Comparative effects of angiotensin-converting enzyme inhibition and angiotensin-receptor blockade on inflammation during hemodialysis

Biomarkers of oxidative stress and inflammation predict cardiovascular events in maintenance hemodialysis patients. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin-receptor blockers (ARBs) reduce cardiovascular mortality in the general population, but their benefit in maintenance hemodialysis patients is not fully explored. To test whether ACE inhibitors and ARBs differentially affect markers of oxidative stress, inflammation, and fibrinolysis during hemodialysis, we conducted a randomized, double-blind, placebo-controlled 3×3 crossover study. We randomly assigned 15 participants undergoing hemodialysis to placebo, ramipril (5 mg/d), and valsartan (160 mg/d) for 7 days, with a washout period of 3 weeks in between the treatments. On the morning of the seventh day of drug treatment, participants underwent serial blood sampling during hemodialysis. Neither ramipril nor valsartan affected BP during hemodialysis. Ramipril increased IL-1β concentrations (P=0.02) and decreased IL-10 concentrations (P=0.04) compared with placebo. Valsartan and ramipril both lowered IL-6 levels during dialysis (P<0.01 for each compared with placebo). Valsartan increased F(2)-isoprostane levels, and ramipril suggested a similar trend (P=0.09). Valsartan and ramipril both lowered D-dimer levels (P<0.01 for both), whereas only ramipril seemed to prevent a rise in vWf levels (P=0.04). In summary, during hemodialysis, valsartan induces a greater anti-inflammatory effect compared with ramipril, although ramipril seems to prevent dialysis-induced endothelial dysfunction as measured by levels of vWf. A prospective clinical trial is necessary to determine whether ACE inhibitors and ARBs also differ with respect to their effects on cardiovascular mortality in this population.

Analysis of the complete genome of Tembusu virus, a flavivirus isolated from ducks in China

During investigations into the outbreak of duck viral infection in 2010 in China, with a severe drop in egg production, a flavivirus was isolated from the affected ducks. It was characterized as a Tembusu virus (TMUV). In this study, we obtained a complete genome sequence of Tembusu virus using RT-PCR and RACE techniques. TMUV genome is a singled-stranded RNA, with 10,990 nucleotides in length, and contains a single open reading frame (3410 amino acids) encoding 11 viral proteins with 5'and 3'non-translated regions (NTRs) of 142 and 618 nt, respectively. We characterized the open reading frame (ORF) with respect to gene sizes, cleavage sites and potential glycosylation sites. The different genomic regions of the virus were also compared with those of six other flaviviruses including Japanese encephalitis virus, West Nile virus (WNV), dengue-2 virus, yellow fever virus, tick-borne encephalitis virus (TBEV) and Bagaza virus. TMUV demonstrated the highest similarity to Bagaza virus. The result of entire ORF scanning shows that TMUV was close to Bagaza viruses in genetic relatedness. These data demonstrate that TMUV is a unique virus among the mosquito-borne flaviviruses and also provide a useful reference for a critically important study to determine why TMUV is a serious pathogen for ducks.

Risk of breast fibrosis following irradiation using a breast-specific SBRT system compared with conventional APBI

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Background: To determine the dosimetric characteristics and risk of breast fibrosis using a normal tissue complication probability (NTCP) model in conjunction with a novel preoperative stereotactic radiotherapy system called the GammaPod. Results are compared with linac based post-lumpectomy APBI plans for the same cohort.

Methods: The GammaPod breast SBRT system consists of a Co-60 irradiation unit in combination with an immobilization device with embedded fiducials. Eight patients were enrolled in an IRB-approved protocol and underwent CT scans in the prone position with breast immobilization. A preoperative target (GTV) was synthesized to match the tumor location and volume reported in imaging studies obtained prior to surgery (0.3-2.4 cc). The GTV was expanded by 1.5 cm to create a CTV, and a PTV was created using an additional 0.3 cm margin. The PTV was prescribed 25.5 Gy in 3 fx, which is radiobiologically equivalent to conventional APBI doses of 38.5 Gy in 10 fx. Following the radioablative experience in NSCLC, we also planned to deliver 60.0 Gy to the GTV+0.3 cm as a simultaneous boost in conjunction with the 25.5 Gy PTV prescription dose. For comparison, linac-based treatment plans were created for the same cohort following NSABP B-39 guidelines. Whole breast dosimetry was analyzed in terms of biologically equivalent dose (BED) and Lyman NTCP analysis was performed.

Results: The volume of ipsilateral breast receiving 10, 20, 50, and 100% of the prescribed dose was substantially smaller in GammaPod vs. APBI plans, with cohort averages of 19.3, 13.0, 7.1 and 4.0% vs. 75.8, 67.3, 48.1 and 27.6% respectively (p<0.001). Even though the PTV equivalent uniform BED (EUD) was substantially higher in GammaPod plans (87.9 Gy vs. 57.3 Gy), the ipsilateral breast EUD was still smaller in these plans, 18.9 ± 5.0 Gy vs. 47.2 ± 3.2 Gy (p<0.001). Corresponding NTCP predictions for breast fibrosis rates following GammaPod and APBI treatments were 0.2 ± 0.1% vs. 2.8 ± 0.8% (p<0.001), respectively.

Conclusions: The GammaPod system improves upon traditional post-lumpectomy linac-based APBI by decreasing dose to the ipsilateral breast as well as the predicted rates of breast fibrosis.

Nomograms for predicting the risk of arm lymphedema after axillary dissection in breast cancer

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Background: Lymphedema (LE) after axillary dissection (AD) is a multifactorial, chronic, and disabling condition that currently affects an estimated 4 million people worldwide. Although several risk factors have been described, it is difficult to estimate the risk in individual patients. We therefore developed nomograms based on a large data set.

Methods: Clinicopathological features were collected from a prospective cohort study of 1,054 women with unilateral breast cancer undergoing AD as part of their surgical treatment from 8/2001 to 11/2002. LE was defined as a volume difference of at least 200 mL between arms at 6 months or more after surgery. The cumulative incidence of LE was ascertained by the Kaplan-Meier method, and Cox proportional hazards models were used to predict the risk of developing LE based on the available data at each timepoint: (I) preoperatively; (II) within 6 months from surgery; and (III) 6 months or later after surgery.

Results: The 5-year cumulative incidence of LE was 30.3%. Independent risk factors for LE were age, body mass index, ipsilateral arm chemotherapy infusions, level of AD, location of radiotherapy field, development of postoperative seroma, infection, and early edema. When applied to the validation set, the concordance indexes were 0.706, 0.729, and 0.736 for models I, II, and III, respectively.

Conclusions: The proposed nomograms can help physicians and patients to predict the 5-year probability of LE after AD for breast cancer. Free online versions of the nomograms will be available.

Risk of breast cancer (BC) relapse after 5 years of adjuvant tamoxifen (AT) in estrogen/progestrone-positive (ERP) patients (pts)

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Background: Current standard of care for pts with ERP BC is 5 years of AT or aromatase inhibitors (AIs). Based on MA17 data, practitioners offer extended adjuvant therapy with AIs to post menopausal women. Extended therapy is costly and has side effects. Identifying pts with higher risk of relapse will allow practitioners to offer extended therapy to selected pts.

Methods: Among 334 pts from the Cleveland Clinic BC surgery dataset, 38 had relapsed (local and systemic) and 39 had died of other causes. The 5 year absolute risk of late recurrence was calculated by cumulative incidence. We used a multivariable competing risks regression (CRR) analysis to determine the association of clinical parameters with late recurrence and treat death from other causes as competing risk. The predictor variables we tried to include are age at surgery, stage, pathology, progesterone receptor status and Charlson Comorbidity Index (CCI). Due to the limited number of recurrences, a parsimonious model with 3 predictors was desired. The model with the highest discrimination accuracy (quantified by Concordance index (CI)) selected as the basis of the final nomogram (ng). The ng was internally validated using ten fold cross-validation. The calibration of the ng prediction was checked visually by plotting the ng predicted risk of 5 year recurrence against the observed cumulative incidence from the data.

Results: The 5-year risk of late recurrence or death from other causes were 0.066 (0.039 – 0.093) or 0.050 (0.026 – 0.073) respectively. The model that included age (<=60 vs > 60), stage (I vs others) and CCI had the highest discrimination (CI = 0.551), on which a final ng was constructed for predicting the 5-year probabilities of late recurrence. In our previous work we showed that CI in Adjuvnat Online (AO) is 0.569. Our calibration curve after ten-fold cross-validation looks comparable to AO model.

Conclusions: We built and internally validated a ng for predicting the absolute probability of late recurrence for pts who completed five-year AT. Given the small size of our data set and the low number of recurrences our ng has fair discrimination and good calibration; however we were unable to outperform AO.

Increasing tamoxifen dose in breast cancer patients based on CYP2D6 genotypes and endoxifen levels: effect on active metabolite isomers and the antiestrogenic activity score

Tamoxifen (Tam), the major drug for estrogen receptor (ER)-positive breast cancer, is converted to its active metabolites, Z- and Z'-endoxifen and 4-OH-Tam isomers, primarily by cytochrome P450 CYP2D6. In 117 patients taking 20 mg/day of Tam, we determined CYP2D6 genotypes and measured the plasma levels of Tam metabolites. The Z-endoxifen levels increased while Z'-endoxifen levels decreased with increasing metabolizer phenotype activity (MPA) score (P ≤ 0.0004). The dosage in patients with endoxifen <40 nmol/l and/or CYP2D6 MPA scores of 0 was increased to 30 mg/day and their metabolite isomers were monitored for up to 90 days. Of the 24 patients on the increased dose, 90% showed an increase in active isomers by day 60; the rate of increase correlated with the MPA score. Notably, their antiestrogenic activity scores (AASs), which estimate total isomer biologic activity, increased from a baseline median of 17 to 26 at day 60. Further studies involving increasing/decreasing the Tam dosage based on the AAS may determine whether dose adjustment can optimize treatment and improve long-term survival.

Adenoid Cystic Carcinoma: Benefit of Surgery Plus Adjuvant Radiation

Objective: Evaluate the role of adjuvant radiation compared with surgical resection alone in treatment of adenoid cystic carcinoma of the head and neck. In addition, given the varied course and presentation of the disease, to analyze the impact of perineural invasion, margin status, and AJCC Tumor stage on survival.

Method: Retrospective review of 92 patients treated for adenoid cystic carcinoma of the head and neck between 1978 and 2010 at a single tertiary care academic center. Kaplan-Meier survival curves and Cox Proportional Hazards Model were used to evaluate the impact of treatment modality and clinical and pathological parameters on survival.

Results: The oropharynx was the most common site (30.4%). Overall 2-, 5-, and 10-year survival rates were 75%, 51%, and 22%. Mean follow-up was 75.9 months. All but 3 patients were treated with surgery and 60 out of 92 (65.2%) underwent postoperative radiation. Mean time to recurrence was 45.6 months and occurred in 45 out of 90 patients (50%). Significantly more T3/T4 staged patients underwent surgery plus adjuvant radiation than T1/T2 patients ( P < .045).

Conclusion: Despite being classified with more advanced disease (T3/T4 Stage), patients in the surgery plus radiation group had similar outcomes to patients who received surgery alone. Adjuvant radiation should be considered in all patients with adenoid cystic carcinoma of the head and neck.

Identification and characterization of inward K(+) -channels in plasma membranes ofArabidopsis root cortex cells

Patch clamping whole-cell recording techniques were applied to study the inward K(+) -channels inArabidopsis root cortex cells. The inward K(+) -channels in the plasma membranes of the root cortex cell protoplasts were activated by hyperpolarized membrane potentials. The channels were highly selective for K(+) ions over Na(+) ions. The channel activity was significantly inhibited by the external TEA(+) or Ba(2+). The changes in cytoplasmic Ca(2+) concentrations did not affect the whole-cell inward K(+) -currents. The possible association between the channel selectivity to K(+) and Na(+) ions and plant salt-tolerance was also discussed.