13,345 research outputs found

    Barriers to the Adoption of the ART Approach as Perceived by Dental Practitioners in Governmental Dental Clinics, in Tanzania.

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    This study aimed to determine the magnitude of the barriers to the practice of Atraumatic Restorative Treatment (ART) as perceived by dental practitioners working in pilot dental clinics, and determine the influence of these barriers on the practice of ART. A validated and tested questionnaire on barriers that may hinder the practice of ART was administered to 20 practitioners working in 13 pilot clinics. Factor analysis was performed to generate barrier factors. These were patient load, management support, cost sharing, ART skills and operator opinion. The pilot clinics kept records of teeth extracted; teeth restored by conventional approach and teeth restored by ART approach. These treatment records were used to compute the percentage of ART restorations to total teeth treated, percentage of ART restorations to total teeth restored and percentage of total restorations to total teeth treated. The mean barrier scores were generated and compared to independent variables, using the t-test. The influence of barriers to ART-related dependent variables was determined using Pearson correlation coefficients. Mean barrier values were low, indicating low influence on ART practice. Female practitioners had higher scores on patient load than male practitioners (p = 0.003). Assistant Dental Officers had higher scores on cost sharing than Dental Therapists (p = 0.024). Practitioners working in urban clinics had higher mean scores on patient load than those who worked in rural clinics (p = 0.0008). All barrier factors were negatively correlated with ART practice indices but all had insignificant association with ART practice indices. The barriers studied were of low magnitude, with no significant impact on practice of ART in dental clinics in the pilot area

    Mechanism of antiandrogen action: Conformational changes of the receptor

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    Androgen receptor mRNA was translated in vitro, and androgen- and antiandrogen-bound receptor complexes were studied using limited proteolytic digestion by trypsin. Partial proteolysis of androgen-bound receptor protein resulted in a 29-kDa proteolysis-resisting fragment, whereas antiandrogen binding stabilised a 35-kDa fragment. Both fragments contain the entire ligand binding domain, and the 35-kDa fragment extended into the hinge region of the receptor. Several antiandrogens show agonistic properties for a mutated androgen receptor (LNCaP cell variant); trypsin digestion of antiandrogen-bound mutated receptor also resulted in a 29-kDa fragment. Our results point to an important difference between antiandrogens and antagonists of other steroid hormone receptors. Antiandrogens result in protection of both the hinge region and C-terminus of the androgen receptor against proteolytic attack, whereas other studies showed that antiestrogens and antiprogestagens expose the C-terminal end of the ligand binding domain of their respective receptors to protease. Differences in conformation of the hinge region distinguish androgen-bound from antiandrogen-bound receptor complexes, which represents an important feature of antiandrogen action

    Twisted algebra R-matrices and S-matrices for bn(1)b_n^{(1)} affine Toda solitons and their bound states

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    We construct new Uq(a2n1(2))U_q(a^{(2)}_{2n-1}) and Uq(e6(2))U_q(e^{(2)}_6) invariant RR-matrices and comment on the general construction of RR-matrices for twisted algebras. We use the former to construct SS-matrices for bn(1)b^{(1)}_n affine Toda solitons and their bound states, identifying the lowest breathers with the bn(1)b^{(1)}_n particles.Comment: Latex, 24 pages. Various misprints corrected. New section added clarifying relationship between R-matrices and S-matrice

    Dental Practitioners' Attitudes, Subjective Norms and Intentions to Practice Atraumatic Restorative Treatment (ART) in Tanzania.

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    The aim of this study was to describe the attitude and subjective norm of dental practitioners towards practicing the atraumatic restorative treatment (ART) in Tanzania. A pre-tested questionnaire on attitudes and subjective norms to practice ART was mailed to all 147 dental practitioners working in the regional and district government clinics. The independent variables were: gender, working experience, qualification and ever heard of ART. The dependent variables were: attitude, subjective norm and intention to practice ART. Chi-square tests and multiple regression analysis were used to test for effects between independent and dependent variables. Significance level was set at 5%. A total of 138 practitioners returned completed questionnaires. More experienced dental practitioners encountered moderate social pressure than less experienced dental practitioners, who met strong social pressure (p=0.045). A total of 73.2% of dental practitioners felt that ART was worth introducing in Tanzania, 92.8% recommended ART training for all dental practitioners and 97.8% recommended inclusion of ART in dental curricula. Positive attitude, strong subjective norm and high intention to practice ART were recorded in 76.3%, 28.1% and 90.6% of the practitioners, respectively. Only subjective norm had a statistically significant influence on the intention to practice ART (p<0.0001). The results indicated that dental practitioners were willing to have ART introduced in Tanzania and had positive attitudes towards practicing this technique. Nevertheless, their intention to perform ART was strongly influenced by social pressures. Therefore, in order to have a successful introduction of ART in Tanzania, people who matter in the daily practice of dental practitioners need to accept and appraise the ART approach positively

    Cyclodehydration reaction of polyhydrazides. III. Influence of the sample history

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    The influence of preparation history upon the thermal cyclodehydration reaction of polyhydrazide samples has been investigated. Solid polyhydrazide samples were prepared from DMSO solutions using the phase-inversion technique. Significant differences in conversion rates were observed between samples prepared by nonsolvent immersion precipitation and by evaporation of solvent. It appeared that contact with the nonsolvent water during the sample preparation process has considerable influence on the conversion rate. Not only does the immersion in and washing with water lead to a better removal of the solvent also the pH of the water determines the rate of conversion. A distinct change in the conversion rate is found for washing water at a pH of 7. Basic washing solutions showing lower conversion rates than acid ones. A mechanism explaining these phenomena is proposed

    Effects of antiandrogens on transformation and transcription activation of wild-type and mutated (LNCaP) androgen receptors

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    LNCaP cells contain androgen receptors with a mutation in the steroid binding domain (Thr 868 changed to Ala) resulting in a changed hormone specificity. Both the wild-type and mutated androgen receptors were transfected into COS cells. Transcription activation was studied in cells co-transfected with an androgen sensitive reporter (CAT) gene. The wild-type androgen receptor was activated by the agonist R1881, but the antiandrogens did not enhance transcription apart from a partial agonistic effect at high concentrations of cyproterone acetate. The mutated androgen receptor was fully activated by R1881, cypoterone acetate and hydroxyflutamide, but not by ICI 176,334. Receptor transformation to a tight nuclear binding state was studied by preparation of detergent washed nuclei and Western blotting with a specific antibody against the androgen receptor. Nuclei of COS cells transfected with wild-type receptor retained the receptor when the cells had been treated with the agonist R1881, partially retained receptors when treated with antiandrogen cyproterone acetate, but did not retain receptor when treated with hydroxyflutamide or ICI 176,334. The cells transfected with the mutated receptor additionally retained nuclear receptors after treatment with hydroxyflutamide. We conclude that each one of the three antiandrogens tested displayed different characteristics with respect to its effect on transformation and transcription activation
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