ABSTRACT
Developmental dysplasia of the hip (DDH) is the most common orthopaedic disorder in newborns. While the Pavlik harness is one of the most frequently used treatments for DDH, there is immense variability in treatment parameters reported in the literature and in clinical practice, leading to difficulties in standardizing teaching and comparing outcomes. In the absence of definitive quantitative evidence for the optimal Pavlik harness management strategy for DDH, we addressed this problem by obtaining international expert-based consensus on the subject. METHODS: An initial list of items relevant to Pavlik harness treatment was derived by a review of the literature. Delphi methodology was used to guide serial rounds of surveying and obtaining feedback from content matter experts from the International Hip Dysplasia Institute (IHDI), which continued in the same manner until consensus based on standard statistical analysis was reached. This was followed by a corroboration of face validity to derive the final set of management principles. RESULTS: Four rounds of structured surveying were required to reach consensus. Following 2 rounds of peer review, and from an initial list of 66 items in 8 categories, we were able to derive 2 simplified, yet comprehensive, print-friendly tables consisting of 28 items in 8 categories to assist clinicians in managing DDH with a Pavlik harness. The tables contain principles of treatment initiation, application and follow-up of the harness, complications, weaning, and end-of-treatment decision-making as well as specific criteria based on the severity of the DDH. Furthermore, highly contentious items were identified as important areas of future study. CONCLUSIONS: We developed a comprehensive set of principles based on expert consensus to assist clinicians in the management of DDH using the Pavlik harness. This study also generated a list of the most controversial areas in the nonoperative management of DDH, which should be considered high priority for future study to further refine and optimize outcomes. LEVEL OF EVIDENCE: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.
ABSTRACT
Formation of adducts between Ru(TAP)3(2+) (TAP = 1,4,5,8-tetraazaphenanthrene) and DNA has been monitored by gel electrophoresis, UV-vis spectroscopy and dialysis methods. Adduct formation is found for both single- and double-stranded nucleic acids. The reaction with double-stranded DNA is found to be insensitive to solution pH or aeration. Spectroscopic changes similar to those for DNA are found with GMP in oxygen-free pH 5 solution. However, different reactions occur with GMP at higher pH or when the solution contains oxygen. Comparative experiments with double-stranded poly[d(G-C)] or poly[d(A-T)] indicate that the adduct with DNA involves binding to the guanosine moiety. It is proposed that the product is formed by the reaction of the reduced ruthenium complex and oxidised guanine species produced by photo-induced electron transfer.
Subject(s)
DNA/chemistry , Deoxyguanine Nucleotides , Guanosine Monophosphate , Oligodeoxyribonucleotides/chemistry , Organometallic Compounds/chemistry , Phenanthrenes/chemistry , Radiation-Sensitizing Agents/chemistry , Base Sequence , Molecular Sequence Data , Poly dA-dT/chemistry , Polydeoxyribonucleotides/chemistry , SpectrophotometryABSTRACT
A series of ruthenium polypyridyl complexes has been covalently bound to poly(L-lysine), bovine serum albumin, human serum albumin, ovalbumin, and immunoglobulin G using different binding methods. The conjugation ratios and the luminescence properties of the bioconjugates are reported. All conjugates show nonsingle-exponential decay curves. Quenching of the emission by oxygen has been studied.
Subject(s)
Albumins/chemistry , Fluorescent Dyes/chemistry , Immunoglobulin G/chemistry , Organometallic Compounds/chemistry , Polylysine/chemistry , Pyridines/chemistry , Animals , Chemical Phenomena , Chemistry, Physical , Chromatography, High Pressure Liquid , Enzyme-Linked Immunosorbent Assay , Indicators and Reagents , Mice , Ovalbumin/chemistry , Ovalbumin/immunology , Ruthenium/chemistry , Serum Albumin/chemistry , Serum Albumin/immunology , Serum Albumin, Bovine/chemistry , Serum Albumin, Bovine/immunologyABSTRACT
The interaction of complexes Ru(bpy)n(TAP)3-n2+ (1a-1d for n = 0-3) with DNA has been investigated using photophysical methods (emission spectroscopy and laser flash photolysis), by studying the induction of single-strand breaks in plasmid DNA and the formation of adducts using 32P-labelled 27-mer oligonucleotides. Two classes of behaviour are found. Complexes 1a and 1b show quenched emission in the presence of calf thymus DNA and yield photoadducts with the 27-mer, whereas 1c and 1d show enhanced emission and do not form photoadducts. 1a and 1b are more efficient sensitizers for single-strand breaks than are 1c and 1d. It is proposed that the excited states of 1a and 1b, which are stronger oxidizing agents than those of 1c and 1d, are capable of oxidizing guanine. Direct evidence for electron transfer has been obtained from laser flash photolysis of Ru(TAP)3(2+) and dGMP, CT-DNA and polynucleotides.
