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Biomedical subjects

B Lindelöf

Publications and source records attributed to B Lindelöf.

72 records · Page 4Linked to original sources
PubMed1988

Grenz ray therapy: practical aspects of protecting office personnel from radiation.

The exposure to grenz rays of office personnel handling a grenz ray unit working with 10 kV voltage was investigated for different treatment situations. Scattered and leakage radiation, and primary radiation at some distance from the grenz ray unit were measured. Air absorption was found to be most important. Direct exposure of the operator to the primary grenz ray beam at a distance of 4 m was practically nil. At a distance of 2 m from the unit, the operator is permitted to be exposed 100 h per year; at a distance of 1 m, the permitted exposure of the direct beam is 3 h per year. Scattered and leakage radiation from the unit was of no importance and certain clothing was demonstrated to promote absorption.

Dermatology↗
PubMed1988

Human hair form. Morphology revealed by light and scanning electron microscopy and computer aided three-dimensional reconstruction.

The alleged relationship between the cross sectional shape of the hair shaft and the form of the hair, eg, curly or straight hair, has been challenged. By serial sections of human hair follicles from ten patients representing the three biological races, the relation between the follicle form and the hair form was studied. Using three-dimensional computer-aided reconstruction it was demonstrated that the follicle form determines the hair form, eg, the Negroid follicle has a helical form, whereas that of the Oriental follicle is completely straight. The caucasoid follicle represent variation between these extremes. However, even a straight caucasoid follicle may produce a hair shaft that has an oval cross section.

Adult↗
PubMed1987

A double-blind study of Grenz ray therapy in chronic eczema of the hands.

The effect of Grenz ray therapy as an adjunct to topical therapy in chronic symmetrical eczema of the hands was assessed in 24 patients by randomly allocating active treatment to one hand while the other, which received simulated therapy, served as a control. Three Gy of Grenz rays were applied on six occasions at intervals of 1 week. There was a significantly better response to active treatment 5 and 10 weeks after the start of treatment compared with the untreated control.

Chronic Disease↗
PubMed1987

Additional effect of grenz rays on psoriasis lesions of the scalp treated with topical corticosteroids.

In a double-blind study comprising 17 patients with symmetrical psoriasis lesions of the scalp, the combination of grenz ray treatment and topical steroid showed a faster clearing than with the topical steroid alone. The results also indicate a longer remission time with the combination therapy compared to grenz rays alone. Therefore both the faster clearing and the longer remission time with the combination therapy, as compared to our previous study of grenz ray treatment of scalp psoriasis, are probably due to the additional effect of steroid therapy, on grenz rays.

Administration, Topical↗
PubMed1987

The effect of grenz rays on irritant skin reactions in man.

To investigate the effect of grenz rays on irritant contact reactions, eleven healthy volunteers were studied. They were given 3 Gy of grenz rays, once a week for 3 weeks, to a defined area of the back. Twenty-four hours after the last treatment, serial dilution sodium lauryl sulphate patch tests were applied both on the grenz ray treated area and on the untreated control skin. Biopsy specimens were taken from the irritant reactions both from the grenz ray treated area and from the control area and different cell populations in dermis and epidermis were identified by monoclonal antibodies (Leu 2, 3, 4, 7, Leu M1, B1, OKT6). In the grenz ray treated epidermis there was a pronounced reduction of OKT6-positive cells but the composition of the dermal cellular infiltrate did not differ between control and grenz ray treated skin. The assessment of the patch test reactions did reveal a tendency towards weaker reactions in the grenz ray pre-treated skin but this difference was not statistically significant. It is concluded that grenz rays do not have a marked effect on the elicitation of irritant reactions.

Adult↗
PubMed1987

Grenz ray therapy in dermatology. An experimental, clinical and epidemiological study.

Grenz rays (ultrasoft X-rays, Bucky rays) have been used in the treatment of benign skin disorders for more than 60 years. The mechanism of action, the clinical effect, and the potential carcinogenic effect have been mainly unknown, and many of the reported studies are obsolete today. In the present work these concepts have been studied by means of immuno-histological methods, transmission electron microscopy, patch testing, clinical evaluation and epidemiological methods. The results can be summarized as follows. The number of Langerhans' cells (OKT-6 positive cells) decreases in human epidermis after grenz ray radiation and this reflects a true disappearance of the Langerhans' cells as shown by electron microscopy. Grenz ray treatment was found to--suppress the expression of nickel allergy in sensitive individuals--have a tendency to suppress irritant skin reactions--have a very good effect on psoriasis of the scalp. Grenz ray therapy cannot be excluded as a risk factor in the development of non-melanoma skin tumors, but this risk factor is small, if any, when certain therapy recommendations are followed.

Female↗
PubMed1986

Incidence of malignant skin tumors in 14,140 patients after grenz-ray treatment for benign skin disorders.

During the years 1949 to 1975, 14,237 patients received therapeutic doses of grenz rays for the treatment of benign skin disorders such as chronic eczema, psoriasis, and warts. The records of 14,140 of these patients (99.3%) formed the basis for an epidemiologic study of the incidence of skin malignancies in this population. Information about the patients, diagnoses, doses, and sites of treatment was obtained from separate records. The follow-up time was 15 years on the average. We searched the Swedish Cancer Registry, Stockholm, for records reporting the incidence of malignant skin tumors in the study population (incidences of basal cell carcinoma are not registered). The expected number of malignancies was calculated on the basis of age- and sex-standardized incidence data from the Swedish Cancer Registry. In 58 patients, a malignant skin tumor was diagnosed more than five years after grenz-ray therapy had first been administered. Nineteen patients had malignant melanomas, and 39 patients had other malignant skin tumors. The expected number of melanomas was 17.8, and that of other malignant skin tumors was 26.9. None of the patients with melanomas, and only eight of the patients with other malignant skin tumors, had received grenz-ray therapy at the site of the tumor. Six of these eight patients had also been exposed to other known carcinogens. Four hundred eighty-one patients had received an accumulated high dose of grenz rays (greater than or equal to 10 000 rad [greater than or equal to 100 Gy]) on one and the same area. No malignancies were found on those areas. Although we cannot exclude grenz-ray therapy as a risk factor in the development of nonmelanoma skin malignancies, this risk, if any, is small, if recommendations for therapy are followed.

Adolescent↗
PubMed1985

The effect of grenz rays on the expression of allergic contact dermatitis in man.

To investigate the effect of grenz rays on the expression of allergic contact dermatitis, six patients hypersensitive to nickel were studied. They were given 3 Gy of grenz rays, once a week for 3 weeks, to a defined area of the back. Twenty-four hours after the last treatment serial dilution nickel patch tests were applied on the grenz-ray-treated area and on untreated control skin. There was an almost total suppression of the allergic contact dermatitis at the site of grenz ray treatment. Biopsy specimens were taken from nickel-challenged and unchallenged skin, both from the grenz-ray-treated area and from the control area. Different cell populations in epidermis and dermis were identified by monoclonal antibodies (Leu 2, 3, 4, 7, Leu M1, B1, OKT6). In the grenz-ray treated epidermis there was a pronounced reduction of OKT6-positive cells, regarded as Langerhans cells. No other differences were observed between control and grenz-ray-treated skin. Our results suggest that Langerhans cells might be required also for the effector phase of the allergic contact dermatitis.

Adult↗
PubMed1985

Kveim test reactivity in Melkersson-Rosenthal syndrome (cheilitis granulomatosa).

The relation between the Melkersson-Rosenthal syndrome (MRS) and sarcoidosis is unclear. The Kveim test, a test for sarcoidosis, was performed in seven patients, two with complete and five with abortive forms of Melkersson-Rosenthal syndrome. All were found to be negative. Serum levels of angiotensin converting enzyme and calcium were normal. These facts make it unlikely that MRS is a type of sarcoidosis.

Adult↗
PubMed1985

The effect of grenz rays on psoriasis lesions of the scalp: a double blind bilateral trial.

Sixteen patients with symmetrical psoriasis lesions of the scalp were treated with grenz rays. In a double blind fashion, one side of the scalp was irradiated with 4 Gy of grenz rays applied on 6 occasions at intervals of 1 week, and the other side of the scalp was given placebo treatment. The patients were seen before and after X-ray therapy. A significantly (P less than 0.0001) better therapeutic result was recorded on the side of the scalp which had received active grenz ray therapy. In 14 of the 16 patients there was complete healing on the grenz ray-treated side after 6 wk of treatment. Nine patients were still free of lesions of the scalp 3 months after the start of the grenz ray therapy.

Adult↗
PubMed1985

Electron microscopic observations of Langerhans' cells in human epidermis irradiated with grenz rays.

The effect of grenz rays on Langerhans' cells and epidermal morphology was studied at electron microscopic resolution in humans. Biopsies were obtained before and after grenz ray therapy (3 Gy X 3, 1 week interval) from 6 subjects. There was a pronounced reduction of the number of Langerhans' cells 24 hours after the final treatment. There appeared to be no consistent differences in keratinocyte morphology or changes of the intercellular space.

Adult↗
PubMed1984

Effect of grenz rays on Langerhans' cells in human epidermis.

In order to investigate the effect of grenz rays on Langerhans' cells in human epidermis, five healthy volunteers were treated with a single dose of 4 gray of grenz rays on a limited area of buttock skin. Biopsies were obtained before irradiation and from the irradiated site 30 min, 6 hours, 24 hours, 1 week and 3 weeks after X-ray therapy. There was a slight reduction after 30 min and a very pronounced reduction of OKT-6 positive cells regarded as Langerhans' cells, 1 and 3 weeks after irradiation.

Adult↗