SEARCH · PubMed Health
Results for “Skin Absorption”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Metabolism and dosimetry of tritium.
This document was prepared as a review of the current knowledge of tritium metabolism and dosimetry. The physical, chemical, and metabolic characteristics of various forms of tritium are presented as they pertain to performing dose assessments for occupational workers and for the general public. For occupational workers, the forms of tritium discussed include tritiated water, elemental tritium gas, skin absorption from elemental tritium gas-contaminated surfaces, organically bound tritium in pump oils, solvents and other organic compounds, metal tritides, and radioluminous paints. For the general public, age-dependent tritium metabolism is reviewed, as well as tritiated water, elemental tritium gas, organically bound tritium, organically bound tritium in food-stuffs, and tritiated methane.
What are the functions of skin lost in burn injury that affect short- and long-term recovery?
Explore the source record for details and available documents.
Texture of the skin graft, with special reference to the hydration state of the stratum corneum.
The water contained in the superficial portion of the stratum corneum plays an important role in keeping the skin surface soft and smooth. In an attempt to study the true nature of the "texture" of grafted skin, in vivo water sorption-desorption tests were performed on grafts, on normal skin adjacent to grafts, and on normal skin surrounding the donor sites. The results showed that skin grafted to sites other than the face maintained a functional similarity to normal skin surrounding the donor site. However, in skin grafted to the face, the functions of the stratum corneum, as measured in terms of hydration state, increased, and this was associated with an improved water-holding capacity that probably results from the effect of abundant sebum and sweat excretion in adjacent skin. From these results it is suggested that the recipient site plays an important role in determining the difference in the function of the stratum corneum, i.e., the "texture" between grafts on the face and those on other sites.
Occupational exposure to polychlorinated biphenyls and cancer risk.
Polychlorinated biphenyls (PCBs) are a class of chemicals characterized by a long-term persistence and diffusion in the environment, and by bioaccumulation through the food chain. The highest exposures occurred in occupational cohorts through inhalation or skin absorption in work environments. These cohorts can therefore provide important information on health risk from exposure to PCBs in the general population. To provide comprehensive evidence on cancer risk from PCB exposure, we have thus reviewed the epidemiological studies on workers occupationally exposed to PCBs. Overall, no excess for all cancer mortality was observed in the six studies providing information (573 cancer deaths versus 630.4 expected, corresponding to a standardized mortality ratio (SMR) of 91). Among neoplasms potentially related to PCB exposure, there were 12 deaths from liver cancer compared with 9.5 expected (SMR=126). No excess was found for cancers of the breast (40 observed versus 47.4 expected, SMR=84) and of the lymphatic and haematopoietic system (51 observed versus 53.2 expected, SMR=96). Therefore, studies on occupational exposure to PCBs do not show any excess in all cancer mortality, or in mortality for specific cancer sites of interest.
Fetal toxicology of environmental tobacco smoke.
During the past decade, new evidence has been collected regarding the fetal risks of environmental tobacco smoke. Throughout gestation, the unborn baby is exposed to increasing concentrations of nicotine through maternal blood and gastrointestinal and skin absorption of the nicotine in the amniotic fluid. Recent research shows measurable concentrations of cotinine in the hair of infants born to passively smoking mothers. This exposure has been recently associated with effects on fetal growth.
Switching to the patch.
Explore the source record for details and available documents.
Strategies, systems, value judgements and dieldrin in control of locust hoppers.
The physiology and field biology of locusts have been extensively studied, and ecological control of Red Locusts has been investigated by field experiment. No fruitful or even promising non-insecticidal method of control has emerged. An effective and economical system requires an insecticide that is: (i) effective at very small area dosages, as a stomach poison placed on the natural vegetation can be, if it is also cumulative; (ii) persistent enough in sunshine and rain to retain effectiveness over the locust's non-feeding periods; (iii) capable of being well distributed by well-tried methods; and (iv) not dangerous to users or consumers and posing a minimal overall risk. Only one insecticide, dieldrin, satisfies all these requirements. Dieldrin is not in the small class of insecticides that are dangerous to man by skin absorption (such as parathion, arsenicals, DNC) and, at the area dosages needed for locust control, is not dangerous to stock. The Sayer exhaust sprayer in a Land Rover, with work rates of the order of square kilometres per hour is excellent for many situations; aircraft spraying at he rate of square kilometres per minute is quicker and less subject to difficulties of terrain, but requires trained and appropriately directed aircrew. Apart from checking, aircraft methods require no party on the ground to find, assess and control locust hoppers. Several ideas about dieldrin are found to be based on insufficient evidence and are probably not true: for example that dieldrin in the atmosphere at a few parts in a million million (10(12)) becomes concentrated in a food web and harmful to man, or that dieldrin is carcinogenic in man. It is noteworthy, however, that one species of antelope in South Africa is exceptionally susceptible to dieldrin poisoning, though harm occurs at area dosages considerably greater than are required in the method of aircraft spraying of Courshee & McDonald (1963). To attack tsetse flies, emissions two orders of magnitude greater have been used. Care must be taken with any insecticide, but the risks of using dieldrin as properly used in locust hopper control have been exaggerated by propaganda. If harm is to be expected, then a quantitative comparison of that with the undoubted benefits of locust control is required to enable one to make a value judgement.
Structural organization of the stratum corneum in certain scaling disorders of the skin.
Explore the source record for details and available documents.
The effect of actinomycin D on the incorporation of labeled vitamin A acid in normal and tumor epithelium.
Explore the source record for details and available documents.
Effects of fluocinolone acetonide cream on the skin window record of inflammatory exudates.
Explore the source record for details and available documents.
Combination of 4-hydroxyanisole and all-trans retinoic acid produces synergistic skin depigmentation in swine.
A combination of 4-hydroxyanisole (4HA) and all-trans retinoic acid (TRA) was found to synergistically cause moderate to complete depigmentation of Yucatan swine skin. Two hyperpigmentation models were used: Natural dark-skinned swine, a potential model for melasma-like disorders, and ultraviolet light-stimulated hyperpigmentation, a model of solar lentigines. Test materials were applied twice daily, 5 d/week, to dorsal flank skin. Application sites were graded at weekly intervals for skin color using a 0 to 4 grading scale. After 8 weeks of treatment of naturally dark swine skin, a combination of 2% 4HA and 0.01% TRA produced grade 2 hypopigmentation (definite but moderate hypopigmentation). In contrast, 2% 4HA alone or 0.01% TRA alone did not produce significant hypopigmentation. After cessation of treatment, the 4HA/TRA-treated sites reverted to normal color within 7-12 weeks. The 4HA/TRA combination completely reversed the hyperpigmentation induced by ultraviolet light after 8 weeks of treatment. In vitro skin-penetration studies using hairless mouse and human skin show that skin penetration of 4HA was not significantly affected by adding 0.01% TRA. These data suggest that the observed synergy is not due to enhanced bioavailability of 4HA. We have demonstrated that combining low concentrations of 4HA and TRA results in effective skin lightening without causing irreversible depigmentation and with minimal local skin irritation.
The influence of water content, chemical treatment and temperature on the rheological properties of stratum corneum.
The elastic modulus is determined as a function of water content for untreated stratum corneum, and stratum corneum treated with urea and LiBr. The modulus is also determined for stratum corneum at temperatures from 2 degrees C to 45 degrees C and on samples with the water solubles extracted. The modulus is independent of temperature, but may be modified by binding of small molecules to the protein in stratum corneum. The modulus is found to be a function of water content, not water activity.
Biomechanical properties of delipidized stratum corneum.
Explore the source record for details and available documents.
Stratum corneum hydration and flexibility are useful parameters to indicate clinical severity of congenital ichthyosis.
To determine any correlation between the stratum corneum barrier function and the phenotypic severity of congenital ichthyosis, we studied stratum corneum hydration, flexibility, thickness and transepidermal water loss (TEWL) in patients with congenital ichthyosis. Seven patients with congenital ichthyosis aged 2-46 years and age-matched controls were included in the present study. We divided seven patients into two groups; patients with non-bullous type (non-bullous congenital ichthyosiform erythroderma patients) and patients with the bullous type of congenital ichthyosis (bullous congenital ichthyosiform erythroderma and ichthyosis bullosa of Siemens). Stratum corneum hydration, thickness and flexibility were measured using a Corneometer ASA-M2. The stratum corneum thickness was also examined using a skin biopsy technique. TEWL was measured using Evaporimeter AS-TW1. The clinical severity of ichthyosis phenotype was evaluated using a visual analogue scale (VAS). Stratum corneum hydration and flexibility were significantly reduced in both congenital ichthyosis patient groups. Stratum corneum thickness was significantly increased in both groups. In the patient group with non-bullous congenital ichthyosis, significant negative correlations were confirmed between the VAS score and stratum corneum hydration and between the VAS score and flexibility. A significant, positive correlation was also observed between the VAS score and stratum corneum thickness. There was a positive correlation between the VAS score and TEWL on both the extensor and flexor sides of the forearm and back. We conclude that stratum corneum hydration, flexibility and thickness measured by the corneometer, and TEWL on the arm may be a useful indicator of the severity of ichthyosis phenotype.
Comparison of biophysical properties of skin measured by using non-invasive techniques in the KM mice following 595 nm pulsed dye, 1064 nm Q-Switched Nd:YAG and 1320 nm Nd:YAG laser non-ablative rejuvenation.
BACKGROUNDS/AIMS: The aim of the study was to compare the changes of the biophysical properties and to objectify the effects of 595 nm pulsed dye, 1064 nm Q-switched Nd:YAG and 1320 nm Nd:YAG lasers non-ablative rejuvenation by non-invasive techniques. METHODS: KM mice were used for the study. The 595 nm pulsed dye, 1064 nm Q-switched Nd:YAG and 1320 nm Nd:YAG laser treatments were evaluated with biophysical parameter measurements including skin elasticity, skin color, skin trans-epidermal water loss (TEWL) and skin hydration. RESULTS: All three lasers improved the biophysical properties in the skin of KM mice. In skin elasticity measurements, the 1064 nm laser treatment showed the lowest ratio (0.61+/-0.09) while the 1320 nm laser showed the highest one (0.76+/-0.07) on day 60. For erythema values, a significant increase was observed immediately after the 1064 nm laser treatment (196.67+/-19.17), but the lowest values occurred with the 1320 nm laser treatment (189.83+/-16.54). None of the three lasers resulted in obvious changes of skin melanin. TEWL increased immediately after laser irradiation, then began to recover and decreased 60 days after the 595 and 1064 nm laser treatments. With the 1320 nm laser treatment the TEWL began to decrease from day 7 and obtained the lowest mean values (5.23+/-1.13). The water-holding capacity increased initially for the 595 and 1320 nm laser irradiation, while decreased for the 1064 nm laser. At day 60 of the experiment, skin hydration values in all animals were superior to those of the controls. The 1320 nm laser treatment caused the highest ratio (1.29+/-0.26). Both the values of TEWL and skin hydration for the 1320 nm laser treated areas differed significantly from the other two lasers. CONCLUSIONS: Our data showed the 1064 nm Q-switched Nd:YAG laser treatment was most effective in improving the skins' mechanical properties, while the 1320 nm Nd:YAG laser can enhance greatly the skin barrier function and the water-holding capacity. Moreover, we demonstrated the biophysical properties differed considerably between different areas.
Free residual chlorine in bathing water reduces the water-holding capacity of the stratum corneum in atopic skin.
Some patients with atopic dermatitis (AD) develop dry skin or exacerbated cutaneous inflammations with frequent swimming in public pools or after bathing. We examined the effects of residual chlorine in bathing water on the function of the stratum corneum (SC) in patients with AD and determined the lowest chlorine concentration showing an effect. In addition, we investigated the relationship between the free residual chlorine concentration in bathing water and the water-holding capacity of the SC in patients with AD. Twenty patients with AD and 10 normal control (NC) subjects were included in this study. The hydration status of the SC on the flexor surface of the forearm was measured with a corneometer before and after the subject's arms were immersed in tubs filled with comfortably hot water (40 degrees C) containing residual chlorine at concentrations of 0, 0.5, 1.0 and 2.0 mg/L for 10 minutes in a room maintained at normal temperature (24 degrees C) and relative humidity (55%). The water-holding capacity of the SC after immersion was calculated by integration of the hydration status determined every 30 seconds over a period of 10 minutes. In the patients with AD, the average SC hydration status after immersion in comfortably hot water containing residual chlorine at 1.0 and 2.0 mg/L was significantly lower than that following immersion in water containing a negligible concentration of residual chlorine (i.e., less than 0.03 mg/L) (p<0.05). In the NC subjects, significant differences were observed only between the 2.0 mg/L and the negligible residual chlorine groups (p<0.05). The water-holding capacity of the SC was significantly decreased with a residual chlorine concentration of 0.5 mg/L or higher in the patients with AD (p<0.01). However, in the NC subjects, a significant decrease in water-holding capacity was observed only at a residual chlorine concentration of 2 mg/L (p<0.01). These results indicate, first, that the water-holding capacity of the SC in patients with AD is more sensitive to free residual chlorine exposure than that in NC subjects without AD. Second, these results suggest that free residual chlorine exposure in patients with AD may play a role in the development or exacerbation of AD.