Pharmacokinetic Modeling of Ceftiofur Sodium Using Non-linear Mixed-Effects in Healthy Beagle Dogs

Ceftiofur (CEF) sodium is a third-generation broad-spectrum cephalosporin commonly used in an extra-label manner in dogs for the treatment of respiratory and urinary system infections. To contribute to the literature supporting CEF use in companion animals, we have developed a compartmental, non-linear mixed-effects (NLME) model of CEF pharmacokinetics in dogs (PK). We then used the mathematical model to predict (via Monte Carlo simulation) the duration of time for which plasma concentrations of CEF and its pharmacologically active metabolites remained above minimum inhibitory concentrations (respiratory tract Escherichia coli spp.). Twelve healthy beagle dogs were administered either 2.2 mg/kg ceftiofur-sodium (CEF-Na) intravenously (I.V) or 2.2 mg/kg CEF-Na subcutaneously (S.C). Plasma samples were collected over a period of 72 h post-administration. To produce a measurement of total CEF, both CEF and CEF metabolites were derivatized into desfuroylceftiofur acetamide (DCA) before analysis by UPLC-MS/MS. No adverse effects were reported after I.V or S.C dosing. The NLME PK models were parameterized using the stochastic approximation expectation maximization algorithm as implemented in Monolix 2018R2. A two-compartment mamillary model with first-order elimination and first-order S.C absorption best described the available kinetic data. Final parameter estimates indicate that CEF has a low systemic clearance (0.25 L/h/kg) associated with a low global extraction ratio E = 0.02) and a moderate volume of distribution (2.97 L/kg) in dogs. The absolute bioavailability after S.C administration was high (93.7%). Gender was determined to be a significant covariate in explaining the variability of S.C absorption. Our simulations predicted that a dose of 2.2 mg/kg CEF-Na S.C would produce median plasma concentrations of CEF of at least 0.5 μg/mL (MIC₅₀) for ~30 h.

Glucose-6-Phosphate Dehydrogenase from the Oleaginous Microalga Nannochloropsis Uncovers Its Potential Role in Promoting Lipogenesis

Microalgae have long been considered as potential biological feedstock for the production of wide array of bioproducts, such as biofuel feedstock because of their lipid accumulating capability. However, lipid productivity of microalgae is still far below commercial viability. Here, a glucose-6-phosphate dehydrogenase from the oleaginous microalga Nannochloropsis oceanica is identified and heterologously expressed in the green microalga Chlorella pyrenoidosa to characterize its function in the pentose phosphate pathway. It is found that the G6PD enzyme activity toward NADPH production is increased by 2.19-fold in engineered microalgal strains. Lipidomic analysis reveals up to 3.09-fold increase of neutral lipid content in the engineered strains, and lipid yield is gradually increased throughout the cultivation phase and saturated at the stationary phase. Moreover, cellular physiological characteristics including photosynthesis and growth rate are not impaired. Collectively, these results reveal the pivotal role of glucose-6-phosphate dehydrogenase from N. oceanica in NADPH supply, demonstrating that provision of reducing power is crucial for microalgal lipogenesis and can be a potential target for metabolic engineering.

Nomogram to predict overall survival and disease-specific survival with appendiceal mucinous adenocarcinoma

To predict the survival of appendiceal mucinous adenocarcinoma (AMA) by prognostic nomogram.A total of 3234 patients with AMA were collected from the Surveillance, Epidemiology, and End Results (SEER) database from 1973 to 2015. Univariate and multivariate Cox proportional hazards (PH) regression analyses were used to generate independent prognostic factors. These variables were included in the nomogram to predict overall survival (OS) and disease-specific survival (DSS) at 1-, 3-, and 5- years. These data are validated both internally and externally. The consistency index (C-index) and calibration chart were used to estimate the accuracy of the nomogram.The study cohort was randomly divided into the training (n = 2155) and validation group (n = 1799). According to univariate and multivariate analyses, age at diagnosis, marital status, sex, histological differentiation, SEER extent of disease, number of local lymph nodes examined, whether they were positive, and surgical methods were independent prognostic factors for OS and DSS. These factors were incorporated into the nomogram. Internal validation in the training cohort showed that the C-index values for nomogram predictions of OS and DSS were 0.73 (95% CI 0.70-0.76) and 0.77 (95% CI 0.73-0.81), respectively. Similarly, the corresponding C-index values in the external validation cohort were 0.76 (95% CI 0.70-0.81) and 0.75 (95% CI 0.71-0.80). The Calibration plots revealed that the actual survival and nomogram prediction had a good consistency.Build a nomogram in the SEER database to predict OS and DSS in patients with AMA. It can provide accurate and personalised survival prediction for clinicians and patients.

Safety and Efficacy of Transvenous Embolization of Ruptured Brain Arteriovenous Malformations as a Last Resort: A Prospective Single-Arm Study

BACKGROUND AND PURPOSE

The efficacy and safety of transvenous embolization for brain arteriovenous malformations remains unclear, given the very limited number of cases reported. This prospective study was performed to assess this technique in ruptured AVMs.

MATERIALS AND METHODS

Twenty-one consecutive patients with ruptured brain AVMs who underwent transvenous embolization were prospectively followed between November 2016 and November 2018. The Spetzler-Martin grade was I in 3 AVMs (14.3%), II in four (19.0%), III in eleven (52.4%), and IV in three (14.3%). The complete AVM occlusion rate was calculated from 6-month follow-up DSA images. Occurrence of hemorrhage and infarction after embolization was evaluated using CT and MR imaging within 1 month after the operation. The mRS was used to assess the functional outcomes.

RESULTS

Complete AVM nidus obliteration was shown in 16 (84%) of 19 patients with technically feasible AVMs immediately after embolization. One (5%) patient with a small residual nidus after treatment showed complete obliteration at 13-month follow-up. There were 5 hemorrhages and 1 infarction; 4 patients' symptoms improved gradually. The percentage of cases with mRS ≤ 2 rose from 57.1% (12/21) before embolization to 66.7% (14/21) at 1-month follow-up. Both the morbidity and mortality rates were 4.8% (1/21).

CONCLUSIONS

Transvenous embolization can be performed only in highly selected hemorrhagic brain AVMs with high complete obliteration rates, improved functional outcomes, and acceptable morbidity and mortality rates, but it should not be considered as a first-line treatment.

Epileptic negative myoclonus restricted to lower limbs in benign childhood focal epilepsy with vertex spikes

BACKGROUND AND PURPOSE

The aim was to determine the electroclinical findings in benign childhood focal epilepsy with vertex spikes (BEVS) with epileptic negative myoclonus (ENM) restricted to the lower limbs.

METHODS

The electroencephalogram database of Peking University First Hospital and medical records of patients with BEVS and ENM restricted to the lower limbs were reviewed.

RESULTS

Twenty-seven patients with BEVS had ENM restricted to the lower limbs. Twelve started as ENM restricted to the lower limbs. The age at seizure onset ranged from 1.5 to 4.8 years. During the course, half of the 12 patients developed focal sensorimotor seizures and then were diagnosed as benign childhood epilepsy with centrotemporal spikes (BECTS), with BEVS (four cases) and without BEVS (two cases). Five of them had electrical status epilepticus during sleep (ESES) and met the diagnostic criteria of atypical benign partial epilepsy (ABPE). Fifteen of the 27 patients had ENM restricted to the lower limbs during the course. The age at seizure onset ranged from 1.3 to 9.8 years. All had ESES and were diagnosed as ABPE, 11 as ABPE with BEVS and four as ABPE evolving into BEVS.

CONCLUSIONS

Benign childhood focal epilepsy with vertex spikes (BEVS) might represent a specific epileptic syndrome of the continuum of benign childhood focal epilepsy. ENM restricted to the lower limbs was a special phenomenon in BEVS. BEVS could overlap with BECTS or evolve into BECTS and further into ABPE and vice versa. Ignorance of vertex spikes with associated ENM restricted to the lower limbs might lead to a misunderstanding of BEVS, a specific type of benign childhood focal epilepsy.

The Association Between AXIN2 Gene Polymorphisms and the Risk of Breast Cancer in Chinese Women

Background: The protein AXIN2 is involved in the negative feedback regulation of the Wnt/β-catenin signaling pathway; it functions by promoting β-catenin degradation. AXIN2 mutations have been studied in various cancers. In this study, we genotyped three single nucleotide polymorphisms in the AXIN2 gene and investigated their association with the risk of breast cancer (BC) in the Chinese Han population. Methods: In a population of 415 BC patients and 528 controls the expression of AXIN2 was measured using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and compared with the overall survival (OS) of BC patients analyzed through Oncomine and Kaplan-Meier plotter databases. Bioinformatic analyses demonstrated that AXIN2 mRNA levels were downregulated in BC patients; this in turn correlated with a poorer survival rate for BC patients. Results: The polymorphisms rs11079571 and rs3923087, but not rs3923086, were associated with an increased risk of BC. The minor allele containing genotypes of polymorphism rs3923087 were positively associated with lymph node metastases. A haplotype analysis demonstrated that the ATA haplotype was correlated with an increased risk of BC. Conclusion: In conclusion, the downregulation of AXIN2 is related to poorer OS for BC patients. Its polymorphisms rs11079571 and rs3923087 confer susceptibility to BC. These findings should be confirmed with larger studies that include more diverse ethnic populations.

Enhanced protoplast assay by transfecting PCR-assembled gene expression cassettes with telomeric repeats and thiophosphate modifications

Transient expression assays are invaluable complements to the stable transgenic assay for studying gene functions by providing desirable time and labor efficiencies and high-throughput potential or circumventing technical difficulties of stable transgenic expression. The protoplast transient expression system is one of the mainstream transient expression assays used in plant research. Here, we developed a PCR amplicon-mediated protoplast transient (PROMPT) assay by using overlapping PCR assembled gene expression cassettes for Arabidopsis protoplast transfection without the need for time- and labor-consuming plasmid construction. When 200 μl of Arabidopsis protoplasts were transfected with 1 μg of PCR amplicons or plasmid DNA, we detected substantially higher gene expression in the former. Moreover, we found that adding telomeric repeats and thiophosphate modifications to the 5' end of the nonsense strand through the reverse primer could further increase the PCR amplicon-mediated gene expression in protoplasts. Importantly, these improvements could also be applied to the protoplast assays in other dicot and monocot species including tobacco, rice and wheat. In addition, the subcellular localization of immune receptor FLS2 could be analyzed by PROMPT method. The PROMPT assay allows an accelerated and robust transient gene expression in protoplasts from diverse plant species.

Epigallocatechin-3-gallate inhibits proliferation and induces apoptosis in odontogenic keratocyst keratinocytes

OBJECTIVE

The aim of this study was to investigate the effects of epigallocatechin-3-gallate on the proliferation and apoptosis of odontogenic keratocyst (OKC) keratinocytes in vitro.

MATERIALS AND METHODS

Keratinocytes isolated from the epithelial lining of the OKC were cultured in keratinocyte serum-free medium and identified by CK10, CK14, pan-cytokeratin and vimentin immunofluorescence staining. The cells were exposed to EGCG at different concentrations, and proliferation inhibition was measured by cell counting kit 8 assay. Cell cycle and apoptosis were assessed by flow cytometry, and expression of the WNT signalling pathway-related proteins FZD3 and JNK3 was detected by quantitative real-time PCR and Western blotting. Human oral keratinocytes (HOKs) were used as the control.

RESULTS

The OKC keratinocytes were successfully cultured. The primary cells were tile-like and expressed the epithelial biomarkers CK10, CK14 and pan-cytokeratin. Epigallocatechin-3-gallate inhibited cell proliferation in a dose- and time-dependent manner, arrested cell cycle in the G₁ phase and induced apoptosis of OKC keratinocytes. FZD3 and JNK3 were overexpressed in OKC keratinocytes compared with HOKs and were downregulated by epigallocatechin-3-gallate treatment.

CONCLUSION

Epigallocatechin-3-gallate inhibited proliferation and induced apoptosis in OKC keratinocytes, possibly by suppressing the WNT/JNK signalling pathway. It may thus be potentially used for OKC treatment.

Abstract P3-13-09: Increased mortality with repeat lumpectomy alone after ipsilateral breast tumor recurrence: A propensity-adjusted, population-based SEER analysis

Background: The benefit of repeat lumpectomy for ipsilateral breast tumor recurrence (IBTR) after breast conserving surgery (BCS) is currently inconclusive. This issue has become even more important as small and isolated recurrent tumors were frequently diagnosed.

Methods: IBTR patients with definitive surgery were identified in the Surveillance, Epidemiology, and End Results registry between 1973 and 2013. The effect of different IBTR surgeries on overall and cancer-specific mortality was assessed using risk-adjusted Cox proportional hazard regression modeling and stratified propensity score matching analysis (PSMA).

Results: Based on the selection criteria, 5098 patients were recruited. Of those, 4048 (79.4%) women underwent mastectomy and 1050 (20.1%) underwent repeat lumpectomy after IBTR. Patients who received repeat lumpectomy had lower grade (23.7% vs 15% for well-differentiated) and smaller recurrent tumor (47% vs 36.2% for ≤ 1 cm) but earlier recurrence (23.9% vs 11.2% for interval times < 48 months) than those who underwent mastectomy. A minority of each group (24.7% of those undergoing repeat lumpectomy and 3% of the mastectomy group) underwent RT after surgery. In multivariable Cox regression analysis, repeat lumpectomy was associated with increased overall mortality (Hazard ratio (HR) = 1.58, 95% CI = 1.353 to 1.844, P < 0.001) and cancer-specific mortality (HR = 1.721, 95% CI = 1.345 to 2.202, P< 0.001). Similar HRs were derived from the PSMA cohort. However, we found no significant difference in overall mortality for women who underwent repeat lumpectomy followed by RT compared with that for those who underwent mastectomy (P= 0.411). Moreover, IBTR patients with small tumors (≤ 1 cm) who underwent repeat lumpectomy with RT rather than without had similar overall and cancer-specific survival rates to those who underwent mastectomy (P= 0.189 and P= 0.604, respectively).

Conclusions: Our investigation suggests that compared with mastectomy, repeat lumpectomy for IBTR is associated with higher overall and cancer-specific mortality under real-world observational conditions. Furthermore, repeat lumpectomy with RT is equivalent to mastectomy with respect to overall mortality and may influence treatment decision making for patients with small IBTR.

Citation Format: Su Y, Guo R, Xue J, Chi Y, Wu J. Increased mortality with repeat lumpectomy alone after ipsilateral breast tumor recurrence: A propensity-adjusted, population-based SEER analysis [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-09.

Abstract P6-09-11: NFATC2 suppresses the metastatic cascade in breast cancer patients

For the patients with breast cancer, the pathological status of axillary lymph nodes is one of the most important predictor of prognosis. In recent years, the application of sentinel lymph node biopsy has provided us with an opportunity for the further study on the mechanism of lymph node metastasis in breast cancer. Through detailed pathological examination of sentinel lymph nodes, we can easily find patients who are in the early stage of lymph node metastasis - that is, the tumor cells from the primary tumor, invading the lymph nodes and successfully colonized, but not yet break through the lymph node microenvironment defense to the subsequent lymph node. It is the most important stage during lymph node metastasis.

In the present study, we selected the pairing samples from breast cancer patients with early stage lymph node metastasis to carry out differential genomics research. A total of 182 genes with significant function and involved in significant signal transduction pathways were obtained. Bioinformatics method was used to screen out the mRNA, microRNA and transcription factor in the process of lymph node metastasis of breast cancer. We investigated the role of activated T cells c2 (NFATC2) in the core transcription factors as a target for further clinical and basic research.

The expression of NFATC2 was detected in the tissue microarray prepared from 200 patients with primary breast cancer. After the median follow-up period of 89.5 months, it showed that the prognosis of patients with NFATC2 overexpression was significantly better than that of the control group (p = 0.022). We also measured the expression of NFATC2 in 50 pairs of breast cancer patients with lymph node metastasis. The results showed that the expression of NFATC2 in the primary tumor was significantly higher than that in the matched lymph node, suggesting that in patients with breast cancer, the down-regulate or deficiency of NFATC2 expression may be related with lymph node metastasis. We also attempted to add the expression of NFATC2 as a new parameter in the prediction model of lymph node metastasis based on preoperative clinical and pathological parameters. The area under the ROC curve obtained in the newly established model was 0.767, the expression state of NFATC2 had impact on the performance of the prediction model. Furthermore, when we removed the NFATC2 parameter, it could reduce the area under the ROC curve in the validation group, suggesting that the expression of NFATC2 in the primary tumor may be used as a predictor of the pathological state of axillary lymph nodes.

In vitro and in vivo experiments, we demonstrated that NFATC2 has a significant suppression effect on the proliferation, migration and invasion of breast cancer cells. The potential NFATC2-target genes were determined by RNAseq and Chipseq. Nine differentially expressed genes were found to be regulated by NFATC2 in the Chip-seq analysis and bound to the promoter region of the gene, whereas GRAMD3 and SRGAP2 in the subsequent validation showed a positive correlation with the expression of NFATC2, suggesting that the two genes are likely to have a positive regulatory relationship with NFATC2.

This study clarifies that NFATC2 may represent a therapeutic target for early metastasis breast cancer.

Citation Format: Xue J, Chi Y, Chen J, Wu J. NFATC2 suppresses the metastatic cascade in breast cancer patients [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-09-11.

Pharmacokinetics of vitacoxib in rabbits after intravenous and oral administration

This study describes the pharmacokinetics of vitacoxib in healthy rabbits following administration of 10 mg/kg intravenous (i.v.) and 10 mg/kg oral. Twelve New Zealand white rabbits were randomly allocated to two equally sized treatment groups. Blood samples were collected at predetermined times from 0 to 36 hr after treatment. Plasma drug concentrations were determined using UPLC-MS/MS. Pharmacokinetic analysis was completed using noncompartmental methods via WinNonlin^™ 6.4 software. The mean concentration area under curve (AUC_last ) for vitacoxib was determined to be 11.0 ± 4.37 μg hr/ml for i.v. administration and 2.82 ± 0.98 μg hr/ml for oral administration. The elimination half-life (T_1/2λz ) was 6.30 ± 2.44 and 6.30 ± 1.19 hr for the i.v. and oral route, respectively. The C_max (maximum plasma concentration) and T_max (time to reach the observed maximum (peak) concentration at steady-state) following oral application were 189 ± 83.1 ng/ml and 6.58 ± 3.41 hr, respectively. Mean residence time (MRT_last ) following i.v. injection was 6.91 ± 3.22 and 11.7 ± 2.12 hr after oral administration. The mean bioavailability of oral administration was calculated to be 25.6%. No adverse effects were observed in any rabbit. Further studies characterizing the pharmacodynamics of vitacoxib are required to develop a formulation of vitacoxib for rabbits.

Pharmacokinetics of the novel COX-2 selective inhibitor vitacoxib in cats: The effects of feeding and dose

The purpose of this study was to determine the pharmacokinetics and dose-scaling model of vitacoxib in either fed or fasted cats following either oral or intravenous administration. The concentration of the drug was quantified by UPLC-MS/MS on plasma samples. Relevant parameters were described using noncompartmental analysis (WinNonlin 6.4 software). Vitacoxib is relatively slowly absorbed and eliminated after oral administration (2 mg/kg body weight), with a T_max of approximately 4.7 hr. The feeding state of the cat was a statistically significant covariate for both area under the concentration versus time curve (AUC) and mean absorption time (MAT_fed ). The absolute bioavailability (F) of vitacoxib (2 mg/kg body weight) after oral administration (fed) was 72.5%, which is higher than that in fasted cats (F = 50.6%). Following intravenous administration (2 mg/kg body weight), Vd (ml/kg) was 1,264.34 ± 343.63 ml/kg and Cl (ml kg^-1  hr^-1 ) was 95.22 ± 23.53 ml kg^-1  hr^-1 . Plasma concentrations scaled linearly with dose, with C_max (ng/ml) of 352.30 ± 63.42, 750.26 ± 435.54, and 936.97 ± 231.27 ng/ml after doses of 1, 2, and 4 mg/kg body weight, respectively. No significant undesirable behavioral effects were noted throughout the duration of the study.

The Effects of a Single Oral Dose of Pyridoxine on Alpha-Aminoadipic Semialdehyde, Piperideine-6-Carboxylate, Pipecolic Acid, and Alpha-Aminoadipic Acid Levels in Pyridoxine-Dependent Epilepsy

Purpose: To evaluate the effects of a single oral dose of pyridoxine on lysine metabolites including α-aminoadipic semialdehyde (a-AASA), piperideine-6-carboxylate (P6C), the sum of AASA and P6C (AASA-P6C), pipecolic acid (PA), and α-aminoadipic acid (α-AAA) in PDE patients. Methods: The lysine metabolites of 15 patients with molecularly confirmed PDE were detected before and 4 h after taking a single oral dose of pyridoxine, respectively, using liquid chromatography-mass spectrometry (LC-MS/MS) method. Five types of samples were freshly prepared, including plasma, serum, dried blood spots (DBS), urine, and dried urine spots (DUS). Results: All the patients had been treated with long-term oral pyridoxine for several months to years, with doses of 30-360 mg/d. The concentrations of a-AASA, P6C, AASA-P6C, PA, and a-AAA before and after taking a single oral dose of pyridoxine for the same analyte detected in the same type of sample varied among patients. The mean concentrations increased in almost all the metabolites after taking an oral dose of pyridoxine, with or without statistical significance. Whereas, the metabolites concentrations might increase or decrease among different patients, or in different samples of the same patient, without a regular tendency. There was no statistical correlation between the concentrations before and after taking pyridoxine in the same type of sample for most metabolites. Conclusions: No obvious relationship between the metabolite levels or concentration differences and the age, pyridoxine dose (a single oral dose and long-term maintenance dose), duration of treatment, or neurodevelopmental phenotype was found at present study. The large individual differences among patients, probably affected by various genotypes, leading to quite different effects of pyridoxine on the change degree of metabolites concentrations. Our study suggested that long-term pyridoxine treatment could control seizures rather than getting toxic lysine metabolites such as a-AASA and P6C back to normal. In the future, more therapies should be focused to alleviate the metabolites accumulation and further improve the prognosis of PDE.

The pharmacokinetics of moxidectin following intravenous and topical administration to swine

The pharmacokinetic parameters of moxidectin (MXD) after intravenous and pour-on (topical) administration were studied in sixteen pigs at a single dose of 1.25 and 2.5 mg/kg BW (body weight), respectively. Blood samples were collected at pretreatment time (0 hr) over 40 days. The plasma kinetics were analyzed by WinNonlin 6.3 software through a noncompartmental model. For intravenous administration (n = 8), the elimination half-life (λ_Z ), the apparent volume of distribution (V_z ), and clearance (Cl) were 10.29 ± 1.90 days, 89.575 ± 29.856 L/kg, and 5.699 ± 2.374 L/kg, respectively. For pour-on administration (n = 8), the maximum plasma drug concentration (C_max ), time to maximum plasma concentration (T_max ), and λ_Z were 7.49 ng/ml, 1.72, and 6.20 days, respectively. MXD had a considerably low absolute pour-on bioavailability of 9.2%, but the mean residence time (MRT) for pour-on administration 10.88 ± 1.75 days was longer than 8.99 ± 2.48 days for intravenous administration. These results showed that MXD was absorbed via skin rapidly and eliminated slowly. The obtained data might contribute to refine the dosage regime for topical MXD administration.