selectivity, optimization of irradiation modalities, and prospective randomized clinical trials, e.g. in superficial bladder cancer. Photodynamic fluorescence diagnosis (PDD) can be performed easily in clinical conditions with the use of the topically applicable fluorescent marker delta amino levulinic acid (ALA). There is a need for controlled clinical trials to check the efficacy suggested for PDD by the very promising data yielded by pilot studies.

Carcinoma in Situ↗
PubMed1975

The effect of cobalt on haemoglobin synthesis in primate reticulocytes.

The effect of cobalt on haemoglobin synthesis was studied in reticulocytes obtained from marmosets, new world monkeys. By means of different inhibitors the conditions necessary for either cobalt-induced stimulation or inhibition were determined. Cobalt-induced inhibition of globin synthesis was not reversible by the addition of either delta-amino levulinic acid or haem. Globia synthesis, however, in iron-deficient reticulocytes was stimulated by the addition of cobalt. Cobalt did not apparently require complexing with protoporphyrin for activity, since the effect was observed whether the haem-biosynthetic pathway was inhibited or not. The data have been interpreted to suggest cobalt operates by affecting a rate controlling step in the synthesis of globin.

Aminolevulinic Acid↗
PubMed1993

[Photodynamic therapy of skin tumors].

Photodynamic therapy (PDT) is still an experimental modality using red light in conjunction with a systemic or topical photosensitizer. The photosensitizers have a longer retention time in malignant tumors compared with the normal surrounding tissue. Irradiation with a red light at wavelength of 630 nm results in photochemical generation of cytotoxic singulet oxygen. The systemic sensitizer mostly used is hematoporphyrin derivative (HPD) and the light sources are argon-pumped dye lasers, gold vapour lasers and even more simple light sources based on conventional lamps. The most important side effect of systemic application of HPD is light hypersensitivity in the UVA range, which lasts up to several weeks. Multiple studies in recent years have proved that superficial basal cell carcinomas, squamous cell carcinomas, Bowen's disease and epidemic Kaposi's sarcoma respond to systemic PDT. Up to now, however studies with greater numbers of patients and a sufficient follow-up have been lacking. Topical application of sensitizers like amino-levulinic acid (ALA) and tetraphenylporphine sulfonate (TPPS) have been used for the treatment of superficial basal cell carcinomas and squamous cell carcinomas. Possible future applications of PDT are virus papillomas and psoriasis. Even if PDT is an experimental therapeutical modality at present, it may become more clinical relevant in the future.

Basal Cell Carcinoma↗
PubMed1996

Lead exposure in indoor firing ranges: environmental impact and health risk to the range users.

Health risk from airborne lead exposure were evaluated in 54 trainees and 31 firearm instructors at two indoor firing ranges in Amman, Jordan. Airborne lead concentration was measured during shooting sessions of conventional lead ammunition. Venous blood was collected from the trainees, instructors and controls. The levels of blood lead (PbB) and the activity of amino levulinic acid dehydrogenase (ALAD) were measured. High concentrations of air lead that markedly exceeded the internationally adopted safe exposure levels were found on both ranges. Despite the absence of symptoms of lead poisoning, there was a significantly higher PbB in the instructors (19 +/- 7 micrograms/dl) and trainees (22.9 +/- 4.6 micrograms/dl) than in the controls (2.1 +/- 1.4 micrograms/dl). Furthermore, the activity of ALAD was significantly lower in both groups (29.2 +/- 1.3, 18.9 +/- 1.2 U/L, respectively) than in the controls (47.5 +/- 1.1 U/L) indicating a subcritical lead effect. In the trainees, levels of PbB rose from a pre-training mean of 2.2 to 22.9 micrograms/dl and the activity of ALAD decreased from 46.9 to 18.9 U/L. It is concluded that indoor firing range users are at risk of lead absorption and intoxication and, therefore, periodic biological monitoring of the frequent users of firing ranges is highly recommended. Environmental hygienic actions to control excessive emissions of lead on the ranges are also imperative.

Adolescent↗
PubMed1995

Lead poisoning--a hazard of traffic and industries in Pakistan.

We measured blood lead level, hemoglobin, and urinary amino-levulinic acid (ALA) in industrial workers and in individuals exposed to vehicle smoke. Industrial workers and people exposed to traffic smoke had comparatively higher blood lead levels than the controls (p < 0.0001). Similarly, urinary ALA was 3.82 mg/dL in industrial subjects, 3.68 mg/dL in traffic-exposed people, and 0.8 mg/dL in control subjects (p < 0.001). The hemoglobin level was lower in the industrial group and in the traffic exposure group compared with the control group (p < 0.01). Traffic smoke-exposed persons, such as traffic police staff, had higher blood lead level than those handling lead material, Government Transport Service (GTS) workshop staff. The length of exposure showed no relationship with the lead levels. However, a positive correlation was observed between the duration of exposure and urinary ALA in both sample groups. The major signs and symptoms of the population studied included headache, generalized body pain, hypertension, and depression.

Adult↗
PubMed1980

Identification of porphyrin present in apo-cytochrome C oxidase of copper-deficient yeast cells.

Heme a was not detected either in mitochondria isolated from copper-deficient yeast or in the intact cells. Nevertheless, the intracellular concentration of free porphyrins indicated that the pathway of porphyrin and heme synthesis was not impaired in copper-deficient cells. The immunoprecipitated apo-oxidase from copper-deficient cells revealed an absorption spectrum with maxima at 645, 592, 559, 519 and 423 nm, similar to that of purified porphyrin a. When solubilized mitochondria from [3H]leucine and delta-amino[14C]levulinic acid-labeled copper-deficient yeast cells were incubated with rabbit antiserum against cytochrome c oxidase, a precipitate was obtained. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of this immunoprecipitate showed [3H]leucine associated with six bands and delta-amino[14C]levulinic acid resolved in a single band. HCl fractionation of copper-deficient mitochondria labeled with delta amino[14C]levulinic acid showed a high specific radioactivity in the fraction extracted by 20% HCl, a solvent which extracts porphyrin a. Thin-layer chromatography of the radioactivity found in 20% HCl showed an RF value identical to that of purified porphyrin a. When delta-amino[3H]levulinic acid-labeled, copper-deficient yeast cells are grown in copper-supplemented medium, the porphyrin a accumulated in copper-deficient cells was converted into heme a, and this conversion was prevented by cycloheximidine. These observations suggest that porphyrin a is present in the apo-oxidase of copper-deficient cells, but that the conversion to heme a does not occur. This conversion reaction appears to be a point in the biosynthetic pathway of cytochrome c oxidase which is blocked by copper deficiency.

Aminolevulinic Acid↗
PubMed1977

[Biochemical evaluation of damage due to lead: importance and significance of erythrocyte zinc-protoporhyrin IX and urinary amino acid determination].

The early detection of lead intoxitation needs practical, simple, reproducible and diagnostically valid screening test. The determination of ALA-D (delta-amino-levulinic acid-dehydratase) in erythrocytes is one of the most reliable test for the evaluation of the occupational exposure to lead. However this test is difficult to standardize, sensible to lead contamination of laboratory glassware and the activity of enzyme decreases rapidly if stored. The determination of erythrocytes ZPP (zinco-protoporphyrin IX) was proposed as useful, alternative test. The protoporphyrin IX is a metabolic intermediate in heme biosynthesis; in erythrocytes is present as free form and zinc-boundend compound. The ZPP give high values only in lead intoxication and sideropenic anemia. The ALA-D and ZPP in erythrocytes were measured and compared in a group of workers exposed to lead. We have shown a good correlation between these two biochemical parameters. Aminoacid excretion in urine from workers exposed to lead was measured and compared with other biochemical parameters of intoxication. All lead workers examined had excessive urinary CP (coproporphyrin) and ALA (delta-amino-levulinic acid) excretion. An abnormal excretion of glycine was present in eight workers (32%), whereas in other four (15%) the glycinuria was at limit of normal values. An abnormal excretion of lysine was present in six workers (21%). The last data appear very interesting because the action of lead in lysine metabolism was not known.

Aminolevulinic Acid↗