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Biomedical subjects

M J Olsson

Publications and source records attributed to M J Olsson.

31 records · Page 2Linked to original sources
PubMed1995

Transplantation of melanocytes in vitiligo.

We report the results of a study on 100 patients (aged 12-68) with vitiligo, who were treated by transplantation of cultured autologous melanocytes to the depigmented areas, after removal of the epidermis at the recipient site by dermabrasion. The melanocytes were cultured from a 2 x 3 cm2 superficial shave biopsy taken from pigmented buttock skin. After 2-3 weeks in culture, 700-1000 cells per mm2 were applied on 60-500 cm2 dermabraded areas, and occluded for 1 week. The repigmented portion of the total treated area amounted to 95-100% in 40 patients, 65-94% in 32, 20-64% in 22, and 0-19% in six. It was more difficult to achieve complete pigmentation on the fingers, elbows and knees. In the first few months following the procedure, the treated areas were often hypo- or hyperpigmented, but after 6-8 months they had acquired the same colour as the surrounding skin. No scarring or other side-effects occurred. The donor site had repigmented after 3-6 months in all but two patients, who also showed poor pigmentation in the transplanted areas. At follow-up after 1 and 2 years in 50 and 10 patients, respectively, the repigmented areas remained unchanged. The method is time-consuming, but the results obtained indicate that the procedure can be valuable in motivated patients, when the extent of vitiligo does not exceed 30% of the total body area, and when the areas to be treated are not actively extending.

Adolescent↗
PubMed1994

Pigment cell transplantation for treatment of vitiligo: a progress report.

BACKGROUND: Because available treatments for vitiligo generally provide unsatisfactory results, the search for viable therapeutic alternatives continues. OBJECTIVE: Our purpose was to evaluate several transplantation procedures with cultured autologous melanocytes for their practicality in treating patients with vitiligo. METHODS: Twenty-seven patients with stable or active vitiligo were treated after superficial dermabrasion with application of suspensions of autologous cultured melanocytes, melanocyte-keratinocyte mixtures, or epidermal sheets established in vitro. RESULTS: Regardless of disease activity, use of each method resulted in repigmentation to a similar degree and without scarring in all patients. Melanocyte suspensions offer several advantages: They are easily prepared, can be applied in a controlled manner, permit coverage of large areas, and produce a homogeneous skin color that affords the best cosmetic restoration. The ultrastructure of transplant sites resembled that of uninvolved skin, with one exception: the melanocytes were located slightly higher than in uninvolved skin. CONCLUSION: Application of cultured autologous melanocytes to lightly abraded skin is an advantageous addition to the treatments available for patients with vitiligo.

Adolescent↗
PubMed1994

Vitiligo: repigmentation with cultured melanocytes after cryostorage.

We have developed a technique through which we can multiply melanocytes in culture from a small specimen of normally pigmented buttock skin and reimplant them into depigmented sites of vitiligo. To date, 90 patients have benefited in our hands from such autologous transplantation of pigment cells. Often we have an excess of cells which we would like to store for later use in the event a patient requires further treatment. We report here on 4 cases in which we have cryostored cultured melanocytes for 6-12 months, reimplanted them into vitiliginous sites of the donor after one week of reculture, and obtained optimal repigmentation. We now routinely freeze melanocytes left over after treatment.

Adult↗
PubMed1994

An interaction model for odor quality and intensity.

The perceived intensity and quality of binary odor mixtures are studied in relation to how their components are perceived when presented separately. Subjects judged the perceived intensity and quality of 6 concentrations of pyridine, 6 concentrations of n-butanol, and their 36 possible combinations. The results show that the perceived intensity of the mixture can be predicted from the perceived intensity of its components presented separately (RA and RB) by the Euclidian arithmetic model. The maximum probability of identifying a mixture as a "mixture" is reached when RA and RB are equally strong. An interaction model for mixtures that relates perceived intensity and quality is presented and tested. The test reveals that both the perceived intensity of a mixture and the probability that it will be identified as the one or the other component can, by a simple interaction model, be successfully predicted from RA and RB.

Female↗
PubMed1993

Biosynthesis of 3,4-didehydroretinol from retinol by human skin keratinocytes in culture.

The uptake and metabolism of radiolabelled retinol was studied in cultivated human skin cells. Normal epidermal keratinocytes in primary culture were able to incorporate unbound [11,12-3H]all-trans-retinol from the growth medium and transform it into 3,4-didehydroretinol (dehydroretinol) in a dose- and time-dependent manner. A total of 23% of the radioactive label became cell-associated during a 48-h incubation period when added at 7 nM to differentiated keratinocytes submerged in serum-containing, high-calcium (1.56 mM) culture medium. At that time point, 25-30% of cell-bound radioactive retinol had been converted into dehydroretinol, with no labelled retinal, dehydroretinal, retinoic acid or dehydroretinoic acid being detected in cells or medium. Thus dehydroretinol, which occurs physiologically in mammalian skin tissue in vivo, was identified as the predominant neutral retinol metabolite in cultured keratinocytes using h.p.l.c. and anhydro-derivatization procedures. At least 94% of the product, along with its precursor, was present in the cells in esterified form, with no traces of the compound being secreted into the cell environment. The rate of formation of dehydroretinol from its precursor was significantly lower in keratinocytes grown in serum-free, low-calcium (0.09 mM) culture medium, and in medium pre-incubated with excess unlabelled substrate. Furthermore, the application of 13-cis-retinoic acid (isotretinoin), a therapeutic retinoid drug known to markedly reduce dehydroretinol levels in human skin, blocked the biosynthesis of this metabolite in cultured keratinocytes. The 3,4-dehydrogenation pathway observed in this study could not be shown to operate to any significant extent in cultures of human epidermal melanocytes or dermal fibroblasts, supporting the hypothesis that keratinocytes represent the principal cell type involved in dehydroretinol formation from retinol in human skin.

Cells, Cultured↗
PubMed1993

Odor-intensity interaction in binary mixtures.

Four principles underlying odor summation in mixtures were examined on the bases of 10 Ss' magnitude estimates of 41 mixtures and their components (pyridine and DMDS). Thus, the overall intensity summation for mixtures are compared to self-addition reflected by the power function for single substances: Hypoaddition is a characteristic of both. Compromise is found for 25% of the mixtures, but it is not inherent in the power function. No level dependency is found for mixtures, although it is in accordance with the power function. Asymmetrical summation exists for mixtures and is inconsistent with the power function. Therefore, the idea of a congruence in odor-intensity summation processes is rejected. The results also constitute a successful cross-validation of the angle alpha (99 degrees vs. 102 degrees) of the perceptual vector model reported by B. Berglund et al. (1973).

Adolescent↗
PubMed1993

Odor-intensity interaction in binary and ternary mixtures.

Eight subjects scaled the overall perceived odor intensity of binary and ternary mixtures of the odorous substances pyridine, acetone, and ethyl acrylate. The results concerning basic principles of additivity for binary mixtures comply with those of earlier studies. For the ternary mixtures, the degree of arithmetic additivity in odor intensity seemed lower when a third component was added to a binary mixture than when the second component was added to a single odor, but this did not reach statistical significance. In general, the degree of arithmetic additivity inherent in the power function for single substances was found to be of the same size as the degree of additivity for binary as well as ternary mixtures. However, for binary mixtures, the additivity of the mixtures was found to approximate that of the substance with the lower exponent. In addition, the degree of additivity of the binary mixture was monotonically related to the average arithmetic additivity of the power functions for the two components.

Acetone↗
PubMed1990

Effects of prolonged treatment with phthalate ester on rat liver.

Rats were fed a diet containing 2%, 0.2% or 0.02% di(2-ethylhexyl)phthalate (DEHP) for a period of 102 weeks. Only the 2% diet caused a substantial decrease in body weight. Both peroxisomal palmitoyl-CoA dehydrogenase and mitochondrial carnitine acetyltransferase activities were greatly induced by exposure to the highest dose of phthalate ester, reaching maximal plateau values after about 20 weeks of treatment. The diet containing 0.2% DEHP increased both activities slowly, but continuously, and at the end of the two-year period these increases were almost comparable to those obtained with the highest dose. Even the lowest dose gave a slowly increase in these activities. Both microsomal NADPH-cytochrome c reductase activity and the level of cytochrome P-450 were increased initially by exposure to 2% DEHP, but returned almost or completely to the control level after about 30 weeks of exposure. Depending on the dose of DEHP in the diet, peroxisomal catalase activity was elevated above the control level during the first year of treatment but was about the same as in the control animals during the second year. A substantial decrease in peroxisomal urate oxidase activity was observed throughout the entire experimental period. When treatment was ceased after one year, all activities returned to the control values within 2-3 weeks. These results demonstrate the complex nature of the effects caused by prolonged treatment with DEHP with cumulative increases at low doses.

Animals↗
PubMed1989

The influence of di(2-ethylhexyl)phthalate on protein turnover in rat liver.

Treatment of rats with the plasticizer di(2-ethylhexyl)phthalate increases liver weight and leads to proliferation of mitochondria and peroxisomes. Using in vivo labelling with [3H]leucine, an increased rate of incorporation into the total protein of mitochondria and microsomes was observed. The half-lives of proteins in subcellular fractions were determined using [35S]methionine labelling. The half-lives for the total protein of mitochondria, microsomes, and supernatant were increased from 6 to 25 days, from 3.5 to 5.5 days and from 2.5 to 5 days upon treatment with phthalate esters. Experiments with [14C]guanidino-L-arginine indicated that some reutilization of [35S]methionine occurred, but this did not influence the results substantially. It appears that phthalate esters increase protein synthesis and decrease protein breakdown, the former effect being of greater importance.

Amino Acids↗
PubMed1989

Fatty acid oxidation in hepatic peroxisomes and mitochondria after treatment of rats with di(2-ethylhexyl)phthalate.

Rats were fed a diet containing di(2-ethylhexyl)-phthalate, which increases the number of peroxisomes and mitochondria in the liver. This proliferation does not change the ratio of phospholipid to protein in mitochondria or microsomes, but causes certain changes in the fatty acid composition of the phospholipids. The highest rates of peroxisomal and mitochondrial beta-oxidation are obtained with 12:0 and 16:0 fatty acids as substrates, respectively. A 3-4 fold increase in the rate of beta-oxidation by both organelles is caused by DEHP treatment, but there are no qualitative changes in the relative rates of oxidation of individual fatty acids. Short- and medium-chain carnitine acyltransferases in peroxisomes, microsomes and mitochondria, as well as the mitochondrial long-chain carnitine acyltransferase are induced to various extents. These results indicate that the increased beta-oxidation of fatty acids caused by phthalate treatment involves the same peroxisomal and mitochondrial pathways which operate under normal conditions.

Animals↗
PubMedDate not supplied

Naevus anaemicus with teleangiectatic vessels.

We describe a 20-year-old man with naevus anaemicus on the chest where, after dermabrasion of the epidermis, enlarged teleangiectatic dark-red vessels were seen within the previously pale area. They were clearly different from those seen on dermabrasion at this site in normal skin and in patients with vitiligo where the area is lighter red with only small punctual bleedings from arterial capillaries. The naevus anaemicus and a port-wine stain (naevus flammeus) in the same location is a phenomenon of vascular twin spotting, which was revealed when the epidermis was removed. The area was transplanted with thin epidermal grafts and healed within 2 weeks. One year later the naevus looked the same as before grafting. Much thicker grafts than those used by us will be needed, but they are not cosmetically acceptable.

Adult↗