Research on rat models of hypobaric hypoxia-induced pulmonary hypertension

OBJECTIVE

Rat models of hypobaric hypoxia-induced pulmonary hypertension are commonly used in studies of chronic mountain sickness, while there are few researches specially focusing on these rats model. This study aims to exploring possible pathogenesis of hypobaric hypoxia-induced pulmonary hypertension by experimenting on hypobaric hypoxia-induced PH rat models at different simulate- altitudes.

MATERIALS AND METHODS

32 healthy male SD rats were randomly divided into six groups of different degree and time period of hypobaric hypoxia. The mean pulmonary arterial pressure (m PAP), right ventricular pressure (RVSP), the right ventricle (RV), left ventricular (LV), ventricular septal (S), the right ventricular hypertrophy index (RVHI) [calculated under the formula of RV / (LV + S)], hematoxylin-eosin staining, elastic fibers staining, the ratio of the thickness of vascular wall to its outer diameter (MT%), the ratio of the cross-sectional area of the middle vascular wall to the total vascular cross-sectional area (MA%); the α-SMA, and the Ki6 expressions were detected to evaluated the pulmonary hypertension.

RESULTS

There were significant differences of the mPAP, RVSP and RVHI value between the hypobaric hypoxia groups and the control group (p < 0.05). The mPAP, RVSP, RVHI, MT%, MA%, α-SMA, and Ki6 of rats in model groups at an altitude of 3KM were higher than those of the control group, which raised gradually with the number of weeks increasing. The mPAP, RVSP, RV / (LV + S) value, MT%, MA%, α-SMA, and Ki67 of the 5KM-4W group were significantly higher than those of the control group (p < 0.05).

CONCLUSIONS

Rat models with pulmonary hypertension at different altitudes have been successfully established by automatic adjusting hypobaric hypoxia chamber. Exposure to a low oxygen environment at a simulate-altitude of 3 km for 8 weeks have caused the pathological remodeling of pulmonary vascular walls and pulmonary hypertension, and further led to a series of pathological changes, including right ventricular hypertrophy. This model is easy to be replicated with good reproducibility and provides evidence for clinical trial of drugs.

Epitope analysis of Ara h 2 and Ara h 6: characteristic patterns of IgE-binding fingerprints among individuals with similar clinical histories

BACKGROUND

Ara h 2 and Ara h 6 are moderately homologous and highly potent peanut allergens.

OBJECTIVE

To identify IgE-binding linear epitopes of Ara h 6, compare them to those of Ara h 2, and to stratify binding based on clinical histories.

METHODS

Thirty highly peanut-allergic subjects were stratified by clinical history. Sera were diluted to contain the same amount of anti-peanut IgE. IgE binding to overlapping 20-mer peptides of Ara h 2 and Ara h 6 was assessed using microarrays.

RESULTS

Each subject had a unique IgE-binding fingerprint to peptides; these data were coalesced into epitope binding. IgE from subjects with a history of more severe reactions (n = 19) had a smaller frequency of binding events (BEs) for both Ara h 2 (52 BEs of 152 (19X8epitopes) possible BEs and Ara h 6 (13 BEs of 133 (19X7 epitopes) possible BEs) compared to IgE from those with milder histories (n = 11) (Ara h 2: 47 BEs of 88 (11X8 epitopes) possible BEs, P < 0.01; Ara h 6: 25 BEs of 77 (11X7 epitopes) possible BEs, P < 0.001). Using an unsupervised hierarchal cluster analysis, subjects with similar histories tended to cluster. We have tentatively identified a high-risk pattern of binding to peptides of Ara h 2 and Ara h 6, predominantly in subjects with a history of more severe reactions (OR = 12.6; 95% CI: 2.0-79.5; P < 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

IgE from patients with more severe clinical histories recognize fewer linear epitopes of Ara h 2 and Ara h 6 than do subjects with milder reactions and bind these epitopes in characteristic patterns. Close examination of IgE binding to epitopes of Ara h 2 and Ara h 6 may have prognostic value.

Algal Feedback and Removal Efficiency in a Sequencing Batch Reactor Algae Process (SBAR) to Treat the Antibiotic Cefradine

Many previous studies focused on the removal capability for contaminants when the algae grown in an unexposed, unpolluted environment and ignored whether the feedback of algae to the toxic stress influenced the removal capability in a subsequent treatment batch. The present research investigated and compared algal feedback and removal efficiency in a sequencing batch reactor algae process (SBAR) to remove cefradine. Three varied pollution load conditions (10, 30 and 60 mg/L) were considered. Compared with the algal characteristics in the first treatment batch at 10 and 30 mg/L, higher algal growth inhibition rates were observed in the second treatment batch (11.23% to 20.81%). In contrast, algae produced more photosynthetic pigments in response to cefradine in the second treatment batch. A better removal efficiency (76.02%) was obtained during 96 h when the alga treated the antibiotic at 60 mg/L in the first treatment batch and at 30 mg/L in the second treatment batch. Additionally, the removal rate per unit algal density was also improved when the alga treated the antibiotic at 30 or 60 mg/L in the first treatment batch, respectively and at 30 mg/L in the second treatment batch. Our result indicated that the green algae were also able to adapt to varied pollution loads in different treatment batches.

Spatially Weighted Principal Component Analysis for Imaging Classification

The aim of this paper is to develop a supervised dimension reduction framework, called Spatially Weighted Principal Component Analysis (SWPCA), for high dimensional imaging classification. Two main challenges in imaging classification are the high dimensionality of the feature space and the complex spatial structure of imaging data. In SWPCA, we introduce two sets of novel weights including global and local spatial weights, which enable a selective treatment of individual features and incorporation of the spatial structure of imaging data and class label information. We develop an e cient two-stage iterative SWPCA algorithm and its penalized version along with the associated weight determination. We use both simulation studies and real data analysis to evaluate the finite-sample performance of our SWPCA. The results show that SWPCA outperforms several competing principal component analysis (PCA) methods, such as supervised PCA (SPCA), and other competing methods, such as sparse discriminant analysis (SDA).

Factors influencing independent oral feeding in preterm infants

OBJECTIVE

Determine the mean post-menstrual age when preterm infants attain independent oral feeding skills and whether gestational age, common neonatal morbidities, gender, race, delivery route, or birth year affects this reflex.

METHODS

A retrospective chart review of 2700 preterm infants, born before 37 weeks gestational age admitted to a level III NICU between January 1978 and July 2013, to determine the post-menstrual age when independent oral feedings occur.

RESULTS

Mean post-menstrual age at achievement of independent oral feeding was 36 + 4/7 weeks ± 14 days. Gestational age under 29 weeks correlated with delayed post-menstrual age at achievement of independent oral feeding at 37 + 3/7 weeks versus 36 + 1/7 weeks for gestational age 29-33 weeks and 36 + 3/7 weeks for late preterm infants (p < 0.0001). Preterm infants with certain morbidities experienced a delay in independent oral feeding: necrotizing enterocolitis at 38 + 6/7 weeks (p < 0.0001), bronchopulmonary dysplasia at 38 + 1/7 weeks (p < 0.0001), severe intraventricular hemorrhage at 37 + 6/7 weeks (p < 0.001). Preterm infants born before the year 2000 achieved independent oral feeding two days later than preterm infants born since the year 2000 (p < 0.0001). Preterm infants delivered vaginally achieved independent oral feeding three days sooner than infants delivered via c-section (p < 0.0001). Female infants orally fed one day sooner than male preterm infants (p = 0.0008).

CONCLUSIONS

Preterm infants achieve independent oral feeding at 36 + 4/7 weeks. Factors negatively influencing when the preterm infant will achieve independent oral feeding include gestational age under 29 weeks and major morbidities, whereas vaginal delivery and ongoing advances in neonatal care may accelerate the transition to independent oral feeding.

The degradation of antibiotic amoxicillin in the Fenton-activated sludge combined system

The present study investigated the removal efficiency of amoxicillin by the Fenton process, individual activated sludge process and Fenton-activated sludge combined system. For the antibiotic at 1 g L(-1), the optimal conditions of the Fenton process included: 4 mL FeSO4·7H2O solution (20.43 g  L(-1)), 6 mL H2O2 solution (3%) and 40°C. Under the optimal conditions, the removal rate of amoxicillin achieved up to 80% in 70 min. In addition, the impact of amoxicillin on microorganism limited the removal capacity of the activated sludge process. When the concentration of amoxicillin was less than 350 mg L(-1), 69.04-88.79% of the antibiotic was removed. However, the antibiotic could not be treated by the activated sludge when the concentration increased up to 650 mg L(-1). On the other hand, ifamoxicillin was pretreated partly by the Fenton process it was then degraded completely by the same activated sludge. Thus, the combined system included two steps: 80% amoxicillin was degraded in step I and was removed completely in the cheaper biological treatment (step II). Our result showed that compared with the individual activated sludge process, the Fenton process improved the removal capacity of the subsequent activated sludge process in the combined system.

Activation of p38 MAPK in the rostral ventromedial medulla by visceral noxious inputs transmitted via the dorsal columns may contribute to pelvic organ cross-sensitization in rats with endometriosis

Whether visceral organ cross-sensitization is involved in endometriosis-associated pain remains elusive. Previous studies have shown that visceral noxious stimuli may trigger a cascade of signal transductions in the rostral ventromedial medulla (RVM) via the spinal dorsal column (DC) pathway and the RVM plays a critical role in the descending control of visceral nociception. In the current study, we hypothesized that the p38 mitogen-activated protein kinase (MAPK) activation in the RVM by noxious visceral inputs from ectopic growths via the DC was involved in the development of pelvic organ cross-sensitization in established endometriosis. A rat model of experimental endometriosis was established. To examine ectopic growths-to-colon cross-sensitization, graded colorectal distention (CRD) was performed and abdominal withdrawal reflex (AWR) scores were recorded in female rats at 8weeks after the uterine or fat (control) auto-transplantation. Western blot study was carried out to examine the phosphorylated form and the total level of p38 MAPK protein in the RVM. Our results showed that lesions of bilateral DCs immediately following uterine or fat auto-transplantation in female rats significantly attenuated the later development of ectopic growths-to-colon cross-sensitization and the increased p38 MAPK activation in the RVM, as compared to sham DC lesions. Furthermore, intra-RVM microinjection of a p38 MAPK inhibitor (SB 203580), but not vehicle, in female rats with established endometriosis significantly attenuated ectopic growths-to-colon cross-sensitization and the increased activation of p38 MAPK in the RVM. These findings suggest that the noxious inputs from ectopic growths may activate p38 MAPK in the RVM via the DC, which may contribute to the development of ectopic growths-to-colon cross-sensitization in established endometriosis.

Understanding the algal contribution in combined UV-algae treatment to remove antibiotic cefradine

The aim of this study is to investigate the algal contribution in a combined UV-algae treatment to remove the commonly used antibiotic cefradine.

Evaluation of the aquatic toxic effect varied during the degradation of capecitabine under the environmental abiotic and biotic processes

Environmental risk due to the growing use of anticancer drugs has drawn wide public concern.

Enhancement by the artificial controlled culture for the algal treatment of antibiotic ceftazidime: a three-step response performance and high-removal efficiency

The improved activity of alga is critical for the biological enhanced treatment to remove contamination.

The process-dependent impacts of dimethoate on the feeding behavior of rotifer

Traditional toxicological studies usually depict the dose-effect relationship at the given exposure time while ignore how toxic effects vary during and after the exposure. In the present study, feeding depression of the rotifer Brachionus calyciflorus under the impact of dimethoate was evaluated not only in the exposure time but also in the post-exposure time. Both the filtration rates (F) and the ingestion rates (I) of the rotifers varied during the exposure period under any concentration of dimethoate. A three-stepwise stress was observed when the rotifers were exposed to 0.2 and 1.0 mg L(-1) of the pesticide respectively, whereas 1.8 mg L(-1) dimethoate caused only one-step stress on the rotifers during the whole period. In addition, although the feeding behaviors of the rotifers recovered after the exposure, two feeding rates both got even more depressed at 8h in the post-exposure time. The latent inhibition after exposure was related to the exposure concentrations and the exposure time. Our works indicated that the impact of dimethoate on the feeding behavior of the rotifers was highly process-dependent that caused the stepwise stress during the exposure period and the latent stress after the exposure.

An algal process treatment combined with the Fenton reaction for high concentrations of amoxicillin and cefradine

The goal of the current study was to create a combined technique for the removal of two common antibiotics (amoxicillin and cefradine) using Fenton and an algal action process.

Assessing the impacts of dimethoate on rotifers' reproduction through the pre-exposure history

Organism usually undergoes an exposure of environmental pollution after a maternal exposure before birth. Traditional toxicological studies often initiated with rotifer neonates derived from the unexposed mothers while ignoring the pre-exposure (maternal exposure). The present study assessed the effect of dimethoate on the reproduction of the rotifer Brachionus calyciflorus, considering how the pre-exposure occurred in the parental generation influenced the subsequent impact. The F0 generation rotifers were exposed to the pesticide at five concentrations until the first F1 generation rotifers were reproduced. The neonates (F1 generation) were then exposed to the pesticide at the corresponding concentrations. The offspring reproduction, the time begins to reproduce, the duration of the reproductive period and the lifespan of the F1 generation rotifers were evaluated. Our results indicated that dimethoate influenced the maturation and reproduction of the rotifers. The highest concentration (1.8 mg L(-1)) of dimethoate caused an inhibition in the offspring reproduction, shortened the life span and reduced the duration of the reproductive period. In addition, of particular interest in our study was that reproduction is also accelerated by the lowest concentration (0.2 mg L(-1)). However, the pre-exposure had a significant effect on the subsequent impact. The dimethoate pre-exposure increased the impacts when the F1 generation rotifers were exposed to the substance, even at the same concentrations as in pre-exposure. It suggests that the maternal exposure history before birth is also important and has the long-lasting consequence from one generation to another.

Effects of plant roots on the hydraulic performance during the clogging process in mesocosm vertical flow constructed wetlands

The aim of this study was to evaluate the effects of plant roots (Typha angustifolia roots) on the hydraulic performance during the clogging process from the perspective of time and space distributions in mesocosm vertical flow-constructed wetlands with coarse sand matrix. For this purpose, a pair of lab-scale experiments was conducted to compare planted and unplanted systems by measuring the effective porosity and hydraulic conductivity of the substrate within different operation periods. Furthermore, the flow pattern of the clogging process in the planted and unplanted wetland systems were evaluated by their hydraulic performance (e.g., mean residence time, short circuiting, volumetric efficiency, number of continuously stirred tank reactors, and hydraulic efficiency factor) in salt tracer experiments. The results showed that the flow conditions would change in different clogging stages, which indicated that plants played different roles related to time and space. In the early clogging stages, plant roots restricted the flow of water, while in the middle and later clogging stages, especially the later stage, growing roots opened new pore spaces in the substrate. The roots played an important role in affecting the hydraulic performance in the upper layer (0-30 cm) where the sand matrix had a larger root volume fraction. Finally, the causes of the controversy over plant roots' effects on clogging were discussed. The results helped further understand the effects of plant roots on hydraulic performance during the clogging process.

Estimating energy expenditure using heat flux measured at a single body site

INTRODUCTION

The Personal Calorie Monitor (PCM) is a portable direct calorimeter that estimates energy expenditure (EE) from measured heat flux (i.e., the sum of conductive, convective, radiative, and evaporative heat).

PURPOSE

The primary aim of this study was to compare EE estimated from measures of heat flux with those measured using indirect calorimetry in a thermoneutral environment (26°C). A secondary aim was to determine whether exposure to ambient temperature below thermoneutral condition (19°C) influences the accuracy of the PCM.

METHODS

Thirty-four adults (mean ± SD: age, 28 ± 5 yr; body mass index, 22.9 ± 2.6 kg · m(-2)) were studied for 5 h in a whole-room indirect calorimeter (IC) in thermoneutral and cool conditions. Participants wore the PCM on their upper arm and completed two 20-min treadmill walking bouts (0% grade, 3 mph). The remaining time was spent sedentary (e.g., watching television, using a computer).

RESULTS

In thermoneutral conditions, EE values (mean (95% confidence interval)) measured by IC and PCM were 560.0 (526.5-593.5) and 623.3 (535.5-711.1) kcal, respectively. In cool conditions, EE values measured by IC and PCM were 572.5 (540.9-604.0) and 745.5 (668.1-822.8) kcal, respectively. Under thermoneutral conditions, mean PCM minute-by-minute EE tracked closely with IC, resulting in a small nonsignificant bias (63 kcal (-5.8 to 132.4)). During cool conditions, mean PCM minute-by-minute EE did not track IC, resulting in a large bias (173.0 kcal (93.9-252.1)) (P <; 0.001).

CONCLUSIONS

This study demonstrated the validity of using measured heat flux to estimate EE. However, accuracy may be impaired in cool conditions possibly because of excess heat loss from the exposed limbs.

Identifying keys to success in reducing readmissions using the ideal transitions in care framework

BACKGROUND

Systematic attempts to identify best practices for reducing hospital readmissions have been limited without a comprehensive framework for categorizing prior interventions. Our research aim was to categorize prior interventions to reduce hospital readmissions using the ten domains of the Ideal Transition of Care (ITC) framework, to evaluate which domains have been targeted in prior interventions and then examine the effect intervening on these domains had on reducing readmissions.

METHODS

Review of literature and secondary analysis of outcomes based on categorization of English-language reports published between January 1975 and October 2013 into the ITC framework.

RESULTS

66 articles were included. Prior interventions addressed an average of 3.5 of 10 domains; 41% demonstrated statistically significant reductions in readmissions. The most common domains addressed focused on monitoring patients after discharge, patient education, and care coordination. Domains targeting improved communication with outpatient providers, provision of advanced care planning, and ensuring medication safety were rarely included. Increasing the number of domains included in a given intervention significantly increased success in reducing readmissions, even when adjusting for quality, duration, and size (OR per domain, 1.5, 95% CI 1.1 - 2.0). The individual domains most associated with reducing readmissions were Monitoring and Managing Symptoms after Discharge (OR 8.5, 1.8 - 41.1), Enlisting Help of Social and Community Supports (OR 4.0, 1.3 - 12.6), and Educating Patients to Promote Self-Management (OR 3.3, 1.1 - 10.0).

CONCLUSIONS

Interventions to reduce hospital readmissions are frequently unsuccessful; most target few domains within the ITC framework. The ITC may provide a useful framework to consider when developing readmission interventions.

Comparison of radiological and clinical features of temporal lobe necrosis in nasopharyngeal carcinoma patients treated with 2D radiotherapy or intensity-modulated radiotherapy

BACKGROUND

To compare the imaging and clinical features of temporal lobe necrosis (TLN) in nasopharyngeal carcinoma (NPC) patients treated with two-dimensional radiotherapy (2D-RT) or those with intensity-modulated radiotherapy (IMRT).

METHODS

We retrospectively analysed NPC patients who underwent 2D-RT (72 patients, 128 temporal lobes) or IMRT (36 patients, 50 lobes) and developed radiation-induced, MRI-confirmed TLN.

RESULTS

White-matter lesions (WMLs), contrast-enhanced lesions, cysts and local mass effects were present in 128 out of 128 vs 48 out of 50 (P=0.078), 123 out of 128 vs 47 out of 50 (P=0.688), 10 out of 128 vs 1 out of 50 (P=0.185) and 57 out of 128 vs 13 out of 50 (P=0.023) temporal lobes, respectively, in the 2D-RT and IMRT groups. The WMLs were more extensive in the 2D-RT group (P<0.001). The maximum diameter of contrast-enhanced lesions was greater in the 2D-RT group (P<0.001), and these lesions tended to extend far away from the nasopharynx. The WMLs and enhancement had no impact on cyst development (both P=1). Local mass effects were always accompanied with contrast-enhanced lesions (P=0.024) but were not correlated with WMLs or cysts (P=0.523 and 0.341, respectively). There were no between-group differences in clinical features (all P-values>0.05), whereas the difference in the incidence of severe debility was of marginal significance (18.1% vs 5.6%, P=0.077).

CONCLUSIONS

The IMRT-induced TLN was less extensive and milder than 2D-RT-induced TLN, but both had similar clinical features.

Birth outcomes and maternal residential proximity to natural gas development in rural Colorado

BACKGROUND

Birth defects are a leading cause of neonatal mortality. Natural gas development (NGD) emits several potential teratogens, and U.S. production of natural gas is expanding.

OBJECTIVES

We examined associations between maternal residential proximity to NGD and birth outcomes in a retrospective cohort study of 124,842 births between 1996 and 2009 in rural Colorado.

METHODS

We calculated inverse distance weighted natural gas well counts within a 10-mile radius of maternal residence to estimate maternal exposure to NGD. Logistic regression, adjusted for maternal and infant covariates, was used to estimate associations with exposure tertiles for congenital heart defects (CHDs), neural tube defects (NTDs), oral clefts, preterm birth, and term low birth weight. The association with term birth weight was investigated using multiple linear regression.

RESULTS

Prevalence of CHDs increased with exposure tertile, with an odds ratio (OR) of 1.3 for the highest tertile (95% CI: 1.2, 1.5); NTD prevalence was associated with the highest tertile of exposure (OR = 2.0; 95% CI: 1.0, 3.9, based on 59 cases), compared with the absence of any gas wells within a 10-mile radius. Exposure was negatively associated with preterm birth and positively associated with fetal growth, although the magnitude of association was small. No association was found between exposure and oral clefts.

CONCLUSIONS

In this large cohort, we observed an association between density and proximity of natural gas wells within a 10-mile radius of maternal residence and prevalence of CHDs and possibly NTDs. Greater specificity in exposure estimates is needed to further explore these associations.

A simple and sensitive gas chromatography method for determination of isosorbide dinitrate and its metabolites in human plasma: application to pharmacokinetics study on oral spray

A sensitive method for the simultaneous determination of isosorbide dinitrate (ISDN) and its mononitrate metabolites, isosorbide 2-mononitrate and isosorbide 5-mononitrate (IS-2-MN and IS-5-MN), in human plasma was developed using capillary gas chromatography with electron-capture detection, whereas 1,2,4-butanetriol trinitrate was used as internal standard. The analytes were extracted with a simple liquid-liquid extraction from plasma and separated on a DB-1 column. The results of method validation demonstrated that the calibration curves were linear in range of 2-60 ng/mL for ISDN and IS-5-MN, 1-20 ng/mL for IS-2-MN, respectively. The precision (RSD%) was less than 15%, and the lower limit of quantitation was identifiable and reproducible at 2 ng/mL for ISDN and IS-5-MN, 1 ng/mL for IS-2-MN. The analytes in plasma were stable after being stored for more than 30 days and after 2 freeze-thaw cycles (-20 to 25°C). And then this method was successfully applied to a pharmacokinetic investigation on isosorbide dinitrate oral spray in healthy volunteers.

The swimming speed alteration of two freshwater rotifers Brachionus calyciflorus and Asplanchna brightwelli under dimethoate stress

Two common freshwater rotifer species Brachionus calyciflorus and Asplanchna brightwelli were employed as test organisms to investigate the toxic effects of the widely used organophosphate pesticide, dimethoate. The swimming angular speed and linear speed alteration of two rotifers were evaluated under the toxic stress in four concentrations (0.4, 0.8, 1.2, and 1.6 mg L(-1)). For B. calyciflorus, the rotifer swimming angular speed and linear speed were both adversely affected as a function of the toxicant concentrations. After a 2h exposure, the angular speeds at four concentrations were 39.37, 30.74, 26.68 and 23.96° s(-1), 65.30%, 50.98%, 44.25% and 39.74% of that of the control, respectively, while the mean linear speed decreased from 194.80 to 91.85×10(-3) mm s(-1), which was 70.12%, 48.14%, 34.02% and 33.06% of that of the control (277.82×10(-3) mm s(-1)), respectively. The pesticide also significantly inhibited the swimming angular speed of A. brightwelli. After a 2h exposure, the angular speeds of this rotifer at four concentrations were 39.37, 30.74, 26.68 and 23.96° s(-1), only 22.99%, 17.16%, 16.21% and 13.63% of that of the control (170.80° s(-1)), respectively. Compared with the results of B. calyciflorus, A. brightwelli was more sensitive on the swimming angular speed when exposed to the toxicant. It implied that A. brightwelli should be an alternative candidate model species about the toxicities of aquatic pollutants. In addition, when the rotifer A. brightwelli was exposed to four pesticide concentrations, the swimming linear speed displayed symptoms of hormesis, characterized by the conversion of low-concentration stimulate to high-concentration inhibition. Our results show that dimethoate had a significant effect on swimming of freshwater rotifers.

Abstract P6-06-50: Obesity and the influence on tumor biology as determined by the intermediate risk 21-gene recurrence scores (RS) and the 70-gene breast cancer recurrence signature (70-GS) assay

BACKGROUND

Obesity is an apparent risk factor for postmenopausal breast cancer (BC), estrogen receptor (ER) positive BC, larger tumors, lymph node (LN) involvement, as well as recurrence of BC and BC death despite treatment. However, the specific mechanism of these increased risks remains unclear. Our prior work described the negative influence of metabolic syndrome on BC recurrence in patients assessed by a 21 gene recurrence score (RS) in the low risk and intermediate risk tertiles (Lakhani et al PSABCS 2012). The objective of this study was to analyze the interaction of obesity and BC biology in patients assessed by the 70 gene signature (70-GS) for BC recurrence and the 80 gene molecular subtyping.

METHODS

We studied consecutive patients with newly diagnosed ER positive, LN negative BC treated at Loyola University Medical Center between 2005 -2012 who had an intermediate RS. The 70-GS was done on these same paraffin-embedded tumor blocks for risk level and molecular subtype. Standard descriptive statistics are reported. Wilcoxon rank sum tests were performed for the comparison of BMI by groups defined by RS scores (≤24 vs ≥25) and the 70 gene signature assay (high risk vs low risk). In addition, Chi-squared test, or Fisher's exact test as appropriate, was used to examine the association between BMI tertiles and the 70GS or molecular subtype.

RESULTS

From 102 patients with intermediate RS, the 70-GS was successful in 89 samples. The average age was 61 years (range 41-79). The median body mass index (BMI) was 29 (range 18-53). There was a significant association between BMI and RS (p = 0.0110): median BMI = 28 in patients with RS ≤24; median BMI 33 in patients with RS ≥25. There was a significant association between BMI and the 70-GS (p = 0.0116). Median BMI 27 in low risk group; median BMI 32 in high risk group. There was a significant association between the 70-GS and BMI (p = 0.0190).

Association between the 70-GS and BMI70-GS RiskHealthy (18-25)Overweight (26-30)Obese (&gt;30)TotalHigh (n pts)1292950Low (n pts)15131139

There was a significant association between molecular subtype and BMI tertiles (p = 0.0803).

Association between molecular subtype and BMI tertiles HealthyOverweightObeseTotalLuminal A (n pts)14131239Luminal B (n pts)1392648

CONCLUSION

There is a striking interaction of obesity and BC biology as defined by the RS and 70-GS assays. Our data suggest that BC in obese women may have more aggressive tumor biology and higher risk of recurrence than BC in those with a low BMI. Further molecular characterization of the BC from obese patients may elucidate the role obesity plays in BC development and progression, as well as provide rationale for targeted therapeutic trials. Clinical trials targeting known carcinogenic pathways related to obesity (such as metformin and statins) are ongoing. Several genes in the 70-GS are the same genes expressed in obese patients. Additional studies examining the prognostic and predictive value of the 70-GS need to be conducted for this patient population.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-50.

Neural systems for choice and valuation with counterfactual learning signals

The purpose of this experiment was to test a computational model of reinforcement learning with and without fictive prediction error (FPE) signals to investigate how counterfactual consequences contribute to acquired representations of action-specific expected value, and to determine the functional neuroanatomy and neuromodulator systems that are involved. 80 male participants underwent dietary depletion of either tryptophan or tyrosine/phenylalanine to manipulate serotonin (5HT) and dopamine (DA), respectively. They completed 80 rounds (240 trials) of a strategic sequential investment task that required accepting interim losses in order to access a lucrative state and maximize long-term gains, while being scanned. We extended the standard Q-learning model by incorporating both counterfactual gains and losses into separate error signals. The FPE model explained the participants' data significantly better than a model that did not include counterfactual learning signals. Expected value from the FPE model was significantly correlated with BOLD signal change in the ventromedial prefrontal cortex (vmPFC) and posterior orbitofrontal cortex (OFC), whereas expected value from the standard model did not predict changes in neural activity. The depletion procedure revealed significantly different neural responses to expected value in the vmPFC, caudate, and dopaminergic midbrain in the vicinity of the substantia nigra (SN). Differences in neural activity were not evident in the standard Q-learning computational model. These findings demonstrate that FPE signals are an important component of valuation for decision making, and that the neural representation of expected value incorporates cortical and subcortical structures via interactions among serotonergic and dopaminergic modulator systems.

The influence of food on the pharmacokinetics of amlodipine and losartan after single-dose of its compound tablets in healthy chinese subjects

We aim to identify the effects of food on the pharmacokinetics (PK) of amlodipine, losartan and losartan's active metabolite (EXP3174) after oral administration of the Compound Amlodipine Tablets with single dose in healthy Chinese subjects. 12 subjects took the compounds (10 mg/100 mg, amlodipine/losartan) at the conditions of a high-fat breakfast and an overnight fast with a washout period of 14 days. Plasma samples were obtained at scheduled time, and determined by HPLC-MS/MS for the concentrations of amlodipine and HPLC-MS for the concentrations of losartan and EXP3174, respectively. PK parameters were calculated using Software Drug and Statistics (Version 2.0). When tablets were co-administered with food, there was no significant difference of AUC for amlodipine and losartan, but the AUC of EXP3174 was reduced by 19.1%. Meanwhile, the Cmax of amlodipine, losartan and EXP3174 were reduced by 11.4%, 20.0% and 41.4%, and the Tmax of losartan and EXP3174 were 1.3 and 1.8 h longer, respectively. No significant difference was found at t1/2 following food intake. In conclusion, the Compound Amlodipine Tablets, are affected by food administration by reducing the AUC of EXP3174. It is thus suggested that the Compound Amlodipine Tablets should be administered 1 h before or 2 h after meal.

Application of (15)N- (18)O double stable isotope tracer technique in an agricultural nonpoint polluted river of the Yangtze Delta Region

One strategy to combat nitrate (NO3-N) contamination in rivers is to understand its sources. NO3-N sources in the East Tiaoxi River of the Yangtze Delta Region were investigated by applying a (15)N-(18)O dual isotope approach. Water samples were collected from the main channel and from the tributaries. Results show that high total N and NO3-N are present in both the main channel and the major tributaries, and NO3-N was one of the most important N forms in water. Analysis of isotopic compositions (δ (18)O, δD) of water suggests that the river water mainly originated from three tributaries during the sampling period. There was a wide range of δ (15)N-NO3 (-1.4 to 12.4 ‰) and a narrow range of δ (18)O-NO3 (3.7 to 9.0 ‰) in the main channel waters. The δ (15)N and δ (18)O-NO3 values in the upper, middle, and lower channels along the river were shifted as 8.2, 3.5, and 9.5 ‰, and 9.0, 4.2, and 6.0 ‰, respectively. In the tributary South Tiao, the δ (15)N and δ (18)O-NO3 values were as high as 9.5 and 7.0 ‰, while in the tributaries Mid Tiao and North Tiao, NO3-N in most of the samples had relatively low δ (15)N and δ (18)O-NO3 values from 2.3 to 7.5 ‰ and 4.7 to 7.0 ‰, separately. Our results also suggest that the dual isotope approach can help us develop the best management practice for relieving NO3-N pollution in the rivers at the tributary scale.

Occurrence of Grapevine Leafroll-Associated Viruses in China

To characterize the prevalence of viruses associated with grapevine leafroll disease in China, 249 grapevine (Vitis spp.) samples (86 popular cultivars and a rootstock) from 19 provinces and regions were collected and tested for Grapevine leafroll-associated virus 1 (GLRaV-1), GLRaV-2, GLRaV-3, GLRaV-4, and GLRaV-4 strain 5 by SYBR Green real-time reverse-transcription polymerase chain reaction (RT-PCR), and RT-PCR and sequencing. GLRaV-3 was found in 100% of the samples while GLRaV-1, GLRaV-2, and GLRaV-4 were detected in 24.9% (62/249), 15.3% (38/249), and 0.80% (2/249) of the samples, respectively. Single infections with GLRaV-3 were found in 66.3% (165/249) of the samples, and the remaining samples were mixed infections of GLRaV-3 with one or two other GLRaVs, those with GLRaV-1 being the most common (18.5%, 46/249). The genetic variability of Chinese GLRaV-3 isolates was characterized based on the coat protein (CP) gene. In total, 153 full-length CP gene sequences (94 sequences newly generated) of Chinese GLRaV-3 isolates from different grapevine-growing regions showed 89.3 to 100.0% and 92.7 to 100.0% identity at the nucleotide and amino acid levels, respectively. The average nucleotide diversity for the population of Chinese GLRaV-3 isolates was estimated at 0.037 (standard error = 0.0032). GLRaV-3 isolates from China segregated into five distinct phylogenetic groups and two novel recombination events were found in the viral population. This is the first and most extensive report of the prevalent species of GLRaV in China, which also provides an assessment of genetic variability of GLRaV-3 Chinese isolates.

Dosage of amyloid precursor protein affects axonal contact guidance in Down syndrome

Amyloid precursor protein (APP), encoded on Hsa21, functions as a cell adhesion molecule (CAM) in axonal growth cones (GCs) of the developing brain. We show here that axonal GCs of human fetal Down syndrome (DS) neurons (and of a DS mouse model) overexpress APP protein relative to euploid controls. We investigated whether DS neurons generate an abnormal, APP-dependent GC phenotype in vitro. On laminin, which binds APP and β1 integrins (Itgb1), DS neurons formed enlarged and faster-advancing GCs compared to controls. On peptide matrices that bind APP only, but not on those binding exclusively Itgb1 or L1CAM, DS GCs were significantly enlarged (2.0-fold), formed increased close adhesions (1.8-fold), and advanced faster (1.4-fold). In assays involving alternating stripes of monospecific matrices, human control GCs exhibited no preference for any of the substrates, whereas DS GCs preferred the APP-binding matrix (cross-over decreased significantly from 48.2 to 27.2%). Reducing APP expression in DS GCs with siRNA normalized most measures of the phenotype, including substrate choice. These experiments show that human DS neurons exhibit an APP-dependent, abnormal GC phenotype characterized by increased adhesion and altered contact guidance. The results suggest that APP overexpression may perturb axonal pathfinding and circuit formation in developing DS brain.

Different transcriptional responses of heat shock protein 70/90 in the marine diatom Ditylum brightwellii exposed to metal compounds and endocrine-disrupting chemicals

Environmental hazard assessments using diatoms have been well documented; however, their molecular toxicology has not been sufficiently studied. In this study, we characterized heat shock protein (HSP) 70/90 of the diatom Ditylum brightwellii (Db) and evaluated their transcriptional profiles in response to various environmental stresses (e.g., thermal shocks and metal and non-metal pollutants). Putative DbHSP70 (658aa, 71.7 kDa) and DbHSP90 (707aa, 80.2 kDa) proteins had conserved HSP family motifs but different C-terminus motifs, that is, "EEVD" in DbHSP70 and "MEEVD" in DbHSP90. Phylogenetic analyses of both proteins showed that D. brightwellii was well clustered with other diatoms. Real-time PCR analysis showed that thermal stress considerably upregulated DbHSP70 and DbHSP90. As for chemical pollutants, DbHSP70 greatly responded to CuSO4 and NiSO4 exposure, but not CuCl2 or NiCl2. However, DbHSP90 was significantly upregulated by all the metal compounds tested (CuSO4, NiSO4, CuCl2, and NiCl2). Strikingly, the expression of both genes was not induced by the organic pollutants tested, such as endocrine-disrupting chemicals. These data suggest that DbHSP70 and DbHSP90 are differentially involved in the defense response against various environmental stressors. Moreover, metal toxicity may be specifically affected by the conjugated anion in the metal compounds (e.g., SO4(2-) and Cl(-)).

Pharmacokinetic and bioequivalence studies of ibuprofen suspension after a single-dose administration in healthy Chinese volunteers

OBJECTIVE

The aim of this study was to assessed the pharmacokinetic and bioequivalence of 2 formulations of ibuprofen suspension.

METHOD

20 healthy volunteers were enrolled into this random, single-dose, 2-way crossover, open-label, single-centre, pharmacokinetic study. After overnight fasting, 2 formulations (test and reference) of ibuprofen (400 mg ibuprofen/20 mL suspension) were administered as a single dose on 2 treatment days separated by a 7-day washout period. After dosing, blood samples were drawn for a period of 12 h. The plasma samples were analyzed for the presence of ibuprofen by HPLC with ultraviolet detection. Pharmacokinetic parameters were determined from plasma concentrations for both formulations.

RESULTS

The main pharmacokinetics parameters of test and reference were as follows: t1/2 was (1.94±0.38) h and (1.95±0.28) h; Cmax was (33.41±7.83) μg · mL- 1 and (31.08±9.30) μg · mL- 1; AUC0-12 was (91.44±19.26) μg · mL-1 · h and (84.75±24.45) μg · mL-1 · h; AUC0-∞ was (92.82±19.94) μg · mL-1 · h and (85.97±24.99) μg · mL-1 · h; median Tmax was 0.5 h (range, 0.25, 2) and 0.5 h (range, 0.25, 1.5). The 90% confidence intervals of the test/reference treatment ratios for Cmax, AUC0-12 and AUC0-∞ were observed to be within the predetermined acceptable interval of 80-125%.

CONCLUSION

This single-dose study in healthy Chinese fasted volunteers was shown that the ibuprofen test and reference met the requirement of the State Food and Drug Administration, and the test and reference were bioequivalent.

Surgical incision induces phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites and GluR1 trafficking in spinal cord dorsal horn via a protein kinase Cγ-dependent mechanism

Spinal α-amino-3-hydroxy-5-methy-4-isoxazole propionate (AMPA) receptor plays an important role in acute pain induced by surgical tissue injuries. Our previous study has shown that the enhanced phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites by protein kinase C (PKC) in the spinal cord dorsal horn is involved in post-surgical pain hypersensitivity. However, which isoforms of PKC are responsible for the phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites remains to be established. In the present study, using an animal model of postoperative pain, we found that surgical tissue injuries enhanced the membrane translocation level of PKCγ, but not PKCα, βI, and βII, and induced the trafficking of GluR1, but not GluR2 into neuronal plasma membrane. Intrathecal (i.t.) pretreatment of small interfering RNA targeting PKCγ to reduce the PKCγ expression in the spinal cord significantly attenuated the pain hypersensitivity and inhibited the phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites as well as GluR1 membrane trafficking. Our study indicates that the surgical incision-induced phosphorylation of AMPA receptor GluR1 subunits at Serine-831 sites and GluR1 trafficking are regulated by a PKCγ-dependent mechanism.

OVERCOMING INCOMPATIBILITY PROBLEMS IN ELASTOMER BLENDS BY TAILORED SURFACE PROPERTIES OF RUBBER ADDITIVES

Rubber is a challenging composite material, whose functionality strongly depends on the affinity of the different materials in the composite and its morphology. One way to tailor polarity and chemistry of the filler surface is plasma coating. When using acetylene, thiophene, or pyrrole as monomers, the coating results in a reduced polarity of the filler compared with untreated silica, and unsaturated C–C bonds are formed on the surface. This improves the compatibility of the filler–polymer blends. In a SBR/EPDM blend, the filler–polymer compatibility is improved for all plasma-coated fillers compared with untreated silica. The best dispersion is achieved by plasma–pyrrole coating, as measured by the Payne effect and reinforcement parameter. The rubber–filler interaction is also highest for this blend, as measured by the bound rubber content. As expected, this results in improved tensile properties. In NBR/EPDM, the filler–filler interaction is significantly reduced by the plasma–pyrrole coating, which indicates a balanced compatibility of the pyrrole-treated silica in both polymers. The properties of the vulcanizate show the combinatorial effect of dispersion, filler–polymer interaction, polymer entanglements, and cross-link density. All plasma-treated, silica-filled NBR/EPDM materials show a considerable increase in tensile strength compared with untreated silica, with polyacetylene-treated silica resulting in the best properties. When plasma-coated curatives are used in SBR/EPDM blends, the scorch safety of the compounds is increased and the rupture energy is enhanced. In NBR/EPDM blends, all packages of the modified curatives provide an increased maximum torque compared with the control. Mechanical properties of the NBR/EPDM blend are improved even more than they are with SBR/EPDM. This indicates a more-balanced distribution of cross-links, along with a more-homogeneous carbon black dispersion over the different rubber phases. A better polarity match between additives and polymers usually results in improved material properties. The wide variety of monomers for the plasma polymerization allows researchers to tailor the surface properties of the additives.

A more rapid, sensitive, and specific HPLC-MS/MS method for nifedipine analysis in human plasma and application to a pharmacokinetic study

A more rapid, sensitive and specific high-performance liquid chromatography coupled to -tandem mass spectrometry (HPLC-MS/MS) was developed and validated for the quantification of nifedipine in human plasma, and applied to the pharmacokinetic study of nifedipine in Chinese healthy volunteers. Nifedipine and internal standard (IS) acetaminophen in plasma were extracted with ethyl acetate, separated on a C18 (150 mm×4.6 mm, 5 µm) reversed-phase column, eluted with acetonitrile mixed with 5 mM ammonium acetate solution (pH=6.62) (60:40, v/v), ionized by negative ion pneumatically assisted electrospray and detected in the multi-reaction monitoring mode using precursor→product ions of m/z 354.1→222.2 for nifedipine and 150.1→107.1 for the IS. A single oral dose of 20 mg nifedipine sustained release tablets and blood samples (4 mL) was collected before and 1, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 8, 12, 24, and 36 h after administration. The main pharmacokinetic parameters of nifedipine, as Tmax, t1/2α, t1/2β, t1/2z, Cmax, AUC0~36, AUC0~∞ were 2.80±0.50 h, 6.78±2.52 h, 6.82±2.53 h, 6.69±2.22 h, 76.69±19.51 (ng/mL), 546.49±162.28 (ng · h/mL) and 564.05±176.74 (ng · h/mL), respectively. The calibration curve was linear over the concentration range of 0.17-102 ng/mL (r2>0.99, n=5) with a lower limit of quantification (LLOQ) of 0.17 ng/mL. The intra- and inter-day precision was less than 15% for all quality control samples at concentrations of 0.42, 6.53 and 81.60 ng/mL and the accuracy (relative error, RE) was - 3.92% to 7.31% at 3 quality control levels. The specificity, matrix effect, recovery, sensitivity, linearity, accuracy, precision and stabilities were validated, and can fulfill the requirement of pharmacokinetic study of nifedipine sustained release tablets in Chinese volunteers.

Abstract P1-12-04: Carboplatin, nab-paclitaxel and bevacizumab as first-line treatment for metastatic breast cancer

Background: Bevacizumab added to weekly paclitaxel resulted in improved progression free survival (PFS) and objective response rates (ORR) compared to weekly paclitaxel alone. Nab-paclitaxel and the platins are active in MBC. We conducted an efficacy and safety study of carboplatin, nab-paclitaxel and bevacizumab.

Methods: A phase II open label prospective multi-site study enrolled patients (pts) who had measurable MBC according to RECIST 1.1 criteria and no prior chemotherapy for advanced disease. The primary endpoint was PFS with secondary endpoints of overall survival (OS), ORR, and safety. Pts initially received carboplatin AUC 6 day 1, 22,43, plus weekly nab-paclitaxel 100mg/m2 and bevacizumab 15mg/m2 day 1,22,43 of a 56 day cycle. This was later changed to carboplatin AUC 6 day 1, nab-paclitaxel 100mg/m2 day 1,8,15, and bevacizumab 10mg/m2 day 1,15 of a 28 day cycle. Thirty-two pts were required to detect an increase in median PFS from 6.7 to 10.5 mo with 80% power based on a one-sided p = 0.05. Kaplan–Meier analyses estimated PFS and OS. The log rank test was used for the comparison of survival curves between pts with triple negative MBC (TNBC) and pts with non-TNBC.

Results: Thirty-two pts were enrolled between 2/2008 and 11/2011 by 1 academic and 5 community oncology practices. Two pts were ineligible due to non-measurable disease and not included in the response analyses. The median age was 58 years (range 35–81), 22 pts (69%) had an ECOG PS 0, 9 (28%) had a PS 1, 1 (3%) PS 2. Twenty-four (75%) pts had ER+ disease, 7 (22%) had TNBC, 1 (3%) had ER-HER2+ disease not eligible for trastuzumab-based therapy. Metastatic sites were bone (26%), liver (18%), loco-regional (16%), and lung (12%). One pt (3%) had bone and loco-regional disease only, 19 (59%) had visceral dominant disease. The median number of weeks on treatment was 28.9 (range 5–131). The median PFS in all pts was 13.6 months (mo) (95% CI 11.2–21.9), with a median OS of 26.8 mo (95% CI 13.3–41.2). The ORR (2 CR and 18 PR) was 66.7% (CI 47.2–82.7). There also were 6 (20%) unconfirmed PR and 3 (10%) stable disease, resulting in a clinical benefit rate of 96.7% (CI 82.78–99.92). There was no significant difference in PFS (median 13.6 vs 16.1mo, p = 0.37) or OS (median 13.6 vs 26.8mo, p = 0.32) in pts with TNBC versus non-TNBC disease. The most common toxicities of any grade (gr) include neutropenia and thrombocytopenia in 24 pts (75%) each, leukopenia and fatigue in 17 pts (53%) each, anemia in 15 (47%), and neuropathy in 10 (31%). Gr 4 neutropenia was seen in 7 pts (22%) without febrile neutropenia, and gr 4 thrombocytopenia occurred in 6 (19%). There were no pts with gr 4 sensory neuropathy. All pts required chemotherapy dose delays, 15 (47%) had chemotherapy dose reductions.

Conclusions: The carboplatin, nab-paclitaxel and bevacizumab combination is highly effective with good tolerance in first line MBC. As the role of anti-angiogenic therapy in first line metastatic breast cancer is being clarified, this would be an attractive regimen to test in the (neo)adjuvant setting and together with novel molecular targeted agents.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-12-04.

Abstract PD10-02: Metabolic syndrome and recurrence within the 21-gene recurrence score assay risk categories in lymph node negative breast cancer

Background: The incidence of the metabolic syndrome (MS) has been increasing in the United States and elsewhere. The interaction of MS with breast cancer (BC) incidence, tumor biology and outcomes are under study. We hypothesized that the presence of MS would predict BC recurrence to a variable degree across the diverse BC biology as defined by the risk categories of the 21-gene recurrence score (RS) assay.

Patients and Methods: We studied consecutive patients (pts) with newly diagnosed, estrogen receptor (ER) positive, lymph node (LN) negative BC treated in our institution between 2006–2011 who had a 21-gene RS assay done on their tumors. All pts were treated with standard systemic and local therapy. The electronic medical record was queried for key diagnoses including MS and its constituent parts. The WHO definition was used to categorize pts as having MS defined as diabetes mellitus (DM) or glucose intolerance, plus at least 2 of the following: hypertension (HTN), dyslipidemia (HL), central obesity and microalbuminemia. Tumor characteristics including Ki67 index, grade, tumor size, HER2/neu status; and pt characteristics including age, race, menopausal status, body mass index were recorded. The association of MS and the tumor and patient characteristics with the RS tertiles of low, intermediate and high risk was analyzed.

Results: We identified 332 pts, median age 62 years, of whom 88 (27%) had MS. There was no significant association between the MS and any of the patient or tumor variables including the 21-gene RS assay, except for race (p = 0.004). Eleven of 21 (52%) African-American women had MS, 68 of 284 (24%) Caucasian women had MS, and 9 of 21 (43%) others including Hispanic and Asian women had MS. However, there was a significant association between recurrence and MS (p = 0.0002) independent of other factors. Of the 21 pts who recurred, 13 (61.9%) had MS. There was an association of recurrence and MS within RS tertiles. For pts with low risk scores, 7/44 (15.9%) with MS vs. 1/126 (0.79%) without MS had recurrence (p = 0.0003). For pts with intermediate risk scores, 5/30 (16.67%) with MS vs. 4/83 (4.82%) without MS had recurrence (p = 0.05). For patients with high risk scores, 1/9 (11.11%) with MS vs. 2/15 (13.33%) without MS had recurrence (p = 1).

Conclusion: MS is an independent risk factor for BC recurrence among women with LN negative, ER positive BC treated with standard adjuvant therapy. There is a striking impact of MS on recurrence in pts with tumor biologies defined by low (and to a lesser degree) intermediate risk 21-gene RS assay scores. However, there is no difference in recurrence risk by MS among those pts with high RS. This implies that interventions directed at modifying MS in newly diagnosed pts with early BC may potentially favorably impact survival in those with specific tumor biologies as defined by multigene assays. Thus, long-term prospective studies should be conducted to further evaluate both the short and long term effects of MS on BC outcomes.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD10-02.

Pharmacokinetics of ginkgolide B injection in beagle dogs

A liquid chromatography-mass spectrometry method was developed, validated, and applied to the pharmacokinetic study with doses of 0.68, 2.73 and 10.92 mg/kg of ginkgolide B in beagle dogs after intravenous infusion.An aliquot of blood samples were -collected, separated and quantitatively analyzed by liquid chromatography-mass spectrometry method with mobile phase of acetonitrile-0.02% ammonia solution (33:67, v/v) at a flow rate of 0.8 mL/min on the UltimateTM XB-C18 column (5 μm, 4.6×150 mm).The method was sensitive, accurate and convenient, and can be used for the determination of ginkgolide B in beagle dogs. The Cmax and AUC0-∞ of GB increased with dose escalation, but ANOVA analyses showed that no significant difference was observed in other pharmacokinetic parameters between different doses.An LC/MS method was developed with good sensitivity, reproducibility and specificity. In the pharmacokinetic study of GB in beagle dogs, linear pharmacokinetics was found at doses from 0.62 to 10.92 mg/kg after a single-dose intravenous infusion. Gender differences were not observed in the pharmacokinetics of GB.

A new method for analysis of the toxicity of organophosphorus pesticide, dimethoate on rotifer based on response surface methodology

This study analyzed the toxicity of organophosphorus pesticide, dimethoate on freshwater rotifer Brachionus calyciflorus, using swimming angular and linear speed alteration as the sub-lethal endpoints. Response surface methodology (RSM) was applied in experimental design and data analysis to consider two related factors: toxic concentration, exposure time and their interaction. In general, inhibition effect of the pesticide on rotifer swimming was observed clearly at any given toxicant concentration. The highest inhibition rates in angular and linear speed were obtained in the shortest exposure time (11.36 min) and the highest dimethoate concentration (1.85 mg L(-1)). The RSM used for the analysis of treatment combinations showed that a cubic polynomial regression model was in good agreement with experimental results, with R(2)=0.992 and 0.9997, for swimming angular speed inhibition rate and linear speed inhibition rate (p<0.01, F-test, respectively). 3D reference surface plots and contour plots showed that the toxic effect was influenced not only by dimethoate concentration, but also by the exposure time. A time-step effect was observed clearly. Thus, the pesticide dimethoate had toxic stress on the swimming behavior of rotifers.

Transcriptional responses of heat shock protein 70 (Hsp70) to thermal, bisphenol A, and copper stresses in the dinoflagellate Prorocentrum minimum

The heat shock protein 70 (Hsp70) family is an important part of the cell's machinery for protein folding, and helps to protect cells from environmental stress. Although Hsp70 functions have been discovered in various organisms, studies on dinoflagellate Hsps are limited, except for a few phylogenetic attempts. In this study, we sequenced the complete open reading frame of the dinoflagellate Prorocentrum minimum Hsp70 (PmHsp70), and characterized its molecular functions. The putative PmHsp70 protein contained 3 signature patterns of the Hsp70 family. Phylogenetic analysis revealed that PmHsp70 belonged to the dinoflagellate clade. Real-time (RT)-PCR analyses revealed that PmHsp70 was upregulated by thermal stress. Further, we examined the transcriptional response of PmHsp70 to copper (Cu) and bisphenol A (BPA) exposures. In toxicity assays, Cu and BPA exhibited EC(50)-72 h values of 1.07 ± 0.138 mg L(-1) and 1.51 ± 0.110 mg L(-1), respectively, in P. minimum. Expression of PmHsp70 was significantly upregulated in response to Cu and BPA exposures (one-way ANOVA, P<0.05). PmHsp70 displayed different expression patterns in response to different concentrations of Cu and BPA. This study evaluated typical characteristics and, for the first time, toxicant-related functions of PmHsp70. The results suggest that Hsp70 genes may play a vital role in the environmental stress responses of dinoflagellates.

Assessment the toxic effects of dimethoate to rotifer using swimming behavior

The toxic effects of the common organophosphorus pesticide dimethoate on freshwater zooplankton Brachionus calyciflorus (rotifer) were tested. Because of the advantages of behavioral response in environmental monitoring, swimming behavior was used as the endpoint in this research. After exposure 6 h at five dimethoate concentrations (0.18, 0.53, 0.88, 1.23 and 1.59 mg·L(-1)), the pesticide disrupted the balance in rotifer swimming direction and caused an obvious direction preference. It also inhibited significantly the swimming angular and linear speed. Our results showed that dimethoate has a sublethal toxic effect on this aquatic invertebrate.