Associations of ApoE4 status and DHA supplementation on plasma and CSF lipid profiles and entorhinal cortex thickness.

Apolipoprotein ε allele 4 (APOE4) influences the metabolism of polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA). The entorhinal cortex (EC) in the brain is affected early in Alzheimer's disease and is rich in DHA. The purpose of this study is to identify the effect of APOE4 and DHA lipid species on the EC. Plasma and cerebrospinal fluid (CSF) lipidomic measurements were obtained from the DHA Brain Delivery Pilot, a randomized clinical trial of DHA supplementation (n = 10) versus placebo (n = 12) for six months in nondemented older adults stratified by APOE4 status. Wild-type C57B6/J mice were fed a high or low DHA diet for 6 months followed by plasma and brain lipidomic analysis. Levels of phosphatidylcholine DHA (PC 38:6) and cholesterol ester DHA (CE 22:6) had the largest increases in CSF following supplementation (P < 0.001). DHA within triglyceride (TG) lipids in CSF strongly correlated with corresponding plasma TG lipids, and differed by APOE4, with carriers having a lower increase than noncarriers. Changes in plasma PC DHA had the strongest association with changes in EC thickness in millimeters, independent of APOE4 status (P = 0.007). In mice, a high DHA diet increased PUFAs within brain lipids. Our findings demonstrate an exchange of DHA at the CSF-blood barrier and into the brain within all lipid species with APOE having the strongest effect on DHA-containing TGs. The correlation of PC DHA with EC suggests a functional consequence of DHA accretion in high density lipoprotein for the brain.

Triggered release from thermosensitive liposomes improves tumor targeting of vinorelbine.

Triggered drug delivery strategies have been shown to enhance drug accumulation at target diseased sites in comparison to administration of free drug. In particular, many studies have demonstrated improved targetability of chemotherapeutics when delivered via thermosensitive liposomes. However, most studies continue to focus on encapsulating doxorubicin while many other drugs would benefit from this targeted and localized delivery approach. The proposed study explores the therapeutic potential of a thermosensitive liposome formulation of the commonly used chemotherapy drug vinorelbine in combination with mild hyperthermia (39-43 °C) in a murine model of rhabdomyosarcoma. Rhabdomyosarcoma, the most common soft tissue sarcoma in children, is largely treated using conventional chemotherapy which is associated with significant adverse long-term sequelae. In this study, mild hyperthermia was pursued as a non-invasive, non-toxic means to improve the efficacy and safety profiles of vinorelbine. Thorough assessment of the pharmacokinetics, biodistribution, efficacy and toxicity of vinorelbine administered in the thermosensitive liposome formulation was compared to administration in a traditional, non-thermosensitive liposome formulation. This study shows the potential of an advanced formulation technology in combination with mild hyperthermia as a means to target an untargeted therapeutic agent and result in a significant improvement in its therapeutic index.

Turning down the heat: The case for mild hyperthermia and thermosensitive liposomes.

"A single disappointing study does not mean an end to the future of ThermoDox®", writes Michael Tardugno (CEO of Celsion Corporation), after announcing the termination of Celsion's second Phase III clinical trial. The OPTIMA trial, as it was known, evaluated their thermosensitive liposome (TSL) formulation of doxorubicin (ThermoDox®) in combination with radiofrequency ablation for the treatment of hepatocellular carcinoma (HCC). The purpose of this perspective is to review the case of ThermoDox and to address questions related to its clinical translation. Specifically, what has prevented the clinical translation of this once highly regarded breakthrough technology? Is this the end of TSLs? What can we learn from the challenges faced in the clinical development of this multi-modal therapy? As formulation scientists working in the field, we continue to believe that heat-triggered drug delivery platforms have tremendous potential as chemotherapy. Herein, we highlight potential limitations in the design of many of the Thermodox clinical trials, and we propose that despite these setbacks, TSLs have the potential to become an effective component of cancer therapy.

Targeting sirtuin activity with nicotinamide riboside reduces neuroinflammation in a GWI mouse model.

Gulf War Illness (GWI) affects 30% of veterans from the 1991 Gulf War (GW), who suffer from symptoms that reflect ongoing mitochondria dysfunction. Brain mitochondria bioenergetics dysfunction in GWI animal models corresponds with astroglia activation and neuroinflammation. In a pilot study of GW veterans (n = 43), we observed that blood nicotinamide adenine dinucleotide (NAD) and sirtuin 1 (Sirt1) protein levels were decreased in the blood of veterans with GWI compared to healthy GW veterans. Since nicotinamide riboside (NR)-mediated targeting of Sirt1 is shown to improve mitochondria function, we tested whether NR can restore brain bioenergetics and reduce neuroinflammation in a GWI mouse model. We administered a mouse diet supplemented with NR at 100µg/kg daily for 2-months to GWI and control mice (n = 27). During treatment, mice were assessed for fatigue-type behavior using the Forced Swim Test (FST), followed by euthanasia for biochemistry and immunohistochemistry analyses. Fatigue-type behavior was elevated in GWI mice compared to control mice and lower in GWI mice treated with NR compared to untreated GWI mice. Levels of plasma NAD and brain Sirt1 were low in untreated GWI mice, while GWI mice treated with NR had higher levels, similar to those of control mice. Deacetylation of the nuclear-factor κB (NFκB) p65 subunit and peroxisome proliferator-activated receptor gamma coactivator 1-α (PGC-1α) was an increase in the brains of NR-treated GWI mice. This corresponded with a decrease in pro-inflammatory cytokines and lipid peroxidation and an increase in markers of mitochondrial bioenergetics in the brains of GWI mice. These findings suggest that targeting NR mediated Sirt1 activation restores brain bioenergetics and reduces inflammation in GWI mice. Further evaluation of NR in GWI is warranted to determine its potential efficacy in treating GWI.

JOURNAL CLUB: Longitudinal Qualitative Characterization of MRI Features After Laser Interstitial Thermal Therapy in Drug-Resistant Epilepsy.

OBJECTIVE: Laser interstitial thermal therapy (LITT), a method for ablating brain tissue under real-time MR thermometry, has been used more frequently in recent years to treat nonmalignant lesions. The purpose of this study is to longitudinally characterize MRI features after LITT in patients with drug-resistant epilepsy, primarily in the setting of mesial temporal sclerosis. MATERIALS AND METHODS: MR images from 23 consecutive patients who underwent LITT were retrospectively reviewed. All patients had images obtained immediately after the ablation. Multiple patients had follow-up imaging at various time points after treatment, from postoperative days 7 through 1539. A total of 54 MRI studies were reviewed. RESULTS: Immediately after LITT, MR images showed a ring-enhancing lesion at the ablation site with minimal surrounding edema. Seven images showed increased enhancement of the ipsilateral choroid plexus. Images in the subacute phase showed a mild increase in edema with similar enhancement. Images in the transitional phase showed a decrease in edema with variable enhancement. Images in the chronic phase showed minimal gliosis with or without cavity formation or cavity formation alone, with either decreased or no enhancement. CONCLUSION: This report describes the time course of the imaging findings after LITT for drug-resistant epilepsy. The typical stages include rim-enhancing lesion with minimal edema, followed by an increase in edema, to eventual gliosis and nonenhancing cavity formation. Radiologists need to be familiar with the postablation findings to minimize misdiagnosis and prevent unnecessary workup.

Atom Probe Tomographic Mapping Directly Reveals the Atomic Distribution of Phosphorus in Resin Embedded Ferritin.

Here we report the atomic-scale analysis of biological interfaces within the ferritin protein using atom probe tomography that is facilitated by an advanced specimen preparation approach. Embedding ferritin in an organic polymer resin lacking nitrogen provided chemical contrast to visualise atomic distributions and distinguish the inorganic-organic interface of the ferrihydrite mineral core and protein shell, as well as the organic-organic interface between the ferritin protein shell and embedding resin. In addition, we definitively show the atomic-scale distribution of phosphorus as being at the surface of the ferrihydrite mineral with the distribution of sodium mapped within the protein shell environment with an enhanced distribution at the mineral/protein interface. The sample preparation method is robust and can be directly extended to further enhance the study of biological, organic and inorganic nanomaterials relevant to health, energy or the environment.

What Do People Believe About Memory? Implications for the Science and Pseudoscience of Clinical Practice.

We examine the evidence concerning what people believe about memory. We focus on beliefs regarding the permanence of memory and whether memory can be repressed and accurately recovered. We consider beliefs about memory among the undergraduate and general population, mental health professionals, judges, jurors, and law enforcement officers to provide a broad canvass that extends to the forensic arena, as well as to psychiatry, psychology, and allied disciplines. We discuss the implications of these beliefs for the education of the general public and mental health professionals regarding the science and pseudoscience of memory and the use of suggestive procedures in psychotherapy.

Impedance variations over time for a closed-loop neurostimulation device: early experience with chronically implanted electrodes.

OBJECTIVE: Responsive neurostimulation (RNS®) is an investigational treatment modality for intractable focal epilepsy. We analyzed impedance values over time to gain a better understanding of RNS device stability, potential differences between depth and strip electrodes, and general implications of long-term electrode implantation. MATERIALS AND METHODS: Impedance measurements were retrospectively reviewed from seven patients over a 3-year period. Statistical analysis was performed to investigate trends in impedance values over time and to determine if any differences existed between the means and variances of impedance values for the two different electrodes. RESULTS: Intraparenchymal depth electrodes demonstrated lower mean impedances and had less variation over time when compared to subdural strip electrodes. There was no significant change in mean impedance over time for depth electrodes, while that of subdural electrodes increased over time to peak at 16-20 months and returned to baseline by 2 years. CONCLUSION: The RNS device provides unique long-term data for both depth and subdural electrodes in human subjects. Although changes in impedance were observed with respect to time after implantation and electrode type, these variations were of a clinically insignificant magnitude. As a constant-current system, the device is ultimately able to administer stable therapeutic doses in the setting such minor variability. While further animal research and post mortem investigations in human subjects are necessary to broaden our understanding of the mechanisms occurring at the electrode-neural interface and the biocompatibility of chronically implanted electrodes, the relative stability of impedances seen in this cohort of chronic implants brings promise to future implementations of chronic intracranial neural implants.

Role of P450 1A1 and P450 1A2 in bioactivation versus detoxication of the renal carcinogen aristolochic acid I: studies in Cyp1a1-/-, Cyp1a2-/-, and Cyp1a1/1a2-/- mice.

Exposure to aristolochic acid I (AAI) is associated with aristolochic acid nephropathy, Balkan endemic nephropathy, and urothelial cancer. Individual differences in xenobiotic-metabolizing enzyme activities are likely to be a reason for interindividual susceptibility to AA-induced disease. We evaluated the reductive activation and oxidative detoxication of AAI by cytochrome P450 (P450) 1A1 and 1A2 using the Cyp1a1(-/-) and Cyp1a2(-/-) single-knockout and Cyp1a1/1a2(-/-) double-knockout mouse lines. Incubations with hepatic microsomes were also carried out in vitro. P450 1A1 and 1A2 were found to (i) activate AAI to form DNA adducts and (ii) detoxicate it to 8-hydroxyaristolochic acid I (AAIa). AAI-DNA adduct formation was significantly higher in all tissues of Cyp1a1/1a2(-/-) than Cyp1a(+/+) wild-type (WT) mice. AAI-DNA adduct levels were elevated only in selected tissues from Cyp1a1(-/-) versus Cyp1a2(-/-) mice, compared with those in WT mice. In hepatic microsomes, those from WT as well as Cyp1a1(-/-) and Cyp1a2(-/-) mice were able to detoxicate AAI to AAIa, whereas Cyp1a1/1a2(-/-) microsomes were less effective in catalyzing this reaction, confirming that both mouse P450 1A1 and 1A2 are both involved in AAI detoxication. Under hypoxic conditions, mouse P450 1A1 and 1A2 were capable of reducing AAI to form DNA adducts in hepatic microsomes; the major roles of P450 1A1 and 1A2 in AAI-DNA adduct formation were further confirmed using selective inhibitors. Our results suggest that, in addition to P450 1A1 and 1A2 expression levels in liver, in vivo oxygen concentration in specific tissues might affect the balance between AAI nitroreduction and demethylation, which in turn would influence tissue-specific toxicity or carcinogenicity.

Tumor Cell Selective Cytotoxicity and Apoptosis Induction by an Herbal Preparation from Brucea javanica.

The plant Brucea javanica has shown impressive efficacy for treating various diseases including cancer. However, the mechanism by which B. javanica acts is poorly understood. We have established tissue culture assays to study the effects of B. javanica on cervical and several other cancer cells. Our results demonstrated that the aqueous extract from B. javanica is selectively toxic to cancer cells. Induction of apoptosis by B. javanica appears to be a possible mechanism by which it kills cancer cells. Interestingly, a significant increase of p53 protein level was observed in these apoptotic cells. Our studies indicated that both p53-dependent and p53-independent activities contributed to herb-induced cell death. These results imply that further studies with B. javanica may lead to the development of novel anti-cancer drugs.

Case of fatal Blastoschizomyces capitatus infection occurring in a patient receiving empiric micafungin therapy.

We report the first case, to our knowledge, of Blastoschizomyces capitatus infection occurring in a patient receiving empirical echinocandin therapy for neutropenic fevers. Clinicians should consider B. capitatus infection in those neutropenic patients who remain febrile despite echinocandin therapy or who develop yeast bloodstream infections while receiving an echinocandin.

Potent and highly selective hypoxia-activated achiral phosphoramidate mustards as anticancer drugs.

A series of achiral hypoxia-activated prodrugs were synthesized on the basis of the DNA cross-linking toxin of the prodrug, ifosfamide. The hypoxia-selective cytotoxicity of several of the compounds was improved over previously reported racemic mixtures of chiral bioreductive phosphoramidate prodrugs. Prodrugs activated by 2-nitroimidazole reduction demonstrated up to 400-fold enhanced cytotoxicity toward H460 cells in culture under hypoxia versus their potency under aerobic conditions. Compounds were further assessed for their stability to cytochrome P450 metabolism using a liver microsome assay. The 2-nitroimidazole containing lead compound 3b (TH-302) was selectively potent under hypoxia and stable to liver microsomes. It was active in an in vivo MIA PaCa-2 pancreatic cancer orthotopic xenograft model as a monotherapy and demonstrated dramatic efficacy when used in combination with gemcitabine, extending survival with one of eight animals tumor free at day-44. Compound 3b has emerged as a promising antitumor agent that shows excellent in vivo efficacy and is currently being evaluated in the clinic.

Molecular identification of a danger signal that alerts the immune system to dying cells.

In infections, microbial components provide signals that alert the immune system to danger and promote the generation of immunity. In the absence of such signals, there is often no immune response or tolerance may develop. This has led to the concept that the immune system responds only to antigens perceived to be associated with a dangerous situation such as infection. Danger signals are thought to act by stimulating dendritic cells to mature so that they can present foreign antigens and stimulate T lymphocytes. Dying mammalian cells have also been found to release danger signals of unknown identity. Here we show that uric acid is a principal endogenous danger signal released from injured cells. Uric acid stimulates dendritic cell maturation and, when co-injected with antigen in vivo, significantly enhances the generation of responses from CD8+ T cells. Eliminating uric acid in vivo inhibits the immune response to antigens associated with injured cells, but not to antigens presented by activated dendritic cells. Our findings provide a molecular link between cell injury and immunity and have important implications for vaccines, autoimmunity and inflammation.