Search results for "human skin"
showing 10 items of 75 documents
Regular consumption of fresh orange juice increases human skin carotenoid content
2015
Dermal carotenoids are a good indicator of antioxidant status in the body. This study aimed to determine whether regular consumption of orange juice could increase dermal carotenoids. Two types of orange juice, obtained from regularly (CI) and partially (PRD) irrigated trees, were tested to reveal any possible association between juice and dermal carotenoids. Soluble solids, titratable acidity, and total carotenoids were quantified in the juice; skin carotenoid score (SCS) was assessed by Raman spectroscopy. Carotenoid content was 7.3% higher in PRD than in CI juice, inducing no difference in SCS. In a first trial with daily juice intakes for 25 days, SCS increased linearly (10%) in the ind…
Catecholamine release in human skin--a microdialysis study.
2003
Dermal microdialysis might be a promising tool to investigate properties of sympathetic neurons in the skin as investigation of peripheral noradrenergic neurons in humans usually relies on highly variable vasoconstrictor reflexes or on indirect measurements like skin temperature recordings. To evaluate this technique, 21 experiments were performed in 15 healthy subjects with four intracutaneous microdialysis fibers (diameter, 200 microm; cutoff, 5 kDa) at hands or feet. After 60 min, saline perfusion tyramine at concentrations of 0.195 to 200 microg/ml was applied for 15 min followed by a 15-min saline perfusion again. Catecholamine concentrations were detected through high-performance liqu…
In vivo release of non-neuronal acetylcholine from human skin by dermal microdialysis: Effects of sunlight, UV-A and tactile stimulus
2007
Non-neuronal acetylcholine (ACh) is expressed in epithelial, endothelial and immune cells. For example, the in vivo release of ACh from the human skin pretreated with botulinum toxin has recently been demonstrated. In the present experiments the effects of light (sunlight and solar radiation by a commercial UV-A applier) and of a tactile stimulus on the release of non-neuronal ACh were investigated. Release of ACh from the proximal and distal shin, i.e. anterior tibial region, was measured by dermal microdialysis in 20 min samples over a time period of at least 140 min. Control experiments were performed in a dark room throughout. In some experiments volunteers were exposed to sunshine (80-…
Zolmitriptan inhibits neurogenic inflammation and pain during electrical stimulation in human skin.
2014
Background Triptans are agonists to 5-HT 1B/D/F receptors, which are present on nociceptive neurons not only within but also beyond the trigeminal system. The aim of this study was to investigate whether zolmitriptan interacts with peptidergic nociceptive afferents in human skin. Methods Twenty participants (13 women, median age: 25; interquartile range: 23–26 years) entered the randomized, double-blind, cross-over study. Electrically induced neurogenic flare and pain was assessed after either placebo or zolmitriptan on the ventral thigh. Mechanical pain thresholds were investigated at baseline and after electrical stimulation at the stimulation site. Results The size of the neurogenic flar…
Increased acetylcholine levels in skin biopsies of patients with atopic dermatitis.
2003
Recent experimental evidence indicates that non-neuronal acetylcholine is involved in the regulation of basic cell functions. Here we investigated the cholinergic system in the skin of healthy volunteers and patients with atopic dermatitis (AD). The synthesizing enzyme, choline-acetyltransferase (ChAT), was studied by anti-ChAT immunohistochemistry and enzyme assay. Skin biopsies taken from healthy volunteers and from AD patients were separated into the 2 mm superfical (epidermis and upper dermis) and 3 mm underlying portion (deeper dermis and subcutis). ChAT enzyme activity was detected in homogenized skin and subcutaneous fat (about 13 nmol/mg protein/h). ChAT immunoreactivity was express…
Reciprocal altered expression of E-cadherin and P-cadherin in mucous membrane pemphigoid.
2011
E- and P- cadherins are involved in the selective adhesion of epidermal cells. To gain insight into the role of cadherins on the acantholysis of keratinocytes and further investigate the pathogenesis of Mucous Membrane Pemphigoid, we examined the expression of P-cadherin and E-cadherin, in normal human oral mucosa, lesional and peri-lesional mucosa in MMP. Twenty-nine samples from paraffin-embedded specimens of MMP were used for the study. Five specimens of healthy oral mucosa were evaluated as control group. To evaluate the E- and P-Cadherin expression, a mean percentage of positive cells was determined from the percentage of positive cells derived from the analysis of 100 cells in ten ra…
Spreading of sudomotor axon reflexes in human skin.
2005
Acetylcholine (ACh) activates both sudomotor fibers and primary afferent nociceptors. This leads to sudomotor and vasodilator axon reflexes, which can be diminished, for example, in neuropathies. In some neuropathies, however, there is increased axon reflex sweating, a response pattern that has never been observed for vasodilator flares.To compare both types of axon reflexes and to elucidate possible differences.In healthy young male subjects, sweat response and flare reaction in response to ACh were quantified. Constant-current iontophoresis (300 mC) of ACh was performed on the lateral lower legs. The sudomotor axon reflex was visualized with iodine starch staining, and the sweat response …
Age-related dermal collagen changes during development, maturation and ageing - a morphometric and comparative study.
2014
The tissue organisation of dermal collagen is gaining importance as a contributing factor both in development and ageing, as well as in skin maturation processes. In this work we aim to study different representative parameters of this structural organisation in 45 human skin samples of assorted ages, by means of image analysis. The variation of these parameters on the basis of age was assessed using several regression models (linear, quadratic and cubic). The area occupied by collagen was significantly reduced as a function of age in the papillary dermis (R(2) = 0.437, P < 0.0001), as well as the thickness of the collagen bundles (R(2) = 0.461, P < 0.0001), following statistical models of …
Cytokeratin 20 Is a General Marker of Cutaneous Merkel Cells While Certain Neuronal Proteins Are Absent
1995
Merkel cells are difficult to identify in tissue sections. Previous studies have used cytokeratins (CK) 8, 18, and 19 as histologic markers of Merkel cells. However, these CKs are also expressed in some outer root sheath keratinocytes and some early fetal epidermal cells and thus are not truly specific of Merkel cells in general. Using selective antibodies against a newly described CK, number 20--originally found in intestinal epithelium and Merkel cell carcinomas--in comparison to a key protein of neuroendocrine cells, chromogranin A, we established CK 20 as a specific Merkel cell marker in skin of humans, pigs, and mice. CK 20 seems to be an even more general and sensitive Merkel cell mar…
Photobleaching effects onin vivoskin autofluorescence lifetime
2015
The autofluorescence lifetime of healthy human skin was measured using excitation provided by a picosecond diode laser operating at a wavelength of 405 nm and with fluorescence emission collected at 475 and 560 nm. In addition, spectral and temporal responses of healthy human skin and intradermal nevus in the spectral range 460 to 610 nm were studied before and after photobleaching. A decrease in the autofluorescences lifetimes changes was observed after photobleaching of human skin. A three-exponential model was used to fit the signals, and under this model, the most significant photoinduced changes were observed for the slowest lifetime component in healthy skin at the spectral range 520 …