Background
The management of complex orthopedic infections usually includes a
prolonged course of intravenous antibiotic agents. We investigated whether
oral antibiotic therapy is noninferior to intravenous antibiotic therapy for
this indication.
Methods
We enrolled adults who were being treated for bone or joint infection
at 26 U.K. centers. Within 7 days after surgery (or, if the infection was
being managed without surgery, within 7 days after the start of antibiotic
treatment), participants were randomly assigned to receive either
intravenous or oral antibiotics to complete the first 6 weeks of therapy.
Follow-on oral antibiotics were permitted in both groups. The primary end
point was definitive treatment failure within 1 year after randomization. In
the analysis of the risk of the primary end point, the noninferiority margin
was 7.5 percentage points.
Results
Among the 1054 participants (527 in each group), end-point data were
available for 1015 (96.3%). Treatment failure occurred in 74 of 506
participants (14.6%) in the intravenous group and 67 of 509 participants
(13.2%) in the oral group. Missing end-point data (39 participants, 3.7%)
were imputed. The intention-to-treat analysis showed a difference in the
risk of definitive treatment failure (oral group vs. intravenous group) of
−1.4 percentage points (90% confidence interval [CI], −4.9 to
2.2; 95% CI, −5.6 to 2.9), indicating noninferiority. Complete-case,
per-protocol, and sensitivity analyses supported this result. The
between-group difference in the incidence of serious adverse events was not
significant (146 of 527 participants [27.7%] in the intravenous group and
138 of 527 [26.2%] in the oral group; P = 0.58). Catheter complications,
analyzed as a secondary end point, were more common in the intravenous group
(9.4% vs. 1.0%).
Conclusions
Oral antibiotic therapy was noninferior to intravenous antibiotic
therapy when used during the first 6 weeks for complex orthopedic infection,
as assessed by treatment failure at 1 year. (Funded by the National
Institute for Health Research; OVIVA Current Controlled Trials number,
ISRCTN91566927.)
Parallel studies of the preparation of Re and (99m)Tc agents aid in interpreting the nature of tracer (99m)Tc radiopharmaceuticals. Aqueous solutions of the fac-[(99m)Tc(CO)(3)(H(2)O)(3)](+) cation are gaining wide use and are readily prepared, but such solutions of the fac-[Re(CO)(3)(H(2)O)(3)](+) cation (1) are not so easily accessible. Herein we describe a new, reliable, and straightforward preparation of aqueous solutions of 1, characterized by HPLC and ESI-MS. Treatment of solutions of 1 with thioether-bearing amino acids, AAH = S-methyl-l-cysteine (MECYSH), S-propyl-l-cysteine (PRCYSH), and methionine (METH), gave high yields of fac-Re(CO)(3)AA complexes. X-ray crystallographic and NMR analyses indicated that MECYS(-), PRCYS(-), and MET(-) were bound in fac-Re(CO)(3)AA complexes as tridentate monoanionic ligands through amino, thioether, and alpha-carboxyl groups. In CD(3)OD, (1)H NMR spectra have broad signals but have two sets of signals at -10 degrees C, consistent with two isomers with different configurations at the pyramidal sulfur; these interconvert slowly on the NMR time scale at low temperatures. Indeed, the crystal structure of the fac-Re(CO)(3)(PRCYS) reveals a mixture of the two possible diastereoisomers. S-(Carboxymethyl)-l-cysteine (CCMH(2)) and 1 gave two products, 5A (kinetically favored) and 5B (thermodynamically favored). X-ray crystallographic analyses of a crystal of 5B and of a 1:1 cocrystal of 5A and 5B showed that 5A and 5B are diastereoisomers with the CCMH(-) alpha-carboxyl group dangling. In addition to the amino and thioether groups, the S-(carboxymethyl) carboxyl group is coordinated, a feature that slows interconversion of diastereoisomers relative to the other fac-Re(CO)(3)AA complexes because interconversion can now occur only after the rupture of Re-ligand bonds. These N, O, and S tridentate adducts are quite stable, and the grouping has promise in (99m)Tc(CO)(3) tracer development.
The need for simple and accurate methods to measure renal function is self-evident. This need increases as techniques for intervention become available. The demand for evaluation of indi vidual kidney function has increased with its role in the diagnosis and follow-up of unilateral renal disease and in decision making for conservative or surgical treatment based on residual renal function. The role of nuclear medicine in this area has been inhibited by confusion about conflicting methodologies. This report is meant to provide guidance to those centers that would like to initiate clear ance procedures but have difficulty in choosing appropriate meth odology.
Radionuclide renal scintigraphy provides important functional data to assist in the diagnosis and management of patients with a variety of suspected genitourinary tract problems, but the procedures are underutilized. Maximizing the utility of the available studies (as well as the perception of utility by referring physicians) requires a clear understanding of the clinical question, attention to quality control, acquisition of the essential elements necessary to produce an informed interpretation, and production of a report that presents a coherent impression that specifically addresses the clinical question and is supported by data contained in the report. To help achieve these goals, part 1 of this review covers information that should be provided to the patient before the scan, describes the advantages and limitations of the available radiopharmaceuticals, discusses quality control elements needed to optimize the study, summarizes approaches to the measurements of renal function, and focuses on recommended quantitative indices and their diagnostic applications. Although the primary focus is the adult patient, aspects of the review also apply to the pediatric population.
Normal limits adjusted for age and sex have been established. Applying normal ranges to quantitative MAG3 parameters may assist in the interpretation of MAG3 scintigraphy and facilitate appropriate patient management.
To develop a 99m Tc renal tracer with a capacity to measure effective renal plasma flow comparable to that of the clinical gold standard 131 I-o-iodohippurate ( 131 I-OIH) and superior to that of 99m TcO-mercaptoacetyltriglycine, which has a clearance only 50%260% that of 131 I-OIH, we investigated 99m Tc-tricarbonyl nitrilotriacetic acid (Na 2 [ 99m Tc(CO) 3 (NTA)]). This radiopharmaceutical, which is based on an aminopolycarboxylate ligand, is formed as a single species and has a dangling carboxylate group favoring tubular transport. Methods: Na 2 [ 99m Tc(CO) 3 (NTA)] was prepared by using commercially available NTA and an IsoLink kit and isolated by high-performance liquid chromatography. The stability of Na 2 [ 99m Tc(CO) 3 (NTA)] in isotonic saline was assessed for 24 h and was further evaluated by incubation in 0.1 M cysteine and histidine for 4 h at 37°C. The biodistribution of Na 2 [ 99m Tc (CO) 3 (NTA)], coinjected with 131 I-OIH as an internal control, was evaluated in 5 normal Sprague-Dawley rats at 10 min, 5 normal Sprague-Dawley rats at 60 min (group A), and 6 rats with renal pedicle ligation at 60 min (group B) after injection. Clearance and extraction fraction studies were conducted in 2 normal Sprague-Dawley rats, and urine and plasma from 2 additional normal rats each were analyzed for metabolites by high-performance liquid chromatography. Results: The radiochemical purity of Na 2 [ 99m Tc(CO) 3 (NTA)] was greater than 99%, the complex was stable for 24 h at physiologic pH, and the challenge experiments showed no degradation. In normal rats, the percentage dose in the urine at 10 and 60 min was 108% 6 9% and 101% 6 5%, respectively, that of 131 I-OIH; minimal hepatic or gastrointestinal activity was demonstrated. In group B rats, Na 2 [ 99m Tc(CO) 3 (NTA)] was better retained in the blood and had less excretion into the bowel than did 131 I-OIH (P , 0.01). The plasma clearances of Na 2 [ 99m Tc(CO) 3 (NTA)] and 131 I-OIH were comparable, but the extraction fraction of Na 2 [ 99m Tc(CO) 3 (NTA)] was 93.5% 6 3.8%, compared with 67.9% 6 6.1% for 131 I-OIH. Plasma protein binding of Na 2 [ 99m Tc(CO) 3 (NTA)] averaged 67% 6 7%, and red cell uptake was 7% 6 2%. Conclusion: Na 2 [ 99m Tc (CO) 3 (NTA)] is stable, exists as a single species, and has pharmacodynamic properties in rats comparable to those of 131 I-OIH.Key Words: 99m Tc-tricarbonyl; renal radiopharmaceuticals; 99m Tc(CO) 3 (NTA); 131 I-ortho-iodohippurate ( 131 I-OIH); 99m Tcmercaptoacetyltriglycine ( 99m
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