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Standard Control (standard + control)

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Medical Sciences100%

Selected Abstracts

The pros and cons of noninferiority trials

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2003
Stuart J. Pocock
Abstract Noninferiority trials comparing new treatment with an active standard control are becoming increasingly common. This article discusses relevant issues regarding their need, design, analysis and interpretation: the appropriate choice of control group, types of noninferiority trial, ethical considerations, sample size determination and potential pitfalls to consider. [source]

Quantitative analysis of human mitochondrial DNA using a real-time PCR assay

HIV MEDICINE, Issue 3 2003
K Gourlain
Objectives Known for their ability to inhibit the human DNA polymerase-,, nucleoside analogues induce toxic effects on mitochondria ranging from increased serum lactate levels to fatal lactic acidosis. DNA polymerase-, ensures the mitochondrial DNA (mtDNA) replication and, thus, its inhibition leads to the decrease of the mtDNA. We describe a real-time PCR assay for mtDNA quantification associating DNA extraction procedures applied on peripheral blood mononuclear cells (PBMCs) and subcutaneous adipose tissues and to study the antiretroviral effect on mitochondria. Methods Total DNA was extracted from PBMCs and subcutaneous adipose tissues. Nuclear and mitochondrial genes were amplified to determine the number of copies of mtDNA per cell using a cyt-b recombinant plasmid as standard control. We analysed eight HIV-infected asymptomatic patients never treated, four patients who had been treated for 6 months with highly active antiretroviral therapy (HAART) and six non-infected donors. Results The mtDNA quantification gave rise to reproducible results as the mean coefficients of variation were 1.09% for replicates of samples undertaken 10 times within the same run, and 5.78% and 3.7% for replicates tested in five different runs at 1:100 and 1:1000 dilutions, respectively. Median levels of mtDNA in PBMCs of healthy donors, naive and treated HIV-infected patients were 2.94, 2.78 and 1.93 log HIV-1 RNA copies/mL, respectively. Whereas DNA from PBMCs was shown to be devoid of inhibitors, subcutaneous adipose tissues needed an extra treatment as they were found to be highly inhibited. Conclusions The method generated consistent and reproducible results and was successfully applied to DNAs extracted from PBMCs and subcutaneous adipose tissues with adapted extraction. The mtDNA changes in PBMCs were found to be fast as they fall off after 6 months' therapy, decreasing from 2.78 to 1.93 log copies/mL. [source]

Hyptis pectinata essential oil: chemical composition and anti- Streptococcus mutans activity

ORAL DISEASES, Issue 6 2008
PFC Nascimento
Objectives:, The aim of the present study was to evaluate the anti- Streptococcus mutans activity of Hyptis pectinata essential oil, and present its promising potential against oral diseases. Materials and methods:, The essential oil of H. pectinata was obtained by hydrodistillation from dried leaves and analyzed by GC / MS. The effectiveness of this essential oil regarding the antimicrobial activity against several S. mutans strains was investigated by the agar diffusion and microdilution methods, and chlorohexidine was used as a standard control. Results:, The H. pectinata essential oil exhibited considerable inhibitory effect against either all the clinical isolates obtained from patients' saliva or the ATCC strains tested, with minimum inhibitory and bactericidal concentrations of 200 ,g ml,1. The study also compared the efficiency of the emulsifying agents Tween 20, Tween 80, dimethyl sulfoxide and propylene glycol in H. pectinata essential oil when tested against S. mutans. The data obtained confirmed the better inhibitory effect of the oil when using all tested diluents, although Tween 80 seemed to be more suitable for emulsification. Conclusion:, According to our results, H. pectinata essential oil can be considered a promising alternative to chlorhexidine for the control of oral bacteria-related diseases and hygiene. [source]

Utility of the thromboplastin-plasma cell-block technique for fine-needle aspiration and serous effusions

DIAGNOSTIC CYTOPATHOLOGY, Issue 2 2009
D.M.L.T., Manisha B. Kulkarni M.Sc.
Abstract (I) To assess the feasibility of thromboplastin-plasma (TP) method for cell block, (II) to concentrate the minimal cellular material from effusions and needle-rinses by block preparation and improve visual details, (III) to compare conventional cytological smears with cell blocks for final assessment, and (IV) to assess utility of immunocytochemistry (ICC) for diagnostic accuracy. Seventy cell blocks were prepared by TP technique using surplus fluid from 38 serous effusions, and for 32 ultrasonography-guided fine-needle aspiration cytology (FNAC) material, rinses of syringes and needles were collected in normal saline after conventional cytological smears. Then, cell blocks were compared with conventional smears for adequacy, morphologic preservation, and ICC. Absolute concordance seen in 66 cases (94%) between the smears and cell blocks. Advantages with the blocks were cellular concentration in a limited field and better cellular preservation with architectural pattern. Quality of ICC was comparable to that of standard controls. Diagnostic discrepancy was seen in two cases where cell blocks were positive but smears were negative. Two cell blocks were nonrepresentative. Cell block serves as a useful adjunct to traditional cytological smears. TP method is simple, cost effective, and reproducible. It is easy when compared with agar-embedding technique. Ancillary techniques like ICC can be performed successfully. Diagn. Cytopathol. 2009. © 2008 Wiley-Liss, Inc. [source]

AUSTRALASIAN SURVEY OF SPLIT SKIN GRAFT DONOR SITE DRESSINGS

ANZ JOURNAL OF SURGERY, Issue 2 2000
Patrick W. Lyall
Background: There is an ever increasing array of products available for wound dressings. The aim of the present study was to establish which dressings should be used as standard controls for future studies; what factors are regarded as most important in assessing a dressing; what the level of satisfaction is with the available products; what the strengths and weaknesses of the commonly used dressings are; and what dressings would be preferred if cost were no issue. Methods: A postal survey was sent to every plastic and reconstructive surgeon registered in Australasia (n = 217). A total of 53% responded. Results: The most commonly used dressing type overall is the calcium alginates, despite the fact that they were not the highest performing dressings. This is also the most commonly used in Australia. In contrast scarlet red is still used most commonly in New Zealand. The level of satisfaction with the most commonly used dressing varied very little. The factor regarded most important was patient comfort level. A profile of the commonly used dressing was constructed. Calcium alginates and or scarlet red should be used as the control for new product comparisons. Conclusions: Most of the respondents were satisfied with their preferred dressing and were not interested in trying alternative dressings. [source]