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Biomedical subjects

J Serup

Publications and source records attributed to J Serup.

At least 91 records · Page 5Linked to original sources
PubMed1989

Skin reactions to irritants assessed by non-invasive bioengineering methods.

Pathophysiological components of irritant contact dermatitis caused by 3 chemically-different irritants were investigated. 20 healthy volunteers were patch tested with sodium lauryl sulphate, nonanoic acid and hydrochloric acid on the flexor side of the upper arm. The skin response was evaluated after 24, 48 and 96 h by visual scoring and measured by the following bioengineering methods: transepidermal water loss measurement, electrical conductance for measurement of skin hydration, laser Doppler flowmetry for measurement of cutaneous blood flow and 20 MHz ultrasound A-scan for measurement of skin thickness. In spite of homogeneous inflammatory responses, significant differences in the severity of the injury to the skin barrier function caused by the different irritants were found. Also significant differences between irritants were found in the time course of development of maximum irritant reactions. Bioengineering methods indicating inflammatory responses (measurement of blood flow and skin thickness) were helpful in quantifying the irritant response in general, while bioengineering methods indicating epidermal damage (measurement of TEWL and electrical conductance) were helpful in classifying the individual irritants.

Adult↗
PubMed1989

Different skin irritation abilities of different qualities of sodium lauryl sulphate.

A marked variation in the concentration of sodium lauryl sulphate (SLS) used for irritant patch testing is found in the literature, but is hitherto unexplained. In the present study, 2 different qualities of SLS were tested clinically on healthy volunteers. The skin responses were evaluated by visual scoring as well as by non-invasive measurement of transepidermal water loss (TEWL), blood flow and oedema. A significant difference in the skin response to the 2 qualities was found both clinically and by non-invasive methods used for quantitation. 5 different qualities of SLS were investigated by high-performance liquid chromatography (HPLC). Marked discrepancies in the quantity of C12 carbon chains in the products were found, offering an explanation for the proven difference in the clinical response. It is concluded that only SLS qualities of high purity should be used for irritant patch testing, and that both the quality and the purity of SLS should be stated.

Adult↗
PubMed1989

Effects of single application of a moisturizer: evaporation of emulsion water, skin surface temperature, electrical conductance, electrical capacitance, and skin surface (emulsion) lipids.

Effects of single application of an oil in water emulsion were studied on the forearm skin of 12 healthy volunteers. Five different non-invasive methods were used. Values were followed for 360 min after application of the emulsion, with the contralateral forearm as untreated control. The evaporation of emulsion water from the skin surface immediately rose to high values, but within 15 min returned to the original level. A parallel initial increase in conductance was observed; however, this was followed by a slightly increased level throughout the 360 min study. Electrical capacitance was also slightly increased throughout the study. Skin surface lipids, dominated by emulsion lipids, were increased, with high values for at least 120 min, followed by a gradual decline toward normal. Single application of emulsion is characterized by an initial evaporation phase, with evaporation of emulsion water, which lasts less than 15 min, followed by a lipidization phase, which lasts at least 360 min, dominated by the oil-constituent of the emulsion undergoing epidermal absorption. During the lipidization phase, epidermal hydration parameters are slightly but consistently improved.

Aged↗
PubMed1989

Effects of repeated application of a moisturizer.

Epidermal hydration following repeated application of an oil in water emulsion was studied on the forearm skin of 16 healthy females by non-invasive methods. The lotion was applied twice daily for 7 days, and values were followed 7 days after cessation of treatment. The opposite forearm served as an untreated control. Electrical conductance and capacitance showed similar results, i.e. increased values (p less than 0.001) after 2 days of application, reaching a plateau during further applications. Two days after cessation, values were still increased (p less than 0.001), and the conductance was also increased 7 days after cessation of treatment. The water evaporation and the cutaneous blood flow did not change, i.e. indicating no mild irritant effect. Skin surface lipids did not change, i.e. indicating that no significant amounts of emulsion oil remained on the skin at the time of recording. Probably components of the oil phase of the emulsion are absorbed into the epidermis, which is associated with improved hydration as a later event.

Adult↗
PubMed1989

Ultrasound structure of the human nail plate.

The structure of the normal human nail plate is described using an ultrasound scanner (20 MHz A). Postmortem studies, including examination of nail plate biopsy specimens before and after desiccation, were performed and compared with in vivo structures. Two compartments could be identified in the nail, ie, a dry and superficial compartment with the ultrasound velocity of 3103 m/s and a humid and deeper compartment with an ultrasound velocity of 2125 m/s. The ultrasound velocity of the entire nail was 2459 m/s, and the water content was 35% wt/wt. Underneath the nail, echoes from the nail bed were seen. Ultrasound was concluded useful for noninvasive measurement of nail thickness and examination of internal nail structure.

Adult↗
PubMed1988

Allergic and irritant skin reactions evaluated by laser Doppler flowmetry.

Skin blood flow (SBF) in allergic and irritant reactions was determined by laser Doppler flowmetry (LDF) in an attempt to differentiate these reactions in an objective way. 12 subjects with known allergy to nickel were patch tested with nickel sulphate, nickel chloride, and with sodium lauryl sulphate (SLS) 1, 2, 5 and 10%. A positive correlation between the concentration of SLS and SBF was found. Compared with control sites, SBF in weak (+) and strong (++) positive allergic and irritant reactions was increased approximately 5-10 fold 1 and 2 days after application, and decreased towards normal 7 days after application. At day 7, the mean SBF was higher in allergic reactions than in irritant reactions. However, no consistent differences were found. It is concluded that although LDF can be used to quantify the strength of allergic and irritant skin reactions, this method cannot be used solely to separate these 2 types of reaction.

Adult↗
PubMed1988

Contact thermography for assessment of skin damage due to experimental irritants.

Irritant dermatitis after application of experimental irritants was studied by means of contact thermography. Sixteen healthy persons were patch-tested, using the following irritants: Sodium lauryl sulphate, benzalkonium chloride, nonanoic acid, hydrochloric acid, croton oil, sapo kalinus and sodium hydroxide. A main finding was that croton oil after 24 h caused a warm skin lesion, and sodium lauryl sulphate after 96 h caused a cold skin lesion. This study emphasizes the differences in the skin reactions to different irritants.

Croton Oil↗
PubMed1988

Assessment of skin moisture. Measurement of electrical conductance, capacitance and transepidermal water loss.

Experiments on skin moisture, i.e. the hydration state of the outer epidermis, were undertaken using three different types of equipment, i.e. the Skicon-100 and Corneometer CM 420 hydrometers and the Servo Med EPI evaporimeter. The studies included 10 healthy volunteers. Water was applied to test sites on the forearm and the palm of the hand, and effects monitored by the three methods. Parallel increases in conductance, capacitance and transepidermal water loss were registered for a duration of about 5 min. The Skicon-100 was more sensitive for measurement of increased hydration, while the Corneometer CM 420 might be more sensitive for measurement of decreased hydration. Inter- and intra-individual variations were minor with all instruments. According to reproducibility studies, the Corneometer CM 420 was more accurate than the Skicon-100. Technical experiments indicated that the Corneometer CM 420 depicts changes of hydration down to a depth of 0.1 mm, while the Skicon-100 measures very superficially. In conclusion, both hydrometers were deemed relevant and valid for assessment of skin moisture. The methods are complementary, and their combined use is recommended.

Adult↗
PubMed1987

Differentiation of allergic and irritant reactions by transepidermal water loss.

12 patients with known allergy to nickel were patch tested with nickel sulphate, nickel chloride, and sodium lauryl sulphate 1, 2, 5 and 10%. 2 parallel series were performed, i.e., one with 24-h and one with 48-h application time. Reactions were followed by measurement of transepidermal water loss (TEWL). Allergic reactions showed a normal TEWL after 24-h application, and after 48 h, only strong reactions resulted in increased TEWL. In contrast, irritant reactions showed increased TEWL in both series, irrespective of the strength of the reaction. The deficient water barrier of allergic reactions is secondary, probably resulting from the underlying inflammatory process. Consequently, if TEWL measurements are used for the purpose of differentiating allergic and irritant skin reactions, a short application period, i.e., in this study 24 h, is preferable, with recordings performed shortly after removal of test chambers.

Adolescent↗
PubMed1987

Hydration studies on scaly hand eczema.

Transepidermal water loss (TEWL) and electrical conductance by a high-frequency (3.5 MHz) method were measured in 20 patients with chronic scaly hand eczema. Eczematous skin was compared with uninvolved skin of the same anatomical region. TEWL of eczematous skin was increased in all patients. In contrast, the conductance was decreased in all patients except for one, who showed equal values in pathological and uninvolved skin. This indicates that the water-holding capacity of eczematous skin is reduced. There was no correlation between clinical grading of scaling, and TEWL and electrical conductance. TEWL and conductance were not correlated, and the 2 methods are therefore supplementary for assessment of eczema and scaling. TEWL may be useful for monitoring the primary effect of therapy, and conductance for the final documentation of healing.

Adolescent↗
PubMed1987

Ultrasound for assessment of allergic and irritant patch test reactions.

The oedema formation of patch test reactions was quantified by high-frequency ultrasound measurement of skin thickness. Patch testing with nickel sulphate, nickel chloride and sodium lauryl sulphate 1, 2, 5 and 10% was performed in 12 individuals with known nickel allergy. Oedema was greater in allergic than in irritant reactions similar in strength according to the clinical reading. In allergic reactions, the oedema appeared more transcutaneous, while in irritant reactions, more superficial. For differentiation of the 2 types of reaction, application of substances for a 24-h period with measurements the following day is preferable. For rating of allergic and irritant reactions, 48 h of application is preferable with measurements performed on the day patches are removed.

Adolescent↗
PubMed1987

Skin reactions to irritants assessed by polysulfide rubber replica.

Skin damage after application of experimental irritants was evaluated under blind conditions and by the use of polysulfide rubber replica. Closed patch tests with 7 different irritants, solvents and empty chambers were applied to 16 volunteers, and the skin damage was evaluated visually and by a replica technique after 24, 48 and 96 h. We found that 3 of the irritants (sodium lauryl sulphate, hydrochloric acid and croton oil) were capable of causing specific and significantly different patterns of skin damage. The patterns could be divided into papular (hydrochloric acid, croton oil) and non-papular (sodium lauryl sulphate, sapo kalinus, sodium hydroxide) types. Nonanoic acid caused a non-paular pattern, but propanol, used as a solvent, by itself also produced a non-papular pattern. The time between application of the irritant and appearance of the characteristic alteration in the skin surface differed, depending on the irritant applied.

Adult↗
PubMed1987

Fundus fluorescein angiography in generalized scleroderma.

Fundus affliction with generalized scleroderma was studied in 21 patients by ophthalmoscopy, fundus ocular photography and fluorescein angiography. Slitlamp examination of the anterior chamber, the iris and the lens revealed no evident affections. Neither did ophthalmoscopy reveal obvious abnormalities related to scleroderma. Abnormalities of pigmentation were not noted. Visual acuity was normal in 20 patients, and 1 patient had reduced visual acuity due to macular degeneration. Fundus fluorescein angiography was within normal physiological variation in 14, and definitely abnormal in 7 patients as assessed independently by 2 ophthalmologists. Angiographic abnormalities consisted of variable hyperfluorescence of the pigment epithelium layer, and, additionally, in 2 cases minute hyperfluorescence of the retinal layer. These angiographic abnormalities indicated affection of the retinal pigment epithelium probably caused by a vascular lesion of the choroidal layer. Retinal vessels were in general not affected. In conclusion, the choroidal vasculature appears affected in 1/3 of patients with generalized scleroderma as assessed by fundus fluorescein angiography.

Adult↗