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Concept: Coal tar

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Abstract The Goeckerman regimen, consisting of the application of crude coal tar combined with exposure to ultraviolet radiation, was formulated in 1925 for the treatment of psoriasis. While some centers have adapted the Goeckerman regimen for the treatment of eczema, there are no published reports of its efficacy in this condition. Here, we explain how the Goeckerman regimen has been modified for use in an eczema population at the University of California San Francisco (UCSF). We reviewed the treatment records of eczema patients treated with the modified Goeckerman regimen over a 6-year period at UCSF. We found that the Goeckerman regimen was effective in treating patients with severe baseline disease, inducing a mean remission period of 7.2 months. The treatment was tolerated well with mild folliculitis and occasional ultraviolet B phototoxicity noted as the only adverse reactions. Since the use of Goeckerman as a treatment for severe eczema is both effective and safe, it should be considered an excellent alternative or adjunct to the systemic therapies currently being used.

Concepts: Cancer, Ultraviolet, Electromagnetic spectrum, Sunlight, Eczema, Psoriasis, Psoralen, Coal tar

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BACKGROUND: The majority of people with psoriasis have localised disease, where topical therapy forms the cornerstone of treatment. OBJECTIVE: To summarise evidence on relative efficacy, safety and tolerability of different topical treatments used in plaque psoriasis METHODS: Systematic review and meta-analyses of randomised trial data of UK-licensed topical therapies. The primary outcome was clear or nearly clear status stratified for (i) trunk and limbs and (ii) scalp. Network meta-analyses allowed ranking of treatment efficacy. RESULTS: 48 studies were available for trunk and limb psoriasis and 17 for scalp psoriasis (n=22,028); the majority included people with at least moderate psoriasis severity. Strategies containing potent corticosteroids (alone or in combination with a vitamin D analogue) or very potent corticosteroids, dominated the treatment hierarchy at both sites (trunk and limbs, scalp); coal tar and retinoids were no better than placebo. No significant differences in achievement of clear/nearly clear status were observed between twice and once daily application of the same intervention or between any of the following: combined vitamin D analogue and potent corticosteroid (applied separately or in a single product), very potent corticosteroids, or potent corticosteroids (applied twice daily). Investigator and patient assessment of response differed significantly for some interventions (response rate to very potent corticosteroids 78% and 39% respectively). No significant differences were noted for tolerability or steroid atrophy, but data were limited. CONCLUSIONS: Corticosteroids are highly effective and safe in psoriasis when used continuously for up to 8 weeks and intermittently for up to 52 weeks. Coal tar and retinoids are of limited benefit. There is a lack of long-term efficacy and safety data available on topical interventions used for psoriasis.

Concepts: Vitamin D, Ultraviolet, Randomized controlled trial, Sunlight, Efficacy, Psoriasis, Coal tar, Dandruff

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Crude coal tar and its derivatives have been used in modern medicine for the treatment of psoriasis since at least 1925 as part of the Goeckerman regimen. To this day, coal tar remains a safe and highly effective option for the treatment of psoriasis vulgaris. However, the mechanism by which coal tar has its therapeutic effect is not known. This review summarizes current knowledge of the mechanism by which coal tar has its therapeutic effect in the treatment of psoriasis vulgaris.

Concepts: Pharmacology, Medicine, Petroleum, Effectiveness, Therapy, Psoriasis, Coal tar, Dandruff

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Palmoplantar psoriasis is often disabling and refractory to conventional therapy. Systemic drugs are indicated in its severe form, but side effects are a concern with their use. Methotrexate is one such systemic drug which is effective and cheap. To reduce systemic toxicity, methotrexate has been tried topically but results have been inconsistent due to poor drug penetration into the skin by passive diffusion. Iontophoresis may enhance its absorption and efficacy.

Concepts: Pharmacology, Effectiveness, Drug, Skin, Psoriasis, Coal tar

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Coal tars are a mixture of organic and inorganic compounds and were by-products from the manufactured gas and coke making industries. The tar compositions varied depending on many factors such as the temperature of production and the type of retort used. For this reason a comprehensive database of the compounds found in different tar types is of value to understand both how their compositions differ and what potential chemical hazards are present. This study focuses on the heterocyclic and hydroxylated compounds present in a database produced from 16 different tars from 5 different production processes.

Concepts: Oxygen, Carbon monoxide, Chemical compound, Charcoal, Coal, Tar, Coal tar, Coal gas

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Coal tars are a mixture of organic and inorganic compounds and were by-products from the manufactured gas and coke making industries. Different manufacturing processes have resulted in the production of distinctly different tar compositions. This study presents a comprehensive database of compounds produced using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS), analysing 16 tar samples produced by 5 distinct production processes.

Concepts: Oxygen, Carbon monoxide, Coal, Manufacturing, Industry, Tar, Coal tar, Coal gas

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Coal tars are a mixture of organic and inorganic compounds and were produced as a by-product from the manufactured gas and coke making industries. The composition of the tar produced varied depending on many factors; these include the temperature of production and the type of retort used. As different production processes produce different tars, a comprehensive database of the compounds present within coal tars from different production processes is a valuable resource. Such a database would help to understand how their chemical properties differ and what hazards the compounds present within these tars might pose. This study focuses on the aliphatic and aromatic compounds present in a database of 16 different tars from 5 different production processes.

Concepts: Benzene, Carbon monoxide, Chemical compound, Charcoal, Coal, Tar, Coal tar, Coal gas

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coal gasification tar residue (CGTR) is a kind of environmentally hazardous by-product generated in fixed-bed coal gasification process. The extracted CGTR by ethyl acetate was used to prepare powdered activated carbon (PAC) and applied for phenol adsorption. The results showed that the prepared PAC under the optimum conditions had enormous mesoporous structure, and the iodine number reached 2030.11 mg/g, with specific surface area of 1981 m(2)/g and total pore volume of 0.92 ml/g. Especially, without loading other substances the PAC had a strong magnetic, easy to be separated after adsorbing phenol. The phenol adsorption by PAC was studied as functions of contact time, temperature, PAC dosage, solution concentration and pH. The results showed fast adsorption speed and high adsorption capacities of PAC. The adsorption process was exothermic and conformed to the Freundlich models. The adsorption kinetics fitted better to the pseudo second order model. These results could offer an effective way for CGTR used as potential adsorbent for phenols in wastewater.

Concepts: Adsorption, Charcoal, Coal, Activated carbon, Surface chemistry, Gasification, BET theory, Coal tar

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Creosote is a distillation product of coal tar and is widely used as wood preservative for railway sleepers, utility poles and for other applications. Creosote can have potentially negative effects on the environment and many of the components are toxic. This study presents the analysis of a Creosote sample from a former wood impregnation plant located in the UK. The sample was analysed using two dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) and a database of compounds that could be detected was produced. The GCxGG-TOFMS was capable of detecting 1505 individual compounds, which is far more than previous estimates for the number of compounds present within Creosote. Post extraction derivatization using BTSFA with 1% TMCS was employed to increase the potential number of compounds detected with 255 derivatized compounds detected, 231 of which would not have been detected without prior derivatization. Selected derivatized compounds were quantified with limits of detection ranging from 0.6 mg/kg to 1.6 mg/kg from a concentrated dense non-aqueous phase liquid (DNAPL). This work presents the first published full analysis of a Creosote using GCxGC-TOFMS combined with derivatization.

Concepts: Dimension, Manifold, Cartesian coordinate system, Coal tar

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The feasibility of ultrasound assisted, thermally activated persulfate for effective oxidation of twenty 2-6 ringed coal tar PAHs in a biphasic tar/water system and a triphasic tar/soil/water system were investigated and established. The results indicate that ultrasonic assistance, persulfate and elevated reaction temperature are all required to achieve effective oxidation of coal tar PAHs, while the heating needed can be provided by ultrasonic induced heating as well. Further kinetic analysis reveals that the oxidation of individual PAH in the biphasic tar/water system follows the first-order kinetics, and individual PAH oxidation rate is primary determined by the mass transfer coefficients, tar/water interfacial areas, the aqueous solubility of individual PAH and its concentration in coal tar. Based on the kinetic analysis and experimental results, the contributions of ultrasound, persulfate and elevated reaction temperature to PAHs oxidation were characterized, and the effects of ultrasonic intensity and oxidant dosage on PAHs oxidation efficiency were investigated. In addition, the results indicate that individual PAH degradability is closely related to its reactivity as well, and the high reactivity of 4-6 ringed PAHs substantially improves their degradability.

Concepts: Chemistry, Temperature, Solubility, Ultrasound, Heat transfer, Kinetics, Mass transfer, Coal tar