Biomedical subjects

R Jindra

Publications and source records attributed to R Jindra.

6 recordsLinked to original sources

PubMed1999

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. In addition, an Nd:YAG pumped dye laser (652 nm) was used to illuminate the cervical canal (total energy: 50 J/cm2, fluence rate: 300 mW/cm2). Preliminary results of follow-ups at 1, 3, 6, and 9 months posttherapy showed a cytological improvement in the grading of the PAP smears in 19 patients and the eradication of cervical HPV in 80%. These results demonstrate that ectocervical dysplasia and associated HPV infections can be treated by PDT.

Administration, Intravaginal↗

PubMed1996

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. Hypericin was administered subcutaneously (20 micrograms hypericin in 200 microliters Nacl/pyridine solution) into the ante brachium (forearm) of two volunteers. After the diffusion and equilibration of 120 min phototesting was carried out using outdoor light exposure, halogen lamp, laser 514 nm (argon), laser 632 nm (argon dye) and laser 670 nm (diode laser), from 60 to 120 J cm-2. Positive phototests to outdoor light exposure, halogen lamp and laser 514 nm were characterized by rubescence, oozing, vesiculation and darting pain. Phototests with laser 632 nm and 670 nm showed no effects after irradiation. When hypericin was administered topically on skin, erythema and flaring could not be induced by any irradiation. These results suggest that hypericin is a potent photosensitizer only within the UV and green light ranges. This characteristic photoresponse could also be obtained in guinea pig papillary muscle (GPPM) bioassay, which may be established as a model for photosensitizer testing. Irradiation of hypericin-incubated GPPM with 514 nm (20 J cm-2) led to a decrease of the contractile force of about 31%. However, excitation with 632 nm and 670 nm did not cause inotropic effects on GPPM. In addition, hypericin and Photosan 3 were shown to be capable of sensitizing the photo-oxidation of sodium linoleate. This assay should be established for testing interactions between photosensitizers and light sources in vitro.

Animals↗

PubMed1996

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. Most of the patients (10/15) received doses of 2 mg Photosan III kg-1 body weight (BW), four received a lower dose of 1-1.5 mg kg-1 BW and one patient received 3 mg kg-1 BW. Only one remarkable side-effect (tachyarrhythmia) during Photosan III infusion occurred. All patients were treated by an argon dye laser system. The light dose was 200 J cm-2 (11 patients) and 150 J cm-2 (four patients). Complete response occurred in six lesions, including one M. Queyrat and five basaliomas. Two patients had significant partial response with distinct regression of tumour (one pretreated basalioma of the upper lip and one superficially spreading mesothelioma of the scrotum). Five patients (all basaliomas) demonstrated only local response and two patients gave no response (one basalioma, one melanoma metastasis). The results obtained from this small sample suggest the necessity of an optical dosimetric system. At present, PDT should be restricted for selected or pretreated cases.

Basal Cell Carcinoma↗

PubMed1979

[Interactions between nitrous oxide and central depressants].

The combined effects on mice of N2O and various central depressants were investigated. A loss of the righting reflex was taken as the criterion for the drug effects. Essential differences could be demonstrated in the type of interaction: diazepam, flunitrazepam, and medazepam have a supra-additive effect in combination with N2O; the solvent of diazepam and an experimental product, Ro 21-3981 (8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo [1,5-a] [1,4]-benzodiazepine maleate) a simply additive one. However, the interactions between N2O and barbiturates (pentobarbitone and phenobarbitone), and N2O and ethanol were found to be infra-additive. The results of this and previous investigations indicate that additive or supra-additive interactions can only be expected in those cases in which at most one of the two active ingredients in addition to its depressive effect also exhibits an excitatory component.

Animals↗

PubMed1977

Effect of harmaline on the cerebello-rubral system.

Harmaline induces synchronous rhythms in both the cerebellum and the red nucleus of the rabbit. The level of synchronization is lower in the red nucleus than in the cerebellar cortex, probably because the cerebello-rubral pathway and the red nucleus neurons only participate poorly in the harmaline-induced olivo-cerebellar rhythm.

Alkaloids↗

PubMedDate not supplied

[Intracranial complications of sinusitis].

A rare case of cerebral abscess is presented. Sinusitis was identified as a predisposing factor. Rhinogenous endocranial complications are almost ten times less frequent than the otogenous ones. Despite great progress in the treatment of infections of different localizations, the lethality from cerebral abscess has remained relatively high ranging between 30 and 60%. We report on one of our patients and give a critical review of the contemporary diagnostic and therapeutical possibilities in the treatment of cerebral abscess. The case is interesting since brain abscess has been completely cured inoperatively. Although the treatment of cerebral abscess has been considerably improved, this remains one of the most severe diseases, requiring further improvement of diagnostic and therapeutical methods.

Adolescent↗