Effects of Δ(9)-tetrahydrocannabinol (THC) on human amniotic epithelial cell proliferation and migration

BACKGROUND

The deleterious effects of cannabis consumption for fertility and pregnancy outcome are recognized for years. The main psychoactive molecule of cannabis, Δ(9)-tetrahydrocannabinol (THC) is able to cross the placenta barrier and cause alterations in fetal growth, low birth weight and preterm labor. However, the effects of THC on the human placenta amnion are still unknown.

METHODS

The distributions of CB1R and CB2R in human amnion tissues were observed by immunohistochemistry (IHC). Human amniotic epithelial cell proliferation and migration in response to THC treatment were measured by MTS and transwell assays, respectively. The PCR array was performed to study the key regulators involved in the cell migration. The protein levels of CB1R, CB2R in amnion tissues and MMP2, MMP9 in cells were detected by western blotting. Small interfering RNAs (siRNAs) were used to knockdown MMP2 and MMP9 in WISH cells.

RESULTS

Our results indicated that both CB1R and CB2R primarily identified in the epithelial layer of human placental amnion tissue. The CB1R expression in the amnion tissue was higher in the preterm group than normal control. High-dose of THC (30uM, but not 20 and 10uM) significantly inhibited (p<0.01) human amniotic epithelial cell lines (WISH) proliferation. Meanwhile, THC at both 10uM and 20uM (p<0.05) significantly suppressed cells migration in both WISH and primary human amniotic epithelial cells. The PCR array data and siRNA experiments demonstrated that MMP2/9 were tightly involved in the regulation of THC-inhibited cell migration in WISH cells.

CONCLUSION

These results suggested that THC inhibited the migration of human amniotic epithelial cell through the regulation of MMP2 and MMP9, which in turn altered the development of the amnion during the gestation and partially resulted in preterm labor and other adverse pregnancy outcomes.

ANTI-INFLAMMATORY ACTIVITY OF PLATYCODIN D ON ALCOHOL-INDUCED FATTY LIVER RATS VIA TLR4-MYD88-NF-κB SIGNAL PATH

BACKGROUND

The current study was designed to evaluate the effect of Platycodin D (PD), triterpenoid saponins extracted from the roots of Platycodon grandiflorum (PG) on alcohol-induced fatty liver (AFL) and investigate the possible mechanism.

METHODS AND MATERIALS

A rat model was set up by feeding ethanol and fish oil to experimental rats, which then were treated with PD of 10, 20, 30 mg/kg body weight/day for 4 weeks, respectively, whereafter, liver function enzymes, endotoxin of serum and liver lipid were assayed by biochemical methods, cytokines, histochemistry of hepatic tissue, the protein expression of CD14 and TLR4, the mRNA expression of MD-2, MyD 88 and TRAF-6 were assayed.

RESULTS

Treatment with PD on AFL rats significantly decreased the levels of serum ALT, AST and TBIL, coefficient of liver index and the hepatic tissue contents of TG, additionally and dramatically decreased serum endotoxin levels, down-regulated MD-2 and CD14 levels, as well as the mRNA expression of TLR4, MyD88 and TRAF-6, accordingly suppressed NF-κB: p65 as well as endotoxin-mediated inflammatory factors such as TNF-α and IL-6.

CONCLUSIONS

Treatment with PD effectively protects against AFL through anti-inflammatory and anti-endotoxic process, and the confirmed mechanism is that PD treatment ameliorate alcoholic-induced liver injury mainly via TLR4-MyD88-NF-K: B signal path in AFL rat. List of Abbreviations: AFL: alcoholic-induced fatty liver, CD14: cluster of differentiation 14, LPS: lipopolysaccharide, LBP: lipopolysaccharide-binding protein, TLR4: toll-like receptor 4, MD-2: molecule myeloid differential protein-2, MyD 88: myeloid differentiation primary response protein 88, TRAF-6: TNF-receptor associated factor-6, NF-κB: nuclear transcription factor kappa B, IL-6: interleukin-6, TNF-α: tumor necrosis factor-α, PG: Platycodon grandiflorum, PD: Platycodin D.

[Application of swallow tail appearance in patients with Parkinson's disease]

OBJECTIVE

To evaluate the clinical value of swallow tail appearance in detecting the patient with Parkinson's disease at 3.0 T MRI.

METHODS

A total of 42 patients with clinical diagnosis of Parkinson's disease(PD) and 27 age-matched normal controls underwent the brain MR examination with conventional and E-SWAN sequences. Patients were divided into 4 groups based on Hoehn-Yahr stage and 2 groups according the treatment condition (treated, untreated). Substantia nigra (SN) was selected as region of interest (ROI) and observed the swallow tail appearance on magnitude imagines of E-SWAN sequence. Nonparametric test was used for comparison between patients groups and normal controls. There was statistically difference if the P value was lower than 0.05.

RESULTS

The swallow tail appearance lost was significantly correlated with Parkinson's disease (P=0.000). The swallow tail appearance lost was not correlated with the usage of drugs(P=0.833) and Hoehn-Yahr stage(P=0.189). The sensitivity of diagnosis of PD by using the swallow tail disappearance was 95.5% (42/44), the specificity was 83.3% (25/30), the accuracy was 90.5%(67/74).

CONCLUSIONS

Assessing the substantia nigra on E-SWAN for the typical swallow tail appearance has potential to become a new and easy applicable 3.0 T MRI diagnostic tool for PD, however, it was meaningless for prognosis and staging.

Mineralization of sulfamethizole in photo-Fenton and photo-Fenton-like systems

In this investigation, UV/H2O2, UV/H2O2/Fe(2+) (photo-Fenton) and UV/H2O2/Fe(3+) (photo-Fenton-like) systems were used to mineralize sulfamethizole (SFZ). The optimal doses of H2O2 (1-20 mM) in UV/H2O2 and iron (0.1-1 mM) in photo-Fenton and photo-Fenton-like systems were determined. Direct photolysis by UV irradiation and direct oxidation by added H2O2, Fe(2+) and Fe(3+) did not mineralize SFZ. The optimal dose of H2O2 was 10 mM in UV/H2O2 and that of iron (Fe(2+) or Fe(3+)) was 0.2 mM in both UV/H2O2/Fe(2+) and UV/H2O2/Fe(3+) systems. Under the best experimental conditions and after 60 min of reaction, the SFZ mineralization percentages in UV/H2O2, UV/H2O2/Fe(2+) and UV/H2O2/Fe(3+) systems were 16, 90 and 88%, respectively. The UV/H2O2/Fe(2+) and UV/H2O2/Fe(3+) systems effectively mineralized SFZ.

Effect of atorvastatin on plasma NT-proBNP and inflammatory cytokine expression in patients with heart failure

The aim of this study was to explore the effect of atorvastatin intervention on plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) and inflammatory cytokine levels in patients with heart failure (HF). One hundred and twenty-three HF patients were selected from our hospital and randomly divided into control (N = 61) and observation (N = 62) groups; the former received conventional treatment, while the latter were given conventional treatment combined with atorvastatin. Plasma NT-proBNP, inflammatory cytokines [high-sensitive C-reactive protein (hs-CRP), interleukin (IL)-6, IL-10] and cardiac function [left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF), end-diastolic maximum flow rate ratio (E/A)] were compared among groups. The effective rate of treating HF significantly increased after atorvastatin treatment. The plasma NT-proBNP, IL-6, IL-10, hs-CRP, and LVEDD levels significantly decreased (P < 0.05), while the LVEF and E/A levels significantly increased (P < 0.05) in the observation group compared to the control group and before intervention. The NT-proBNP and cytokine levels significantly differed among patients with different classes of heart function (P < 0.05); the NT-proBNP and cytokine levels increased with the severity of heart function. Pearson's correlation analysis revealed a negative correlation between the NT-proBNP and inflammatory cytokine levels and LVEF and E/A values, and a positive correlation between these factors and LVEDD (P < 0.05). In conclusion, atorvastatin significantly improves cardiac function; the mechanism atorvastatin action was related to the decrease in plasma NT-proBNP and inflammatory cytokine levels.

Abstract B154: Application of preclinical combination pharmacokinetic(PK)/efficacy(E) modeling to investigate and translate the preclinical scheduling effect for MLN1117 and Taxotere combination

During preclinical development of investigational compound, MLN1117, combination efficacy studies of MLN1117 and Taxotere in mice bearing lung cancer tumor xenografts indicated the presence of a scheduling effect. In many instances, pre-dosing Taxotere resulted in improved tumor growth inhibition as compared to concomitant dosing with MLN1117. Furthermore both in vitro and in vivo PD studies demonstrated that sequential administration of MLN1117 (PI3Ka inhibitor) and Taxotere resulted in increased apoptosis as compared to concomitant treatment.

To further investigate and translate these observations, combination PK/E modeling was performed on preclinical PK and efficacy data. A scheduling efficacy study was executed in small cell lung cancer NCI-H1048 model. The study was designed to compare the anti-tumor activity of the combination under varying levels of PK concomitance between the two compounds. Using a non-linear mixed effects approach, dynamic PK/E modeling was performed to describe the individual mouse tumor growth curves as a function of the instantaneous plasma drug concentration of MLN1117 and Taxotere. The combination effect in the dynamic model was described using the following expression:

(PK/E)MLN1117 + (PK/E)Taxotere + Tau* (PK/E)Taxotere * (PK/E)MLN1117

The combination interaction (Tau) between MLN1117 and Taxotere was estimated to be negative but associated with significant inter-tumor variability. A negative Tau implied the combination behaved sub-additively under conditions of concomitant dosing. Pre-dosing Taxotere made the combination non-concomitant which explains the improved anti-tumor activity associated with it. The variability associated with the positive effects of pre-dosing Taxotere or non-concomitant dosing was attributed to the variability in Tau. In general, the modeling results favored the use of non-concomitant dosing for the MLN1117/Taxotere combination to eliminate the dependence of the combination efficacy on the negative Tau.

Although the emphasis of this study has been on SCLC cancer model NCI-H1048, early preclinical data from other cancer models of different origin indicate that this phenomenon could be ubiquitous. The combination PK/E model though empirical in nature, provided a useful and translatable tool to guide combination schedule selection. The modeling framework focused on understanding the behavior of the combination i.e. combination interaction term (Tau) and translating this understanding to optimize combination scheduling choices for the clinic.

Citation Format: Ekta Kadakia, Natasha Iartchouk, Karuppiah Kannan, Keli Song, Dong Mei Zhang, Christopher Zopf, Christopher Zopf, Munjal Patel, Chirag Patel, Swapan Chowdhury, Wen Chyi Shyu, Jing-Tao Wu, Arijit Chakravarty. Application of preclinical combination pharmacokinetic(PK)/efficacy(E) modeling to investigate and translate the preclinical scheduling effect for MLN1117 and Taxotere combination. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B154.

Mapping the functional connectivity of the substantia nigra, red nucleus and dentate nucleus: A network analysis hypothesis associated with the extrapyramidal system

This study aimed to examine the functional networks related to the extrapyramidal system using a temporal oscillation signal correlation analysis method based on critical nodes in the substantia nigra (SN), red nucleus (RN) and dentate nucleus (DN). Nineteen healthy subjects underwent resting-state fMRI and susceptibility weighted imaging (SWI). For the brain network analysis, the SN, RN and DN were positioned on susceptibility weighted images and used as seeds for temporal correlations analyzed via BOLD data. T-tests were performed for the correlation coefficients of each seed. We demonstrated that the SN, RN and DN were functionally connected to each other, and, in general, their connectivity maps overlapped in a series of subcortical extrapyramidal structures and regions of cerebral cortices. A Granger causality analysis indicated that the effective connectivity graphs within extrapyramidal structures mainly exhibited a spacial up-down pattern for the positive and negative influences, respectively. Our findings suggest that extensive regions involved in the extrapyramidal system constituted a relatively exclusive network via spatial-temporal correlation signals that analogously corresponded to the anatomical structures. The investigation of extrapyramidal system networks may have potential clinical implications.

Abstract 4527: Dosing schedule effects on combination activity from first principles

Introduction

Finding the ideal dosing schedule to optimize efficacy while balancing toxicity is a challenge for single agent clinical development, and takes on added complexity for combinations. In this work, we use theoretical modeling to investigate the role of schedule in determining combination activity, and propose a novel method of using dosing schedule to identify the in vivo interaction strength pre-clinically.

Methods

To evaluate the effect of schedule on tumor growth inhibition, we built a dynamic pharmacokinetic (PK)/effect (E) model to simulate tumor volume as a function of plasma concentration of a drug combination. The PK of each single agent was simulated using a one compartment model, and the inhibition of tumor growth rate was modeled as the sum of single agent effects and their product scaled by an interaction coefficient. We first simulated this model for various relative dosing frequencies and offsets between the two drugs to understand the relationship between schedule and activity for a synergistic combination. We next assessed the accuracy of estimating the interaction parameter using the activity discrepancy between in- and off-phase dosing schedules versus a traditional isobologram analysis. Using Fourier analysis of single agent PK profiles, we then identified an efficient study design to identify both the interaction parameter and optimal relative dosing schedule of the two drugs.

Results

Simulation of the PK/E model with parameter sweeps of dosing frequency and offsets led to a phase plot for combination activity showing peaks and valleys related to the concomitant exposure of the two drugs. From this, we surmised the interaction could be estimated based on the difference in tumor growth inhibition between schedules, and a comparison of in- and off-phase schedules performed well compared to isobologram analysis. Fourier analysis of simulated PK profiles of the two drugs revealed the concomitance as a function of dosing offset, and the pattern was maintained in the simulated activity. Using a study design with only four dose groups with different dosing offsets, we show it is possible to determine both the interaction coefficient (comparing one group at the peak and one at the valley of concomitance) and any effect of dose-ordering (two groups at different offsets but with the same predicted concomitance). Additionally, we demonstrate the difference in activity between synergistic and additive combinations manifests as beat frequencies present in the frequency spectrum, another possibility to identify synergy.

Conclusions

While combination development offers unique challenges, building an understanding of the PK/E relationship from first principles provides a framework to investigate drug interaction effects. The insights gained from studying combinations in vivo with a pre-clinical scheduling study may provide translational guidance on clinical questions around concomitance and dose-ordering.

Citation Format: Andrew Chen, Jing-Tao Wu, Wen Chyi Shyu, Arijit Chakravarty, Christopher J. Zopf. Dosing schedule effects on combination activity from first principles. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4527. doi:10.1158/1538-7445.AM2015-4527

Abstract 3242: Xenograft dose-response from intra-mouse dose escalation

Introduction

Xenograft response has been shown to hold predictive value for the clinical efficacy of a drug, but growth sensitivity to a drug candidate can vary widely between xenografts models. As the ability to test pre-clinically for broad biological activity across many xenografts models is often resource-limited, in this work we develop a mathematical approach based on evolutionary dynamics to derive dose-response information from a single xenograft tumor.

Methods

We propose to estimate a dose-response curve of xenograft growth inhibition by treating a single tumor with a series of different dose strengths. Exponential tumor growth rate (GR) may be quickly estimated to determine the inhibition effect of a particular exposure during week-long intervals of constant dose strength. We next considered the possibility of a dose strength ordering effect on tumor growth due to cellular heterogeneity in GR and drug sensitivity within a tumor. To determine to what extent dose history could influence the observed growth inhibition, we developed an evolutionary model of tumor growth for a heterogeneous population of cancer cells with joint-distributed clonal GR and drug sensitivities, and simulated tumor response to treatment for distributions having variable degrees of correlation. Finally, we tested the ability to estimate dose-response curves from single tumors in vivo compared to the typical method of assessing drug effect based on multiple dose-groups.

Results

For the three possible orders of dosing three different treatment strengths, we found that the simulated study design with escalating dose intervals lead to the least error compared to assessing each dose in a separate tumor. Additionally, the discrepancy between the growth inhibition effects of different dose orders peaks when the correlation between GR and drug sensitivity decreases to negative. We then show that this study design allows efficient, accurate estimation of the range of dose-responses in a broad set of simulated tumor types (e.g., fast-growing and sensitive, or slow-growing and insensitive). An in vivo dose-response study validates the estimation of dose-response curves from a single xenograft by comparing favorably with the single dose per mouse method.

Conclusions

The mathematical approach described here allows efficient estimation of a dose-response curve for a xenograft model using a single tumor. By reducing the resources required to determine the response of a single model, a molecule's anticancer effect can be tested against a larger sample of tumor types pre-clinically. A more accurate picture of a drug candidate's broad biological activity will allow for greater confidence in translational projections of clinical efficacy.

Citation Format: Andrew Chen, Christopher J. Zopf, Jing-Tao Wu, Wen Chyi Shyu, Arijit Chakravarty. Xenograft dose-response from intra-mouse dose escalation. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3242. doi:10.1158/1538-7445.AM2015-3242

Abstract 4520: Biological coupling: Drug synergy, cross-resistance, and schedule effects in combination therapy

Introduction

Combination therapy promises to enhance and extend benefit to oncology patients, but development of drug combinations engenders challenges beyond those of single agents. In this work, we use theoretical models of combination efficacy to demonstrate a potential link between drug interactions, cross-resistance, and dosing schedule effects.

Methods

First, we investigated the relationship between efficacy interaction and schedule effects by building a dynamic pharmacokinetic (PK)/efficacy (E) model to generate theoretical tumor volume trajectories in response to exposure to two drugs. We used a single compartment PK model to simulate the plasma exposure to each drug following various dosing schedules, and exponential tumor growth was inhibited by a drug effect model consisting of the sum of single agent effects and their product with an interaction coefficient. Simulations of this PK/E model for 1000 pairs of drugs with randomized properties and interaction strengths were compared for dosing schedules with high or low concomitance, respectively. Next, we used a Moran simulation to study the effect of interaction strength on sensitivity loss in a heterogeneous population. For a tumor initially comprising 1000 subclones (either doubly sensitive, singly resistant to either drug, or doubly resistant), we simulate based on relative subclone fitnesses the time steps until fixation of a resistant population. We then apply the PK/E model assuming a multi-clone tumor to elucidate the relationship between synergy, dosing schedule, and the rise of cross-resistance by comparing response to in-phase and off-phase combination dosing and across a range of interaction strengths.

Results

Simulation of the PK/E model demonstrates that tumor growth inhibition of in-phase and off-phase dosing schedules diverges in a linear relationship with the interaction strength. Moran simulations show synergistic compounds are more likely to lead to fixation of a doubly resistant subclone within a population of tumor cells, and that it will happen faster than with nonsynergistic combinations. Comparing the tumor volume and sensitive fraction trajectories in response to either in-phase or off-phase dosing of a synergistic combination revealed prolonged sensitivity and reduced tumor load when dosing out of phase to avoid the synergistic interaction. Sweeping the interaction strength shows a minimum in long-term tumor growth rate when the combination exerts its effect additively.

Conclusions

While synergistic drug combinations may provide increased efficacy beyond additive effects of the drugs, this theoretical framework predicts that positive interactions will lead to scheduling challenges and faster resistance emergence. Counter-intuitively, it suggests the best strategy for long-term patient benefit is to use drugs with additive efficacy or non-concomitant dosing to avoid synergistic interactions.

Citation Format: Andrew Chen, Christopher J. Zopf, Jing-Tao Wu, Wen Chyi Shyu, Arijit Chakravarty. Biological coupling: Drug synergy, cross-resistance, and schedule effects in combination therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4520. doi:10.1158/1538-7445.AM2015-4520

Abstract 3759: Xenograft rebound kinetics are consistent with the founder effect

Introduction

Tumors are often composed of a heterogeneous cell population growing over time subject to the forces of evolutionary dynamics. These principles offer insights not only for bulk tumor growth, but also for small cell populations such as in metastases or de-bulked tumors following treatment. In this work, we investigate whether the evolutionary effects of small population sizes are evident in in vivo pre-clinically through a meta-analysis of xenograft rebound growth kinetics following treatment.

Methods

We first used a HCT116 cell fitness distribution we have previously measured in soft agar to demonstrate the expected population fitness trajectory as a function of starting population size. We sampled subclone fitnesses from this distribution to initialize either large or small theoretical tumors, and simulated tumor growth as a Moran process to find the probability distribution of expected outcomes in final tumor population fitness.

Since initial tumor volumes in xenografts experiments have a narrow range of volume (equivalently, population size), we next identified tumor volume measurements following suspension of treatment with anticancer agents from in-house historical xenograft growth datasets. Each of 1359 tumor volume trajectories after treatment was fit using non-linear regression to determine the exponential growth rate (population fitness), and compared to both the volume at treatment end as well as the average control group growth rate from the corresponding experiment.

Results

The simulated tumors demonstrate the “founder effect” in heterogeneous populations: large populations become dominated by the fastest growing, most fit subclones while small populations are sensitive to initial clonal sampling as well as random births and deaths. Rebound growth in xenografts post-treatment displayed large variability compared to the growth of the corresponding experimental control group. Post-treatment and untreated growth rates are poorly correlated (R2 = 0.1) consistent with a significant change in the tumor cell population following a period of selective pressure. Two additional observations are coherent with a founder effect following a bottleneck event (i.e., treatment). The relationship between post-treatment starting volume and growth rate has a positive slope (p = 0.01, F-test) while growth rate variance decreases with starting volume (p &lt; 0.01 F-test). Both results concur with the Moran simulations showing smaller populations have more stochastic outcomes while larger populations deterministically drift to greater fitness.

Conclusions

We find that xenograft growth kinetics following cessation of treatment with anticancer agents are consistent with a selection process and the founder effect. Application of evolutionary theory to small cell populations in preclinical models may yield new strategies to combat metastases and resistance emergence.

Citation Format: Andrew Chen, Christopher J. Zopf, Jing-Tao Wu, Wen Chyi Shyu, Arijit Chakravarty. Xenograft rebound kinetics are consistent with the founder effect. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3759. doi:10.1158/1538-7445.AM2015-3759

Imaging findings of solitary fibrous tumor in the abdomen and pelvis

PURPOSE

The purpose of this study was to investigate the imaging characteristics of solitary fibrous tumor (SFT) in the abdomen and pelvis.

METHODS

Nine cases of SFT confirmed by surgery and pathology were retrospectively analyzed in terms of computed tomography (CT, eight cases) and magnetic resonance imaging (MRI, one case).

RESULTS

SFT were located in the retroperitoneum (4/9), abdominal cavity (1/9), pelvis (4/9). Eight cases were single (8/9) and one case (1/9) with three tumors. The average tumor size of 11 lesions was 9.7 cm (4.7-20 cm). Nine tumors were round or ovoid, and two lesions were irregular. The CT value of the plain scans ranged from 33 to 43 Hounsfield units (HU, mean 37.6 HU) in five cases. Arterial-phase CT found solid parts demonstrate avid enhancement (eight cases) and five of them presented with multiple circuitous vessels along the periphery with a CT value of 68-89 HU (mean 76.6 HU). In the venous and delayed phases, enhancement was strengthened progressively. The CT values at venous (eight cases) and delayed phases (five cases) were 108-115 and 112-123 HU respectively, with averages of 109.8 and 114.8 HU. Patch or nodular no-enhanced areas were observed in eight cases during the enhanced phases. One case showed isointensity on T1-weighted images and high signal intensity on T2-weighted images accompanied by linear or curvilinear hypointense lines. Intense enhancements along with linear no-enhancement areas are seen in the arterial and venous phases.

CONCLUSION

The possibility of SFT should be considered when a single or multiple masses with sharp border, inhomogeneous density or signal are detected, especially, with inhomogeneous intense enhancement in the arterial phase being maintained in the venous and delayed phases.

Preliminary epidemiological assessment of MERS-CoV outbreak in South Korea, May to June 2015

South Korea is experiencing the largest outbreak of Middle East respiratory syndrome coronavirus infections outside the Arabian Peninsula, with 166 laboratory-confirmed cases, including 24 deaths up to 19 June 2015. We estimated that the mean incubation period was 6.7 days and the mean serial interval 12.6 days. We found it unlikely that infectiousness precedes symptom onset. Based on currently available data, we predict an overall case fatality risk of 21% (95% credible interval: 14–31).

Preliminary epidemiological assessment of MERS-CoV outbreak in South Korea, May to June 2015

South Korea is experiencing the largest outbreak of Middle East respiratory syndrome coronavirus infections outside the Arabian Peninsula, with 166 laboratory-confirmed cases, including 24 deaths up to 19 June 2015. We estimated that the mean incubation period was 6.7 days and the mean serial interval 12.6 days. We found it unlikely that infectiousness precedes symptom onset. Based on currently available data, we predict an overall case fatality risk of 21% (95% credible interval: 14–31).

Preclinical drug metabolism and pharmacokinetics, and prediction of human pharmacokinetics and efficacious dose of the investigational Aurora A kinase inhibitor alisertib (MLN8237)

Alisertib (MLN8237) is an investigational potent Aurora A kinase inhibitor currently under clinical trials for hematological and nonhematological malignancies. Nonclinical investigation showed that alisertib is a highly permeable compound with high plasma protein binding, low plasma clearance, and moderate volume of distribution in rats, dogs, monkeys and chimpanzees. Consistent with the above properties, the oral bioavailability in animals was greater than 82%. The predicted human oral pharmacokinetic (PK) profile was constructed using allometric scaling of plasma clearance and volume of distribution in the terminal phase from animals. The chimpanzee PK profiles were extremely useful to model absorption rate constant, which was assumed to be similar to that in humans, based on the fact that chimpanzees are phylogenetically closest to humans. The human plasma clearance was projected to be low of 0.12 L/hr/kg, with half-life of approximately 10 hr. For human efficacious dose estimation, the tumor growth inhibition as a measure of efficacy (E) was assessed in HCT116 xenograft mice at several oral QD or BID dose levels. Additionally, subcutaneous mini-pump infusion studies were conducted to assess mitotic index in tumor samples as a pharmacodynamic (PD) marker. PK/PD/E modeling showed that for optimal efficacy and PD in the xenograft mice maintaining a plasma concentration exceeding 1 µM for at least 8-12 hr would be required. These values in conjunction with the projected human PK profile estimated the optimal oral dose of approximately 103 mg QD or 62.4 mg BID in humans. Notably, the recommended Phase 2 dose being pursued in the clinic is close to the projected BID dose.

Photodegradation of sulfonamide antimicrobial compounds (sulfadiazine, sulfamethizole, sulfamethoxazole and sulfathiazole) in various UV/oxidant systems

This study used Na₂S₂O₈, NaBrO8 and H₂O₂to degrade sulfadiazine (SDZ), sulfamethizole (SFZ), sulfamethoxazole (SMX) and sulfathiazole (STZ) under ultraviolet (UV) irradiation. The initial concentration of sulfonamide and oxidant in all experiments was 20 mg/L and 5 mM, respectively. The degradation rate for sulfonamides satisfies pseudo-first-order kinetics in all UV/oxidant systems. The highest degradation rate for SDZ, SFZ, SMX and STZ was in the UV/Na₂S₂O₈, UV/NaBrO₃, UV/Na₂S₂O₈ and UV/H₂O₂ system, respectively. In the UV/Na₂S₂O₈ system, the photodegradation rate of SDZ, SFZ, SMX and STZ was 0.0245 min⁻¹, 0.0096 min⁻¹, 0.0283 min⁻¹ and 0.0141 min⁻¹, respectively; moreover, for the total organic carbon removal rate for SDZ, SFZ, SMX and STZ it was 0.0057 min⁻¹, 0.0081 min⁻¹, 0.0130 min⁻¹ and 0.0106 min⁻¹, respectively. Experimental results indicate that the ability of oxidants to degrade sulfonamide varied with pollutant type. Moreover, UV/Na₂S₂O₈ had the highest mineralization rate for all tested sulfonamides.

Clinical severity of human infections with avian influenza A(H7N9) virus, China, 2013/14

Assessing the severity of emerging infections is challenging because of potential biases in case ascertainment. The first human case of infection with influenza A(H7N9) virus was identified in China in March 2013; since then, the virus has caused two epidemic waves in the country. There were 134 laboratory-confirmed cases detected in the first epidemic wave from January to September 2013. In the second epidemic wave of human infections with avian influenza A(H7N9) virus in China from October 2013 to October 2014, we estimated that the risk of death among hospitalised cases of infection with influenza A(H7N9) virus was 48% (95% credibility interval: 42-54%), slightly higher than the corresponding risk in the first wave. Age-specific risks of death among hospitalised cases were also significantly higher in the second wave. Using data on symptomatic cases identified through national sentinel influenza-like illness surveillance, we estimated that the risk of death among symptomatic cases of infection with influenza A(H7N9) virus was 0.10% (95% credibility interval: 0.029-3.6%), which was similar to previous estimates for the first epidemic wave of human infections with influenza A(H7N9) virus in 2013. An increase in the risk of death among hospitalised cases in the second wave could be real because of changes in the virus, because of seasonal changes in host susceptibility to severe infection, or because of variation in treatment practices between hospitals, while the increase could be artefactual because of changes in ascertainment of cases in different areas at different times.

High-precision distribution of highly stable optical pulse trains with 8.8 × 10⁻¹⁹ instability

The high-precision distribution of optical pulse trains via fibre links has had a considerable impact in many fields. In most published work, the accuracy is still fundamentally limited by unavoidable noise sources, such as thermal and shot noise from conventional photodiodes and thermal noise from mixers. Here, we demonstrate a new high-precision timing distribution system that uses a highly precise phase detector to obviously reduce the effect of these limitations. Instead of using photodiodes and microwave mixers, we use several fibre Sagnac-loop-based optical-microwave phase detectors (OM-PDs) to achieve optical-electrical conversion and phase measurements, thereby suppressing the sources of noise and achieving ultra-high accuracy. The results of a distribution experiment using a 10-km fibre link indicate that our system exhibits a residual instability of 2.0 × 10⁻¹⁵ at1 s and8.8 × 10⁻¹⁹ at 40,000 s and an integrated timing jitter as low as 3.8 fs in a bandwidth of 1 Hz to 100 kHz. This low instability and timing jitter make it possible for our system to be used in the distribution of optical-clock signals or in applications that require extremely accurate frequency/time synchronisation.

Comparative study of intestinal tuberculosis and primary small intestinal lymphoma

AIM: To characterize the clinical, radiological, endoscopic and pathological features of intestinal tuberculosis (ITB) and primary small intestinal lymphoma (PSIL).

METHODS: This was a retrospective study from February 2005 to October 2012 of patients with a diagnosis of ITB (n = 41) or PSIL (n = 37). All patients with ITB or PSIL underwent computed tomography (CT) and pathological examination. Thirty-five patients with ITB and 32 patients with PSIL underwent endoscopy. These patients were followed for a further 18 mo to ascertain that the diagnosis had not changed. Clinical, endoscopic, CT and pathological features were compared between ITB and PSIL patients.

RESULTS: Night sweating, fever, pulmonary TB and ascites were discovered significantly more often in ITB than in PSIL patients (P < 0.05), however, abdominal mass, hematochezia and intestinal perforation were found significantly more frequently in PSIL than in ITB patients (P < 0.05). Ring-like and rodent-like ulcers occurred significantly more often in ITB than in PSIL patients (P < 0.05), however, enterorrhagia and raised lesions were significantly more frequent in PSIL than in ITB patients (P < 0.05). The rate of granuloma was significantly higher in ITB than in PSIL patients (87.8% vs 13.5%, χ² = 43.050, P < 0.05), and the incidence of confluent granulomas with caseous necrosis was significantly higher in ITB than in PSIL patients (47.2% vs 0.0%, χ² = 4.034, P < 0.05). Multi-segmental lesions, mural stratification, mural gas sign, and intestinal stricture were more frequent in ITB than in PSIL patients (P < 0.05), however, a single-layer thickening of bowel wall, single segmental lesions, and intussusception were more common in PSIL than in ITB patients (P < 0.05). Necrotic lymph nodes, comb sign and inflammatory mass were more frequent in ITB than in PSIL patients (P < 0.05). The bowel wall enhancement in ITB patients was greater than that in PSIL patients (P < 0.05), while the thickening and lymph node enlargement in PSIL patients were higher than those in ITB patients (P < 0.05).

CONCLUSION: Combined evaluation of clinical, radiological, endoscopic and pathological features is the key to differentiation between ITB and PSIL.