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At least 55 records · Page 3Linked to original sources
PubMed1998

Mapping of a protein-RNA kissing hairpin interface: Rom and Tar-Tar*.

An RNA 'kissing' complex is formed by the association of two hairpins via base pairing of their complementary loops. This sense-antisense RNA motif is used in the regulation of many cellular processes, including Escherichia coli ColE1 plasmid copy number. The RNA one modulator protein (Rom) acts as a co-regulator of ColE1 plasmid copy number by binding to the kissing hairpins and stabilizing their interaction. We have used heteronuclear two-dimensional NMR spectroscopy to map the interface between Rom and a kissing complex formed by the loop of the trans -activation response (Tar) element of immunodeficiency virus 1 (HIV-1) and its complement. The protein binding interface was obtained from changes in amide proton signals of uniformly 15N-labeled Rom with increasing concentrations of unlabeled Tar-Tar*. Similarly, the RNA-binding interface was obtained from changes in imino proton signals of uniformly 15N-labeled Tar with increasing concentrations of unlabeled Rom. Our results are in agreement with previous mutagenesis studies and provide additional information on Rom residues involved in RNA binding. The kissing hairpin interface with Rom leads to a model in which the protein contacts the minor groove of the loop-loop helix and, to a lesser extent, the major groove of the stems.

Bacterial Proteins↗
PubMed1975

Evaluation of coal tar fractions for use in psoriasiform diseases using the mouse tail test. (I) High and low temperature tars and their constituents.

'High' and 'low' temperature tars were evaluated on parakeratotic mouse tail skin, which was used as a model for the psoriatic keratinization process. The skin was examined histologically for signs of induced granular layers in previously scaly areas; epidermal thicknesses were also measured. It appears that the acidic (phenolic) fractions of coal tars induce granular layers and cause epidermal thickening, whereas neutral constituents alone only cause thickening. It is suggested that tar acids should be further investigated for anti-psoriatic activity.

Animals↗
PubMed1980

Studies on the toxicity of coal-tar dyes. III. Reason of acute toxicity to fish caused by coal-tar dyes and their industrial effluents.

Reason of acute toxicity to fish caused by coal-tar dyes and their industrial effluents were studied from the three points of view. 1) Partition coefficient (n-octanol/water) was determined on several coal-tar dyes, and it was found that the larger the ratio was, the stronger was toxicity to fish. 2) As a result of determination about existent form of xanthene dyes under photo-irradiation, it was clarified that dyes in solution were in the form of excited triplet state and halogen in dye molecule was liberated in free form. 3) When coal-tar dyes were treated with sodium hypochlorite, harmful chloroform was detected from dye solution. Chloroform and its homologous compounds showed the low TLm value and had the serious effect on fish.

Animals↗
PubMed1989

Low concentration dithranol and coal tar (Psorin) in psoriasis: a comparison with alcoholic coal tar extract and allantoin (Alphosyl).

Psoriasis is difficult to manage in general practice, mainly because the standard treatments produce side effects, or are ineffective in both the short and long term. In recent years, the main topical therapies have included extracts of coal tar or dithranol. In a six-week within-patient trial, 23 patients applied two different treatments to the left and right halves of their bodies. A new preparation (Psorin, Thames Laboratories), containing relatively low concentrations of dithranol and crude coal tar, was significantly more effective and more acceptable than a refined alcoholic extract of coal tar with allantoin (Alphosyl, Stafford Miller Ltd).

Adolescent↗
PubMed2003

Cyclic PNA-based compound directed against HIV-1 TAR RNA: modelling, liquid-phase synthesis and TAR binding.

A cyclic molecule including a hexameric PNA sequence has been designed and synthesized in order to target the TAR RNA loop of HIV-1 through the formation of a "kissing complex". For comparison, its linear analogue has also been investigated. The synthesis of the cyclic and linear PNA has been accomplished following a liquid-phase strategy using mixed PNA and fully N-protected (aminoethylglycinamide) fragments. The interactions of this cyclic PNA and its linear analogue with TAR RNA have been studied and the results indicate clearly that no interaction occurs between the cyclic antisense PNA and TAR RNA, whereas a tenuous interaction has been detected with its linear PNA analogue.

Cyclization↗
PubMedDate not supplied

Low-tar and high-tar cigarettes.

Mice were exposed for 7 to 8 minutes on weekdays to fresh smoke from high-tar (HT) or low-tar (LT) cigarettes for varying periods of up to 36 weeks. Mice exposed to HT cigarettes exhibited more marked alterations in humoral immune responsiveness, hematological profiles, and pulmonary pathologic findings than those exposed to LT cigarettes. However, cell-mediated immune responsiveness to both bacterial and tumor-specific antigens was depressed similarly in animals exposed to HT or LT cigarettes. Furthermore, the growth rates of subcutaneously established tumors were enhanced similarly in the two groups, with respect to those in control animals.

Animals↗
PubMed1985

1-hydroxypyrene in human urine after exposure to coal tar and a coal tar derived product.

A method for isolating 1-hydroxypyrene from urine is described. The presence of 1-hydroxypyrene in urine was identified by fluorescence excitation and emission scanning after HPLC-separation. 1-Hydroxypyrene could be detected in the urine of rats following oral administration of as little as 0.5 microgram pyrene. The dose-dependence of 1-hydroxypyrene in urine was evident after a wide range of pyrene dosing. After therapeutical coal tar treatment of dermatological patients the enhanced excretion of 1-hydroxypyrene was highly significant. Employees of a creosote impregnating plant showed an excretion pattern of 1-hydroxypyrene which could be related to their work. 1-Hydroxypyrene in urine of non-exposed people was very low, but detectable. It is suggested that the method reported is suitable for the assessment of uptake of man to pyrene, a compound that is commonly present in work environments which are associated with pollution of polycyclic aromatic hydrocarbons.

Adult↗
PubMed1988

Airborne concentrations, skin contamination, and urinary metabolite excretion of polycyclic aromatic hydrocarbons among paving workers exposed to coal tar derived road tars.

The exposure of surface dressing workers to polycyclic aromatic hydrocarbons (PAH) was studied. Four different paving sites, at which coal tar-containing binders were applied, were selected as work sites with high exposure levels of PAH. Breathing zone airborne particulates, contamination of the skin with PAH, and 1-hydroxypyrene in urine of the workers involved in chip sealing were determined. Substantial concentrations of cyclohexane-soluble airborne particulate matter were found (GM = 0.2 mg/m3, n = 28). Skin contamination was determined using two different methods: with exposure pads and by hand washing. Pads were mounted on several parts of the body: wrist, elbow, neck, shoulder, and ankle. The pads located on the wrist appeared to be the most contaminated (pyrene: GM = 22 ng/1.77 cm2, n = 40). The end-of-shift hand washing showed that the hands of the workers were contaminated with PAH (pyrene: GM = 70 micrograms, n = 35). Preshift hand washing showed far lower, but detectable, quantities of PAH on workers' hands (pyrene: GM = 5 micrograms, n = 35). Enhanced levels of urinary 1-hydroxypyrene among the workers were found. The highest levels were found in the end-of-shift urine samples. Correlations between the pyrene exposure variables were studied. Significant positive correlations were found between pyrene on the wrist pad versus end-of-shift urinary 1-hydroxypyrene; between pyrene on the hands versus end-of-shift urinary 1-hydroxypyrene; and between the two different skin contamination variables.

Air Pollution↗
PubMed1975

Evaluation of coal tar fractions for use in psoriasiform diseases using the mouse tail test. III. High boiling tar oil acids.

Twelve phenolic fractions of creosote and anthracene oils derived from a high temperature tar were applied in an ointment base to mouse tail skin. After treatment with the higher boiling acids, formerly parakeratotic scale areas underwent granular layer induction and 'basket-weave' keratin was produced. Changes in distribution of acid phosphatase and in horny layer fluorescence were consistent with the conversion to an orthokeratotic state. It is suggested that some of these phenols may be of value in the treatment of chronic psoriasis.

Acid Phosphatase↗
PubMed1978

Biochemical decomposition of coal-tar dyes. II. Acute toxicity of coal-tar dyes and their decomposed products.

Twenty kinds of coal-tar dyes were subjected to median tolerance limit (TLm) test by use of Himedaka (Oryzias latipes) for the comparision of their acute toxicities. It became clear that 4 kinds of halogens substituted xanthene compounds dyes showed strong acute toxicities. From the fact that uranine had the lower acute toxicity than halogens substituted compounds and the toxicities of these 4 dyes increased through irradiation, it was assumed that halogen atoms in dyes might be responsible for these strong acute toxicities to fish.

Anaerobiosis↗