Mater Sci Eng C Mater Biol Appl
January 2021
The performance of many implantable neural stimulation devices is degraded due to the loss of neurons around the electrodes by the body's natural biological responses to a foreign material. Coating of electrodes with biomolecules such as extracellular matrix proteins is one potential route to suppress the adverse responses that lead to loss of implant functionality. Concurrently, however, the electrochemical performance of the stimulating electrode must remain optimal to continue to safely provide sufficient charge for neural stimulation.
View Article and Find Full Text PDFObjective: With the strong drive towards miniaturization of active implantable medical devices and the need to improve the resolution of neural stimulation arrays, there is keen interest in the manufacture of small electrodes capable of safe, continuous stimulation. Traditional materials such as platinum do not possess the necessary electrochemical properties to stimulate neurons safely when electrodes are very small (i.e.
View Article and Find Full Text PDFIron metabolism is altered in a variety of cancers; however, little is known about the role of iron metabolism in the biology and response to therapy of acute myeloid leukemia (AML). Here we show that SLC40A1, the gene encoding the iron exporter ferroportin (FPN), is variably expressed among primary AMLs and that low levels are associated with good prognosis and improved outcomes. In particular, core binding factor (CBF) AMLs, which are associated with good outcomes with chemotherapy, consistently have low level of SLC40A1 expression.
View Article and Find Full Text PDFBackground: In September 2016, the Food and Drug Administration (FDA) published a draft guidance for industry, , that detailed the factors the Agency considers in determining when a Risk Evaluation and Mitigation Strategy (REMS) is necessary. The objective of this study was to determine how the FDA has applied these criteria for newly approved drugs.
Methods: For the 3-year period, 2015-2017, which included a full year of FDA approvals both before and after the issuance of the draft guidance, publicly available FDA reviews were analyzed for all 113 approved products using the criteria outlined in the guidance.
Wireless power and data transfer to medical implants is a research area where improvements in current state-of-the-art technologies are needed owing to the continuing efforts for miniaturization. At present, lithographical patterning of evaporated metals is widely used for miniature coil fabrication. This method produces coils that are limited to low micron or nanometer thicknesses leading to high impedance values and thus limiting their potential quality.
View Article and Find Full Text PDFWe have identified a new downstream target gene of the Aft1/2-regulated iron regulon in budding yeast Saccharomyces cerevisiae, the late-annotated small open reading frame LSO1. LSO1 transcript is among the most highly induced from a transcriptome analysis of a fet3-1 mutant grown in the presence of the iron chelator bathophenanthrolinedisulfonic acid. LSO1 has a paralog, LSO2, which is constitutively expressed and not affected by iron availability.
View Article and Find Full Text PDFIron is required for cellular proliferation. Recently, using systematic time studies of neuroblastoma cell growth, we better defined the G1 arrest caused by iron chelation to a point in mid-G1, where cyclin E protein is present, but the cyclin E/CDK2 complex kinase activity is inhibited. In this study, we again used the neuroblastoma SKNSH cells lines to pinpoint the mechanism responsible for this G1 block.
View Article and Find Full Text PDFThe Food and Drug Administration Amendments Act of 2007 gave the FDA the authority to require drug sponsors to submit a risk evaluation and mitigation strategies (REMS) program for those medicines with serious risks such that failure to effectively manage these risks would tip the benefit-risk balance. As of August 8, 2013, the 34 distinct individual and shared REMS programs that have specific elements to assure safe use (ETASU) were reviewed to ascertain the types of risks managed, the goals of the REMS, and the tools that were employed targeting prescribers, health care facilities, pharmacists, and particular conditions for safe use. Most REMS (65%) have a combination of risk mitigation and educational goals, but 4 REMS programs (12%) have exclusively educational goals.
View Article and Find Full Text PDFStudies have presented evidence that besides the well described S phase block, treatment of cancer cell lines with the iron chelator deferrioxamine (DFO) also results in an earlier block in G1 phase. In this article, measurements of cell cycle regulatory proteins define this block at a very specific point in G1. DFO treatment results in markedly decreased cyclin A protein levels.
View Article and Find Full Text PDFObjectives: Electrode impedance increases following implantation and undergoes transitory reduction with onset of electrical stimulation. The studies in this paper measured the changes in access resistance and polarization impedance in vivo before and following electrical stimulation, and recorded the time course of these changes.
Design: Impedance measures recorded in (a) four cats following 6 months of cochlear implant use, and (b) three cochlear implant recipients with 1.
Animal and clinical observations of a reduction in electrode impedance following electrical stimulation encouraged the development of an in vitro model of the electrode-tissue interface. This model was used previously to show an increase in impedance with cell and protein cover over electrodes. In this paper, the model was used to assess the changes in electrode impedance and cell cover following application of a charge-balanced biphasic current pulse train.
View Article and Find Full Text PDFThe Cochlear implant or 'Bionic ear' is a device that enables people who do not get sufficient benefit from a hearing aid to communicate with the hearing world. The Cochlear implant is not an amplifier, but a device that electrically stimulates the auditory nerve in a way that crudely mimics normal hearing, thus providing a hearing percept. Many recipients are able to understand running speech without the help of lipreading.
View Article and Find Full Text PDFDrug-induced liver injury (DILI) is of major interest to hepatologists and clinicians in general, patients, government regulators, and the pharmaceutical industry. Understanding why this form of injury occurs only in certain individuals has major implications for the development and availability of drug therapies and in the prevention of these events. A single controlled clinical trial may be unlikely to show cases of such rare events, but in the aggregate, clinical trials offer a unique resource for learning more about individual susceptibility and developing truly predictive new biomarkers for DILI.
View Article and Find Full Text PDFBackground And Objectives: The clinical use of sodium ferric gluconate complex in iron-deficient pediatric patients receiving hemodialysis was recently approved. This study was designed to describe the pharmacokinetic parameters of the medication.
Design, Setting, Participants, & Measurements: Iron-deficient pediatric (< or = 15 yr) hemodialysis patients were randomly assigned to two doses (1.
Objective: To evaluate the effectiveness and issues associated with a research totally implantable cochlear implant (TIKI).
Study Design: Limited patient trial.
Setting: Tertiary referral center.
Neoadjuvant chemotherapy (NACT) has become the standard of care for patients with locally advanced breast cancer (LABC). This was a retrospective review of 21 consecutive women who received NACT as initial treatment of LABC, followed by surgical excision. The pre- and post-treatment breast specimens and post-treatment axillary lymph nodes with metastases were immunostained to evaluate for proliferative index (PI) (MIB-1 Immunotech) and vascular endothelial growth factor (VEGF) expression (Santa Cruz, CA, clone A-20).
View Article and Find Full Text PDFPurpose: To assess changes in isotretinoin prescribing following the implementation of the System to Manage Accutane Related Teratogenicity (SMART) risk management program.
Methods: Using nationally representative commercial data resources on prescription drug dispensing patterns, surveys of office-based physician practices, and a large, claims database from a pharmacy benefits manager (PBM), we examined the total number of isotretinoin prescriptions (new and refill), prescriber speciality, and patient characteristics (age, gender, severity of acne indication) in the year before (April 2001-March 2002) and the year following (April 2002-March 2003) implementation of the SMART program.
Results: In the 12-months prior to SMART, 1 508 000 prescriptions were dispensed for isotretinoin, declining approximately 23% to 1 160 000 prescriptions in the year following SMART.
Study Objectives: To determine the single-dose pharmacokinetics of intravenous sodium ferric gluconate complex in sucrose injection (SFGC) in iron-deficient human volunteers, and to assess iron transport.
Design: Open-label, randomized study.
Setting: Clinical research facility.