A Joint Model for the Kinetics of CTC Count and PSA Concentration During Treatment in Metastatic Castration-Resistant Prostate Cancer.

Assessment of treatment efficacy in metastatic castration-resistant prostate cancer (mCRPC) is limited by frequent nonmeasurable bone metastases. The count of circulating tumor cells (CTCs) is a promising surrogate marker that may replace the widely used prostate-specific antigen (PSA). The purpose of this study was to quantify the dynamic relationships between the longitudinal kinetics of these markers during treatment in patients with mCRPC. Data from 223 patients with mCRPC treated by chemotherapy and/or hormonotherapy were analyzed for up to 6 months of treatment. A semimechanistic model was built, combining the following several pharmacometric advanced features: (1) Kinetic-Pharmacodynamic (K-PD) compartments for treatments (chemotherapy and hormonotherapy); (2) a latent variable linking both marker kinetics; (3) modeling of CTC kinetics with a cell lifespan model; and (4) a negative binomial distribution for the CTC random sampling. Linked with survival, this model would potentially be useful for predicting treatment efficacy during drug development or for therapeutic adjustment in treated patients.

Modeling and predicting optimal treatment scheduling between the antiangiogenic drug sunitinib and irinotecan in preclinical settings.

We present a system of nonlinear ordinary differential equations used to quantify the complex dynamics of the interactions between tumor growth, vasculature generation, and antiangiogenic treatment. The primary dataset consists of longitudinal tumor size measurements (1,371 total observations) in 105 colorectal tumor-bearing mice. Mice received single or combination administration of sunitinib, an antiangiogenic agent, and/or irinotecan, a cytotoxic agent. Depending on the dataset, parameter estimation was performed either using a mixed-effect approach or by nonlinear least squares. Through a log-likelihood ratio test, we conclude that there is a potential synergistic interaction between sunitinib when administered in combination with irinotecan in preclinical settings. Model simulations were then compared to data from a follow-up preclinical experiment. We conclude that the model has predictive value in identifying the therapeutic window in which the timing between the administrations of these two drugs is most effective.

Role of the lean body mass and of pharmacogenetic variants on the pharmacokinetics and pharmacodynamics of sunitinib in cancer patients.

INTRODUCTION: Sunitinib is a multikinase inhibitor active in various cancers types including renal cancers and endocrine tumors. The study analyzed the influence of the lean body mass (LBM) and of pharmacogenetic variants on the exposure to sunitinib and its active metabolite, SU12662, and on sunitinib toxicity and clinical activity. MATERIALS AND METHODS: Exposure to sunitinib and SU12662 was assessed on days 10 and 21 during the first treatment cycle. Acute toxicity was graded using the NCI 4.0 CTCAE ver. 4.0. The LBM and 14 common single nucleotide polymorphisms in the CYP3A4/3A5, NR1I2, NR1I3, ABCB1, and ABCG2 genes were analyzed according to the drug exposure at day 10. Determinants (including sunitinib exposure and pharmacogenetic variants) for toxicities were assessed, as well as the relationship between drug exposure and survival in renal cancer patients. RESULTS: Ninety-two patients (60 % with renal cancer) were assessable for pharmacokinetics, toxicity and survival, and 66 for genetic analysis. The LBM (p < 0.0001) and a polymorphism in the ABCG2 transporter (421C>A) (p = 0.014) were two independent parameters accounting for the variability of composite (sunitinib + SU12662) exposure. Advanced age (OR = 1.47 [1.01-2.15], p = 0.048) and high sunitinib exposure (OR = 1.16 [1.05-1.28], p = 0.005) were independently associated with any grade ≥ 3 acute toxicity, and high SU12662 exposure was associated with grade ≥ 2 thrombocytopenia (OR = 1.27 [1.03-1.57], p = 0.028). A high composite area under the curve (AUC) >1,973 ng/mL∙h at day 21 was associated with a doubled survival (35.2 vs 16.7 months; log-rank p = 0.0051) in renal cancer patients. CONCLUSIONS: This study indicates that LBM and drug monitoring may be helpful in the management of sunitinib-treated patients.

Prediction of tumour response induced by chemotherapy using modelling of CA-125 kinetics in recurrent ovarian cancer patients.

BACKGROUND: The main objective of the present study was to establish the relationships between CA-125 kinetics and tumour size changes during treatment. METHODS: The data from the CALYPSO-randomised phase III trial, comparing two platinum-based regimens in recurrent ovarian cancer (ROC) patients, was randomly split into a 'learning data set' to estimate model parameters and a 'validation data set' to validate model performances. A kinetic-pharmacodynamic semi-mechanistic model was built to describe tumour size and CA-125 kinetics during chemotherapy. The ability of the model to predict tumour response induced by chemotherapy, based on CA-125 values, was assessed. RESULTS: Data from 535 ROC patients were used to model CA-125 kinetics and tumour size changes during the first 513 days after treatment initiation. Using the validated model, we could predict with accuracy the tumour size changes induced by chemotherapy based on the baseline imaging assessment and longitudinal CA-125 values (mean prediction error: 0.3%, mean absolute prediction error: 10.6%). CONCLUSIONS: Using a semi-mechanistic model, the dynamic relationships between tumour size changes and CA-125 kinetics induced by chemotherapy were established in ROC patients. A modelling approach allowed CA-125 to be assessed as a biomarker for tumour size dynamics, to predict treatment efficacy for research and clinical purposes.

A critical review of the analytical approaches for circulating tumor biomarker kinetics during treatment.

Changes in serum tumor biomarkers may indicate treatment efficacy. Traditional tumor markers may soon be replaced by novel serum biomarkers, such as circulating tumor cells (CTCs) or circulating tumor nucleic acids. Given their promising predictive values, studies of their kinetics are warranted. Many methodologies meant to assess kinetics of traditional marker kinetics during anticancer treatment have been reported. Here, we review the methodologies, the advantages and the limitations of the analytical approaches reported in the literature. Strategies based on a single time point were first used (baseline value, normalization, nadir, threshold at a time t), followed by approaches based on two or more time points [half-life (HL), percentage decrease, time-to-events…]. Heterogeneities in methodologies and lack of consideration of inter- and intra-individual variability may account for the inconsistencies and the poor utility in routine. More recently, strategies based on a population kinetics approach and mathematical modeling have been reported. The identification of equations describing individual kinetic profiles of biomarkers may be an alternative strategy despite its complexity and higher number of necessary measurements. Validation studies are required. Efforts should be made to standardize biomarker kinetic analysis methodologies to ensure the optimized development of novel serum biomarkers and avoid the pitfalls of traditional markers.

Early prediction of treatment resistance in low-risk gestational trophoblastic neoplasia using population kinetic modelling of hCG measurements.

BACKGROUND: In low-risk gestational trophoblastic neoplasia (GTN) patients, a predictive marker for early identification of methotrexate (MTX) resistance would be useful. We previously demonstrated that kinetic modelling of human chorionic gonadotrophin (hCG) measurements could provide such a marker. Here we validate this approach in a large independent patient cohort. METHODS: Serum hCG measurements of 800 low-risk GTN patients treated with MTX were analysed. The cohort was divided into Model and Test data sets. hCG kinetics were described from initial treatment day to day 50 using: '(hCG(time))=hCG0*exp(-k*time)+hCGres', where hCGres is the modelled residual production, hCG0 is the baseline hCG level, and k is the rate constant. HCGres-predictive value was investigated against previously reported predictors of MTX resistance. RESULTS: Declining hCG measurements were well fitted by the model. The best discriminator of MTX resistance in the Model data set was hCGres, categorised by an optimal cut-off value of >20.44 IU l(-1): receiver-operating characteristic (ROC) area under the curve (AUC)=0.87; Se=0.91; Sp=0.83. The predictive value of hCGres was reproducible using the Test data set: ROC AUC=0.87; Se=0.88; Sp=0.86. Multivariate analyses revealed hCGres as a better predictor of MTX resistance (HR=1.01, P<0.0001) and MTX failure-free survival (HR=13.25, P<0.0001) than other reported predictive factors. CONCLUSION: hCGres, a modelled kinetic parameter calculated after fully dosed three MTX cycles, has a reproducible value for identifying patients with MTX resistance.

Theoretical investigation of the efficacy of antiangiogenic drugs combined to chemotherapy in xenografted mice.

Antiangiogenic drugs were developed with the aim to inhibit the formation of intratumoral blood vessels and in consequence the growth of solid tumors. As these drugs are generally combined with classical cytotoxic drugs in the treatment of cancer patients, finding the optimal combinations remains a complex challenge due to possible interactions of the antiangiogenic compound with the hemodynamic property of the treated tumor. To analyze this problem, we developed a multi-scale model of vascular tumor growth combining a molecular model of VEGF signaling pathways and a tissue model of the tumor expansion including the dynamics of cellular and tissue processes of tumor growth and response to treatments. We addressed the potential impact of antiangiogenic drug by defining a new index of vasculature quality which depends on the balance between stable and unstable vessels within the tumor mass. Our goal was to investigate the interactions between a chemotherapy and a antiangiogenic treatment, and, by simulating the model, to identify the optimal delay of chemotherapy delivery after the administration of the antiangiogenic compound. This theoretical analysis could be used in the future to optimize antiangiogenic drug delivery in preclinical settings and to facilitate the translation from preclinical to clinical studies.

Sorafenib in advanced melanoma: a critical role for pharmacokinetics?

BACKGROUND: Inter-patient pharmacokinetic variability can lead to suboptimal drug exposure, and therefore might impact the efficacy of sorafenib. This study reports long-term pharmacokinetic monitoring of patients treated with sorafenib and a retrospective pharmacodynamic/pharmacokinetic analysis in melanoma patients. PATIENTS AND METHODS: Heavily pretreated patients with stage IV melanoma were started on sorafenib 400 mg twice daily (bid). In the absence of limiting toxicity, dose escalation of 200 mg bid levels was done every 2 weeks. Plasma sorafenib measurement was performed at each visit, allowing a retrospective pharmacodynamic/pharmacokinetic analysis for safety and efficacy. RESULTS: In all, 19 of 30 patients underwent dose escalation over 400 mg bid, and 28 were evaluable for response. The overall disease control rate was 61% (95% confidence interval (CI): 42.6-78.8), including three confirmed responses (12%). Disease control rate and progression-free survival (PFS) were improved in patients with high vs low exposure (80% vs 32%, P=0.02, and 5.25 vs 2.5 months, P=0.005, hazard ratio (HR)=0.28 (95% CI: 0.11-0.73)). In contrast, drug dosing had no effect on PFS. In multivariate analysis, drug exposure was the only factor associated with PFS (HR=0.36 (95% CI: 0.13-0.99)). Diarrhoea and anorexia were correlated with drug dosing, while hypertension and hand-foot skin reaction were correlated with drug exposure. CONCLUSIONS: Although sorafenib had modest efficacy in melanoma, these results suggest a correlation between exposure and efficacy of sorafenib. Therefore, dose optimisation in patients with low exposure at standard doses should be evaluated in validated indications.

Predictive values of hCG clearance for risk of methotrexate resistance in low-risk gestational trophoblastic neoplasias.

BACKGROUND: Early identification of patients at high risk for chemoresistance among those treated with methotrexate (MTX) for low-risk gestational trophoblastic neoplasia (GTN) is needed. We modeled human chorionic gonadotropin (hCG) decline during MTX therapy using a kinetic population approach to calculate individual hCG clearance (CL(hCG)) and assessed the predictive value of CL(hCG) for MTX resistance. PATIENTS AND METHODS: A total of 154 patients with low-risk GTN treated with 8-day MTX regimen were retrospectively studied. NONMEM was used to model hCG decrease equations between day 0 and day 40 of chemotherapy. Receiver operating characteristic curve analysis defined the best CL(hCG) threshold. Univariate/multivariate survival analyses determined the predictive value of CL(hCG) and compared it with published predictive factors. RESULTS: A monoexponential equation best modeled hCG decrease: hCG(t) = 3900 x e(-0.149 x t). Median CL(hCG) was 0.57 l/day (quartiles: 0.37-0.74). Only choriocarcinoma pathology [yes versus no: hazard ratio (HR) = 6.01; 95% confidence interval (CI) 2.2-16.6; P < 0.001] and unfavorable CL(hCG) quartile (< or =0.37 versus >0.37 l/day: HR = 6.75; 95% CI 2.7-16.8; P < 0.001) were significant independent predictive factors of MTX resistance risk. CONCLUSION: In the second largest cohort of low-risk GTN patients reported to date, choriocarcinoma pathology and CL(hCG) < or =0.37 l/day were major independent predictive factors for MTX resistance risk.

Chemotherapy may be delivered based on an integrated view of tumour dynamics.

The aim here was to explore the potential of pharmacokinetic (PK)/pharmacodynamic (PD) and physiopathological parameters in explaining the primary effects of an anti-cancer treatment that targets cells in a specific cell cycle phase. The authors applied a theoretical multi-scale disease model of tumour growth that integrates cancer processes at the cellular and tissue scales. The mathematical model at the cell level relies on a dynamic description of cell cycle regulation while the model at the tissue level is based on fluid mechanics considerations. Simulations show that the number of target cells oscillates as the tumour grows after a first cycle of chemotherapy. Both treatment effect and tumour growth processes drive these oscillations. Nonetheless, results indicate that parameters related to physiopathological processes may have greater relevance than classical drug-related parameters in determining the efficacy of a chemotherapy treatment protocol. Physiopathological parameters, in particular those related to cell cycle regulation, may be integrated in PK/PD models aimed at optimising the delivery of phase-specific cytotoxic treatments.

Validation of an HPLC-UV method for sorafenib determination in human plasma and application to cancer patients in routine clinical practice.

Sorafenib, a new oral multikinase inhibitor with antiangiogenic properties, has demonstrated preclinical and clinical activity against several tumor types. The aims of this study were to validate a method for the measurement of sorafenib in plasma from cancer patients, then to test this method in clinical practice. Following liquid-liquid extraction, the compounds were separated with gradient elution (on a C18 ultrasphere ODS column using a mobile phase of acetonitrile/20 mM ammonium acetate), then detected at 255 nm. The calibration was linear in the range 0.5-20 mg/L. Intra- and inter-assay precision was lower than 7 and 10%, respectively, at 0.5, 3 and 20 mg/L. Plasma sorafenib concentrations were measured in 22 cancer patients (99 samples). The mean trough sorafenib concentration (C(min)) and concentration at peak were 4.3+/-2.5 mg/L (n=68, CV=57.5%) and 6.2+/-3.0 mg/L (n=31, CV=47.5%), respectively. Mean sorafenib C(min) in eight patients who experienced grade 3 drug-related adverse events was approximately 1.5-fold greater than that observed in the remaining patients (7.7+/-3.6 mg/L vs. 4.4+/-2.4 mg/L, P=0.0083). In conclusion, the method was successfully used in routine practice to monitor plasma concentrations of sorafenib in cancer patients. Finally, large interindividual variability and higher exposure in patients experiencing severe toxicity support the need for therapeutic drug monitoring to ensure an optimal exposure to sorafenib.

A dynamic model of hand-and-foot syndrome in patients receiving capecitabine.

For the purpose of developing a longitudinal model to predict hand-and-foot syndrome (HFS) dynamics in patients receiving capecitabine, data from two large phase III studies were used. Of 595 patients in the capecitabine arms, 400 patients were randomly selected to build the model, and the other 195 were assigned for model validation. A score for risk of developing HFS was modeled using the proportional odds model, a sigmoidal maximum effect model driven by capecitabine accumulation as estimated through a kinetic-pharmacodynamic model and a Markov process. The lower the calculated creatinine clearance value at inclusion, the higher was the risk of HFS. Model validation was performed by visual and statistical predictive checks. The predictive dynamic model of HFS in patients receiving capecitabine allows the prediction of toxicity risk based on cumulative capecitabine dose and previous HFS grade. This dose-toxicity model will be useful in developing Bayesian individual treatment adaptations and may be of use in the clinic.

MR tracking of iron-labeled glass radioembolization microspheres during transcatheter delivery to rabbit VX2 liver tumors: feasibility study.

PURPOSE: To prospectively test the hypothesis that iron labeling of radioembolization microspheres permits their visualization by using magnetic resonance (MR) imaging for in vivo tracking during transcatheter delivery to liver tumors. MATERIALS AND METHODS: All experiments were approved by the Institutional Animal Care and Use Committee. Phantom studies were performed to quantify microsphere relaxivity and volume susceptibility properties and compare image contrast patterns resulting from aggregate deposition of unlabeled and iron-labeled microspheres. In seven rabbits in which nine VX2 liver tumors were implanted, T2*-weighted gradient-echo (GRE) MR images with negative image contrast (NC), white-marker (WM) GRE images with positive image contrast (PC), and on-resonance water-suppression turbo spin-echo (SE) images with PC were obtained before and after catheter-directed administration of microspheres into the hepatic artery. During each injection, serial GRE acquisitions were performed for real-time visualization of microsphere delivery. Contrast-to-noise ratios (CNRs) were measured between regions of microsphere accumulation and regions of normal liver parenchyma that demonstrated no apparent microsphere accumulation. Pre- and postinjection CNR measurements at identical spatial positions were compared by using paired t test (alpha = .05). RESULTS: Conventional microspheres did not produce detectable image contrast in phantoms. Iron-labeled microspheres produced susceptibility-induced dipole patterns with spatial extent of image contrast increasing with increasing microsphere dose. Real-time image series depicted both preferential delivery to tumor tissues and nontargeted delivery to adjacent organs. T2*-weighted GRE, WM GRE, and on-resonance water-suppression turbo SE each permitted in vivo visualization of the microsphere deposition, with postinjection CNR values (mean, 14.29 +/- 3.98 [standard deviation], 1.87 +/- 0.93, and 19.30 +/- 8.72, respectively) significantly greater than corresponding preinjection CNR values (mean, 2.02 +/- 4.65, 0.02 +/- 0.27, 0.85 +/- 2.65, respectively) (P < .05). CONCLUSION: Microsphere tracking during radioembolization may permit real-time verification of delivery and detection of extrahepatic shunting.

Transcriptional signals of T-cell and corticosteroid-sensitive genes are associated with future acute cellular rejection in cardiac allografts.

BACKGROUND: Profiling mRNA levels of 11 informative genes expressed by circulating immune effector cells identifies cardiac allograft recipients at low risk for current moderate-severe acute cellular rejection (ACR). METHODS: We conducted a nested case-control study of 104 cardiac allograft recipients to investigate the association of transcriptional profiles of blood samples with either a future rejection episode within 12 weeks of a baseline clinical sample or persistent histologic quiescence for the same time period. RESULTS: The transcription profile yielded a score (0 to 40 scale) of 27.4 +/- 6.3 for future rejectors (n = 39) and 23.9 +/- 7.1 for controls (n = 65) (p = 0.01). In patients who were

Gene expression profiling distinguishes a molecular signature for grade 1B mild acute cellular rejection in cardiac allograft recipients.

BACKGROUND: Gene expression profiling distinguishes the absence or presence of moderate to severe grades of acute cellular rejection in cardiac allograft recipients using a 20-gene classifier. We explored the hypothesis that the rejection classifier also differentiates various forms of mild rejection and we performed sub-analyses based on time post-transplant and confirmatory pathology interpretations. METHODS: A post hoc analysis of 265 CARGO study patients and 714 clinical encounters focused on the correlation of rejection classifier-derived gene expression (GE) scores for blood samples accompanying endomyocardial biopsies. Biopsy grades assigned by a study center pathologist (center) were re-interpreted by three pathologists (panel) in a blinded manner. RESULTS: Mean GE scores not only differentiated Grades >or=3A from Grade 0 (p < 0.00001, center or panel), but also from Grades 1A or 2 (p < 0.05, center or panel), based on mild rejection sub-groups defined by the ISHLT 1990 grading system. In contrast, mean GE scores for Grades 1B and >or=3A were indistinguishable, using either center or panel interpretation. Sub-group analyses of encounters from 2 to 6 months or >6 months post-transplant showed similar results for the classifier's ability to discriminate moderate to severe rejection from Grades 1A and 2 mild rejection, but indistinguishable mean GE scores for Grades >or=3A and the Grade 1B sub-group. Of the classifier's 11 informative genes, expression of MIR and WDR40 showed statistically significant increases for both Grade 1B and Grade >or=3A rejection, while expression of PDCD1 or SEMA7A showed similar directional patterns without achieving statistical significance. CONCLUSIONS: These data demonstrate that GE scores discriminate moderate to severe rejection from Grades 1A and 2 mild rejection. However, a sub-group of mild rejection cases, defined as Grade 1B according to the 1990 grading system, share a molecular signature more consistent with moderate to severe rejection. The clinical relevance of these data remains to be defined.

Safety and efficacy of reteplase for the treatment of acute arterial occlusion: complexity of underlying lesion predicts outcome.

We evaluated both the safety and efficacy of reteplase for treatment of acute arterial occlusion as well as outcomes based on treatment of the underlying lesion. From November 2000 to February 2004, reteplase was used to treat arterial occlusions in 81 patients. Catheter-directed intrathrombus thrombolysis was performed with reteplase (0.5 units/hr) continuous infusion. Percutaneous mechanical thrombectomy (Angiojet) was performed in 61% (n = 50) of patients prior to thrombolysis. Unmasking of significant lesions resulted in endovascular intervention (39.5%), open surgical repair (24.6%), or both endovascular and surgical repair (9.8%) of the lesion. No lesion was found in 25.9% of patients. Major and minor complication rates as well as restoration of patency, limb salvage, and amputation-free survival were evaluated. Eighty-one patients received reteplase therapy (median = 10.3 +/- 5.3 units, 19.5 +/- 7.4 hr) followed by next-day arteriogram to assess thrombus removal. Technical success was achieved in 96.2% (n = 78) of cases. Kaplan-Meier life table analysis revealed overall primary patency rates of 76.3%, 60.1%, and 51.6%, at 1, 6, and 12 months, respectively. Overall amputation-free survival rates were 86.4%, 76.4%, and 69.7% at 1, 6, and 12 months, respectively. When subdivided into postlysis intervention, the lysis-only group achieved increased patency (p = 0.0143) and increased limb salvage (p = 0.0219) at 1 year compared to the lysis and endovascular intervention and the lysis and surgical groups. The 30-day complication rate was 17.3% (n = 14), with a major complication rate of 4.9% (n = 4) and a minor complication rate of 12.3% (n = 10). There were no intracranial hemorrhagic complications. Intra-arterial catheter-directed infusion of reteplase for acute lower extremity ischemia is safe and efficacious, as shown by the low risk of bleeding complications, high limb salvage rates, and low mortality rates in this study. The complexity of the lesion that is unmasked through thrombolytic therapy is a predictor of patency and limb salvage.

Does a standardization tool to direct invasive therapy for symptomatic lower extremity peripheral arterial disease improve outcomes?

OBJECTIVES: While decision analysis and treatment algorithms have repeatedly been shown to improve quality of care in many areas of medicine, no such algorithm has emerged for the invasive management of lower extremity peripheral arterial disease. Using the best available evidence-based outcomes data, our group designed a standardization tool, the Lower Extremity Grading System (LEGS) score, which consistently directs limbs to a specific treatment on the basis of presentation. The purpose of this study was to examine whether use of such a tool improves outcomes by directing treatment of lower extremity peripheral arterial disease. METHODS: Over 18 months (July 2001-December 2002) our group intervened in 673 limbs (angioplasty, open surgery, primary limb amputation) with lower extremity peripheral arterial disease. During this time we developed the LEGS score, and implemented its prospective use for the final 362 limbs. For the purpose of this study, all 673 limbs were retrospectively scored with the LEGS score to determine the LEGS recommended best treatment. Of the 673 limbs, 551 (81.9%) received the same treatment as recommended with LEGS and 122 (18.1%) received treatment contrary to LEGS. Limbs treated contrary to LEGS (cases) were then compared with matched control limbs (treated according to LEGS), with similar angiographic findings, clinical presentation, preoperative functional status, comorbid conditions and operative technical factors. Outcomes measured at 6 months included arterial reconstruction patency, limb salvage, survival, and maintenance of ambulatory status and independent living status. Kaplan-Meier curves were used to assess patency, limb salvage, and survival; associated survival curves were compared with the log-rank test. Functional outcomes were compared with the Fisher exact test. RESULTS: After matching case limbs with control limbs, 9 limbs had no control match. Thus 113 limbs in 100 patients treated contrary to LEGS were compared with 113 limbs in 100 patients treated according to LEGS. Limbs treated contrary to LEGS resulted in significantly inferior outcomes at 6 months for measures of primary patency (57.5% vs 84.3%; P < .001), secondary patency (73.2% vs 96.2%; P < .001), limb salvage (89.7% vs 97.2%; P = .04), and maintenance of ambulatory status (78% vs 92%; P = .02). As an additional finding, 29.6% (92 of 311) of interventions performed before implementation of the algorithm were treated contrary to LEGS, and thus contrary to objectively determined best therapy, compared with 8.3% (30 of 362) after LEGS implementation (P < .001). CONCLUSIONS: Limbs treated according to our standardization tool resulted in better outcomes compared with limbs treated contrary to the algorithm. These data suggest that routine use of an appropriately validated treatment standardization algorithm is capable of improving overall results for invasive treatment of lower extremity peripheral arterial disease.

Expression of an engrailed-LMO4 fusion protein in mammary epithelial cells inhibits mammary gland development in mice.

LIM domain factors and associated cofactors are important developmental regulators in pattern formation and organogenesis. In addition, overexpression of two LIM-only factors (LMOs) causes acute lymphocytic leukemia. The more recently discovered LMO factor LMO4 is highly expressed in proliferating epithelial cells, and frequently overexpressed in breast carcinoma. Here we show that while LMO4 is expressed throughout mammary gland development, it is dramatically upregulated in mammary epithelial cells during midpregnancy. The LMO coactivator Clim2/Ldb1/NLI showed a similar expression pattern, consistent with the idea that LMO4 and Clim2 act as a complex in mammary epithelial cells. In MCF-7 cells, LMO4 transcripts were upregulated by heregulin, an activator of ErbB receptors that are known to be important in mammary gland development and breast cancer. To test the hypothesis that LMO4 plays roles in mammary gland development, we created an engrailed-LMO4 fusion protein. This fusion protein maintains the ability to interact with Clim2, but acts as a dominant repressor of both basal and activated transcription when recruited to a DNA-regulatory region. When the engrailed-LMO4 fusion protein was expressed under control of the MMTV promoter in transgenic mice, both ductular development in virgin mice and alveolar development in pregnant mice were inhibited. These results suggest that LMO4 plays a role in promoting mammary gland development.

Ceftriaxone (1 g intravenously) penetration into abdominal tissues when administered as antibiotic prophylaxis during nephrectomy.

A pharmacokinetics study was conducted to determine the effects of ceftriaxone administered before nephrectomy on the occurrence of postoperative wound infection. Ceftriaxone was administered as antibiotic prophylaxis in 11 consecutive patients undergoing nephrectomy who received 1,000 mg intravenously 30 min before surgery. Simultaneous blood and tissue samples were collected at three stages of the surgical procedure: opening of the abdominal cavity, nephrectomy, and closure of the abdominal cavity. Samples of following tissues were assayed: abdominal-wall fat, perirenal fat, kidney cortex and medulla, and urine. During the different stages of surgical procedures, ceftriaxone concentrations remained higher than the MIC90 of the potential pathogens (Staphylococcus aureus, Escherichia coli, and Enterobacteriaceae). In selected patients undergoing nephrectomy and requiring antimicrobial prophylaxis such as malnourished, debilitated, diabetic or immunosuppressed patients, the use of a single dose of ceftriaxone (1,000 mg) makes it possible to offer an optimal bacterial coverage for the prevention of postoperative infection. According to our kinetic evaluation, ceftriaxone is potentially a good antibiotic for prophylaxis in urological surgery.