Assessment of antimicrobial prophylaxis to prevent perioperative infection in patients undergoing prostate brachytherapy: multicenter cohort study.

To propose an appropriate prophylactic antimicrobial therapy for patients undergoing brachytherapy, we evaluated the relationships between various antimicrobial prophylaxis (AMP) protocols and the incidence of postimplant infections in a multicenter cohort study conducted in Japan. The records of 826 patients with localized prostate cancer who underwent a transperineal (125)I brachytherapy procedure between January 2009 and December 2010 were retrospectively reviewed. Perioperative infections, including surgical site and remote infections, were recorded up to postoperative day 30. A total of 6 (0.73%) patients had a perioperative infection following seed implantation, of whom all received AMP for 1 or more days. None of the patients who received a single-dose protocol of AMP using fluoroquinolone p.o. or penicillin with a beta-lactamase inhibitor i.v. developed a perioperative infection. Statistical analysis showed that a single-dose protocol was more significantly related to a lower risk of perioperative infection as compared to the other AMP protocols examined (p = 0.045). Furthermore, our results indicated that bacteriuria and preoperative hair removal were risk factors of perioperative infection with statistical significance (p = 0.007, p = 0.004). Analysis of patient clinical parameters, including age, American Society of Anesthesiologists score, diabetes mellitus, prostate volume, numbers of implanted seeds and needle punctures, operation time, and indwelling duration time of the Foley catheter, did not reveal significant differences in terms of perioperative infection. Our results indicated that a single-dose AMP protocol is sufficient to prevent perioperative infections following seed implantation. On the other hand, AMP is only one of several measures to prevent perioperative infectious complications. It is necessary to know that the patient must have no bacteriuria and that preoperative hair removal should be avoided.

Assessment of change in biofilm architecture by nutrient concentration using a multichannel microdevice flow system.

A new multichannel microdevice flow system with stainless steel flow chamber was used for architecture visualization, development monitoring and structural quantification of GFP-labeled Pseudomonas aeruginosa PAO1 live biofilms. Direct in situ investigations using confocal laser scanning microscopy (CLSM) at 72 h revealed structural pattern differences as a result of nutrient concentration gradients. When grown in LB medium, round, dispersed cellular aggregates were formed whereas in 1/3-diluted LB medium, biofilms were mostly flat and compact. However, COMSTAT analyses showed no considerable differences in biomass and thickness between the two LB concentrations. Characterization of time-dependent development of biofilms grown in 1/3-diluted LB medium showed full maturation of colonies by 120 h reaching maximum biomass at 17.1 µm(3)/µm(2) and average thickness at 44.4 µm. Consequent thinning and formation of openings through interior in colonies occurred by 168 h. These results suggest that the new system tested allowed a fast and thick biofilm development on the surface of the stainless steel flow chamber. These findings may provide better estimates of biofilm activity and systematic evaluation of the effects of different parameters on biofilm morphology and development in industrial and biomedical systems.

Pharmacokinetic-pharmacodynamic target attainment analysis of doripenem in infected patients.

This study was a pharmacokinetic (PK)-pharmacodynamic (PD) target attainment analysis of doripenem. Drug concentration data in plasma (115 samples) and urine (61 samples) from 18 infected patients were concurrently analysed to develop a more accurate population PK model for doripenem. In the final PK model, creatinine clearance (CL(Cr)) was the most significant covariate: CL(r) (L/h)=0.137xCL(Cr); CL(nr) (L/h)=2.49; V(1) (L)=8.29; Q (L/h)=8.10; and V(2) (L)=9.37, where CL(r) and CL(nr) are the renal and non-renal clearances, V(1) and V(2) are the volumes of distribution of the central and peripheral compartments, and Q is the intercompartmental (central-peripheral) clearance. Based on the PK model, a Monte Carlo simulation predicted the probabilities of attaining the bactericidal exposure target (40% of the time above the minimum inhibitory concentration (MIC)) in plasma and defined the PK-PD breakpoints (the highest MIC values at which the target attainment probabilities were >or=90%). The breakpoint for 500 mg every 8h (q8h) (1-h infusion) with a CL(Cr) of 80 mL/min (1 microg/mL) corresponded to those for 250 mg q8h with a CL(Cr) of 40 mL/min and 250 mg every 12h with a CL(Cr) of 20 mL/min. Prolonging the infusion time was a more effective strategy than dose escalation to increase the breakpoint. These results provide guidance for constructing a PK-PD-based strategy for dosing guidance for tailoring doripenem regimens.

Effects of radiofrequency ablation on individual renal function: assessment by technetium-99m mercaptoacetyltriglycine renal scintigraphy.

We quantitatively evaluated total and individual renal function by technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) renal scintigraphy before and after radiofrequency ablation (RFA) of renal tumors. Eleven patients who underwent Tc-99m MAG3 renal scintigraphy 1 week before and after RFA were evaluated (7 men and 4 women; age range: 23-83 years; mean age: 60.6 years). Five patients had solitary kidneys, and five had normally or minimally functioning contralateral kidneys. One patient had a renal cell carcinoma in the contralateral kidney. One patient with a solitary kidney underwent RFA a second time for a residual tumor. In patients with a solitary kidney, MAG3 clearance decreased after 5 of 6 RFAs, and in patients with a normally functioning contralateral kidney, MAG3 clearance decreased after 4 of 5 RFAs, but no significant differences were observed between before and after treatments. In addition to the total MAG3 clearance, the split MAG3 clearance was evaluated in patients with a normally functioning contralateral kidney. MAG3 clearance decreased in 4 of 5 treated kidneys, while it adversely increased in the contralateral kidneys after 4 of 5 RFAs. No significant differences, however, were observed between before and after treatments. The results of our study revealed no significant differences in sCr, BUN, CCr, or MAG3 clearance between pre- and post-RFA values. These results support data regarding the functional impact and safety of renal RFA in published reports. We evaluated total and individual renal function quantitatively using Tc-99m MAG3 renal scintigraphy before and after treatment. This scintigraphy was very useful in assessing the effects of RFA on renal function.

Predicting postoperative renal insufficiency in patients undergoing nephrectomy for renal malignancy: assessment by renal scintigraphy using 99mtechnetium-mercaptoacetyltriglycine.

PURPOSE: We performed Tc-mercaptoacetyltriglycine (MAG3) renal scintigraphy in patients with renal malignancy to evaluate the function of each renal unit before and after nephrectomy to see if postoperative functional deterioration could be predicted based on scintigraphy results and creatinine clearance. MATERIALS AND METHODS: A total of 22 men and 13 women with renal malignancy, including 32 with renal cell carcinoma and 3 with urothelial cancer, were prospectively enrolled in this study. Average patient age was 64.3 years (median 65, range 43 to 88). All patients underwent MAG3 renal scintigraphy before and after unilateral nephrectomy. At the same time serum creatinine and endogenous creatinine clearance were determined. RESULTS: Mean serum creatinine was 0.93 mg/dl before and 1.31 after nephrectomy (p <0.0001). Preoperative endogenous creatinine clearance was 70.8 ml per minute per 1.73 m, which decreased to 49.0 ml per minute per 1.73 m after nephrectomy (p <0.0001). Mean MAG3 clearance of the remaining kidney increased 35.1% above baseline from 156.5 to 211.5 ml per minute per 1.73 m following nephrectomy. Spearman rank core analysis revealed that preoperative MAG3 clearance of the remaining kidney significantly correlated with postoperative creatinine clearance (r = 0.596, p = 0.0005). Preoperative MAG3 clearance of the remaining kidney more than 130 ml per minute per 1.73 m coincided with postoperative creatinine clearance above 40 ml per minute per 1.73 m. CONCLUSIONS: MAG3 renal scintigraphy may be useful for predicting renal insufficiency after nephrectomy. The findings in this study suggest that preoperative MAG3 clearance of the remaining kidney less than 130 ml per minute per 1.73 m is a risk factor for postoperative renal insufficiency.