Search PubMed⌕ Search

Biomedical subjects

J Serup

Publications and source records attributed to J Serup.

At least 55 records · Page 3Linked to original sources
PubMed1994

Variation in color and blood flow of the forearm skin during orthostatic maneuver.

To investigate the influence of arm position on the color and blood flow of the forearm skin, the CIE L*a*b* values, the erythema and melanin indices, and laser-Doppler blood flow values were recorded at three different arm positions (lowered, heart level and raised) in 15 healthy subjects using three kinds of optoelectronic instruments. The values of almost all color parameters, including the melanin index, changed stepwise significantly following the change in the arm position, and blood flow values decreased significantly during arm lowering. These results are most likely due to complex changes in the volume, flow rate and oxygen saturation level of the blood in the superficial vascular plexus, and their influences on each parameter were discussed. To use these instruments effectively for the quantitative evaluation of skin test reactions, a standardized arm position should be kept when the test is carried out in the forearm.

Adult↗
PubMed1994

Enhancement of the granulation tissue formation in hairless mice by a potent vitamin D receptor agonist--KH 1060.

KH 1060 is a 20-epi analogue of 1,25-dihydroxyvitamin D3 and a potent agonist of the vitamin D receptor. Our recent finding that it stimulates glycosaminoglycan synthesis and transforming growth factor-beta 1 (TGF-beta 1) expression in normal skin provided a rationale for investigating its influence on the process of wound healing. Normal and betamethasone-impaired granulation tissue formation was studied in a polytetrafluoroethylene dead space model in hairless mice. The application of KH 1060 increased the indexes of fibroplasia and cellularity ([3H]thymidine incorporation and DNA concentration) of the betamethasone-impaired granulation tissue. Collagen production and deposition, measured as hydroxyproline synthesis and concentration in the granulation tissue, were also increased. The effect of KH 1060 on normal connective tissue repair was less pronounced; DNA and hydroxyproline concentrations in granulation tissue were unchanged. KH 1060 strongly stimulated the expression of TGF-beta 1 in betamethasone-impaired granulation tissue. Thus, it effectively reversed the deleterious effect of betamethasone on granulation tissue. The hyperproliferative response to this vitamin D analogue might be related to the direct stimulation of the vitamin D receptors in the granulation tissue, while the increased collagen synthesis and deposition was probably caused indirectly, via stimulation of TGF-beta 1.

Animals↗
PubMed1994

Skin mechanical properties present adaptation to man's upright position. In vivo studies of young and aged individuals.

In tall animals dependent tissues are stiffer to prevent oedema formation in the upright posture, but whether the same adaptation is operating in man is not known. Skin elasticity and distensibility were measured in vivo in 18 young and 15 aged individuals in the morning before getting up (baseline) and 12 h later. In young individuals skin was stiffer (less distensible) and less elastic in the acral parts of the extremities (ankle, forearm). In the evening distensibility and elasticity of the skin increased. In aged individuals skin was less elastic and no diurnal variability in elasticity and distensibility was detected. We propose that these unique mechanical properties of the acral skin reflect a major role of the integument in the protection against the gravitational stress and the development of the postural oedema. Altered skin mechanical properties may contribute to the poor compensation for gravitational stress in elderly.

Adaptation, Physiological↗
PubMed1994

Microvascular reactions to postural changes in patients with sickle cell anaemia.

Normal microcirculation of the lower extremity is characterized by the venoarteriolar vasoconstriction reflex and the disappearance of vasomotion in the dependent position. Patients with sickle cell disease are prone to develop ischemic leg ulcers at an early age. Dysfunction of the microcirculation might promote the development of leg ulcers in patients with sickle cell disease. Using laser Doppler equipment we have studied the changes of blood flux in the skin overlying the medial malleolus after leg lowering. Contrary to the normal physiological situation seen in our control persons, the venoarteriolar reflex was abolished and vasomotion preserved in the dependent position of the leg in both patients. We conclude that this may represent an adaptation to the dependent position in sickle cell disease.

Adolescent↗
PubMed1994

Impairment of the postural venoarteriolar reflex in aged individuals.

The venoarteriolar vasoconstriction reflex plays a major role in the prevention of leg oedema in the upright position in man. We studied the venoarteriolar vasoconstriction reflex with laser Doppler flowmetry in young (21 subjects, age 17-27) and very old (20 subjects, age 75-100) healthy volunteers. In the group of young volunteers, after lowering of the lower extremity 50 cm below the heart level, cutaneous blood flux decreased to 16.6% of the baseline, whereas in the group of old persons the venoarteriolar reflex was impaired and the flux decreased only to 29.2%. The difference between the two groups was statistically significant (p < 0.001). These results may explain the increased prevalence of postural oedema in old people.

Adolescent↗
PubMed1994

Comparison of narrow-band reflectance spectrophotometric and tristimulus colorimetric measurements of skin color. Twenty-three anatomical sites evaluated by the Dermaspectrometer and the Chroma Meter CR-200.

Two types of portable reflectance instruments, tristimulus colorimeters (Chroma Meter CR-200) and narrow-band spectrophotometers (Dermaspectrometer), have recently become available for the quantification of skin color. In order to know the difference and the relationship between the different color systems, the CIE L*a*b* system and the erythema melanin (E/M) indices, respectively, adopted by the two, the variations in skin color were measured at 23 different anatomical sites of 10 healthy Caucasian male subjects. The reddish tint of the skin color of the face, palm and sole was readily detected by either of them in the increase in the a* value or in the E index, and a strong linear correlation (r = 0.92, p < 0.001) was noted between the two values. The fair color appearance of the trunk was detected in the high L* value and in the low M index, but the correlation between the two was much less significant (r = -0.56, p < 0.001). Although the mean b* values were highest in the trunk, they are significantly lower on the non-light-exposed side than those on the light-exposed side of the arm. The correlation between the b* value and the M index was weak.

Adult↗
PubMed1994

Bioengineering and the skin: from standard error to standard operating procedure.

Bioengineering techniques for examination of the skin, measuring principles and sources of error relative to technique, study design, measuring conditions and variability related to test subjects and preconditioning are reviewed. Principles of validation and standard operating procedures (SOP) are discussed, including guidelines for measurement of transepidermal water loss (TEWL) and laser Doppler cutaneous blood flow. Today typical errors are not related to a measuring device but to the way it is used.

Biomedical Engineering↗
PubMed1993

Time course of occlusive effects on skin evaluated by measurement of transepidermal water loss (TEWL). Including patch tests with sodium lauryl sulphate and water.

The time course for transepidermal water loss (TEWL) for a period of 3 h after removal of occlusive patch tests with sodium lauryl sulphate (SLS), water and empty chambers was studied in healthy volunteers. Patches were applied to the upper arm for 24 h. TEWL was measured immediately after removal of the patches, and every 30 min up to 3 h. For SLS and water patches, TEWL remained significantly increased for 3 h, as compared to normal adjacent skin, while for empty chamber patches, TEWL was only significantly increased for 30 min. A significant decrease from 0 to 30 min and from 30 to 60 min was observed for all patches, and for water patches, a significant decrease in TEWL was found from 60 to 180 min, while SLS patches remained constant. The prolonged increase in TEWL observed after SLS exposure is a well-known occurrence. The prolonged increase in TEWL after exposure to water is interpreted as transient damage to the water barrier of the skin.

Adult↗
PubMed1993

High-frequency ultrasound scan for non-invasive cross-sectional imaging of psoriasis.

Seventeen patients with psoriasis vulgaris were studied by high-frequency (20 MHz) ultrasound imaging. An echo-lucent band located at the dermo-epidermal junction was characteristic. The band represents the combination of acanthotic epidermal thickening and inflammation. Thus, with ultrasound the site within the skin where primary events take place can be studied and followed non-invasively, i.e. with no known disturbance and influence on the course of the disease.

Adolescent↗
PubMed1992

Alterations in skin properties during rapid and slow tissue expansion for breast reconstruction.

This study comprises 23 women who had had mastectomies because of breast cancer. They were randomly divided into two groups when they were admitted for breast reconstruction by tissue expansion. The first group was expanded rapidly, i.e., every day, and the other group was expanded slowly, i.e., every week. There were no other differences in the treatment between the two groups. Three months after completion of expansion, the expander was replaced by a permanent prosthesis. The follow-up time was up to 6 months after the second operation. Three different parameters--distensibility, elasticity, and hysteresis--were measured noninvasively on the breast skin and at a control site on several occasions throughout the treatment. During the treatment period there were no differences in skin properties between rapidly and slowly expanded patients. Of the three parameters, distensibility showed the most prominent changes: decreasing during the expansion period, increasing after the expander had been replaced by a permanent prosthesis, and decreasing during the following 6 months. Elasticity did not change significantly, except decreasing after insertion of the permanent prosthesis, and the hysteresis increased at the same time. These findings indicate that tissue expansion alters breast skin only to a small extent and that the mechanical resistance sometimes encountered during tissue expansion is due to deeper structures such as underlying muscles or capsule formation.

Body Water↗
PubMed1992

Scaling, dry skin and gender. A bioengineering study of dry skin.

Dry skin and scaling was studied in a group of 72 healthy volunteers by using subjective self-assessment and by clinical assessment by a dermatologist, as well as application of noninvasive bioengineering techniques to measure scaling and epidermal hydration. The study revealed that 67% of the volunteers had subjective complaints, while only 5.6% had definite clinical signs of dry skin at the time of examination. Subjective complaints were more common in women than in men (p < 0.001), though neither clinical nor objective measurements showed any sex difference, which suggests that other factors may play a role in the way men and women perceive dry skin. Subjective and clinical scores were correlated (p < 0.02), though neither was significantly correlated to objective measurements. Grading of skin scaling on D-squame tapes correlated with densitometry of the tapes (p < 0.001), as did the electrical capacitance (p < 0.001). Both clinical and objective methods can identify dry skin. However, the study showed that in healthy persons a number of irrational factors play a role in the use of moisturizers, and while these factors cannot be measured, they must be taken into account. Healthy, but dry skin is a vaguely defined clinical entity, which may explain the generally poor correlation between the two methods. This underlines the need for several methods to be used simultaneously in order to elicit complementary information.

Adult↗
PubMed1992

A double-blind comparison of acitretin and etretinate in the treatment of Darier's disease.

The objective of this double-blind study was to compare the therapeutic effects of acitretin with those of etretinate in patients with Darier's disease. Twenty-six patients (10 males and 16 females) were included in the study. Patients were treated with 30 mg daily for the first 4 weeks and with an individually adjusted dose (10-50 mg/day) for the subsequent 12 weeks. Remission or marked improvement was obtained in 10 of the 13 acitretin-treated patients and in 8 of the 11 etretinate-treated patients who completed the 16-week treatment. The usual mucocutaneous adverse reactions of retinoids were observed in all but one patient. There were no significant differences between treatment groups with regard to the incidence of these reactions.

Acitretin↗
PubMed1992

Alterations of skin microcirculatory rhythmic oscillations in different positions of the lower extremity.

Microcirculatory vasomotion is considered to be an important mechanism promoting and facilitating the transfer of blood cells through skin capillaries. Since skin vulnerability of the leg is closely associated with gravitational factors and skin micro-circulation, we investigated by a laser Doppler apparatus influence of postural changes on skin blood flow oscillations in lower limbs of healthy volunteers. Our data show a marked decrease in microcirculatory oscillation amplitudes at a frequency 7.6 (+/- 0.6) min-1 after lowering the leg. This could be reversed by the application of compressive bandage. Our study points toward a potentially important mechanism of microcirculatory impairment during orthostasis.

Adult↗
PubMed1992

Characterization of contact dermatitis and atopy using bioengineering techniques. A survey.

Bioengineering techniques useful in the characterization of contact dermatitis and atopy are surveyed, including non-invasive techniques for the measurement of skin colour, blood flow, skin surface temperature, skin surface contour, water barrier, and skin surface hydration. Ultrasound measurement of skin thickness and edema formation, and ultrasound cross-sectional imaging are also included. Structural and pathophysiological findings in the different types of dermatitis are outlined. Weal or hive formation is covered additionally.

Chronic Disease↗
PubMed1992

A three-hour test for rapid comparison of effects of moisturizers and active constituents (urea). Measurement of hydration, scaling and skin surface lipidization by noninvasive techniques.

An in vivo skin test for rapid comparison of the efficacy of moisturizers is introduced. Test substances were applied to flexor side forearm skin, and measurements by non-invasive techniques were performed after 3 h. As indicators of epidermal hydration, the electrical conductance and capacitance were measured. To quantify the effects on scale pattern, D-Squame tapes were scored and the optical transmission measured. Moreover, skin surface lipids resulting from lotion lipids were measured. Lotions and different concentrations of urea could be ranked in a consistent way, viz. untreated skin < vehicle < 3% urea lotion < 10% urea lotion. Urea was concluded to be very potent as a skin humidifier and as a descaling agent, particularly in 10% concentration. Humidity characteristics correlated much better with the concentration of urea than with lipidization of the skin surface due to lotion lipids. A 3-hour test period was sufficient for the evaluation of the effects of moisturizers on both epidermal hydration and scale pattern. With a rapid test method, sources of variation such as diurnal and day-to-day variations, dosage and non-compliance are easily controlled. Further, by using non-invasive methods, the assessment has been rendered objective.

Adult↗
PubMed1992

A double-blind comparison of two creams containing urea as the active ingredient. Assessment of efficacy and side-effects by non-invasive techniques and a clinical scoring scheme.

From a group of 72 healthy individuals, 47 with evidence of dry skin according to measurements by non-invasive techniques were enrolled for a 3-week study with double-blind and randomized treatment of one forearm, using either 3% urea cream (HTH lotion 'light') or 10% urea cream (HTH lotion 'Original'). The contralateral forearm served as an untreated control. Two volunteers had to be excluded because measurements of skin surface lipids gave evidence of vehicle components on the skin surface at the time of final evaluations. Evaluations took place not less than 12 h after the last application. According to questionnaire replies, the two creams were equally effective. This was confirmed by "blind" evaluation of the skin hydration state by a dermatologist, measurements of electrical capacitance and conductance indicating epidermal and skin surface hydration, and by D-Squame tape assessments including optical transmission of tapes with stratum corneum and scales from adhering skin, as well as visual scoring of the tapes. The methods showed a high degree of correlation, i.a. a definite relation between increase in electrical hydration parameters, reduced scaling according to the D-Squame tape evaluations, and clinical improvement of dryness. In skin treated with 10% urea cream the transepidermal water loss (TEWL) decreased, indicating an improved water barrier function. Skin colour measurement according to the CIE colour system showed that skin treated with the 3% urea cream turned in the direction of yellow, and there was generally a tendency for the brightness to decrease. Thus, the 3% urea cream gave the skin a more golden colour. There was no change in redness with any of the creams. Neither data from the questionnaire, the clinical examination, nor results of TEWL and colour measurements indicated any local irritant effect of urea causing water barrier damage or inflammation. In conclusion, the 3% and 10% urea creams were both found efficient, resulting in improvement of hydration and reduction of scaling. Both were non-toxic. However, specific differences did appear, viz. the 3% urea cream turned the skin colour golden, while the 10% urea cream improved the skin's water barrier function.

Adult↗