Improvement of Oral Chelation Treatment of Methyl Mercury Poisoning in Rats

Abstract Oral administration of sodium–2,3–dimercaptopropane–l–sulphonate leads to a substantially increased urinary excretion of intravenously injected methyl mercury in rat and proved to be clearly superior to equimolar doses of N–acetyl–D, L–homocysteinethiolactone and D–penicillamine.     

Microbiological quality of topical drug formulations: efficacy of antimicrobial preservation against Paecilomyces lilacinus.

BACKGROUND: Microbiological quality of topical products comprises both, the microbiological purity of the unopened product and the efficacy of the antimicrobial preservation system. OBJECTIVE: Subsequent to an outbreak of invasive Paecilomyces lilacinus mycosis among patients of an isolation ward, probably caused by a contaminated skin care product, the microbiological quality of different skin care products from the market was investigated. METHODS: The different products were investigated for their efficacy of antimicrobial preservation in general and especially against P. lilacinus according to a pharmacopoeial routine method slightly adopted for the purpose of this investigation. RESULTS: The products did partially not comply with the British Pharmacopoeia 1993 test for efficacy of antimicrobial preservation. The antimicrobial preservation systems were less effective against P. lilacinus than against the pharmacopoeial reference germs. The antimicrobial preservation efficacy decreased towards the end of the shelf-life of the product. A decreased P. lilacinus inoculum dose was related to an increased growth of the micro-organisms. CONCLUSION: Topical products are, unless not labelled otherwise, non-sterile preparations and their preservation systems are only tested against pharmacopoeial key micro-organisms. The microbiological behaviour following contamination with other germs remains unknown.     

Lip sun protection factor of a lipstick sunscreen.

BACKGROUND AND OBJECTIVE: There is a well-documented need for effective human UVA and UVB photoprotection. Since there are important anatomical variations, the sun protection factor (SPF) of a lipstick sunscreen was measured on the anatomical site intended for use. METHODS: The SPF tests were performed according to Federal US and European COLIPA guidelines. Prior to performing a test on the lip, the minimal erythemal dose (MED) of the unprotected back skin was determined. Subsequently, the sunscreen SPF was measured on the anatomical target site (lip). The evaluator was blinded with respect to scoring the SPF of each sunscreen treatment. Individual test sites were assigned to one of the following treatment conditions: (1) no treatment (MED of unprotected skin); (2) test formulation; (3) reference standard. RESULTS: The MED on unprotected back skin was found to be 25% lower than on unprotected lip skin. The SPF of the lipstick sunscreen was measured 2 units lower than the SPF determined in the classical way on the back skin. CONCLUSION: It was hypothesized that the higher MED of the lower lip compared with back skin was due to the adaptation of this tissue to the continuous exposure to UV radiation.     

Skin Penetration and Sun Protection Factor of Ultra-Violet Filters from Two Vehicles

Purpose. In order to improve our knowledge on the efficacy and safety of sunscreen products, we measured the skin penetration profiles of ultra-violet (UV) filters in vitro and in vivo, and the corresponding sun protection factors (SPF) from two vehicles (an O/W emulsion-gel and petroleum jelly). Methods. The UV filters tested were oxybenzone (5%, A), 2-ethylhexyl 4-methoxycinnamate (7.5%, B), and 2-ethylhexylsalicylate (3%, C). Two mg/cm² were applied for 2 min to 6 h. In vitro penetration measurements were performed with static diffusion cells. In vivo, horny layer concentrations were measured after stripping and the SPF evaluated as recommended by the COLIPA-guidelines. Results. Significant differences between vehicles were noticed in vitro as well as in vivo. In vitro, the emulsion-gel generated higher epidermal concentrations than petroleum jelly. Values at 6 h, expressed as percent of the applied dose for A, B, and C were 4, 9, and 7% for the emulsion-gel and 2, 1, and 2% for petroleum jelly. An opposite trend was noticed, mainly for A, in the deeper skin layers with concentrations of 2% in the dermis and 5% in the receptor fluid for petroleum jelly and 0.6% and 1% for the emulsion-gel respectively. In vivo, for each UV filter, maximal stratum corneum levels (15 strips) were obtained at 0.5 h with percentages of the applied doses of 50% for the emulsion-gel and 15% for petroleum jelly. SPFs, measured 0.5 h after application amounted to 14 for the emulsion-gel and 5 for petroleum jelly, and decreased in both cases by a factor 2.2 after removal of non penetrated product. Conclusions. These preliminary results demonstrated that UV filters penetration and retention as well as expected SPF could be optimized by a suitable vehicle.     

The skin blanching assay with halcinonide,influence of halcinonide concentration and application time ⋆

Objective Instrumental colour readings (Minolta Chromameter CR200) were performed in order to quantify corticosteroid induced skin blanching. Methods Different Halcinonide concentrations in the same vehicle ranging from 0.005% to 0.200% were tested on the volar part of the forearms. Besides dose-response relationships we studied the influence of application time by applying the formulations under occlusion during 2, 12 and 18 h. Results All evaluated formulations provoked a discernible blanching as indicated by the significant increase of the L* parameter and the decrease of the a* parameter. Discrimination between the different Halcinonide concentrations was possible only in the 2 h application experiment. With longer application times a similar blanching was recorded for all Halcinonide concentrations. Conclusion Our results indicate that a shorter application time may lead to a more sensitive skin blanching assay.     

A qualitative estimate of the influence of halcinonide concentration and urea on the reservoir formation in the stratum corneum.

The existence of a stratum corneum reservoir for topically applied substances is well known. Data concerning the stratum corneum retention time are important for the elaboration of optimal topical treatment. We used the re-occlusion technique followed by skin colour measurements (Chromametry) for the evaluation of the stratum corneum retention time of halcinonide. We found a significant reservoir for halcinonide up to 5 days after the initial application. The retention was found to be corticosteroid concentration and formulation dependent.     

Soccer accidents in the French Rh?ne-Alpes Soccer Association

The analysis of 6153 accidents reported to the insurance company of the French Rh?ne-Alpes Soccer Association, for the 1980-81 season was undertaken, providing a survey of acute pathology in French soccer accidents and an estimation of the cost of this pathology to French society. Findings from this study include: injuries--ankle sprain is the most common; fractures prevail in the young players pathology; exposure--the average risk is one accident for 20 matches; the highest risk is for the senior category; collisions with opponents is the main cause of accidents; the first 5 minutes of the second half have a peak of accidents; the players exposure is roughly the same whatever their position on the ground; risk--winter should not increase the risk if the matches are played under good conditions; the risk is unevenly distributed according to the level of practice; cost--the cost for France over 1 year was estimated at US$20,000,000 and the total number of sick leave days at 2000 years; games with several accidents are very common in January and for the adult category. Consequently, tightening up the safety measures would be a very good investment.     

Bioengineering measurements of barrier creams efficacy against toluene and NaOH in an in vivo single irritation test

Background/aims: By now, only a few models have been published with the goal of testing barrier creams in vivo in humans. The aim of this study was to evaluate with a single irritation test, barriers creams in humans against a lipophilic and a hydrophilic irritant, toluene and NaOH, respectively.
Methods: Both irritants were applied for 15 min after pretreatment of the skin with barrier creams. Non-invasive bioengineering methods, such as skin colorimetry (a*) and cutaneous blood flow (CBF) measurements were used to assess product protection.
Results: After toluene application on control sites, the irritation appeared quickly (T_max=3 min after patch removal), was significant (+5-6 units for a* and+80% for CBF) and did not return to base value within 1 h. Skin irritation after NaOH application, as measured by a*, was less important (+2 units) and occurred later ( T "max=40 min after patch removal). For this irritant, CBF response was minor and variable. When testing barrier properties of the products, none of them were able to prevent the skin erythema induced by toluene. Against NaOH, one barrier cream as well as petrolatum and a fatty cream protected the skin significantly.
Conclusion: The present study points out the unsatisfactory effectiveness of several commercially available barrier creams claimed to protect against lipophilic or hydrophilic irritants.     

The influence of diethylenetriaminepentaacetate on the synthesis of DNA, RNA and proteins in the regenerating rat liver

Administration of toxic doses of Ca-DTPA (diethylenetriaminepentaacetate) after partial hepatectomy inhibits the synthesis of DNA, RNA and proteins in the regenerating rat liver. Zn-DTPA proved to be ineffective. Impairment by Ca-DTPA of DNA synthesis can be completely restored by subsequent joint administration of Zn²⁺ and Mn²⁺. The dependence of the inhibitory action of Ca-DTPA on dosage and on the time of its administration is consistent with the assumption that the inhibition of DNA synthesis is not the primary reaction but the consequence of an impaired synthesis of proteins which is tentatively ascribed to a disturbed conformation of RNA due to removal of Zn²⁺ and Mn²⁺. Parallel studies on cell-free systems revealed a direct inhibitory action of Ca- and Zn-DTPA on the syntheses. The different activity pattern in vitro and in vivo is explained by the assumption that in the former case the inhibitory action is partly due to the formation of ternary complexes; a mechanism which is not operative in vivo, because the distribution of the chelates is confined to the extracellular space.