Biomedical subjects

J E Persson

Publications and source records attributed to J E Persson.

At least 19 recordsLinked to original sources

PubMed1992

Single crystals of alpha-chitin.

Single crystals of alpha-chitin were grown by the addition of precipitants to dilute solutions of low molecular weight chitin fractions dissolved in aqueous LiSCN. At temperatures around 200 degrees C, bundles of thin needle-shaped crystals were obtained. Each of these needles was an alpha-chitin single crystal, characterized by a spot electron diffraction pattern which could be indexed along the hk0 reciprocal net corresponding to the Minke and Blackwell unit cell [a = 0.474 nm, b = 1.88 nm, c (fibre axis) = 1.032 nm, space group P2(1)2(1)2(1)]. In a crystal, the a* parameter was along the crystal axis and the b* perpendicular to it.

Chitin↗

PubMed1991

Intracavitary irradiation of prostatic carcinoma by a high dose-rate afterloading technique.

A high dose-rate (60Co) afterloading technique was evaluated in a series of 73 patients with prostatic carcinoma stages I-IV. The intraurethral irradiation was combined with external pelvic radiotherapy. A minimum total dose of 78 Gy was delivered to the target volume. In a subgroup of patients estramustine (Estracyt) was given as adjuvant chemohormonal therapy during irradiation. The median follow-up for the whole group was 63 months. The crude 5-year survival rate was 60% and the corrected survival rate 90%. Survival was related to the tumor grade. Local pelvic recurrences were recorded in 17.8%. 'Viable cells' in posttherapy aspiration biopsy were not associated with tumor recurrences or survival. Four patients (5%) had grade 3 late radiation reactions with urethral stricture or bladder fibrosis. Urinary tract infections and prior transurethral resections were not associated with a higher frequency of reactions. Concurrent estramustine therapy seemed to increase the frequency of both acute and chronic radiation reactions. Local control, recurrence, and survival were not affected by chemohormonal therapy. The use of tomography, magnetic resonance, and ultrasound as aids to computerized dosimetry may improve local dose distribution and reduce the irradiated volume.

Brachytherapy↗

PubMed1981