Stability and compatibility of an intramuscular fetal anesthetic cocktail for fetal intervention.

INTRODUCTION: To evaluate chemical stability and physical compatibility when combining fentanyl, rocuronium, and atropine in a fixed ratio to support intramuscular drug delivery during fetal intervention and surgery. METHODS: A highly concentrated combination of fentanyl, rocuronium, and atropine was created based on common prescribing practices at a maternal fetal care center. Chemical stability testing was completed using liquid chromatograph mass spectrometry-mass spectrometry (LC/MS-MS) to detect and quantitate atropine, rocuronium, and fentanyl, with fentanyl-d5 being an internal standard at 6-, 12, 24-, and 36-hours following sample preparation. Physical compatibility testing was completed using United State Pharmacopeia (USP)<788> recommended analytical technique of light obscuration (LO) in addition to novel backgrounded membrane imaging (BMI) at 6- and 24-hours following sample preparation. Physical compatibility was determined using USP<788> particle count limits for both techniques. RESULTS: Based on LC/MS-MS results, the samples retained expected medication concentrations at all time points tested. For physical compatibility testing, the particle counts met criteria to be considered compatible per USP<788> large volume particle count thresholds at 6 hours by both methods but exceeded tolerable thresholds at 24 hours. DISCUSSION/CONCLUSION: The combination of rocuronium, fentanyl, and atropine for intramuscular fetal administration are physically compatible and chemically stable for 6 hours.

Retraction: Nuclear Morphometric Analysis of Leydig Cells of Male Pubertal Rats Exposed In Utero to Di(n-butyl) Phthalate.

[This retracts the article on p. 439 in vol. 26, PMID: 24526819.].

MRI-guided focused ultrasound blood-brain barrier opening increases drug delivery and efficacy in a diffuse midline glioma mouse model.

Background: Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest pediatric brainstem tumor and is difficult to treat with chemotherapy in part due to the blood-brain barrier (BBB). Focused ultrasound (FUS) and microbubbles (MBs) have been shown to cause BBB opening, allowing larger chemotherapeutics to enter the parenchyma. Panobinostat is an example of a promising in vitro agent in DIPG with poor clinical efficacy due to low BBB penetrance. In this study, we hypothesized that using FUS to disrupt the BBB allows higher concentrations of panobinostat to accumulate in the tumor, providing a therapeutic effect. Methods: Mice were orthotopically injected with a patient-derived diffuse midline glioma (DMG) cell line, BT245. MRI was used to guide FUS/MB (1.5 MHz, 0.615 MPa peak negative pressure, 1 Hz pulse repetition frequency, 10-ms pulse length, 3 min treatment time)/(25 µL/kg, i.v.) targeting to the tumor location. Results: In animals receiving panobinostat (10 mg/kg, i.p.) in combination with FUS/MB, a 3-fold increase in tumor panobinostat concentration was observed, without significant increase of the drug in the forebrain. In mice receiving 3 weekly treatments, the combination of panobinostat and FUS/MB led to a 71% reduction of tumor volumes (P = .01). Furthermore, we showed the first survival benefit from FUS/MB improved delivery increasing the mean survival from 21 to 31 days (P < .0001). Conclusions: Our study demonstrates that FUS-mediated BBB disruption can increase the delivery of panobinostat to an orthotopic DMG tumor, providing a strong therapeutic effect and increased survival.

Metformin does not slow cyst growth in the PCK rat model of polycystic kidney disease.

Metformin (MET) has the potential to activate p-AMPK and block mTORC1-induced proliferation of tubular cells in PKD kidneys. The aim of this study was to determine the effects of MET on cyst growth, kidney function, AMPK and mTOR signaling, and lactate levels in male PCK rats, a Pkhd1 gene mutation model of human autosomal recessive polycystic kidney disease (ARPKD). MET 300 mg/kg/day IP from days 28 to 84 of age resulted in a mean serum metformin level that was 10 times the upper limit of therapeutic, no effect on cyst indices, nephrotoxicity, and increased serum lactate. MET 150 mg/kg resulted in a therapeutic serum metformin level but had no effect on kidney weight, cyst indices, kidney function, or mTOR and autophagy proteins. In summary, a standard dose of MET was ineffective in reducing PKD, did not activate p-AMPK or suppress mTOR and the higher dose resulted in increased lactate levels and nephrotoxicity. In conclusion, the study dampens enthusiasm for human studies of MET in PKD. Doubling the metformin dose resulted in a 10-fold increase in mean blood levels and toxicity suggesting that the dosage range between therapeutic and toxic is narrow.

Effects of pulsatile intravenous follicle-stimulating hormone treatment on ovarian function in women with obesity.

OBJECTIVE: To establish conditions for effective hypothalamic suppression in women with normal and high body mass index (BMI) and test the hypothesis that intravenous (IV) administration of pulsatile recombinant follicle-stimulating hormone (rFSH) can overcome the clinically evident dysfunctional pituitary-ovarian axis in women with obesity. DESIGN: Prospective interventional study. SETTING: Academic medical center. PATIENT(S): Twenty-seven normal-weight women and 27 women with obesity, who were eumenorrheic and aged 21-39 years. INTERVENTION(S): Two-day frequent blood sampling study, in early follicular phase, before and after cetrorelix suppression of gonadotropins and exogenous pulsatile IV rFSH administration. MAIN OUTCOME MEASURE(S): Serum inhibin B and estradiol (E2) levels (basal and rFSH stimulated). RESULT(S): A modified gonadotropin-releasing hormone antagonism protocol effectively suppressed production of endogenous gonadotropins in women with normal and high BMIs, providing a model to address the functional role of FSH in the hypothalamic-pituitary-ovarian axis. The IV rFSH treatment resulted in equivalent serum levels and pharmacodynamics in normal-weight women and those with obesity. However, women with obesity exhibited reduced basal levels of inhibin B and E2 and a significantly decreased response to FSH stimulation. The BMI was inversely correlated with serum inhibin B and E2. In spite of this observed deficit in ovarian function, pulsatile IV rFSH treatment in women with obesity resulted in E2 and inhibin B levels comparable with those in normal-weight women, in the absence of exogenous FSH stimulation. CONCLUSION(S): Despite normalization of FSH levels and pulsatility by exogenous IV administration, women with obesity demonstrate ovarian dysfunction with respect to E2 and inhibin B secretion. Pulsatile FSH can partially correct the relative hypogonadotropic hypogonadism of obesity, thereby providing a potential treatment strategy to mitigate some of the adverse effects of high BMI on fertility, assisted reproduction, and pregnancy outcomes. CLINICAL TRIAL REGISTRATION NUMBER: ClinicalTrials.gov #NCT02478775.

Retraction: In utero-exposed di(n-butyl) phthalate induce dose dependent, age-related changes of morphology and testosterone-biosynthesis enzymes/associated proteins of Leydig cell mitochondria in rats.

Editor's AnnouncementIn utero-exposed di(n-butyl) phthalate induce dose dependent, age-related changes of morphology and testosterone-biosynthesis enzymes/associated proteins of Leydig cell mitochondria in ratsMasaya Motohashi, Michael F. Wempe, Tomoko Mutou, Yuya Okayama, Norio Kansaku, Hiroyuki Takahashi, Masahiro Ikegami, Masao Asari, Shin Wakui(The Journal of Toxicological Sciences, 41, 195-206, 2016) I have retracted the above paper as Editor-in-Chief of The Journal of Toxicological Sciences since I have serious concerns about it, primarily due to inappropriate authorship on a non-negligible scale.When it was brought to my attention that there was inappropriate authorship in this paper, I contacted the co-authors to confirm this point. I found out that the majority of them considered their listing as co-authors to be inappropriate. In addition, the majority agreed to the retraction of this paper.These facts raise concerns about the paper. From the standpoint of maintaining the integrity of the research community, I felt that such a paper should be retracted at once.Accordingly, I sent a summary of my concerns about the paper to the corresponding author, Dr. Shin Wakui. I also had an online interview with him to discuss this matter. I told Dr. Wakui that inappropriate authorship on a non-negligible scale is a serious problem that raises concerns about the paper.I prepared a draft of this Editor's Announcement and sent it to Dr. Wakui for review prior to revision and release. Although he did not agree to the retraction, I have decided to take this action from the standpoint of maintaining the integrity of the research community.I coordinated my response to this issue with Dr. Akira Naganuma, Editor-in-Chief of Fundamental Toxicological Sciences, a sister journal of The Journal of Toxicological Sciences. Toshiyuki Kaji, Ph.D.Editor-in-ChiefThe Journal of Toxicological Sciences.

Novel chromobox 2 inhibitory peptide decreases tumor progression.

BACKGROUND: The Polycomb Repressor Complex 1 (PRC1) is an epigenetic regulator of differentiation and development, consisting of multiple subunits including RING1, BMI1, and Chromobox. The composition of PRC1 dictates its function and aberrant expression of specific subunits contributes to several diseases including cancer. Specifically, the reader protein Chromobox2 (CBX2) recognizes the repressive modifications including histone H3 lysine 27 tri-methylation (H3K27me3) and H3 lysine 9 dimethylation (H3K9me2). CBX2 is overexpressed in several cancers compared to the non-transformed cell counterparts, it promotes both cancer progression and chemotherapy resistance. Thus, inhibiting the reader function of CBX2 is an attractive and unique anti-cancer approach. RESEARCH DESIGN & METHODS: Compared with other CBX family members, CBX2 has a unique A/T-hook DNA binding domain that is juxtaposed to the chromodomain (CD). Using a computational approach, we constructed a homology model of CBX2 encompassing the CD and A/T hook domain. We used the model as a basis for peptide design and identified blocking peptides that are predicted to directly bind the CD and A/T-hook regions of CBX2. These peptides were tested in vitro and in vivo models. CONCLUSION: The CBX2 blocking peptide significantly inhibited both 2D and 3D growth of ovarian cancer cells, downregulated a CBX2 target gene, and blunted tumor growth in vivo.

LAT1 enables T cell activation under inflammatory conditions.

The aim of this study was to assess the L-type amino acid transporter-1 (LAT1) as a possible therapeutic target for rheumatoid arthritis (RA). Synovial LAT1 expression in RA was monitored by immunohistochemistry and transcriptomic datasets. The contribution of LAT1 to gene expression and immune synapse formation was assessed by RNA-sequencing and total internal reflection fluorescent (TIRF) microscopy, respectively. Mouse models of RA were used to assess the impact of therapeutic targeting of LAT1. LAT1 was strongly expressed by CD4+ T cells in the synovial membrane of people with active RA and the level of expression correlated with levels of ESR and CRP as well as DAS-28 scores. Deletion of LAT1 in murine CD4+ T cells inhibited the development of experimental arthritis and prevented the differentiation of CD4+ T cells expressing IFN-γ and TNF-α, without affecting regulatory T cells. LAT1 deficient CD4+ T cells demonstrated reduced transcription of genes associated with TCR/CD28 signalling, including Akt1, Akt2, Nfatc2, Nfkb1 and Nfkb2. Functional studies using TIRF microscopy revealed a significant impairment of immune synapse formation with reduced recruitment of CD3ζ and phospho-tyrosine signalling molecules in LAT1 deficient CD4+ T cells from the inflamed joints but not the draining lymph nodes of arthritic mice. Finally, it was shown that a small molecule LAT1 inhibitor, currently undergoing clinical trials in man, was highly effective in treating experimental arthritis in mice. It was concluded that LAT1 plays a critical role in activation of pathogenic T cell subsets under inflammatory conditions and represents a promising new therapeutic target for RA.

MRI-Guided Focused Ultrasound Blood-Brain Barrier Opening Increases Drug Delivery and Efficacy in a Diffuse Midline Glioma Mouse Model.

Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest pediatric brainstem tumor and is difficult to treat with chemotherapy in part due to the blood-brain barrier (BBB). Focused ultrasound (FUS) and microbubbles (MBs) have been shown to cause BBB disruption (BBBD), allowing larger chemotherapeutics to enter the parenchyma. Panobinostat is an example of a promising in vitro agent in DIPG with poor clinical efficacy due to low BBB penetrance. In this study, we hypothesized that using FUS to disrupt the BBB allows higher concentrations of panobinostat to accumulate in the tumor, providing a therapeutic effect. Mice were orthotopically injected with a patient-derived DMG cell line, BT-245. MRI was used to guide FUS/MB (1.5 MHz, 0.615 MPa PNP, 1 Hz PRF, 10 ms PL, 3 min treatment time) / (25 µL/kg, IV) targeting to the tumor location. In animals receiving panobinostat (10 mg/kg, IP) in combination with FUS/MB, a 3-fold increase in tumor panobinostat concentration was observed, with only insignificant increase of the drug in the forebrain. In mice receiving three weekly treatments, the combination of panobinostat and FUS/MB led to a 71% reduction of tumor volumes by MRI ( p = 0.01). Furthermore, FUS/MB improved the mean survival from 21 to 31 days ( p < 0.0001). Our study demonstrates that FUS-mediated BBBD can increase the delivery of panobinostat to an orthotopic DMG tumor, providing a strong therapeutic effect and increased survival. One Sentence Summary: FUS and microbubbles can increase the delivery of panobinostat to a patient-derived xenograft (PDX) orthotopic DMG tumor, providing a strong therapeutic effect and increased survival.

Extended Stability of Isoproterenol Hydrochloride Injection in Polyvinyl Chloride Bags Stored in Amber Ultraviolet Light Blocking Bags.

Purpose:Evaluate the stability of isoproterenol hydrochloride injection in 0.9% sodium chloride in polyvinyl chloride bags for up to 90 days. Methods: Dilutions of isoproterenol hydrochloride injection to a concentration of 4 µg/mL were performed under aseptic conditions. The bags were stored in amber ultraviolet light blocking bags at room temperature (23°C-25°C) or under refrigeration (3°C-5°C). Three samples of each preparation and storage environment were analyzed on days 0, 2, 14, 30, 45, 60, and 90. Physical stability was performed by visual examination. The pH was assessed at baseline, each analysis day, and upon final degradation evaluation. Sterility of the samples was not assessed. Chemical stability of isoproterenol hydrochloride was evaluated using liquid chromatography with tandem mass spectrometry. Samples were considered stable if there was <10% degradation of the initial concentration. Results: Isoproterenol hydrochloride diluted to 4 µg/mL with 0.9% sodium chloride injection was physically stable throughout the study. No precipitation was observed. At days 2, 14, 30, 45, 60, and 90 all bags diluted to 4 µg/mL had <10% degradation when stored under refrigeration (3°C-5°C) or stored at room temperature (23°C-25°C). Conclusion: Isoproterenol hydrochloride diluted to a concentration of 4 µg/mL with 0.9% sodium chloride for injection in ultraviolet light blocking bags was stable for 90 days at room temperature and under refrigeration.

Extended Stability of Vasopressin Injection in Polyvinyl Chloride Bags and Polypropylene Syringes and Its Impact on Critically Ill Patient Care and Medication Waste.

Background. Vasopressin is frequently utilized for a variety of shock states in critically ill patients. Short stability (≤24 hours) after intravenous admixture with current manufacturer labeling requires just in time preparation and may lead to delays in therapy and increased medication waste. We aimed to evaluate vasopressin stability in 0.9% sodium chloride stored in polyvinyl chloride bags and polypropylene syringes for up to 90 days. Additionally, we evaluated the impact of extended stability on the time to administration and cost savings from reduced medical waste at an academic medical center. Methods. Dilutions of vasopressin to concentrations of 0.4 and 1.0 unit/mL were performed under aseptic conditions. The bags and syringes were stored at room temperature (23°C-25°C) or under refrigeration (3°C-5°C). Three samples of each preparation and storage environment were analyzed on days 0, 2, 14, 30, 45, 60, and 90. Physical stability was performed by visual examination. The pH was assessed at each point and upon final degradation evaluation. Sterility of the samples was not assessed. Chemical stability of vasopressin was evaluated using liquid chromatography with tandem mass spectrometry. Samples were considered stable if there was <10% degradation of the initial concentration. Results. Vasopressin diluted to 0.4 and 1.0 unit/mL with 0.9% sodium chloride injection was physically stable throughout the study. No precipitation was observed. At days 2, 14, 30, 45, 60, and 90 all bags and syringes diluted to 0.4 units/mL had <10% degradation. Vasopressin diluted to 1 unit/mL and stored under refrigeration had <10% degradation at all measured days, but when stored under room temperature was found to have >10% degradation at day 30. Implementation of a batching process resulted in reduced waste ($185 300) and improved time to administration (26 vs 4 minutes). Conclusion. Vasopressin diluted to a concentration of 0.4 units/mL with 0.9% sodium chloride injection is stable for 90 days at room temperature and under refrigeration. When diluted to 1.0 unit/mL with 0.9% sodium chloride injection it is stable for 90 days under refrigeration. Use of extended stability and sterility testing to batch prepare infusions may lead to improved time to administration and cost savings from reduced medication waste.

The Impact of Suboptimal 25-Hydroxyvitamin D Levels and Cholecalciferol Replacement on the Pharmacokinetics of Oral Midazolam in Control Subjects and Patients With Chronic Kidney Disease.

The aim of this study was to investigate the impact of suboptimal 25-hydroxyvitamin D (25-VitD) and cholecalciferol (VitD3 ) supplementation on the pharmacokinetics of oral midazolam (MDZ) in control subjects and subjects with chronic kidney disease (CKD). Subjects with CKD (n = 14) and controls (n = 5) with suboptimal 25-VitD levels (<30 ng/mL) were enrolled in a 2-phase study. In phase 1 (suboptimal), subjects were administered a single oral dose of VitD3 (5000 IU) and MDZ (2 mg). In phase 2 (replete) subjects who achieved 25-VitD repletion after receiving up to 16 weeks of daily cholecalciferol were given the identical single oral doses of VitD3 and MDZ as in phase 1. Concentrations of MDZ and metabolites, 1'-hydroxymidazolam (1'-OHMDZ), and 1'-OHMDZ glucuronide (1'-OHMDZ-G) were measured by liquid chromatography-tandem mass spectrometry and pharmacokinetic analysis was performed. Under suboptimal 25-VitD, reductions in MDZ clearance and renal clearance of 47% and 87%, respectively, and a 72% reduction in renal clearance of 1'-OHMDZ-G were observed in CKD vs controls. In phase 1 versus phase 2, MDZ clearance increased in all control subjects, with a median (interquartile range) increase of 10.5 (0.62-16.7) L/h. No changes in MDZ pharmacokinetics were observed in subjects with CKD between phases 1 and 2. The effects of 25-VitD repletion on MDZ disposition was largely observed in subjects without kidney disease. Impaired MDZ metabolism and/or excretion alterations due to CKD in a suboptimal 25-VitD state may not be reversed by cholecalciferol therapy. Suboptimal 25-VitD may augment the reductions in MDZ and 1'-OHMDZ-G clearance values observed in patients with CKD.

An evaluation of a novel nanoformulation of imatinib mesylate in a mouse model of lupus nephritis.

Studies have suggested imatinib mesylate (ImM) as a potential treatment for systemic lupus erythematosus nephritis (SLEN). However, ImM has limited renal excretion. The goal of the current research was to develop an ImM containing nanoformulation, conduct studies to evaluate pharmacokinetics, and determine whether kidney deposition can be enhanced in a mouse model of SLEN. A fish oil-based ImM oil-in-water nanoemulsion was developed and characterized for particle size, zeta potential, pH, and stability. MRL/MpJ-Faslrp (model of SLEN) and MRL/MpJ (control) mice (12-13 weeks) received one dose of ImM as either a nanoemulsion or naked drug. Pharmacokinetics and kidney deposition studies were performed. Statistics were conducted with a student's T-test. The nanoemulsion characteristics included particle size range of 60-80 nm, zeta potential of -6.6 to -7.8 mV, polydispersity index < 0.3, 3-day stability at 4 °C, and limited ImM leakage from the nanoemulsion in serum. Pharmacokinetics of the nanoformulation showed changes to pharmacokinetic parameters suggesting reduced systemic exposures (with reduced potential for toxicities) to ImM. Kidney deposition of ImM was threefold higher after 4 h in the MRL/MpJ-Faslrp mice that received the nanoformulation vs. naked drug. The current study showed encouraging results for development of a stable and well-characterized nanoemulsion for optimizing kidney deposition of ImM. Future strategies will define dose-efficacy and dose-toxicity relationships and evaluate approaches to further enhance kidney delivery and optimize deposition to the mesangial location of the kidney.

EGCG Inhibits Tumor Growth in Melanoma by Targeting JAK-STAT Signaling and Its Downstream PD-L1/PD-L2-PD1 Axis in Tumors and Enhancing Cytotoxic T-Cell Responses.

Over the last decade, therapies targeting immune checkpoints, such as programmed death-1 (PD-1), have revolutionized the field of cancer immunotherapy. However, low response rates and immune-related adverse events remain a major concern. Here, we report that epigallocatechin gallate (EGCG), the most abundant catechin in green tea, inhibits melanoma growth by modulating an immune response against tumors. In vitro experiments revealed that EGCG treatment inhibited interferon-gamma (IFN-γ)-induced PD-L1 and PD-L2 expression and JAK-STAT signaling. We confirmed that this effect was driven by inhibiting STAT1 gene expression and STAT1 phosphorylation, thereby downregulating the PD-L1/PD-L2 transcriptional regulator IRF1 in both human and mouse melanoma cells. Animal studies revealed that the in vivo tumor-inhibitory effect of EGCG was through CD8+ T cells and that the inhibitory effect of EGCG was comparable to anti-PD-1 therapy. However, their mechanisms of action were different. Dissimilar to anti-PD-1 treatment that blocks PD-1/PD-L1 interaction, EGCG inhibited JAK/STAT signaling and PD-L1 expression in tumor cells, leading to the re-activation of T cells. In summary, we demonstrate that EGCG enhances anti-tumor immune responses by inhibiting JAK-STAT signaling in melanoma. EGCG could be used as an alternative treatment strategy to target the PD-L1/PD-L2-PD-1 axis in cancers.

Pharmacokinetics of oral antimycobacterials and dosing guidance for Mycobacterium avium complex treatment in cystic fibrosis.

BACKGROUND: Treatment failure of Mycobacterium avium complex (MAC) pulmonary disease occurs in about 30% of people with cystic fibrosis (CF) and may be a result of abnormal drug concentrations. METHODS: Prospective, cross-over, single-dose PK study of 20 pancreatic insufficient individuals with CF and 10 healthy controls (HC). CF subjects received simultaneous doses of oral azithromycin, ethambutol, and rifampin in the fasting state and with food and pancreatic enzymes, separated by two weeks. HC received fasting doses only. A non-compartmental model was used to estimate PK parameters of drugs and metabolites. RESULTS: Azithromycin maximum concentration (Cmax ) was higher and rifampin Cmax was lower in fasting CF subjects compared to HC, while other PK measures, including those for ethambutol, were similar. Addition of food and enzymes did not improve the Cmax of the antimycobacterial drugs. Nineteen of 20 CF subjects had one or more abnormal Cmax z-scores in either the fasting or fed state (or both), when compared to HC. CONCLUSION: PK profiles of azithromycin and ethambutol were similar between CF and HC, except azithromycin Cmax was slightly higher in people with CF after a single dose. Rifampin PK parameters were altered in persons with CF. Addition of food and enzymes in CF subjects did not improve PK parameters. Standard dosing guidelines should be used as a starting point for people with CF initiating MAC therapy and therapeutic drug monitoring should be routinely performed to prevent the possibility of treatment failure due to abnormal drug concentrations. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02372383 Prior abstract publication: 1. Martiniano S, Wagner B, Brennan L, Wempe M, Anderson P, Nick J, Sagel S. Pharmacokinetics of oral MAC antibiotics in cystic fibrosis. Am J Resp Crit Care Med A4842-A4842, 2017. 2. Martiniano SL, Wagner BD, Brennan L, Wempe MF, Anderson PL, Nick JA, Sagel SD. Pharmacokinetics of oral MAC antibiotics in cystic fibrosis. J Cyst Fibros 16: S52-53, 2017.

Liver X Receptor Activation with an Intranasal Polymer Therapeutic Prevents Cognitive Decline without Altering Lipid Levels.

The progressive accumulation of amyloid-beta (Aß) in specific areas of the brain is a common prelude to late-onset of Alzheimer's disease (AD). Although activation of liver X receptors (LXR) with agonists decreases Aß levels and ameliorates contextual memory deficit, concomitant hypercholesterolemia/hypertriglyceridemia limits their clinical application. DMHCA (N,N-dimethyl-3ß-hydroxycholenamide) is an LXR partial agonist that, despite inducing the expression of apolipoprotein E (main responsible of Aß drainage from the brain) without increasing cholesterol/triglyceride levels, shows nil activity in vivo because of a low solubility and inability to cross the blood brain barrier. Herein, we describe a polymer therapeutic for the delivery of DMHCA. The covalent incorporation of DMHCA into a PEG-dendritic scaffold via carboxylate esters produces an amphiphilic copolymer that efficiently self-assembles into nanometric micelles that exert a biological effect in primary cultures of the central nervous system (CNS) and experimental animals using the intranasal route. After CNS biodistribution and effective doses of DMHCA micelles were determined in nontransgenic mice, a transgenic AD-like mouse model of cerebral amyloidosis was treated with the micelles for 21 days. The benefits of the treatment included prevention of memory deterioration and a significant reduction of hippocampal Aß oligomers without affecting plasma lipid levels. These results represent a proof of principle for further clinical developments of DMHCA delivery systems.

Circulating cyclic adenosine monophosphate concentrations in milrinone treated paediatric patients after congenital heart surgery.

BACKGROUND: Milrinone is a phosphodiesterase type 3 inhibitor that results in a positive inotropic effect in the heart through an increase in cyclic adenosine monophosphate. The purpose of this study was to evaluate circulating cyclic adenosine monophosphate and milrinone concentrations in milrinone treated paediatric patients undergoing congenital heart surgery. METHODS: Single-centre prospective observational pilot study from January 2015 to December 2017 including children aged birth to 18 years. Milrinone and circulating cyclic adenosine monophosphate concentrations were measured at four time points through the first post-operative day and compared between patients with and without low cardiac output syndrome, defined using clinical and laboratory criteria. RESULTS: Fifty patients were included. Nine (18%) developed low cardiac output syndrome. For all patients, 22% had single ventricle heart disease. The density and distribution of cyclic adenosine monophosphate concentrations varied between those with and without low cardiac output syndrome but were not significantly different. Milrinone concentrations increased in all patients. Paired t-tests demonstrated an increase in circulating cyclic adenosine monophosphate concentrations during the post-operative period among patients without low cardiac output syndrome. CONCLUSIONS: In this prospective observational study, circulating cyclic adenosine monophosphate concentrations increased in those without low cardiac output syndrome during the first 24 post-operative hours and milrinone concentrations increased in all patients. Further study of the utility of cyclic adenosine monophosphate concentrations in milrinone treated patients is necessary.

Comparative Pre-clinical Efficacy of Chinese and Indian Cultivars of Bitter Melon (Momordica charantia) against Pancreatic Cancer.

Given the high rates of incidence and mortality associated with pancreatic cancer (PanC), there is a need to develop alternative strategies to target PanC. Recent studies have demonstrated that fruits of bitter melon (Momordica charantia) exhibit strong anticancer efficacy against PanC. However, the comparative effects of different bitter melon varieties have not been investigated. This has important implications, given that several bitter melon cultivars are geographically available but their differential effects are not known; and that on a global level, individuals could consume different bitter melon varieties sourced from different cultivars for anti-PanC benefits. Considering these shortcomings, in the present study, comparative pre-clinical anti-PanC studies have been conducted using lyophilized-juice and aqueous-methanolic extracts of the two most widely consumed but geographically diverse bitter melon varieties (Chinese [bitter melon juice; BMJ] and Indian [bitter melon extract; BME] variants). We observed that both BMJ and BME possess comparable efficacy against PanC growth and progression; specifically, these preparations have the potential to (a) inhibit PanC cell proliferation and induce cell death; (b) suppress PanC tumor growth, proliferation, and induce apoptosis; (c) restrict capillary tube formation by human umbilical vein endothelial cells, and decrease angiogenesis in PanC tumor xenografts. Thus, given the comparable pre-clinical anti-PanC efficacy of bitter melon cultivars, the geographical non-availability of a certain cultivar should not be a limiting factor in selecting a variant for moving forward for future clinical use/clinical trials either as a preventive or a therapeutic alternative for targeting PanC.

Bitter melon juice intake with gemcitabine intervention circumvents resistance to gemcitabine in pancreatic patient-derived xenograft tumors.

Chemoresistance to gemcitabine (GEM)-a frontline chemotherapeutic, resulting from its dysfunctional uptake and metabolism in cancer cells, is a major contributing factor for failed therapy in pancreatic cancer (PanC) patients. Therefore, there is an urgent need for agents that could reverse GEM resistance and allow continued chemosensitivity to the drug. We employed natural nontoxic agent (with anti-PanC potential) bitter melon juice (BMJ) and GEM to examine their combinatorial benefits against tumorigenesis of PanC patient-derived xenograft (PDX)-pancreatic ductal adenocarcinomas explants PDX272 (wild-type KRAS), PDX271 (mutant KRAS and SMAD4), and PDX266 (mutant KRAS). Anti-PanC efficacy of single agents vs combination in the three tumor explants, both at the end of active dosing regimen and following a drug-washout phase were compared. In animal studies, GEM alone treatment significantly inhibited PDX tumor growth, but effects were not sustained, as GEM-treated tumors exhibited regrowth posttreatment termination. However, combination-regimen displayed enhanced and sustained efficacy. Mechanistic assessments revealed that overcoming GEM resistance by coadministration with BMJ was possibly due to modulation of GEM transport/metabolism pathway molecules (ribonucleotide reductase regulatory subunit M1, human equilibrative nucleoside transporter 1, and deoxycytidine kinase). Study outcomes, highlighting significantly higher and sustained efficacy of GEM in combination with BMJ, make a compelling case for a clinical trial in PanC patients, wherein BMJ could be combined with GEM to target and overcome GEM resistance. In addition, given their specific effectiveness against KRAS-mutant tumors, this combination could be potentially beneficial to a broader PanC patient population.

Preclinical and clinical investigation of intratumoral chemotherapy pharmacokinetics in DIPG using gemcitabine.

BACKGROUND: Hundreds of systemic chemotherapy trials in diffuse intrinsic pontine glioma (DIPG) have not improved survival, potentially due to lack of intratumoral penetration, which has not previously been assessed in humans. METHODS: We used gemcitabine as a model agent to assess DIPG intratumoral pharmacokinetics (PK) using mass spectrometry. RESULTS: In a phase 0 clinical trial of i.v. gemcitabine prior to biopsy in children newly diagnosed with DIPG by MRI, mean concentration in 4 biopsy cores in patient 1 (H3K27M diffuse midline glioma) was 7.65 µM. These compare favorably to levels for patient 2 (mean 3.85 µM, found to have an H3K27-wildtype low-grade glioma on histology), and from a similar study in adult glioblastoma (adjusted mean 3.48 µM). In orthotopic patient-derived xenograft (PDX) models of DIPG and H3K27M-wildtype pediatric glioblastoma, gemcitabine levels and clearance were similar in tumor, pons, and cortex and did not depend on H3K27 mutation status or tumor location. Normalized gemcitabine levels were similar in patient 1 and the DIPG PDX. CONCLUSIONS: These findings, while limited to one agent, provide preliminary evidence for the hypotheses that lack of intratumoral penetration is not why systemic chemotherapy has failed in DIPG, and orthotopic PDX models can adequately model intratumoral PK in human DIPG.