Medical expulsive therapy versus early endoscopic stone removal for acute renal colic: an instrumental variable analysis.

PURPOSE: The use of medical expulsive therapy to hasten stone passage potentially decreases expenditures around episodes of renal colic. However, these efficiency gains may be mitigated if patients treated with medical expulsive therapy have frequent health care encounters due to pain while waiting for the stones to pass. MATERIALS AND METHODS: Using claims data (2002 to 2006) we identified adult men with acute renal colic. We compared 6-week payments as well as frequency of hospitalization and emergency department revisits associated with an initial course of medical expulsive therapy with those for early endoscopic stone removal. To account for unmeasured confounding we performed an instrumental variable analysis, exploiting variation in recommended treatments based on the day of the week that a patient's first emergency department visit occurred. RESULTS: Overall 1,835 and 4,397 men underwent medical expulsive therapy or early endoscopic stone removal, respectively. Although minimal differences existed between men with respect to the day of the week of emergency department presentation, weekend encounters were strongly associated with receiving medical expulsive therapy (p <0.001). Two-stage least squares regression revealed 6-week payments to be tenfold lower for men on medical expulsive therapy who were candidates for either treatment (p <0.001). While there was no difference in frequency of hospitalization, these men were more likely to have a repeat emergency department visit compared to those who underwent endoscopic stone removal (68.8% vs 39.6%, respectively, p = 0.025). CONCLUSIONS: Findings on medical expulsive therapy are mixed, with lower 6-week payments but more frequent repeat emergency department visits. These data inform patients who are candidates for medical expulsive therapy or endoscopic stone removal when making decisions about their care.

A role for matrix metalloproteinases and tumor host interaction in hepatocellular carcinomas.

BACKGROUND: Hepatocellular carcinoma (HCC) occur in livers with injury-remodeling, accomplished by enzymes called matrix metalloproteinases (MMP). Metastasis involves basement membrane invasion also caused by MMP activity. Alterations in MMP expression and their endogenous inhibitor (TIMP) may factor in HCC metastasis. METHODS: HCC specimens and lymph nodes (n = 7), and normal lymph tissue from organ donors (n = 8), were snap-frozen in liquid nitrogen and the mRNA precipitated. A series of reverse transcription-polymerase chain reactions (RT-PCR) were performed using MMP (MMP2, MMP7, MMP9) primers and TIMP (TIMP1, TIMP2) primers. These were semiquantitatively analyzed by comparing concentration with constitutive GADPH expression. RESULTS: There is an increase in MMP2:TIMP2 mRNA expression ratio in the normal and tumor margin tissue compared to the tumor. There are increases in all MMP and TIMP mRNA expression (except TIMP1) and alterations in all of the MMP:TIMP expression ratios in the draining lymph node. CONCLUSIONS: Alterations exist in MMP2:TIMP2: expression at the margin, and all of the MMPs in the draining lymph nodes. This likely reflects a host-tumor interaction that regulates tumor metastasis.