Objective and subjective assessment of physician labor and resource utilization in maintenance percutaneous transluminal angioplasty of nonthrombosed hemodialysis arteriovenous fistulas versus arteriovenous grafts.

PURPOSE: To complement prior studies that have shown that arteriovenous fistula (AVF) thrombectomies require more time and equipment than arteriovenous graft (AVG) thrombectomies by measuring work via established instruments to determine whether there is also a difference in maintenance percutaneous transluminal angioplasty (PTA) of nonthrombosed AVFs versus AVGs. MATERIALS AND METHODS: PTA procedures performed on a consecutive cohort of 42 patients with AVFs and 27 patients with AVGs were prospectively compared. To quantify resource utilization, procedure time and disposable equipment were measured. Established instruments developed by the American Medical Association for Current Procedural Terminology code valuation were used to measure subjective "physician work," including mental effort and judgment, technical skill, physical effort, and psychological stress. These items were scored by 1 of 12 attending interventional radiology physicians performing the procedure. RESULTS: Mean PTA procedure time was 74 minutes (range, 18-183 minutes) for AVFs and 71 minutes (range, 28-204 minutes) for AVGs; hemostasis time was 12 minutes for AVFs and 11 minutes for AVGs. There was no significant difference in equipment use between groups. "Physician work" for AVFs scored significantly higher in four categories (P≤ .05). CONCLUSIONS: Using established subjective instruments, maintenance PTA of AVFs was scored as more cognitively, physically, and psychologically demanding than maintenance PTA of AVGs. However, there was no significant difference in resource utilization between maintenance PTA of AVFs versus AVGs, as has been previously shown with thrombectomy of thrombosed AVFs and AVGs.

Outcomes following fibroid expulsion after uterine artery embolization.

PURPOSE: To evaluate retrospectively the sequelae of fibroid expulsion (FE) after uterine artery embolization (UAE). MATERIALS AND METHODS: From a population of 759 UAE procedures performed from July 1999 to June 2009, 37 patients were found to have a uterine fibroid communicating with the endometrial cavity resulting in "bulk" FE with the passage of large fragments or an entire tumor or "sloughing" FE with shedding or "melting" of the tumor. Medical records and magnetic resonance images were evaluated for clinical information and tumor characteristics, respectively. RESULTS: The mean age of patients with FE was 43 years ± 5 (SD), with 12 nulliparous and 25 parous. Expulsion took place a mean of 14.8 weeks ± 17.7 after UAE (range, 1.6-105.9 wk). FE was asymptomatic in 5% of cases (n = 2) and symptomatic in 95% (n = 35). Among symptomatic cases, 89% (n = 31) had bulk expulsion and 11% (n = 4) had sloughing expulsion. Forty-nine percent of patients (n = 18) had tumor expulsion at home or had an office/emergency room transvaginal myomectomy (TVM), 27% (n = 10) underwent operative TVM, and 8% (n = 3) had hysteroscopic resection. Urgent and elective hysterectomies were performed in 11% (n = 4) and 5% of cases (n = 2), respectively. Nulliparous women showed a trend toward undergoing hysterectomy compared with parous women (33% vs 8%; P =.07, Fisher exact test). CONCLUSIONS: Most women tolerate FE well, with approximately half needing no operative intervention, but some may need to undergo hysteroscopy, operative TVM, or even hysterectomy. Nulliparous women are potentially at greater risk to require hysterectomy.

The case for primary placement of tunneled hemodialysis catheters in acute kidney injury.

PURPOSE: Nontunneled hemodialysis catheters (NTDCs) are widely used for initial hemodialysis access in new-onset renal failure. The National Kidney Foundation recommends NTDC use for hemodialysis duration of less than 1 week in acute kidney injury because of the increased infection risk compared with tunneled hemodialysis catheters (TDCs) with longer use. The present study was performed to determine whether primary placement of TDCs in this setting is more appropriate, and whether there are predictors of recovery of renal function in less than 1 week. MATERIALS AND METHODS: In the authors' practice, patients referred to the interventional radiology unit in whom no contraindications exist receive a TDC; 76 patients who received a primary TDC for acute kidney injury and who eventually recovered renal function were retrospectively reviewed herein. Causes of renal failure, various renal function parameters, and demographics were collected, as were TDC dwell times, in an effort to determine predictors of recovery and/or extended duration of use. RESULTS: Mean TDC dwell time in patients who eventually recovered from acute kidney injury was 34 days; only 15 of 76 (20%) recovered within 1 week. At TDC placement, there were no significant differences between patients who recovered in less than (vs greater than) 1 week. CONCLUSIONS: The present results support primary placement of TDCs in patients with acute kidney injury who require hemodialysis and in whom no contraindications exist, as no predictors of recovery of renal function in less than 1 week were identified.

Androgen ablation mitigates tolerance to a prostate/prostate cancer-restricted antigen.

To understand the T cell response to prostate cancer, we created transgenic mice that express a model antigen in a prostate-restricted pattern and crossed these animals to TRAMP mice that develop spontaneous prostate cancer. Adoptive transfer of prostate-specific CD4 T cells shows that, in the absence of prostate cancer, the prostate gland is mostly ignored. Tumorigenesis allows T cell recognition of the prostate gland--but this recognition is tolerogenic, resulting in abortive proliferation and ultimately in hyporesponsiveness at the systemic level. Androgen ablation (the most common treatment for metastatic prostate cancer) was able to mitigate this tolerance--allowing prostate-specific T cells to expand and develop effector function after vaccination. These results suggest that immunotherapy for prostate cancer may be most efficacious when administered after androgen ablation.

Replication factor C clamp loader subunit arrangement within the circular pentamer and its attachment points to proliferating cell nuclear antigen.

Replication factor C (RFC) is a heteropentameric AAA+ protein clamp loader of the proliferating cell nuclear antigen (PCNA) processivity factor. The prokaryotic homologue, gamma complex, is also a heteropentamer, and structural studies show the subunits are arranged in a circle. In this report, Saccharomyces cerevisiae RFC protomers are examined for their interaction with each other and PCNA. The data lead to a model of subunit order around the circle. A characteristic of AAA+ oligomers is the use of bipartite ATP sites in which one subunit supplies a catalytic arginine residue for hydrolysis of ATP bound to the neighboring subunit. We find that the RFC(3/4) complex is a DNA-dependent ATPase, and we use this activity to determine that RFC3 supplies a catalytic arginine to the ATP site of RFC4. This information, combined with the subunit arrangement, defines the composition of the remaining ATP sites. Furthermore, the RFC(2/3) and RFC(3/4) subassemblies bind stably to PCNA, yet neither RFC2 nor RFC4 bind tightly to PCNA, indicating that RFC3 forms a strong contact point to PCNA. The RFC1 subunit also binds PCNA tightly, and we identify two hydrophobic residues in RFC1 that are important for this interaction. Therefore, at least two subunits in RFC make strong contacts with PCNA, unlike the Escherichia coli gamma complex in which only one subunit makes strong contact with the beta clamp. Multiple strong contact points to PCNA may reflect the extra demands of loading the PCNA trimeric ring onto DNA compared with the dimeric beta ring.