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Biomedical subjects

M Lindberg

Publications and source records attributed to M Lindberg.

At least 127 records · Page 7Linked to original sources
PubMed1991

The influence of a single application of different moisturizers on the skin capacitance.

Moisturizers are believed to improve the skin condition by increasing the water content of the stratum corneum. A variety of techniques for assessing skin hydration has been developed. In the present study the capacitance following a single application of different moisturizers to normal skin on 12 volunteers was measured with the commercial available Corneometer 420. The moisturizers were pure petrolatum and three oil-in-water creams. The latter contained either glycerine, glycerine and pyrollidone carboxylic acid, or urea as humectant agents. The first measurement of the change in the capacitance was done 2 h after application of the products. All tested products increased the capacitance in the same order of magnitude. For the creams the values were significantly enhanced during the experimental period (6 h). Excess product were removed from some skin areas after the 2 h measurement. This caused immediately a significant decrease in the capacitance of the cream treated sites, whereas a tendency towards higher values were noted on the petrolatum-treated sites. These findings indicate that the non-absorbed components influences the capacitance values. Hence, the interpretation of electrical measurements with respect to skin moisture should be made with caution.

Adult↗
PubMed1991

Differential effects of sodium lauryl sulphate and non-anoic acid on the expression of CD1a and ICAM-1 in human epidermis.

Normal human skin was exposed to two different detergents, sodium lauryl sulphate in distilled water and non-anoic acid in isopropanol at different concentrations. The detergents were applied under occlusion in epicutaneous tests for 24 h and biopsies were taken at 24 or 48 h. Frozen sections were labelled with monoclonal antibodies against CD1a, CD3 and ICAM-1. The evaluation of the labelled sections showed that there were differential effects on the expression of ICAM-1 and CD1a+ cells in epidermis. After non-anoic acid application ICAM-reactivity could not be detected and there was a decrease of staining for CD1a after exposure to 80% non-anoic acid. Sodium lauryl sulphate treatment, however, induced ICAM-1 expression on keratinocytes and had minor effects on the number of CD1a+ cells. ICAM-1 expression was also detected in normal epidermis in 3 of 9 unexposed control biopsies and after occlusion with the vehicles distilled water and isopropanol. An increased amount of CD3+ cells was found in the skin exposed to both detergents. The results show that there are dose and time dependent variations in the epidermal response to irritants which might influence the immunological events taken place in the epidermis.

Adult↗
PubMed1991

Studies of irritant reactions on epidermis: the application of energy dispersive x-ray microanalysis.

Modern man is exposed to an increasing amount of chemicals in the environment. The skin is a complex tissue with regards to both structure and function. Contact with external stimuli can lead to various responses in the skin depending on the type of stimuli, the dose and time of exposure and the status of the exposed individual. The electron probe microanalytic technique can be used to obtain information on physiological alterations within the skin and especially the epidermis when the normal homeostasis is disturbed by contact with external stimuli. The present paper presents a review of some aspects of contact dermatitis and the possibility of using the electron probe microanalytic technique for analysis of epidermal events of this condition.

Animals↗
PubMed1989

Use of synthetic oligodeoxyribonucleotides for type-specific identification of coxsackie B viruses.

Synthetic oligodeoxyribonucleotides were used for type-specific identification of members of the coxsackie B virus group by nucleic acid hybridization. Two pairs of oligonucleotide chains were constructed based on nucleotide sequences in the VP1 regions of coxsackieviruses B3 and B4. Each labelled probe had a length of 24 nucleotides. The results showed that the oligonucleotide hybridized in a type-specific manner when assayed with extracts from cells infected with all different coxsackie B viruses. A method based on similar principles may thus be used for enterovirus typing.

Animals↗
PubMed1989

Nucleotide sequence of the gene for a fibronectin-binding protein from Staphylococcus aureus: use of this peptide sequence in the synthesis of biologically active peptides.

Binding of cells of Staphylococcus aureus to fibronectin, which may represent a mechanism of host tissue adherence, involves a fibronectin-receptor protein present on the bacterial surface. Cloning of a gene coding for a staphylococcal fibronectin-binding protein and construction of a fusion protein with fibronectin-binding properties was previously reported from our laboratory. We have now sequenced the gene and deduced a primary sequence of the fibronectin-binding protein. The protein resembles other cell-wall-associated proteins on Gram-positive bacteria in that it (i) appears to be anchored in the cell membrane via its C-terminal end, (ii) contains a proline-rich repeating unit outside the membrane anchor, and (iii) contains a long (36-amino acid) signal sequence at the N terminus. The fibronectin-binding activity has been localized to a domain composed of a 38-amino acid unit repeated completely three times and partially a fourth time; the identity between the three 38-amino acid sequences varies from 42 to 87%. Three synthetic peptides mimicking the structure of each 38-amino acid unit were constructed. All three peptides interacted with fibronectin, as indicated by their ability to inhibit binding of fibronectin to staphylococcal cells, whereas an unrelated 37-amino acid peptide showed no inhibitory activity.

Amino Acid Sequence↗
PubMed1989

Verbal memory function after subarachnoid haemorrhage determined by the localisation of the ruptured aneurysm.

A total of 219 patients who had suffered from subarachnoid haemorrhage (SAH) were given a set of memory tests. The tests comprised immediate free recall (indexing long-term memory, LTM, and short-term memory, STM), final free recall (LTM) and final cued recall (LTM) of words as well as a digit-span test (an index of working memory, WM). STM was highly sensitive to brain damage caused by SAH whereas WM was not. Localisation of the ruptured aneurysm, angiographic vasospasm or mass effect did not have any selective influence on the SAH group's STM or WM. The final free recall test was the most sensitive measure of LTM whereas the LTM part of the immediate free recall test was the least sensitive. LTM impairment was most pronounced for patients with ruptured left anterior communicating artery aneurysms or for patients with angiographic vasospasm or mass effect. It is suggested that, in the SAH patients, a passive phonological short-term store is impaired, but the active maintenance rehearsal mechanism is intact. For patients with LTM dysfunction, deeper, more elaborate, active processing is disrupted, hindering efficient long-term storage.

Adult↗
PubMed1989

Changes in sodium-potassium ratio in guinea pig epidermis in n-hexadecane-induced hyperplasia.

A transient epidermal hyperplasia was induced in guinea pig epidermis by a single application of n-hexadecane. The epidermal response was analysed by light microscopy and by energy dispersive X-ray microanalysis (EDX). The epidermal hyperplasia reached a maximum between 96 and 192 h after the application. The hyperplastic response was associated with a depressed sodium-potassium ratio (increased potassium, decreased sodium) in the keratinocytes at 96 h, beginning already at 48 h. At 24 h there were no major differences in elemental content, compared the controls. The result of the present study is consistent with the hypothesis that alterations in the functional state of the epidermal keratinocytes are associated with changes in the sodium-potassium ratio in the cells. The absence of major elemental changes at 24 h indicates that the initiation of the hyperplastic response occurred prior to this time point.

Alkanes↗
PubMed1989

Sodium lauryl sulfate enhances nickel penetration through guinea-pig skin. Studies with energy dispersive X-ray microanalysis.

The effect of sodium lauryl sulphate (SLS), a common ingredient of detergents, on the penetration of nickel through the stratum corneum in the guinea-pig skin model was studied with energy dispersive X-ray microanalysis (EDX) to evaluate the barrier-damaging properties of this common detergent. The EDX technique allows a simultaneous determination of physiologically important elements, e.g., Na, Mg, P, Cl, K, Ca and S in addition to Ni at each point of measurement in epidermal cell strata. Our results show that SLS reduces the barrier function to Ni-ion penetration of the stratum corneum. In addition we have shown that EDX allows analysis of the influence of different factors involved in nickel penetration through the skin by giving data on the physiological effects on the epidermal cells caused by the applied substances.

Animals↗