High iron and low ascorbic acid concentrations in the dermis of atopic dermatitis patients

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease in which reactive oxygen species (ROS) may be involved. Iron catalyses ROS formation and ascorbic acid (AA) scavenges these species. OBJECTIVE: The aim of this work was to determine iron and AA levels in AD patients' dermis and to compare their concentrations with those of healthy volunteers' dermis. METHODS: Five AD patients and 5 healthy subjects (controls) were enrolled in this study. Iron and AA were collected from human dermis by microdialysis and assessed by atomic absorption spectrometry and gas chromatography-mass spectrometry, respectively. RESULTS: The AD dermis demonstrated higher iron concentrations (44.3 +/- 4.6 microg/l) compared to controls (21.8 +/- 1.2 microg/l) as well as a significantly lower concentration of AA (46.7 +/- 0.6 vs. 176.8 +/- 14.5 microg/ml, respectively). CONCLUSION: These results suggest that iron and AA dermis levels could be indicators of inflammatory tissues and might be implicated in dermatological diseases such as AD.     

Skin Zinc Concentrations in Patients with Varicose Ulcers

The concentration of zinc in the skin has been determined noninvasively in patients with varicose vein ulcers. The examinations were performed with the use of diagnostic x-ray spectrometry, a method based on x-ray fluorescence for in vivo noninvasive evaluation of trace elements. Four skin foci were examined: at the periphery of the ulcer and control areas in a nonulcerated area in the diseased leg, in the noninvolved leg, and in the proximal inner surface of the arm. Zinc levels around the ulcer (mean +/- SD, 9.8 +/- 4.0 micrograms of zinc in 1 g of wet tissue) were higher than those in the nonulcerated skin in the diseased leg (6.9 +/- 3.0 micrograms/g, p greater than 0.05) and those in the noninvolved leg (5.4 +/- 2.0 micrograms/g, p less than 0.01). The concentration of zinc in the inner proximal surface of the arm (9.8 +/- 2.8 micrograms/g) was significantly higher than those of a control group (5.3 +/- 1.9 micrograms/g, p less than 0.01). These results suggest a defect of zinc distribution in patients with varicose vein ulcers.     

Effect of age on the biomechanical and microcirculatory properties of the skin in healthy individuals and during venous ulceration

Background:

With aging there is alteration of elastic properties of the skin and skin-blood flow.

Aim:

The purpose of this study was to compare age-related changes in selected biomechanical parameters of the skin (skin hardness, skin extensibility, relaxation time constant, τ) and subcutaneous microcirculatory quality (SMQ) in individuals with and without venous diseases.

Materials and Methods:

Two groups were studied: the first group was of asymptomatic healthy individuals and the second group included patients with chronic venous insufficiency (CVI) and venous ulceration, without edema. Both groups were subdivided to three age categories (21-40, 41-60 and 61-90 years old). Skin hardness was measured by durometer, extensibility and τ were measured using extensometer and SQM was assessed via postural vasoconstrictive response (LDF).

Results:

Results showed that skin hardness, extensibility, and τ-values were increased, whereas LDF was decreased in the older groups as compared with younger groups. These changes are attributed to alterations in the skin structure and reduced capillaries density networks. Similar behavior was found in the biomechanical and microcirculatory changes in patients with venous ulceration and CVI, but these changes were more increased further in older patients with venous ulceration as compared with older patients with CVI and that can be attribute to more intense response against tissue injury.

Conclusions:

Since aging elevated skin hardness and extensibility, but lowered vasoconstrictive response in individuals, with and without, venous diseases, we conclude that aging process is likely to cause an accumulation of damaged skin tissues and that could induce an apparent antigen-driven response that altered skin structure and the subsequent biomechanical properties obtained in this study.     

Antenatal diagnosis of recessive dystrophic epidermolysis bullosa: collagenase expression in cultured fibroblasts as a biochemical marker

We performed fetoscopy and skin biopsy on a 19-week fetus at risk for recessive dystrophic epidermolysis bullosa (RDEB). Ultrastructural analysis of the tissue revealed dermolytic blister formation in the skin characteristic of the disease. To develop a biochemical test for use in antenatal diagnosis of RDEB, we established skin fibroblast cultures from the 20-week aborted fetus. The collagenase production by fetal RDEB fibroblast cultures was greater than seen in normal fetal fibroblast cultures. The concentration in culture medium from fetal RDEB cultures was 5.42 +/- 0.74 micrograms/ml (mean +/- SE) compared with 2.24 +/- 1.11 micrograms/ml in normal adult control cultures and 2.05 +/- 0.61 micrograms/ml in cultures from patients with other genetic forms of epidermolysis bullosa (p less than 0.025). In contrast, the concentration of collagenase in the fetal RDEB culture medium was not different from that seen in cell cultures from known patients with RDEB (5.34 +/- 1.12 micrograms/ml). Collagenase activity of the fetal RDEB medium was also increased approximately 3.5-fold. These data indicate that enhanced expression of collagenase by fetal RDEB skin fibroblasts can serve as a biochemical adjunct, and possibly an alternative, to morphologic examination of tissue for antenatal diagnosis.     

In vivo assessment of iron and ascorbic acid in psoriatic dermis

Reactive oxygen species play an important role in inflammatory skin diseases such as psoriasis. Reactive oxygen species synthesis is catalysed by iron and some species are scavenged by ascorbic acid. The aim of this work was to assess iron and ascorbic acid in uninvolved and involved psoriatic dermis and to compare the corresponding concentrations in the dermis of healthy subjects. Microdialysis associated with atomic absorption spectrometry and gas chromatography-mass spectrometry was used to assess iron and ascorbic acid, respectively. Seven psoriatic patients and five healthy volunteers were studied. Iron concentrations in the involved (57.1 +/- 19.3 microg/l) and uninvolved (49.7 +/- 27.1 microgl/l) psoriatic dermis were higher than the corresponding value determined in the dermis of healthy subjects (21.8 +/- 2.4 microg/l) (p<0.05). Ascorbic acid in involved (47.3 +/- 8.2 microg/ml) and uninvolved (42.0 +/- 14.0 microg/ml) psoriatic dermis was statistically lower than that found in healthy dermis (176.8 +/- 29.0 microg/ml) (p<0.05). These results demonstrate that psoriatic patients exhibit high iron and low ascorbic acid concentrations in the dermis, but there were no significant differences between involved and uninvolved skin.     

Dermal pericapillary fibrin in venous disease and venous ulceration

Pericapillary fibrin deposition is thought to contribute to the pathogenesis of venous ulceration. To our knowledge, however, there is no previous evidence that pericapillary fibrin is deposited in the tissue adjacent to venous ulcers. We prospectively studied patients with ulcers of the lower extremities for the presence of dermal pericapillary fibrin in the skin adjacent tot he ulcers. On direct immunofluorescence, pericapillary fibrin was found in 14 (93%) of the 15 patients with venous ulceration but in only one (7%) of the 14 subjects with ulcers due to other causes. We also confirmed the presence of dermal pericapillary fibrin in legs with venous disease without ulcerations. We conclude that the pericapillary fibrin is easily demonstrable in the dermis adjacent to venous ulcers. In the evaluation of ulcers due to uncertain causes, the presence of dermal pericapillary fibrin may provide additional diagnostic help.     

Iron, Copper, and Zinc Concentrations in Normal Skin and in Various Nonmalignant and Malignant Lesions

The concentrations of zinc (Zn), copper (Cu), and iron (Fe) in the skin have been noninvasively determined in vivo by diagnostic x-ray spectrometry. The skin of healthy controls was divided into two major groups based upon the distribution of the concentrations of these elements. In the face and upper neck, the following wet weight concentrations were recorded: Fe, 14.2 +/- 3.3 ppm; Cu, 1.3 +/- 0.3 ppm; and Zn, 6.7 +/- 1.1 ppm. In the chest, abdomen, arm, axilla, and lower neck, the concentrations of these elements were as follows: Fe, 10.2 +/- 2.5 ppm; Cu, 0.8 +/- 0.3 ppm; and Zn, 4.5 +/- 1.7 ppm. In most lesions of solar dermatitis, solar keratosis, basal and squamous cell carcinomas, variable elevations of Zn and Fe (up to significant levels) were recorded in most of the contralateral, apparently uninvolved skin. In the majority of pigmented nevi and malignant melanomas, the levels of Fe and Zn were elevated. In some of these, the Cu concentration also was increased.     

An increase of mature type skin collagen cross-link, histidinohydroxylysinonorleucine, in the sclerotic skin of morphea

Histidinohydroxylysinonorleucine (HHL) is a trivalent cross-link of type I collagen that is stable and has physiologic properties. In this study, we conducted a biochemical quantification of HHL in five patients with morphea. We compared the quantity of HHL contained in the lesional skin and the adjacent normal skin. The molar ratio of HHL to collagen in the sclerotic lesion was significantly higher than that of the adjacent normal skin (0.36 +/- 0.09 vs. 0.28 +/- 0.10, P<0.01). We could find no relationship between an increase of HHL content and the duration of the disease. The results indicate that an increased amount of HHL may play a certain role to inducing the sclerotic skin change characteristic of morphea.     

Selective pick-up of increased iron by deferoxamine-coupled cellulose abrogates the iron-driven induction of matrix-degrading metalloproteinase 1 and lipid peroxidation in human dermal fibroblasts in vitro: a new dressing concept.

Using atomic absorption spectrum analysis, we found iron levels in exudates from chronic wounds to be significantly increased (3.71 +/- 1.56 micromol per g protein) compared to wound fluids from acute wounds derived from blister fluids (1.15 +/- 0.62 micromol per g protein, p < 0.02), drainage fluids of acute wounds (0.87 +/- 0.34 micromol per g protein, p < 0.002), and pooled human plasma of 50 volunteers (0.42 micromol per g protein). Increased free iron and an increase in reactive oxygen species released from neutrophils represent pathogenic key steps that --via the Fenton reaction - are thought to be responsible for the persistent inflammation, increased connective tissue degradation, and lipid peroxidation contributing to the prooxidant hostile microenvironment of chronic venous leg ulcers. We herein designed a selective pick-up dressing for iron ions by covalently binding deferoxamine to cellulose. No leakage occurred following gamma sterilization of the dressing and, more importantly, the deferoxamine-coupled cellulose dressing retained its iron complexing properties sufficient to reduce iron levels found in chronic venous ulcers to levels comparable to those found in acute wounds. In order to study the functionality of the dressing, human dermal fibroblasts were exposed to a Fenton reaction mimicking combination of 220 microM Fe(III) citrate and 1 mM ascorbate resulting in a 4-fold induction of matrix-degrading metalloproteinase 1 as determined by a matrix-degrading metalloproteinase 1 specific enzyme-linked immunosorbent assay. This induction was completely suppressed by dissolved deferoxamine at a concentration of 220 microM or by an equimolar amount of deferoxamine immobilized to cellulose. In addition, the Fe(III) citrate and ascorbate driven Fenton reaction resulted in an 8-fold increase in malondialdehyde, the major product of lipid peroxidation, as determined by high pressure liquid chromatography. This increase in malondialdehyde levels could be significantly reduced in the presence of the selective pick-up dressing coupled with deferoxamine suggesting that the deferoxamine dressing, in fact, prevents the development of a damaging prooxidant microenvironment and also protects from unfavorable consequences like matrix-degrading metalloproteinase 1 and lipid peroxide induction.     

Ultrastructural morphometric analysis of human mast cells in normal skin and pathological cutaneous lesions

Electron micrographs of human mast cells in normal neonatal and adult skin and in cutaneous lesions of basal cell carcinoma (BCC), hemangioma and mastocytosis were assessed by morphometric analysis. Using this quantitative histologic approach, adult skin mast cells were found to be significantly larger (47.7 microns 2 +/- 2.4 SEM vs. 38.3 microns 2 +/- 1.8 SEM, p less than or equal to 0.001) and have larger granules (0.63 micron +/- .02 SEM vs. 0.53 micron +/- .02 SEM, p less than or equal to 0.001) than infant mast cells while both mast cell populations had comparable nuclear sizes (13.7 microns 2 +/- 0.9 SEM vs. 14.3 microns 2 +/- 0.8 SEM) and numbers of cytoplasmic granules (72 +/- 4.0 SEM vs. 66 +/- 4.0 SEM). Morphometric analysis of mast cell infiltrates in the adult skin lesions of BCC and hemangioma revealed that these cells were larger than neonatal mast cells but were similar to normal adult controls. Cutaneous mast cells from 2 mastocytosis patients, however, had significantly larger mean cell surface areas (78.0 microns 2 +/- 3.4 SEM and 70.6 microns 2 +/- 3.2 SEM, p less than or equal to 0.001), nuclear areas (20.8 microns 2 +/- 1.1 SEM and 21.3 microns 2 +/- 1.2 SEM p less than or equal to 0.001) and granule diameters (0.82 micron +/- 0.4 SEM and 0.83 micron +/- .03 SEM, p less than or equal to 0.001) when compared with mast cells in normal adult skin and in the other pathologic lesions. No difference in the total number of cytoplasmic granules was observed in the different mast cell populations.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prostaglandin D2 release by guinea pig skin during in vitro anaphylaxis induced by antigen and compound 48/80

The release of prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), and histamine induced by antigen and compound 48/80 was studied using an in vitro model of anaphylaxis in guinea pig skin. Abdominal skin from ovalbumin-sensitized guinea pigs was cut into 0.5-1.0 mm-thick slices which were incubated in Tyrode solution at 37 degrees C with or without either ovalbumin or 48/80. Released PGD2 and PGE2 were measured by radioimmunoassay and gas chromatography-mass spectrometry, respectively. Release of PGD2 was detectable at 2 min after challenge (50 micrograms/ml ovalbumin), reaching a maximum at about 15 min. Histamine release was more rapid, achieving 50% of maximum at about 4 min compared to about 7 min for PGD2. In 11 experiments incubation with ovalbumin (50 micrograms/ml for 10 min) induced a significant 6-fold increase in PGD2 compared to unchallenged controls (399 +/- 53 and 67 +/- 19 ng/g dry weight skin, respectively; mean +/- SEM) and a net 47.2% histamine release. In contrast, a smaller (27%) rise in PGE2 was found. Indomethacin (14 microns) completely suppressed evoked PGD2 and PGE2 synthesis without evident effect on histamine release, suggesting that the release of histamine in this model is not dependent on prostaglandin production. The mast cell degranulating agent compound 48/80 (50 micrograms/ml) released significant amounts of PGD2 (340 +/- 86 ng/g skin compared to 89 +/- 30 ng/g for control skin, n = 5) but had no appreciable effect on PGE2. These results show that guinea pig skin can synthesize significant quantities of PGD2 in anaphylactic reactions. Prostaglandin D2 produced in acute allergic reactions in skin in vivo may contribute to the inflammatory reaction, either directly or in synergism with other mediators.     

Detection of iron deposition in dermal fibrocytes is a useful tool for histologic diagnosis of nephrogenic systemic fibrosis

Nephrogenic systemic fibrosis (NSF) is a fibrotic disease that presents with a history of renal dysfunction. The differential diagnosis generally includes scleromyxedema, systemic sclerosis, and morphea. Especially, scleromyxedema can be extremely difficult to distinguish microscopically. Although the fibrocytes in NSF are often positive for CD34 and procollagen-I, this is not specific for NSF. We identified positive iron staining in the skin of a patient with NSF and investigated whether this was a specific feature among 9 patients with NSF reported in Japan. We found that 6 of 9 patients showed positive iron staining in the dermal fibrocytes. The amount of iron deposition seemed to have no correlation with the degree of fibrosis or duration of the skin lesions but correlated with apparent history of the use of gadolinium-based contrast agents. As controls, skin biopsies from patients with scleromyxedema, morphea, and systemic sclerosis were evaluated by iron staining. None of these control patients showed iron deposition, indicating that positive iron staining may be specific to NSF and can be a useful tool for NSF diagnosis.     

Intranuclear androgen concentrations in facial skin

The concentrations of 5 alpha-dihydrotestosterone (DHT) and testosterone were measured by radioimmunoassay (RIA) in the crude nuclear and cytoplasmic fractions of facial skin containing large sebaceous glands. The data obtained were compared with those obtained with specimens from non-target areas. The intranuclear levels of DHT and testosterone in facial skin were 0.03 +/- 0.3 pg/micrograms DNA and 0.35 +/- 0.03 pg/micrograms DNA, respectively levels in genital skin. By contrast, both androgens were below detection by RIA in non-target skin. There was no significant difference between men and women with respect to the intranuclear androgen levels in facial skin. These findings support the view that the sebaceous gland is a typical androgen target organ irrespective of sex.     

Role of sulphydryl-containing agents in the management of venous (varicose) ulceration. A new approach

This randomized double-blind controlled study examined whether sulphydryl-containing agents influence the healing of venous ulceration occurring for the first time on the medial side of the leg. Graduated compression bandaging, which exerted a mean ankle pressure of 40.6 +/- 0.4 mmHg, and a mean below-knee pressure of 17.1 +/- 0.2 mmHg, healed 70% of ulcers within 12 weeks (n = 46). The addition of the sulphydryl-containing agents DL-cysteine (n = 46) or DL-methionine-methyl sulphonium chloride (n = 45) to the compression bandaging (daily application of the powder for 7 days, followed by once weekly applications until the end of the study 3 months later) significantly (P < 0.01) stimulated healing of venous ulceration relative to control values when studied 4, 8 and 12 weeks after commencing treatment. After 3 months of treatment, both sulphydryl-containing compounds healed 93% of the ulcers. The results show that sulphydryls stimulate healing of venous ulceration.     

UV erythema and the skin oxygen tension of the lower leg—observations with relevance to leg ulcer treatment

Direct measurements of skin oxygen tension on the lower leg have shown low values in the standing position (Dodd, Gaylarde & Sarkany, 1984). This is the result of reflex vasoconstriction stimulated by high venous pressure. Exercise reduces venous pressure in normal limbs and produces a rise in skin oxygen tension, whereas limbs affected by venous ulceration fail to show this response. Recumbency reduces venous pressure and produces a consequent rise in skin oxygen tension, a finding which accords well with the beneficial effect of bed rest on the healing of venous leg ulcers.
Since reflex vasoconstriction appears to be the mechanism by which persistent venous hypertension leads to skin hypoxia and ulceration, an agent capable of reducing this vasoconstriction might be expected to produce a favourable effect on the healing of venous leg ulcers in ambulant patients. Preliminary observations with a number of drugs including glyceryl trinitrate, amyl nitrite, naftidofuryl oxalate, ethyl alcohol and aspirin have shown that they do not block the normal vasoconstrictor response to increased venous pressure and therefore have no beneficial effect on the skin oxygen tension of the lower limb. We have found that the effect of ultraviolet erythema (3 MED of UV-B) is to reduce or abolish the fall in skin oxygen tension normally seen on changing from the recumbent to the standing position and the erythema is accompanied by an increase in oxygen tension in the recumbent position. This phenomenon lasts for approximately 48 h and judiciously repeated UV treatment may be of therapeutic value. Our findings suggest that there is a need to re-examine the role of UV irradiation in the management of skin disorders resulting from venous insufficiency.     

Functions of the stratum corneum in systemic sclerosis as distinct from hypertrophic scar and keloid functions

Both transepidermal water loss (TEWL) and skin surface high-frequency conductance are functions of the skin barrier. Systemic sclerosis (SSc) and hypertrophic scar (HS)/keloid are characterized by abnormal fibrotic changes in the dermis. Since the close interrelationship between the epidermis and the dermis has been well established, we analyzed the stratum corneum functions of forearm skin in 39 SSc patients after assessing the degree of the skin thickening and compared those functions with 10 age-matched normal controls. We also analyzed the stratum corneum functions of HS or keloid lesions in seven patients using the same methods, and compared those functions to adjacent or contralateral normal skin in identical patients. Neither the TEWL, nor high-frequency conductance of forearm skin in SSc patients were significantly different from those in normal controls. There was no correlation between the levels of TEWL or high-frequency conductance and the degree of skin thickening in SSc. In HS or keloid conditions, high-frequency conductance was significantly elevated (42.5+/-8.9 vs. 26.4+/-5.7, P<0.001). Although TEWL was elevated, there was no statistical significance (48.6+/-39.7 vs. 25.1+/-10.1). Our results revealed that stratum corneum functions are distinct between SSc and HS or keloid. This may reflect the various natures of dermal changes, which in turn differentiate the functions of the stratum corneum in the diseases.     

Percutaneous absorption of flurbiprofen in the hairless rat measured in vivo using 19F magnetic resonance spectroscopy.

The objective of this investigation was to develop a new methodology using 19F-magnetic resonance spectroscopy (MRS) to measure the in vivo percutaneous absorption of flurbiprofen through hairless rat skin. A 2% W/V flurbiprofen gel (Klucel HF, hydroxypropyl cellulose 1.5% to 2% W/V) containing isopropyl alcohol, water, and propylene glycol (55:35:10 v/v/v) was prepared. A 2-mg dose (100 mg of gel) was applied to the skin of the lower back of an anesthetized hairless rat, contained with a rubber o-ring, and occluded with a lexan plastic cover slip. The animal was placed on an MR surface coil (3.5-cm diameter tuned to 19F) and measurements taken continuously over approximately 3 h in 10-min intervals with a 2-tesla GE CSI nuclear magnetic resonance (NMR) spectrometer. One measures the disappearance of MR signal intensity per interval, which directly relates to the percent of drug disappearance over time, which in turn was converted to a flux value. The flux of flurbiprofen in vivo was found to be 95 +/- 22 micrograms/cm2/h. This is approximately four times greater than the flux of flurbiprofen through excised human skin reported by Akhter and Barry (22 +/- 14 micrograms/cm2/h). This new in vivo method measures drug disappearance and can be readily transferred to man. This method may be adapted to study other fluorine compounds or other nuclei with magnetic properties. It avoids exposure of a patient or animal to the radiation used in x-ray fluorescence methods or to 14C- or 3H-radiolabeled drugs.     

Skin discoloration in chronic idiopathic thrombocytopenic purpura: detection of local iron deposition by X-ray spectrometry

A forty-six-year-old woman with a 32 years' history of idiopathic thrombocytopenic purpura presented with black-brown discoloration of her lower limbs. Noninvasive diagnostic X-ray spectrometry (DXS) for determination of trace elements in external tissues revealed striking local iron deposition confined to the skin area with the pigmentary changes. Iron deposition in the skin was probably due to recurrent local purpura caused by longstanding bleeding disorder. Hence DXS proved useful in the detection of local iron load and eliminated the need for skin biopsy in this patient with bleeding tendency.     

Neuronal sensitization for histamine-induced itch in lesional skin of patients with atopic dermatitis

OBJECTIVE: Lowered threshold of neurons (ie, neuronal sensitization) in atopic dermatitis was investigated by testing sensitivity to histamine. DESIGN: Comparative study. SETTING: A dermatological clinic and a research laboratory. PARTICIPANTS: Eighteen patients with atopic dermatitis (AD) and 6 patients with chronic plaque-type psoriasis as well as 14 healthy control subjects. INTERVENTIONS: Histamine prick was performed in lesional and nonlesional skin of patients and in control subjects. MAIN OUTCOME MEASURES: Axon reflex flare and wheal were measured planimetrically, and the itch intensity was rated on a numerical scale (0-10). RESULTS: In nonlesional skin of patients with AD, itch intensity and axon reflex flare were both significantly smaller compared with controls (mean +/- SEM maximum itch, 1.5 +/- 0.3 vs 3.1 +/- 0.2 [P<.05]; mean +/- SEM diameter, 12.3 +/- 2.0 vs 25.3 +/- 2.5 mm [P<.01]). In lesional skin of patients with AD, on the contrary, massive itch was provoked (maximum itch, 4.4 +/- 0.3), although flare was relatively small (diameter, 16.1 +/- 3.4 mm). Itch ratings in patients with psoriasis were low both in lesional and nonlesional skin (maximum itch, 1.3 +/- 0.6 and 1.0 +/- 0.4, respectively). CONCLUSION: As the area of axon reflex flare is an indirect measure of activity in primary afferent neurons, our results suggest a decreased activation of peripheral pruriceptors in patients with AD. The massively increased itch in lesional skin of patients with AD might therefore be based on sensitization for itch in the spinal cord rather than in primary afferent neurons. This sensitization does not appear to be simply based on skin inflammation because histamine-induced itch was not augmented in lesional skin of psoriasis.