Effect of alanine supplementation on oxalate synthesis.

The Primary Hyperoxalurias (PH) are rare disorders of metabolism leading to excessive endogenous synthesis of oxalate and recurring calcium oxalate kidney stones. Alanine glyoxylate aminotransferase (AGT), deficient in PH type 1, is a key enzyme in limiting glyoxylate oxidation to oxalate. The affinity of AGT for its co-substrate, alanine, is low suggesting that its metabolic activity could be sub-optimal in vivo. To test this hypothesis, we examined the effect of L-alanine supplementation on oxalate synthesis in cell culture and in mouse models of Primary Hyperoxaluria Type 1 (Agxt KO), Type 2 (Grhpr KO) and in wild-type mice. Our results demonstrated that increasing L-alanine in cells decreased synthesis of oxalate and increased viability of cells expressing GO and AGT when incubated with glycolate. In both wild type and Grhpr KO male and female mice, supplementation with 10% dietary L-alanine significantly decreased urinary oxalate excretion ~30% compared to baseline levels. This study demonstrates that increasing the availability of L-alanine can increase the metabolic efficiency of AGT and reduce oxalate synthesis.

Completed versus aborted radical hysterectomy for node-positive stage IB cervical cancer in the modern era of chemoradiation therapy.

OBJECTIVE: Debate continues about optimal management of patients with node-positive stage I cervical cancer. Our objective was to determine if patient outcomes are affected by radical hysterectomy in the modern era of adjuvant chemoradiation. METHODS: Cervical cancer patients diagnosed from 2000 to 2008 were identified. Demographics, therapy, clinicopathologic data, progression free survival (PFS), overall survival (OS), total radiation exposure, and grade 3-4 complications were analyzed by student t, Mann-Whitney, Fisher's exact, Kaplan-Meier, and log rank tests. RESULTS: This single-institution review evaluated forty-one of 334 (13.4%) patients scheduled to undergo radical hysterectomy that had gross nodal disease diagnosed intraoperatively. 15 underwent aborted radical hysterectomy following lymphadenectomy; the remaining 26 underwent radical hysterectomy and lymphadenectomy. Eleven patients undergoing radical hysterectomy underwent whole pelvic radiation therapy (WPRT) while 8 (30.7%) patients underwent WPRT and postoperative vaginal brachytherapy (BT) for local treatment secondary to close margins. All patients undergoing aborted radical hysterectomy underwent WPRT and BT. With mean follow-up of 42.3 months, there were no significant differences in urinary, gastrointestinal, or hematologic complications between groups. When comparing those undergoing radical hysterectomy to aborted radical hysterectomy, there were no significant differences in local recurrence (11.5% vs 26.7%, p=0.39) or distant recurrence (19.2% vs. 33.3%, p=0.45), PFS (74.9 months vs 46.8 months, p=0.106), or OS (91.8 months vs 69.4 months, p=0.886). CONCLUSIONS: Treatment of patients with early stage cervical cancer and nodal metastasis may be tailored intraoperatively. Completion of radical hysterectomy and lymphadenectomy decreases radiation exposure without apparently compromising safety or outcome in the era of adjuvant chemoradiation.