Abstract P4-02-04: Quantitative MRI features analysis for differentiation of triple negative and HER2 positive subtypes of breast cancer

Objective: The aim of this study was to evaluate ability of quantitative analysis of MRI features to distinguish triple negative (TN) and HER2 positive (HER2+) subtypes of breast cancer, which have different biological characteristics, exhibiting different growth patterns and response to treatment.

Materials and Method: Breast cancer patients, who had MRI exam of the breast in our institution at the time of staging for breast carcinoma and who subsequently had surgery (segmentectomy or mastectomy) from January 1, 2008 through December 31, 2015 were identified. All lesions were evaluated by radiologists in accordance with the BI-RADS lexicon. The patient's age, breast cancer histology, multifocality/multicentricity (MF/MC), lesion size, axillary lymphadenopathy (LAN), MRI morphologic and enhancement characteristics were documented. Quantitative MRI feature analysis was performed using shape, texture, and histogram based features. Machine-learning-based (Xgboost) models were used to predict subtypes, and Leave-one-out cross-validation (LOOCV) was used to avoid model overfitting. Statistical significance was determined using the Student's t-test.

Results: Total of 105 patients, 51 patients with TN and 54 patients with HER2+ breast cancer were included in analysis. Mean age for TN was 50 (range 29-79)) years old and for HER2+ was 49 (range 25-70) years old. Axillary LAN and MF/MC disease was seen more commonly in HER2+ patients when compared to TN patients, but didn't reach statistical significance (13 vs 7, p=0.9; and 31 vs 20, p=0.06, respectively). Mass rim enhancement was associated with TN subtype and irregular mass enhancement was associated with HER2+ subtype of breast cancer (p<0.05). Quantitative analysis showed that six out of the top 10 ranked MRI features: surface to volume ratio, difference variance, difference entropy, inverse difference moment, 75 percentile in histogram and sum average, were significantly different between these 2 subtypes with p<0.05. When the significant features were incorporated to distinguish TN and HER+ subtypes, use of the top 2 features achieved the best accuracy on LOOCV of 0.69.

Conclusion: The quantitative MRI features show promise in distinguishing TN and HER2+ breast cancer subtypes reflecting their underlying biological characteristics and may be used as predictive quantitative biological markers. Further studies in a larger cohort evaluating associations with treatment response are underway.

FeatureIndexP-valueSurface to volume ratioShape30.005Difference VarianceGLCM110.005Difference EntropyGLCM100.009Inverse Difference MomentGLCM50.01875 percentile in histogramHistogram50.043Sum AverageGLCM60.044Median in histogramHistogram 30.08025 percentile in histogramHistogram 40.095VolumeShape10.104Max in histogramHistogram 10.105

Citation Format: Rauch GM, Li H, Zhu H, Adrada BE, Santiago L, Candelaria RP, Wang H, Leung J, Thompson A, Litton J, Wu Y, Lim B, Moulder S, Mittendorf EA, Yang W. Quantitative MRI features analysis for differentiation of triple negative and HER2 positive subtypes of breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-04.

Abstract PD4-08: A microenvironment secretome screen reveals FGF2 as a mediator of resistance to anti-estrogens and PI3K/mTOR pathway inhibitors in ER+ breast cancer

Despite the clinical success of anti-estrogen therapies, phosphatidylinositol 3-kinase inhibitors (PI3Ki), and mechanistic target of rapamycin complex I inhibitors (mTORC1i) for the treatment of patients with ER+ breast cancer, disease recurrence and progression are common. We found that a tumor transcriptional profile reflecting high stromal fibroblast content was associated with poor outcome in 3 cohorts of patients with ER+ breast cancer. We hypothesized that individual factors in the tumor microenvironment (TME) significantly contribute to drug resistance.

To test this hypothesis, we screened 297 recombinant secreted proteins for ability to confer resistance to the anti-estrogen fulvestrant in MCF-7 and T47D ER+ breast cancer cells. Screen results were validated, and expansion screening included the anti-estrogen tamoxifen, the PI3Ki pictilisib, and the mTORC1i everolimus in 4 cell lines. To identify hits are most likely to be relevant to ER+ breast cancer, a bioinformatics filter was developed utilizing gene and protein expression in human tissues relevant to the TMEs of ER+ breast cancer. After filtering, the top screening hit was fibroblast growth factor 2 (FGF2), which confers resistance to anti-estrogens, PI3Ki, and mTORC1i, and is highly expressed in tissues and cell types associated with ER+ breast cancer. FGF2 did not rescue cells from the CDK4/6i palbociclib or the DNA-damaging agent doxorubicin, demonstrating pathway selectivity in the rescue phenotype. FGF2 rescued cells from anti-estrogen-, PI3Ki-, and mTORC1i-induced apoptosis and cell cycle arrest via activation of FGFR signaling through FRS2a, MEK1/2, ERK1/2, and downstream upregulation of cyclin D1 and degradation of Bim. FGF2-mediated anti-cancer effects were abrogated by co-treatment with the FGF2-neutralizing antibody GAL-F2, the pan-FGFR inhibitor PD-173074, the MEK inhibitor trametinib, or palbociclib. Cell cycle- and apoptosis-specific effects of FGF2 were abrogated by RNAi targeting cyclin D1 and Bim, respectively.

We generated a transcriptional signature of FGF2 response by RNA-seq of fulvestrant-treated MCF-7 and T47D cells treated +/- FGF2. In 3 cohorts of patients with ER+ breast cancer, a signature of FGF2 signaling was significantly associated with poor prognosis and predictive of anti-estrogen resistance, including in a multivariate analysis including age, tumor grade, tumor stage, and FGFR amplification status. Finally, the therapeutic potential of targeting FGF2 was confirmed in 3 mouse models of ER+ breast cancer: 1) FGF2 rescue MCF-7 xenografts from fulvestrant; 2) GAL-F2 synergized with fulvestrant to suppress growth of 59-2-HI murine mammary adenocarcinomas that recruit FGF2-secreting stroma; 3) GAL-F2 synergized with fulvestrant to induce regression of HCI-003 patient-derived xenografts. Therapeutic effects coincided with increased tumor cell apoptosis and decreased proliferation, but not changes in tumor vasculature. These findings warrant consideration of FGF2 as a novel therapeutic target in ER+ breast cancer.

Citation Format: Shee K, Hinds JW, Yang W, Hampsch RA, Patel K, Varn FS, Cheng C, Jenkins NP, Kettenbach AN, Demidenko E, Owens P, Lanari C, Faber AC, Golub TR, Straussman R, Miller TW. A microenvironment secretome screen reveals FGF2 as a mediator of resistance to anti-estrogens and PI3K/mTOR pathway inhibitors in ER+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD4-08.

Abstract PD2-09: Association of quantitative MRI features with tumor infiltrating lymphocytes and treatment response prediction in HER2 positive subtype of breast cancer

Objectives: To evaluate associations between qualitative and quantitative MRI features and tumor infiltrating lymphocytes (TIL) levels in HER2+ subtype of breast cancer, as potential prognostic non-invasive imaging markers for treatment response prediction.

Materials and Methods: Retrospective review of breast cancer patients who had MRI at staging, neoadjuvant chemotherapy and surgery from January 1, 2008 through December 31, 2015 was performed. BI-RADS lexicon was used for lesion evaluation. Demographic, imaging, and pathologic data including TIL levels were documented. Quantitative MRI texture analysis was performed using 3 types of textural features (TF): local binary patterns (LBP), gray-level co-occurrence matrix (GLCM), and threshold adjacency statistics (TAS). Associations between MRI quantitative TF, TIL levels, and pathologic complete response (pCR) were evaluated by Pearson correlation and logistic regression.

Results: There were 50 HER2+ patients (median age 51 years, range 29-59) with pretreatment MRI and TIL status for analysis; 27 patients had pCR at surgery. Qualitative MRI analysis showed that mass rim-enhancement (p<0. 05) and fast early enhancement kinetics (p<0.01) were associated with higher TIL levels. No association between qualitative MRI features and pCR was found. Nine TF significantly correlated with pCR (p<0.05): angular 2nd moment (GLCM), 75 percentile (LBP), standard deviation (GLCM), adjacency 0-5 (TAS). This is indicative of association of tumor heterogeneity with pCR. Three TF were significantly associated with high TIL levels (p<0.05): standard deviation, adjacency 1 and 2. Additional four TF had high association with TIL (p<0.1): sum entropy, adjacency 0, 3 and 4. These findings showed that increased heterogeneity, complexity and entropy were associated with high TIL level. Three TF were significantly associated with both, pCR and TIL (p<0.05): 75 percentile, standard deviation, adjacency 8.

Conclusion: Quantitative tumor texture analysis based on statistical modeling showed specific nine TF indicative of tumor heterogeneity associated with pCR; and seven TF indicative of increased heterogeneity, complexity, and entropy associated with high TIL levels in HER2+ breast cancer. Analysis of associations of MRI quantitative TF with pCR and TIL in HER2+ breast cancer may help to develop prognostic non-invasive imaging markers for treatment response prediction.

Citation Format: Rauch GM, Zhu H, Li H, Adrada BE, Santiago L, Candelaria RP, Wang H, Leung J, Litton J, Wu Y, Murthy R, Mittendorf EA, Yang W. Association of quantitative MRI features with tumor infiltrating lymphocytes and treatment response prediction in HER2 positive subtype of breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD2-09.

Abstract P5-01-02: Quantitative assessment of tumor response to neoadjuvant chemotherapy in women with locoregional invasive breast cancer using Tc99m sestamibi molecular breast imaging - preliminary results

Purpose: To report preliminary data in a pilot study evaluating the ability of Tc99m sestamibi Molecular Breast Imaging (MBI) to predict response and assess residual disease at the completion of neoadjuvant chemotherapy (NAC) in breast cancer patients.

Materials and Methods: Patients with localized, invasive breast cancer (T1-T4, N0-N3, M0) planned for NAC were enrolled in this prospective IRB approved clinical trial. All patients had digital mammography (DM), ultrasound (US), and MBI at baseline (T0), after 2 NAC cycles (T1), and at after NAC completion (T2). Tumor size and volume changes were compared with residual disease at surgery. MBI images were corrected for scatter and attenuation using a novel approach and regions of interest (ROI) were drawn over tumors to compute three quantitative MBI uptake metrics for correlation with pathologic response: tumor to background ratio (TBR), fractional activity uptake (FAU), and MBI-specific standardized uptake value (SUV). ROC analysis was performed.

Results: Patients (n=25) who completed NAC, had 75 imaging time points and had surgery, were included in this analysis. Median age was 49 years (range 31 -77). Eleven patients (11/25, 44%) had complete pathologic response (pCR). Absolute TBR values after 2 cycles (T1) and before surgery (T2) had highest correlation with pCR (AUC 0.81; 95% CI 0.63 to 0.99, p=0.01, and AUC 0.78; 95% CI 0.59 to 0.97, p=0.015, respectively). Change in SUV after 2 cycles, Δ SUV1 (T1-T0), (AUC 0.84; 95% CI 0.66 to 1.00, p=0.01) and change in SUV prior to surgery, Δ SUV2 (T2-T0) (AUC 0.80; 95% CI 0.60 to 1.00, p=0.02), were most predictive of pCR. Tumor size and volume showed modest specificity for detecting residual disease, and was highest for MBI (79%), followed by MMG (64%), and lowest for US (55%).

Conclusion: Quantitative MBI metrics show promise for the prediction of pCR in breast cancer patients undergoing NAC. Establishment of quantitative metrics for the early prediction of tumor response during NAC of breast cancer patients may provide an alternate to influencing NAC choice early in the management algorithm. Further investigation with a larger sample size is warranted.

Citation Format: Rauch GM, Adrada BE, Kappadath C, Candelaria RP, Huang ML, Santiago L, Moseley T, Scoggins ME, Knudtson JD, Lopez BP, Hess KR, Krishnamurthy S, Moulder S, Valero V, Yang W. Quantitative assessment of tumor response to neoadjuvant chemotherapy in women with locoregional invasive breast cancer using Tc99m sestamibi molecular breast imaging - preliminary results [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-01-02.

Abstract P6-03-05: Risk of needle-track seeding with serial ultrasound guided biopsies in triple negative breast cancer

Background: Image-guided percutaneous needle biopsy of the breast is a common procedure. In breast cancer patients (pts) undergoing core biopsies and surgical resection on the same day, the rate of tumor cell displacement along the needle track has been reported to be up to 50%. However, the clinical significance of this finding in triple negative breast cancer (TNBC) patients (pts) undergoing serial biopsies while receiving neoadjuvant chemotherapy (NACT) is unknown. Here we report the incidence of needle-track seeding (NTS) in a cohort of TNBC pts enrolled on a molecular triaging protocol involving serial biopsies of the index breast lesion.

Methods: We reviewed the clinical records of 144 consecutive TNBC pts enrolled on a molecular triaging protocol at MD Anderson Cancer Center. Per protocol, all pts underwent a pre-treatment research biopsy and were initiated on anthracycline based NACT (AC). Pts with inadequate response to front-line NACT were encouraged to undergo additional biopsies of the index breast lesion prior to switching therapies. Serial breast ultrasound (US) was performed to monitor therapeutic response and incidental evidence of needle-track seeding noted on US was documented.

Results: Clinicopathological characteristics of the pts are summarized in Table 1. 89% (128/144) of pts had a diagnostic breast biopsy done at another center prior to presenting at MDACC. To date, we have performed 209 US guided biopsies of index breast lesions in 144 pts. 92% (193/209) of these biopsies were done mainly for research purposes. 1.4% (2/144) of pts were found to have evidence of NTS on follow up US. The first pt had a T1N0 (1.9cm), grade 3, invasive ductal carcinoma (IDC) at diagnosis. She underwent a diagnostic biopsy followed by a research biopsy before initiating AC. She was found to have NTS as well as progression of disease (PD) on follow up US after 2 cycles of AC. The second pt had a T2N0 (3cm), grade 3 IDC at diagnosis. She underwent a diagnostic biopsy at another center, followed by a research biopsy before initiating AC. Like the first pt, she was found to have NTS and PD on follow up US after 2 cycles of AC. Both pts are currently on neoadjuvant clinical trials of novel agents.

Conclusion: The rate of NTS detected on US in TNBC pts undergoing serial biopsies of index breast lesions while receiving NACT is low and further studies are needed to determine the impact of serial biopsies on long term outcomes in TNBC.

Table 1: Patient CharacteristicsCharacteristicN=144Age - Median (years, interquartile range)55 (46-62)Tumor Size Mean (cm, standard deviation)3.4 (2.2)T1 – n(%)35 (24)T2 – n(%)89 (62)T3 – n(%)19 (13)T4 – n(%)1 (1)Clinical Nodal Status Negative – n(%)74 (51)Positive – n(%)70 (49)Grade 1 – n(%)1 (1)2 – n(%)17 (12)3 – n(%)124 (86)Unknown – n(%)2 (1)Histologic Subtype Invasive ductal carcinoma – n(%)121 (84)Invasive lobular carcinoma – n(%)2 (1)Mixed ductal and lobular carcinoma – n(%)3 (2)Metaplastic carcinoma – n(%)13 (9)Not specified – n(%)5 (3)Laterality Right – n(%)72 (50)Left – n(%)72 (50)

Citation Format: Yam C, Santiago L, Candelaria RP, Adrada BE, Rauch GM, Hess KR, Litton JK, Piwnica-Worms H, Mittendorf EA, Ueno NT, Lim B, Murthy RK, Damodaran S, Helgason T, Huo L, Thompson AM, Gilcrease MZ, Symmans WF, Moulder SL, Yang W. Risk of needle-track seeding with serial ultrasound guided biopsies in triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-03-05.

Abstract P1-07-22: Androgen receptor positivity is associated with nodal disease in triple negative breast cancer

Background: Gene expression profiling (GEP) has identified several molecularly distinct subtypes of triple negative breast cancer (TNBC). Currently, GEP-based molecular diagnostics are not routinely used in clinical decision making due to the lack of proven benefit, costs involved and long turnaround time. However, two molecularly distinct subtypes of TNBC, the luminal androgen receptor (AR) and mesenchymal subtypes, have surrogate CLIA-certified immunohistochemical (IHC) markers, AR and vimentin (VM), respectively, which have the potential for application in the clinic. Here we report the rates of AR and VM positivity and their association with clinicopathological characteristics in a cohort of TNBC pts receiving NACT.

Methods: As part of an ongoing molecular triaging protocol, 144 pts with stage I-III TNBC underwent a pretreatment biopsy for molecular characterization (MC) prior to initiating neoadjuvant chemotherapy (NACT). IHC for AR and VM were performed using commercially available antibodies. AR+ and VM+ were defined as ≥10% and ≥50% staining, respectively. Pts were randomized 2:1 to know (intervention arm, n=93) and not know (control arm, n=51) the MC results. The charts of pts randomized to the intervention arm were reviewed. Categorical variables were analyzed using Fisher's exact test. Ordinal and continuous variables were analyzed using the Wilcoxon rank-sum test and Student's t test as appropriate.

Results: 31% (29/93) and 16% (15/93) of pts were AR+ and VM+, respectively. Only 4% (4/93) of pts were both AR+ and VM+. Clinicopathological characteristics are summarized in Table 1. AR+ pts were more likely to have clinically node positive disease as compared to AR- pts (66% vs 34%, p=0.007). There were no significant differences in clinical tumor size or grade between AR+ and AR- pts. VM+ and VM- pts had similar clinicopathological characteristics.

Conclusion: Pts with AR+ TNBC were more likely to have node positive disease. The impact of AR+ on long term outcomes should be investigated in prospective studies.

Table 1: Association between patient characteristics and AR/VM status AR  VM   AR+ (n=29)AR- (n=64)p-valueVM+ (n=15)VM- (n=78)p-valueAge - Median (years, interquartile range)58 (48-65)52 (46-61)0.05855 (48-64)56 (47-62)0.88Clinical Tumor Size      Mean (cm, standard deviation)3.5 (1.8)3.0 (1.8)0.2872.7 (1.7)3.3 (1.9)0.31T1 – n(%)5 (17)21 (33)0.2307 (47)19 (24)0.098T2 – n(%)21 (72)36 (56) 7 (47)50 (64) T3 – n(%)3 (10)7 (11) 1 (7)9 (12) Clinical Nodal Status      Negative – n(%)10 (34)42 (66)0.0078 (53)44 (56)1.00Positive – n(%)19 (66)22 (34) 7 (47)34 (44) Grade      2 – n(%)6 (21)5 (8)0.0763 (20)8 (10)0.293 – n(%)23 (79)59 (92) 12 (80)70 (90) 

Citation Format: Yam C, Huo L, Hess KR, Litton JK, Yang W, Piwnica-Worms H, Mittendorf EA, Ueno NT, Lim B, Murthy RK, Damodaran S, Helgason T, Thompson AM, Santiago L, Candelaria RP, Rauch GM, Adrada BE, Symmans WF, Gilcrease MZ, Moulder SL. Androgen receptor positivity is associated with nodal disease in triple negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-22.

Cardiac μ-opioid receptor contributes to opioid-induced cardioprotection in chronic heart failure

BACKGROUND

The therapeutic potential of cardiac μ-opioid receptors in ischaemia-reperfusion (I/R) injury during opioid-modulating diseases, such as heart failure, is unknown. We aimed to explore the changes of cardiac μ-opioid receptor expression during heart failure, and its role in opioid-induced cardioprotection.

METHODS

Rats received doxorubicin (DOX) or were subjected to coronary artery ligation to induce heart failure, or received normal saline (NS) as control. Hearts from NS or DOX rats were isolated and subjected to myocardial ischaemia and reperfusion in an in vitro perfusion system. The opioid [D-Ala,²N-MePhe,⁴ Gly-ol]-enkephalin (DAMGO), with a high μ-opioid receptor specificity, morphine, and remifentanil were administrated before I/R with or without opioid receptor antagonists, or an extracellular signal-regulated kinase (ERK) inhibitor.

RESULTS

Cardiac μ-opioid receptor mRNA concentrations were 3.2 times elevated in DOX-treated rats compared with NS rats, while cardiac μ-opioid receptor protein concentrations showed 6.1- and 3.5-fold increases in DOX-treated and post-infarcted rats, respectively. DAMGO reduced I/R-caused infarct size, expressed as the ratio of area at risk, from 0.50 (0.04) to 0.25 (0.03) in failing rat hearts, but had no effect on infarct size in control hearts. DAMGO promoted phosphorylation of ERK and glycogen synthase kinase (GSK)-3β only in failing hearts. DAMGO-mediated cardioprotection was blocked by an ERK inhibitor. The μ-opioid receptor antagonist D-Pen-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) prevented morphine- and remifentanil-induced cardioprotection and phosphorylation of ERK and GSK-3β in failing hearts. In contrast, δ- and κ-opioid receptor selective antagonists were less potent than CTOP in the failing hearts.

CONCLUSIONS

Cardiac μ-opioid receptors were substantially up-regulated during heart failure, which increased DAMGO-induced cardioprotection against I/R injury.

Site-specific electronic structure of imidazole and imidazolium in aqueous solutions

The electronic structures of aqueous imidazole and imidazolium solutions are studied in an atom- and site-specific fashion using soft X-ray spectroscopy.

Time-resolved diffraction of shock-released SiO2 and diaplectic glass formation

Understanding how rock-forming minerals transform under shock loading is critical for modeling collisions between planetary bodies, interpreting the significance of shock features in minerals and for using them as diagnostic indicators of impact conditions, such as shock pressure. To date, our understanding of the formation processes experienced by shocked materials is based exclusively on ex situ analyses of recovered samples. Formation mechanisms and origins of commonly observed mesoscale material features, such as diaplectic (i.e., shocked) glass, remain therefore controversial and unresolvable. Here we show in situ pump-probe X-ray diffraction measurements on fused silica crystallizing to stishovite on shock compression and then converting to an amorphous phase on shock release in only 2.4 ns from 33.6 GPa. Recovered glass fragments suggest permanent densification. These observations of real-time diaplectic glass formation attest that it is a back-transformation product of stishovite with implications for revising traditional shock metamorphism stages.

Our understanding of shock metamorphism and thus the collision of planetary bodies is limited by a dependence on ex situ analyses. Here, the authors perform in situ analysis on shocked-produced densified glass and show that estimates of impactor size based on traditional techniques are likely inflated.

Clinical evaluation for sublingual immunotherapy with Dermatophagoides farinae drops in adult patients with allergic asthma

PURPOSE

The efficacy and safety of sublingual immunotherapy (SLIT) in house dust mite-induced allergic asthma (AA) have yet to be firmly established, especially in adult patients. Our objective is to evaluate the efficacy of SLIT with Dermatophagoides farinae drops in adult patients with AA.

METHODS

One hundred and thirty-four adult patient data with house dust mite (HDM)-induced AA who had been treated for 2 years were collected. These patient data that we collected were divided into the SLIT group (n = 85) and control group (n = 49). All patients were treated with low to moderate dose of inhaled glucocorticoid and long-acting β2 agonists. Patients in the SLIT group were further treated with D. farinae drops. Clinical scores including the total asthma symptom score (TASS), total asthma medicine score (TAMS), asthma control test (ACT), and peak flow percentage (PEF%) were assessed before treatment and at yearly visits. The presence of adverse events (AEs) were recorded once a month.

RESULTS

Before treatment, the PEF% in the SLIT group was significantly lower than that in the control group (p < 0.05). After 2 years, both treatments were effective in the clinical scores when compared with baseline values (all p < 0.001). Meanwhile, the SLIT group showed significantly lower TASS and TAMS (all p < 0.001) and higher ACT (p < 0.001) and PEF% (p < 0.05) when compared with the control group. No severe systemic AEs were reported.

CONCLUSIONS

SLIT with D. farinae drops plus pharmacotherapy is more effective than routine drug treatment in adult patients with AA.

[Effects of retroperitoneal laparoscopic ureterolithotomy and flexible-ureteroscopic holmium laser lithotripsy for complex upper ureteral calculi]

Objective: To explore the clinical effects of retroperitoneal laparoscopic ureterolithotomy (RPLU) and flexible-ureteroscopic holmium laser lithotripsy (f-UHLL) for complicated upper ureteral calculi. Methods: A total of 45 cases of complicated upper ureteral calculi between March 2014 and January 2016 in Department of Urology, Affiliated Jiangyin Hospital of Southeast University Medical College were retrospectively analyzed, there were 32 males and 13 females, ranging from 27 to 45 years with an average age of (34.1±9.5) years. Of the 45 patients, 28 had ureteral distortion and 17 had concurrent ureteral stones in the lower or middle ipsilateral ureter. In those patients, 20 cases underwent f-UHLL, and 25 cases received RPLU. The stone size, operation time, hospital stay, stone clearance rates and postoperative fever rates between the two groups were compared with t test and χ(2)test. Results: The operation was successfully performed in all patients, no complications with leakage of urine or ureteral perforation occurred, and no significant difference in renal function between the two methods were founded in postoperative period. There was no significant difference in operation time((78.4±8.5) minuetes vs.(73.3±11.3) minuetes, t=0.61, P=0.67), time of double J tube removed ((33.8±3.4)days vs. (37.6±8.9) d, t=2.37, P=0.08) and ipsilateral renal glomerular filtration rates ((41.3±7.6)ml/minuetes vs.(40.5±7.1) ml/min, t=0.78, P=1.27) between the two groups. However, the hospitalization time ((5.9±1.7)days vs. (4.2±1.6) days, t=1.92, P=0.04), postoperative fever rates (4% vs.30%, χ(2)=5.72, P=0.03) and calculus clearance rates (100% vs. 75%, χ(2)=7.03, P=0.01) in RPLU were significantly higher than f-UHLL. Besides, 5 patients in the f-UHLL group had postoperative stone residue and were treated with extracorpore shock wave lithotripsy. Conclusions: Both RPLU and f-UHLL are safety and validity for complex upper ureteral calculi. RPLU can improve the rate of calculus removal and reduce the rate of postoperative fever.

SHP2 is required for BCR-ABL1-induced hematologic neoplasia

BCR-ABL1-targeting tyrosine kinase inhibitors (TKIs) have revolutionized treatment of Philadelphia chromosome-positive (Ph⁺) hematologic neoplasms. Nevertheless, acquired TKI resistance remains a major problem in chronic myeloid leukemia (CML), and TKIs are less effective against Ph⁺ B-cell acute lymphoblastic leukemia (B-ALL). GAB2, a scaffolding adaptor that binds and activates SHP2, is essential for leukemogenesis by BCR-ABL1, and a GAB2 mutant lacking SHP2 binding cannot mediate leukemogenesis. Using a genetic loss-of-function approach and bone marrow transplantation (BMT) models for CML and BCR-ABL1⁺ B-ALL, we show that SHP2 is required for BCR-ABL1-evoked myeloid and lymphoid neoplasia. Ptpn11 deletion impairs initiation and maintenance of CML-like myeloproliferative neoplasm, and compromises induction of BCR-ABL1⁺ B-ALL. SHP2, and specifically, its SH2 domains, PTP activity and C-terminal tyrosines, is essential for BCR-ABL1⁺, but not WT, pre-B cell proliferation. The MEK/ERK pathway is regulated by SHP2 in WT and BCR-ABL1⁺ pre-B cells, but is only required for the proliferation of BCR-ABL1⁺ cells. SHP2 is required for SRC family kinase (SFK) activation only in BCR-ABL1⁺ pre-B cells. RNAseq reveals distinct SHP2-dependent transcriptional programs in BCR-ABL1⁺ and WT pre-B cells. Our results suggest that SHP2, via SFKs and ERK, represses MXD3/4 to facilitate a MYC-dependent proliferation program in BCR-ABL1-transformed pre-B cells.

[Reversed halo sign: chest CT findings in 5 patients and cause analysis]

Objective: To describe diseases that may present with the reversed halo sign (RHS) on high-resolution CT, and therefore to improve the recognition of this thoracic radiological feature. Methods: We retrospectively reviewed the HRCT scans and medical records of 5 patients who presented with RHS on chest CT from Peking University Third Hospital. With "reversed halo sign, fairy ring, atoll sign" as the Chinese and English keywords, 420 cases from the literatures were also reviewed through PubMed, Wanfang and CNKI databases until August 2015. Results: The 5 patients were all males, aging 19-55 years. The diagnosis of the diseases included cryptogenic organizing pneumonia (patient 1), pulmonary tuberculosis (patient 2), pulmonary infarction (patient 3), pulmonary edema (patient 4) and mycoplasma pneumonia (patient 5). Literature review showed that RHS was observed in 206 cases of infectious pulmonary diseases and 219 cases of noninfectious pulmonary diseases. Invasive fungal infection (including 59 cases of mucormycosis and 27 aspergillosis) and pulmonary tuberculosis (79 cases) predominated in infectious pulmonary diseases. However, in non-infectious pulmonary diseases, RHS was most frequently observed in organizing pneumonia (66%), sarcoidosis, lung cancer, pulmonary infarction, pulmonary edema and other interstitial lung diseases. There were some differences in the morphologic findings of RHS among invasive fungal infection, pulmonary tuberculosis and organizing pneumonia. In addition, our patient with mycoplasma pneumonia was the first case reported to present with RHS on HRCT. Conclusions: Although a wide spectrum of pulmonary diseases may present with RHS on chest CT, this sign is still a characteristic thoracic radiological feature, which is more commonly found in organizing pneumonia, pulmonary tuberculosis and invasive fungal infection, and is helpful in differential diagnosis.

Farnesyltransferase inhibitor FTI-277 inhibits PD-L1 expression on septic spleen lymphocytes and promotes spleen lymphocyte activation

Farnesyltransferase inhibitors have been tested in clinical trials for the treatment of tumours. In sepsis, the binding of programmed death 1 (PD-1) to programmed death ligand 1 (PD-L1) promotes lymphocyte apoptosis and decreases cytokine expression, thus affecting survival rates. The PD-1/PD-L1 pathway plays an important role in chronic viral infection, bacterial infection and sepsis. However, the precise immunosuppressive and anti-inflammatory functions of this pathway remain poorly understood. In our previous study, the induction of sepsis by caecal ligation and puncture (CLP) resulted in increased farnesyltransferase activity and farnesylated protein levels in the spleen relative to sham treatment. However, the effect of inhibition of farnesyltransferase activity on overall survival rates in patients with sepsis and the specific signalling pathway involved remain to be investigated. In this study, mice with CLP-induced sepsis were treated with farnesyltransferase inhibitor (FTI-277), and PD-L1 expression on septic spleen lymphocytes was examined. Flow cytometric analysis revealed that PD-L1 is expressed constitutively on lymphocytes and that PD-L1 protein expression was up-regulated strongly following CLP. FTI-277 down-regulated PD-L1 mRNA and protein expression on septic spleen lymphocytes in a dose-dependent manner. This effect was associated closely with nuclear factor kappa B (NF-κB). In addition, the significant damping effect of FTI-277 on the PD-L1 signal promoted interferon (IFN)-γ secretion, interleukin (IL)-2 production and splenocyte proliferation in response to anti-CD3⁺ CD28⁺ antibodies in mice. Furthermore, FTI-277 reduced spleen lymphocyte apoptosis in septic mice. Therefore, FTI-277 regulates spleen lymphocyte activity via the PD-L1 signalling pathway, with significant anti-inflammatory effects attributable to suppression of the NF-κB pathway. Farnesyltransferase represents a valuable therapeutic target for the treatment of sepsis.

[Preliminavy clinical study of the treatment of hemorrhoids by superselective embolization of superior rectal artery]

Objective: To investigate the safety and feasibility of the treatment of hemorrhoids by superselective arterial embolization. Methods: The clinical data of 15 patients with grade Ⅱ to Ⅳ hemorrhoids were collected who were treated by superselective SRA embolization.According to the number and shape of SRA in the vicinity of the dentate line, chosed coils, PVA particles and gelfoam particles, ethanol and bletilla mixture of gelfoam particles for embolization.And intraoperative operations, postoperative complications, follow-up treatment results were observed. Results: The interventional procedures were successfully accomplished in all 15 cases.The operation time was (30±14) min, and the hospital stay was 1-7 (2.0±1.8) days after operation, and the patients recovered to normal life in 12 hours after the operation.Tenesmus (14/15), pain (5/15) and low fever (11/15) can alleviate without special treatment. All patients were follow up (19.0±2.6) months, bleeding symptoms were cured, there's no serious complications. Conclusion: The treatment of hemorrhoids by transcatheter superselective embolization of superior rectal artery is technically safe and feasible.

Effects of Lactobacillus rhamnosus GG on the maturation and differentiation of dendritic cells in rotavirus-infected mice

Rotavirus-related diarrhoea is considered one of the most important diseases in field animal production. In addition to the classic vaccine strategy, a number of studies have utilised probiotics, such as Lactobacillus rhamnosus GG (LGG), to prevent rotavirus-induced diarrhoea. Although it has been partially revealed that Toll-like receptors (TLRs) are involved in the LGG-mediated protection against rotavirus infection, the details of the underlying immunologic mechanisms remain largely unknown. In this study, three-to-four-week-old female BALB/c mice were divided into three groups and orally administered phosphate buffered saline (PBS), PBS plus rotavirus or LGG plus rotavirus, respectively. The differentiation and maturation of dendritic cells (DCs) were then determined by FACS, the expression levels of TLR-3 and nuclear factor kappa beta (NF-κB) were evaluated using real time PCR, and the production of inflammatory cytokines in mesenteric lymph nodes (MLNs) were determined by ELISA. The results demonstrated that rotavirus infection significantly increased the percentage of CD11c⁺CD11b⁺CD8a^- DCs and decreased the percentage of CD11c⁺CD11b^-CD8a⁺ DCs in MLNs. By contrast, the presence of LGG significantly decreased the percentage of CD11c⁺CD11b⁺CD8a^- DCs and increased the percentage of CD11c⁺CD11b^-CD8a⁺ DCs, which indicates that the differentiation of DCs is involved in the protective effects of LGG. Rotavirus infection also resulted in the increased expression of surface markers such as CD40, CD80 and MHC-II in DCs, and the administration of LGG significantly increased the expression level further. The mRNA levels of TLR-3 and NF-κB in the intestine and MLNs were also significantly increased in the presence of rotavirus, which was further increased in the presence of LGG. The production of inflammatory cytokines was also determined, and the results showed that rotavirus caused the increased production of interleukin (IL)-12 and tumour necrosis factor alpha; this effect was further enhanced by LGG. Meanwhile, although rotavirus infection led to the increased production of IL-6 and IL-10, the presence of LGG significantly decreased the mRNA levels of these cytokines. By contrast, rotavirus infection resulted in the decreased production of interferon gamma (IFN-γ), and the administration of LGG significantly increased the levels of IFN-γ. Taken together, the protective effects of LGG were partially due to the modulation of the differentiation and maturation of DCs, the increased production of TLR-3 and NF-κB, and the modulation of inflammatory cytokines.

Gender difference in radiotherapy-induced carotid stenosis

Radiotherapy (RT) is often the first choice of treatment for cancer of the larynx. Studies have shown that the incidence of carotid stenosis (CS) after radiotherapy of laryngeal cancer is increasing, and that gender difference in radiotherapy-induced side effects exist. Thus, we examined the gender difference in the incidence of CS and the impact of microinflammatory factors after radiotherapy. We reported this study on patients who received radiotherapy as part of the treatment for laryngeal cancer in the Jilin Province in China. One hundred sixty-four males and 152 females were treated with radiotherapy between 2006 and 2016. The carotid diameter was determined by measuring carotid intima-media thickness in the common, external and internal carotid artery. Microinflammatory conditions were assessed by measuring the level of high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Other studied risk factors included age, treatment modalities, radiation dose and energy, the height of the radiation field, and the follow-up time. CS was detected in 161 (50.9%) of the 316 patients. Carotid stenosis was mainly clinically unsuspected, two patients had anamnesis of unconsciousness. Importantly, fewer women (36.1%) had CS than men (64.6%) (p=0.004). Furthermore, male patients showed higher serum levels of hs-CRP, IL-6, and TNF-α. Taken together, our study suggested that women underoing radiotherapy of laryngeal cancer are less likely to have CS than men. Therefore, routine assessment after irradiation of laryngeal cancer seems necessary for clinical detection of asymptomatic CS, particularly in male patients.

Differential increments of basal glucagon-like-1 peptide concentration among SLC47A1 rs2289669 genotypes were associated with inter-individual variability in glycaemic response to metformin in Chinese people with newly diagnosed Type 2 diabetes

AIM

To elucidate the effects of rs2289669, an intron variant of the SLC47A1 gene, on glucose response to metformin in Chinese people with newly diagnosed Type 2 diabetes.

METHODS

Rs2289669 was genotyped, using Sequenom, in 291 participants receiving 48 weeks of metformin monotherapy. The changes in HbA_1c were compared among rs2289669 genotypes, and associations with rs2289669 were evaluated using linear regression analysis.

RESULTS

We found that, compared with participants with a homozygous G allele, those carrying the minor A allele had significantly greater HbA_1c reduction and greater increases in basal glucagon-like peptide-1 concentration. Regression analysis showed that there was a significant association between rs2289669 and the glucose response to metformin after adjusting for confounding factors, except for changes in basal glucagon-like peptide-1, for which an association was not observed.

CONCLUSIONS

Our findings suggest that rs2289669 might help predict the glycaemic response to metformin in Chinese people newly diagnosed with Type 2 diabetes, and that differential increases in basal glucagon-like peptide-1 concentration among rs2289669 genotypes might be associated with inter-individual response to metformin.

[The comparation of fusion targeting biopsy and systematic biopsy in the clinical diagnosis of prostate cancer: a meta-analysis]

Objective: To systematically compare the differences in the detection rate of prostate cancer with fusion targeting biopsy and systemic biopsy. Methods: A computer-based search of PubMed, Medline, China Biomedical Literature Database and Wanfang database (from the beginning of establishment of library to October 2016) on the detection rate of prostate cancer by fusion targeting biopsy and systemic biopsy was performed manually.The inclusion and exclusion criteria were formulated by 2 reviewers, and the data were extracted and evaluated respectively. RevMan5.3 software was used to analyze the detection rate of prostate cancer by two biopsy methods. Results: A total of 15 related clinical studies were included, 5 337 cases were enrolled in the study, including 2 667 cases of targeted fusion biopsy and 2 670 cases of routine systemic biopsy. The results showed that the overall detection rate of prostate cancer in targeting fusion biopsy was significantly higher than that of conventional systemic biopsy (OR=1.16, 95% CI 1.04-1.30, P=0.007). The detection rates of prostate cancer with different risk grades by two biopsy methods were conducted. We found that targeted fusion biopsy had a significant advantage compared with conventional system biopsy (OR=1.37, 95% CI 1.19-1.58, P<0.05) in middle and high risk prostate cancer with Gleason ≥ 7 points. In low-risk prostate cancer patients with Gleason score <7, the detection rate of prostate cancer by targeted fusion biopsy was lower (OR=0.76, 95% CI 0.65-0.89, P<0.05) than that of conventional systemic biopsy. Conclusions: Targeted fusion biopsy was significantly better than systemic biopsy in the overall detection rate of prostate cancer and the detection rate of the middle and high risk prostate cancer with Gleason ≥7 points. However, systemic biopsy performed better in patients with Gleason<7 points of low-risk prostate cancer.

Alleviation of enterotoxigenic Escherichia coli challenge by recombinant Lactobacillus plantarum expressing a FaeG- and DC-targeting peptide fusion protein

FaeG is the major subunit of K88 fimbriae. These cell surface attachments are considered to be the major virulence factor of enterotoxigenic Escherichia coli (ETEC), which causes diarrhoea in piglets. The use of dendritic cell-targeting peptide (DCpep) has been demonstrated to be an effective approach to enhance the immunity of vaccines. Lactobacillus plantarum is an attractive candidate for oral vaccination owing to its beneficial effects and safety. In this study, L. plantarum was employed to deliver a FaeG-DCpep fusion antigen, and the immune response in mice was evaluated. The synthesis of FaeG-DCpep dramatically increased the adhesion of recombinant L. plantarum (RLP) to IPEC-J2 cell surfaces, resulting in direct competition between L. plantarum and ETEC during adhesion assays. Significantly higher levels of body weight gain, sera immunoglobulin G and intestinal immunoglobulin A were observed in BALB/c mice immunised with RLP. In addition, the number of CD19+ B cells and CD11c+DC cells and the expression levels of several cytokines in the spleen and lymph nodes increased significantly compared to non-immunised mice. The oral administration of RLP also alleviated the symptoms of ETEC challenge, as shown by haematoxylin-eosin staining, indicating that RLP may be an efficient vaccine candidate.

Mother-young recognition in goitered gazelle during hiding period

The mother-young recognition process is crucial for the growth and survival of progeny. In "follower" ungulate species, vocal and visual cues have been found to play a leading role in the mother-young identification process from the first days postpartum, with olfactory cues also important in establishing the initial selective mother-young bond immediately after birth. In "hider" species, however, much less has been documented of mother-young recognition behaviors, especially in their natural habitat. In this paper, we investigated this process in goitered gazelle (Gazella subgutturosa), a typical hider species, in its native environment in Kazakhstan. Over the course of our study period, we investigated the behaviors of 257 females with twins and 158 females with singles through visual observations. We found that within the first month after birth, when females spend only a short time with their young, mothers recognized their fawns using mostly olfactory cues, while vision was used to locate their hiding offspring. Fawns vocalized very rarely, producing only distress calls that did not seem intended for individual identification. Licking of young by their mothers was observed frequently, not only during the first week after birth, when this action was very important for fawn stimulation for a number of physiological functions, but for several weeks after (until one month of age), when licking lost its physiological importance and likely became more of a recognition procedure. Fawns did not recognize their mothers at all, either through vision or vocalizations, since during their first weeks after birth, they responded to any gazelle that approached their hiding area. By a month after birth, when mothers and fawns began to stay together for longer periods of time, their recognition process became more enhanced, and in addition to olfactory cues, the mother and her young began to use more and more visual cues for longer distance identification, as well as vocalizations for shorter distances. Similar dynamics are likely typical for most hiding species, although information for wild ungulates is still very limited, especially for those with strong hider behaviors.

Mechanical properties of crossed-lamellar structures in biological shells: A review

The self-fabrication of materials in nature offers an alternate and powerful solution towards the grand challenge of designing advanced structural materials, where strength and toughness are always mutually exclusive. Crossed-lamellar structures are the most common microstructures in mollusks that are composed of aragonites and a small amount of organic materials. Such a distinctive composite structure has a fracture toughness being much higher than that of pure carbonate mineral. These structures exhibiting complex hierarchical microarchitectures that span several sub-level lamellae from microscale down to nanoscale, can be grouped into two types, i.e., platelet-like and fiber-like crossed-lamellar structures based on the shapes of basic building blocks. It has been demonstrated that these structures have a great potential to strengthen themselves during deformation. The observed underlying toughening mechanisms include microcracking, channel cracking, interlocking, uncracked-ligament bridging, aragonite fiber bridging, crack deflection and zig-zag, etc., which play vital roles in enhancing the fracture resistance of shells with the crossed-lamellar structures. The exploration and utilization of these important toughening mechanisms have attracted keen interests of materials scientists since they pave the way for the development of bio-inspired advanced composite materials for load-bearing structural applications. This article is aimed to review the characteristics of hierarchical structures and the mechanical properties of two kinds of crossed-lamellar structures, and further summarize the latest advances and biomimetic applications based on the unique crossed-lamellar structures.

Genome-Wide Study Links PNPLA3 Variant With Elevated Hepatic Transaminase After Acute Lymphoblastic Leukemia Therapy

Remission induction therapy for acute lymphoblastic leukemia (ALL) includes medications that may cause hepatotoxicity, including asparaginase. We used a genome-wide association study to identify loci associated with elevated alanine transaminase (ALT) levels after induction therapy in children with ALL enrolled on St. Jude Children's Research Hospital (SJCRH) protocols. Germline DNA was genotyped using arrays and exome sequencing. Adjusting for age, body mass index, ancestry, asparaginase preparation, and dosage, the PNPLA3 rs738409 (C>G) I148M variant, previously associated with fatty liver disease risk, had the strongest genetic association with ALT (P = 2.5 × 10^-8 ). The PNPLA3 rs738409 variant explained 3.8% of the variability in ALT, and partly explained race-related differences in ALT. The PNPLA3 rs738409 association was replicated in an independent cohort of 2,285 patients treated on Children's Oncology Group protocol AALL0232 (P = 0.024). This is an example of a pharmacogenetic variant overlapping with a disease risk variant.

Different clinical prognostic factors are associated with improved glycaemic control: findings from MARCH randomized trial

AIMS

Metformin and acarbose have comparable efficacy as initial therapy for HbA_1c reduction in Chinese patients with newly diagnosed Type 2 diabetes. However, not all participants achieved glycaemic control. Our aim was to discover a monotherapy predictor for therapeutic response in Type 2 diabetes on the basis of baseline features.

METHODS

Data from the MARCH trial were collected, resulting in 698 individuals being available for longitudinal analyses. All participants were divided into subgroups based on successful and unsuccessful achievement of the glycaemic target according to primary endpoints at week 24 (HbA_1c < 53 mmol/mol; 7.0%). Logistic regression analysis with stepwise variable selection was performed to assess the independent risk factors for good glycaemic control of monotherapy with metformin or acarbose.

RESULTS

Median HbA_1c was 66 ± 1 mmol/mol (8.2 ± 0.07%) in the metformin group at baseline, and 66 ± 1 mmol/mol (8.2 ± 0.07%) in the acarbose group. After 24 weeks of monotherapy, 79.8% of participants in the metformin group achieved glycaemic targets compared with 78.7% of those in the acarbose group. Multivariate regression analysis showed that BMI and fasting blood glucose were significant independent predictors for the maintenance of good glycaemic control in the metformin group, whereas phase I insulin secretion (Insulin/Glucose at 30 min, I30/G30) and duration of diabetes were associated with good glycaemic control in the acarbose group.

CONCLUSIONS

For newly diagnosed Type 2 diabetes, some clinical features and laboratory parameters are important prognostic factors for predicting drug responsiveness. Participants with a higher BMI and lower fasting blood glucose achieved good glycaemic control when metformin was selected as the initial treatment. Acarbose was best for participants with higher phase I insulin secretion (I30/G30) and shorter duration of Type 2 diabetes.

[Population pharmacokinetics of vancomycin from severe in patients with lower respiratory tract infection]

Objective: To develop a population pharmacokinetic (PPK) model of vancomycin in Chinese inpatients with severe lower respiratory tract infection. Methods: We gathered serum concentrations of vancomycin from inpatients who received vancomycin during Nov 2011 to Nov 2012.Vancomycin serum concentrations was measured by high performance liquid chromatography. Vancomycin PPK analysis was performed using nonlinear mixed effects model (NONMEM) program. Results: We gathered the data of 70 inpatients with lower respiratory tract infection at respiratory ward or respiratory intensive care unit(RICU) between Nov 2011 to Nov 2012 [58 males, 12 females; 78(23-91) years old; the mean of APACHⅡ score was 16.4±4.8]. A total of 267 concentrations of vancomycin were gathered from 70 patients. A 2-compartment model fit the concentration data best. The final vancomycin PPK model was: CL(i)=1.67×e(η1), V(1i)=33.04×[1-0.199×(60/Scr)] ×e(η2), Q(i)=7.08×2.053(AI)×e(η3), V(2i)=19.29×e(η4).(CL: vancomycin clearance; V(1): distribution volume of the central compartment; Q: intercompartment clearance; V(2): distribution volume of the intercompartment). The population mean values were 1.67 L/h, 33.04 L; 7.08 L/h and 19.29 L respectively. Serum creatinine was the covariate to affect vancomycin apparent distribution volume of the central compartment. Intercompartment clearance was 2.053 times larger in patients with albumin infusion than that in patients without. Conclusions: We found that a 2-compartment model fit the concentration data best in Chinese patients with severe lower respiratory tract infection. Serum creatinine and albumin infusion were the most significant covariates to affect vancomycin PK.