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1.
Sci Rep ; 14(1): 13458, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38862568

ABSTRACT

Late Holocene relative sea-level (RSL) data are important to understand the drivers of RSL change, but there is a lack of precise RSL records from the Sunda Shelf. Here, we produced a Late Holocene RSL reconstruction from coral microatolls in Singapore, demonstrating for the first time the utility of Diploastrea heliopora microatolls as sea-level indicators. We produced 12 sea-level index points and three marine limiting data with a precision of < ± 0.2 m (2σ) and < ± 26 years uncertainties (95% highest density region). The data show a RSL fall of 0.31 ± 0.18 m between 2.8 and 0.6 thousand years before present (kyr BP), at rates between - 0.1 ± 0.3 and - 0.2 ± 0.7 mm/year. Surface profiles of the fossil coral microatolls suggest fluctuations in the rate of RSL fall: (1) stable between 2.8 and 2.5 kyr BP; (2) rising at ~ 1.8 kyr BP; and (3) stable from 0.8 to 0.6 kyr BP. The microatoll record shows general agreement with published, high-quality RSL data within the Sunda Shelf. Comparison to a suite of glacial isostatic adjustment (GIA) models indicate preference for lower viscosities in the mantle. However, more high quality and precise Late Holocene RSL data are needed to further evaluate the drivers of RSL change in the region and better constrain GIA model parameters.

2.
Drugs Aging ; 41(1): 45-54, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37982982

ABSTRACT

BACKGROUND: Patients, family members, and clinicians express concerns about potential adverse drug withdrawal events (ADWEs) following medication discontinuation or fears of upsetting a stable medical equilibrium as key barriers to deprescribing. Currently, there are limited methods to pragmatically assess the safety of deprescribing and ascertain ADWEs. We report the methods and results of safety monitoring for the OPTIMIZE trial of deprescribing education for patients, family members, and clinicians. METHODS: This was a pragmatic cluster randomized trial with multivariable Poisson regression comparing outcome rates between study arms. We conducted clinical record review and adjudication of sampled records to assess potential causal relationships between medication discontinuation and outcomes. This study included adults aged 65+ with dementia or mild cognitive impairment, one or more additional chronic conditions, and prescribed 5+ chronic medications. The intervention included an educational brochure on deprescribing that was mailed to patients prior to primary care visits, a clinician notification about individual brochure mailings, and an educational tip sheets was provided monthly to primary care clinicians. The outcomes of the safety monitoring were rates of hospitalizations and mortality during the 4 months following brochure mailings and results of record review and adjudication. The adjudication process was conducted throughout the trial and included classifications: likely, possibly, and unlikely. RESULTS: There was a total of 3012 (1433 intervention and 1579 control) participants. There were 420 total hospitalizations involving 269 (18.8%) people in the intervention versus 517 total hospitalizations involving 317 (20.1%) people in the control groups. Adjusted risk ratios comparing intervention to control groups were 0.92 [95% confidence interval (CI) 0.72, 1.16] for hospitalization and 1.19 (95% CI 0.67, 2.11) for mortality. Both groups had zero deaths "likely" attributed to a medication change prior to the event. A total of 3 out of 30 (10%) intervention group hospitalizations and 7 out of 35 (20%) control group hospitalizations were considered "likely" due to a medication change. CONCLUSIONS: Population-based deprescribing education is safe in the older adult population with cognitive impairment in our study. Pragmatic methods for safety monitoring are needed to further inform deprescribing interventions. TRIAL REGISTRATION: NCT03984396. Registered on 13 June 2019.


Subject(s)
Deprescriptions , Drug-Related Side Effects and Adverse Reactions , Aged , Humans , Drug-Related Side Effects and Adverse Reactions/prevention & control , Hospitalization
4.
Age Ageing ; 52(1)2023 01 08.
Article in English | MEDLINE | ID: mdl-36702513

ABSTRACT

BACKGROUND: people living with cognitive impairment commonly take multiple medications including potentially inappropriate medications (PIMs), which puts them at risk of medication related harms. AIMS: to explore willingness to have a medication deprescribed of older people living with cognitive impairment (dementia or mild cognitive impairment) and multiple chronic conditions and assess the relationship between willingness, patient characteristics and belief about medications. METHODS: cross-sectional study using results from the revised Patients' Attitudes Towards Deprescribing questionnaire (rPATDcog) collected as baseline data in the OPTIMIZE study, a pragmatic, cluster-randomised trial educating patients and clinicians about deprescribing. Eligible participants were 65+, diagnosed with dementia or mild cognitive impairment, and prescribed at least five-long-term medications. RESULTS: the questionnaire was mailed to 1,409 intervention patients and 553 (39%) were returned and included in analysis. Participants had a mean age of 80.1 (SD 7.4) and 52.4% were female. About 78.5% (431/549) of participants said that they would be willing to have one of their medications stopped if their doctor said it was possible. Willingness to deprescribe was negatively associated with getting stressed when changes are made and with previously having a bad experience with stopping a medication (P < 0.001 for both). CONCLUSION: most older people living with cognitive impairment are willing to deprescribe. Addressing previous bad experiences with stopping a medication and stress when changes are made to medications may be key points to discuss during deprescribing conversations.


Subject(s)
Cognitive Dysfunction , Dementia , Deprescriptions , Humans , Female , Aged , Aged, 80 and over , Male , Caregivers/psychology , Cross-Sectional Studies , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/drug therapy , Polypharmacy , Dementia/diagnosis , Dementia/drug therapy
5.
J Am Geriatr Soc ; 71(3): 774-784, 2023 03.
Article in English | MEDLINE | ID: mdl-36508725

ABSTRACT

BACKGROUND: Polypharmacy is common in older adults with cognitive impairment and multiple chronic conditions, increasing risks of adverse drug events, hospitalization, and death. Deprescribing, the process of reducing or stopping potentially inappropriate medications, may improve outcomes. The OPTIMIZE pragmatic trial examined whether educating and activating patients, family members and clinicians about deprescribing reduces number of chronic medications and potentially inappropriate medications. Acceptability and challenges of intervention delivery in cognitively impaired older adults are not well understood. METHODS: We explored mechanisms of intervention implementation through post hoc qualitative interviews and surveys with stakeholder groups of 15 patients, 7 caregivers, and 28 clinicians. We assessed the context in which the intervention was delivered, its implementation, and mechanisms of impact. RESULTS: Acceptance of the intervention was affected by contextual factors including cognition, prior knowledge of deprescribing, communication, and time constraints. All stakeholder groups endorsed the acceptability, importance, and delivery of the intervention. Positive mechanisms of impact included patients scheduling specific appointments to discuss deprescribing and providers being prompted to consider deprescribing. Recollection of intervention materials was inconsistent but most likely shortly after intervention delivery. Short visit times remained the largest provider barrier to deprescribing. CONCLUSIONS: Our work identifies key learnings in intervention delivery that can guide future scaling of deprescribing interventions in this population. We highlight the critical roles of timing and repetition in intervention delivery to cognitively impaired populations and the barrier posed by short consultation times. The acceptability of the intervention to patients and family members highlights the potential to incorporate deprescribing education into routine clinical practice and expand proven interventions to other vulnerable populations.


Subject(s)
Deprescriptions , Drug-Related Side Effects and Adverse Reactions , Aged , Humans , Caregivers , Hospitalization , Polypharmacy , Potentially Inappropriate Medication List , Pragmatic Clinical Trials as Topic
6.
J Nurs Care Qual ; 38(3): 220-225, 2023.
Article in English | MEDLINE | ID: mdl-36519870

ABSTRACT

BACKGROUND: More than 10% of Americans have diabetes, with higher rates in Hispanics and African Americans. National Healthy People 2030 goals for expected decrease in HbA 1c levels have not been met. LOCAL PROBLEM: No standardized diabetes education or follow-up existed at a free clinic. Patients exhibited diabetic self-management inadequacies and elevated HbA 1c levels. METHODS: A pre/postimplementation study design was used to evaluate changes in HbA 1c levels, medication adherence, missed appointments, and emergency department visits. INTERVENTIONS: Structured diabetes education and follow-up text/phone messages for patients with HbA 1c levels 8% or higher were implemented over 3 months. RESULTS: Outcome data were available for 27 of the 34 participants. Postimplementation, there was a significant 1.7% decrease in mean HbA 1c levels ( P < .001). No significant differences were found for the other outcome measures. CONCLUSIONS: Structured diabetes education and follow-up text/phone messages in a free clinic improved patients' HbA 1c levels.


Subject(s)
Diabetes Mellitus , Telemedicine , Text Messaging , Humans , Follow-Up Studies , Outpatients
7.
JAMA Intern Med ; 182(5): 534-542, 2022 05 01.
Article in English | MEDLINE | ID: mdl-35343999

ABSTRACT

Background: Individuals with dementia or mild cognitive impairment frequently have multiple chronic conditions (defined as ≥2 chronic medical conditions) and take multiple medications, increasing their risk for adverse outcomes. Deprescribing (reducing or stopping medications for which potential harms outweigh potential benefits) may decrease their risk of adverse outcomes. Objective: To examine the effectiveness of increasing patient and clinician awareness about the potential to deprescribe unnecessary or risky medications among patients with dementia or mild cognitive impairment. Design, Setting, and Participants: This pragmatic, patient-centered, 12-month cluster randomized clinical trial was conducted from April 1, 2019, to March 31, 2020, at 18 primary care clinics in a not-for-profit integrated health care delivery system. The study included 3012 adults aged 65 years or older with dementia or mild cognitive impairment who had 1 or more additional chronic medical conditions and were taking 5 or more long-term medications. Interventions: An educational brochure and a questionnaire on attitudes toward deprescribing were mailed to patients prior to a primary care visit, clinicians were notified about the mailing, and deprescribing tip sheets were distributed to clinicians at monthly clinic meetings. Main Outcomes and Measures: The number of prescribed long-term medications and the percentage of individuals prescribed 1 or more potentially inappropriate medications (PIMs). Analysis was performed on an intention-to-treat basis. Results: This study comprised 1433 individuals (806 women [56.2%]; mean [SD] age, 80.1 [7.2] years) in 9 intervention clinics and 1579 individuals (874 women [55.4%]; mean [SD] age, 79.9 [7.5] years) in 9 control clinics who met the eligibility criteria. At baseline, both groups were prescribed a similar mean (SD) number of long-term medications (7.0 [2.1] in the intervention group and 7.0 [2.2] in the control group), and a similar proportion of individuals in both groups were taking 1 or more PIMs (437 of 1433 individuals [30.5%] in the intervention group and 467 of 1579 individuals [29.6%] in the control group). At 6 months, the adjusted mean number of long-term medications was similar in the intervention and control groups (6.4 [95% CI, 6.3-6.5] vs 6.5 [95% CI, 6.4-6.6]; P = .14). The estimated percentages of patients in the intervention and control groups taking 1 or more PIMs were similar (17.8% [95% CI, 15.4%-20.5%] vs 20.9% [95% CI, 18.4%-23.6%]; P = .08). In preplanned subgroup analyses, adjusted differences between the intervention and control groups were -0.16 (95% CI, -0.34 to 0.01) for individuals prescribed 7 or more long-term medications at baseline (n = 1434) and -0.03 (95% CI, -0.20 to 0.13) for those prescribed 5 to 6 medications (n = 1578) (P = .28 for interaction; P = .19 for subgroup interaction for PIMs). Conclusions and Relevance: This large-scale educational deprescribing intervention for older adults with cognitive impairment taking 5 or more long-term medications and their primary care clinicians demonstrated small effect sizes and did not significantly reduce the number of long-term medications and PIMs. Such interventions should target older adults taking relatively more medications. Trial Registration: ClinicalTrials.gov Identifier: NCT03984396.


Subject(s)
Cognitive Dysfunction , Dementia , Deprescriptions , Aged , Aged, 80 and over , Cognitive Dysfunction/drug therapy , Female , Humans , Male , Pharmaceutical Preparations , Potentially Inappropriate Medication List , Primary Health Care
8.
J Am Med Inform Assoc ; 29(7): 1217-1224, 2022 06 14.
Article in English | MEDLINE | ID: mdl-35348718

ABSTRACT

OBJECTIVE: Tumor registries in integrated healthcare systems (IHCS) have high precision for identifying incident cancer but often miss recently diagnosed cancers or those diagnosed outside of the IHCS. We developed an algorithm using the electronic medical record (EMR) to identify people with a history of cancer not captured in the tumor registry to identify adults, aged 40-65 years, with no history of cancer. MATERIALS AND METHODS: The algorithm was developed at Kaiser Permanente Colorado, and then applied to 7 other IHCS. We included tumor registry data, diagnosis and procedure codes, chemotherapy files, oncology encounters, and revenue data to develop the algorithm. Each IHCS adapted the algorithm to their EMR data and calculated sensitivity and specificity to evaluate the algorithm's performance after iterative chart review. RESULTS: We included data from over 1.26 million eligible people across 8 IHCS; 55 601 (4.4%) were in a tumor registry, and 44848 (3.5%) had a reported cancer not captured in a registry. The common attributes of the final algorithm at each site were diagnosis and procedure codes. The sensitivity of the algorithm at each IHCS was 90.65%-100%, and the specificity was 87.91%-100%. DISCUSSION: Relying only on tumor registry data would miss nearly half of the identified cancers. Our algorithm was robust and required only minor modifications to adapt to other EMR systems. CONCLUSION: This algorithm can identify cancer cases regardless of when the diagnosis occurred and may be useful for a variety of research applications or quality improvement projects around cancer care.


Subject(s)
Delivery of Health Care, Integrated , Neoplasms , Adult , Algorithms , Data Collection , Electronic Health Records , Humans , Neoplasms/diagnosis
9.
Appl Neuropsychol Adult ; 29(5): 941-945, 2022.
Article in English | MEDLINE | ID: mdl-33032451

ABSTRACT

Rapport in the context of neuropsychological testing refers to the level of interpersonal ease between examiner and examinee. However, scant research has examined the impact of rapport on neuropsychological test performance. The purpose of this between-subjects experiment was to investigate the impact of rapport on Stroop test performance. College students (N = 114) were randomly assigned to either a high or a low rapport condition and administered the D-KEFS Color-Word Interference Test. Individuals in the low rapport condition took longer to complete the Inhibition Trial of the Stroop test but did not vary on the Inhibition/Switching Trial. Low rapport may distract examinees, sapping attentional resources on the Inhibition Trial.


Subject(s)
Attention , Inhibition, Psychological , Humans , Neuropsychological Tests , Reaction Time , Stroop Test , Students
10.
J Pers Med ; 11(11)2021 Nov 13.
Article in English | MEDLINE | ID: mdl-34834546

ABSTRACT

Guidelines currently state that genetic testing is clinically indicated for all individuals diagnosed with ovarian cancer. Individuals with a prior diagnosis of ovarian cancer who have not received genetic testing represent missed opportunities to identify individuals with inherited high-risk cancer variants. For deceased individuals, post-mortem genetic testing of pathology specimens allows surviving family members to receive important genetic risk information. The Genetic Risk Assessment in Ovarian Cancer (GRACE) study aims to address this significant healthcare gap using a "traceback testing" approach to identify individuals with a prior diagnosis of ovarian cancer and offer genetic risk information to them and their family members. This study will assess the potential ethical and privacy concerns related to an ovarian cancer traceback testing approach in the context of patients who are deceased, followed by implementation and evaluation of the feasibility of an ovarian cancer traceback testing approach using tumor registries and archived pathology tissue. Descriptive and statistical analyses will assess health system and patient characteristics associated with the availability of pathology tissue and compare the ability to contact and uptake of genetic testing between patients who are living and deceased. The results of this study will inform the implementation of future traceback programs.

11.
J Am Chem Soc ; 143(12): 4714-4724, 2021 03 31.
Article in English | MEDLINE | ID: mdl-33739832

ABSTRACT

Prodrugs engineered for preferential activation in diseased versus normal tissues offer immense potential to improve the therapeutic indexes (TIs) of preclinical and clinical-stage active pharmaceutical ingredients that either cannot be developed otherwise or whose efficacy or tolerability it is highly desirable to improve. Such approaches, however, often suffer from trial-and-error design, precluding predictive synthesis and optimization. Here, using bromodomain and extra-terminal (BET) protein inhibitors (BETi)-a class of epigenetic regulators with proven anticancer potential but clinical development hindered in large part by narrow TIs-we introduce a macromolecular prodrug platform that overcomes these challenges. Through tuning of traceless linkers appended to a "bottlebrush prodrug" scaffold, we demonstrate correlation of in vitro prodrug activation kinetics with in vivo tumor pharmacokinetics, enabling the predictive design of novel BETi prodrugs with enhanced antitumor efficacies and devoid of dose-limiting toxicities in a syngeneic triple-negative breast cancer murine model. This work may have immediate clinical implications, introducing a platform for predictive prodrug design and potentially overcoming hurdles in drug development.


Subject(s)
Antineoplastic Agents/pharmacology , Drug Design , Prodrugs/pharmacology , Proteins/antagonists & inhibitors , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Humans , Macromolecular Substances/chemical synthesis , Macromolecular Substances/chemistry , Macromolecular Substances/pharmacology , Mammary Neoplasms, Experimental/drug therapy , Mammary Neoplasms, Experimental/metabolism , Mammary Neoplasms, Experimental/pathology , Mice , Molecular Structure , Prodrugs/chemical synthesis , Prodrugs/chemistry , Proteins/metabolism
12.
Nat Biomed Eng ; 2(11): 822-830, 2018 11.
Article in English | MEDLINE | ID: mdl-30918745

ABSTRACT

At present there are no drugs for the treatment of chronic liver fibrosis that have been approved by the Food and Drug administration of the United States. Telmisartan, a small-molecule antihypertensive drug, displays antifibrotic activity, but its clinical use is limited because it causes systemic hypotension. Here, we report the scalable and convergent synthesis of macromolecular telmisartan prodrugs optimized for preferential release in diseased liver tissue. We optimized the release of active telmisartan in fibrotic liver to be depot-like (that is, a constant therapeutic concentration) through the molecular design of telmisartan brush-arm star polymers, and show that these lead to improved efficacy and to the avoidance of dose-limiting hypotension in both metabolically and chemically induced mouse models of hepatic fibrosis, as determined by histopathology, enzyme levels in the liver, intact-tissue protein markers, hepatocyte necrosis protection, and gene-expression analyses. In rats and dogs, the prodrugs are retained long-term in liver tissue and have a well-tolerated safety profile. Our findings support the further development of telmisartan prodrugs that enable infrequent dosing in the treatment of liver fibrosis.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/therapeutic use , Drug Design , Liver Cirrhosis/drug therapy , Prodrugs/therapeutic use , Telmisartan/therapeutic use , Angiotensin II Type 1 Receptor Blockers/chemistry , Angiotensin II Type 1 Receptor Blockers/pharmacokinetics , Animals , Carbon Tetrachloride/toxicity , Disease Models, Animal , Female , Gene Expression Regulation/drug effects , Half-Life , Liver/metabolism , Liver Cirrhosis/chemically induced , Liver Cirrhosis/pathology , Male , Mice , Mice, Inbred BALB C , Polymers/chemistry , Prodrugs/chemistry , Prodrugs/pharmacokinetics , Rats , Rats, Sprague-Dawley , Telmisartan/chemistry
13.
Nat Biomed Eng ; 2(9): 707, 2018 Sep.
Article in English | MEDLINE | ID: mdl-31015683

ABSTRACT

In the version of this Article originally published, the author Peter Blume-Jensen was not denoted as a corresponding author; this has now been amended and the author's email address has been added. The 'Correspondence and requests for materials' statement was similarly affected and has now been updated with the author's initials 'P.B-J.'

14.
Biomaterials ; 105: 136-144, 2016 10.
Article in English | MEDLINE | ID: mdl-27521616

ABSTRACT

New treatments for glioblastoma multiforme (GBM) are desperately needed, as GBM prognosis remains poor, mainly due to treatment resistance, poor distribution of therapeutics in the tumor tissue, and fast metabolism of chemotherapeutic drugs in the brain extracellular space. Convection-enhanced delivery (CED) of nanoparticles (NPs) has been shown to improve the delivery of chemotherapeutic drugs to the tumor bed, providing sustained release, and enhancing survival of animals with intracranial tumors. Here we administered gemcitabine, a nucleoside analog used as a first line treatment for a wide variety of extracranial solid tumors, within squalene-based NPs using CED, to overcome the above-mentioned challenges of GBM treatment. Small percentages of poly(ethylene) glycol (PEG) dramatically enhanced the distribution of squalene-gemcitabine nanoparticles (SQ-Gem NPs) in healthy animals and tumor-bearing animals after administration by CED. When tested in an orthotopic model of GBM, SQ-Gem-PEG NPs demonstrated significantly improved therapeutic efficacy compared to free gemcitabine, both as a chemotherapeutic drug and as a radiosensitizer. Furthermore, MR contrast agents were incorporated into the SQ-Gem-PEG NP formulation, providing a way to non-invasively track the NPs during infusion.


Subject(s)
Brain Neoplasms/drug therapy , Deoxycytidine/analogs & derivatives , Glioblastoma/chemistry , Glioblastoma/drug therapy , Nanocapsules/administration & dosage , Polyethylene Glycols/chemistry , Absorption, Physicochemical , Animals , Antimetabolites, Antineoplastic/administration & dosage , Antimetabolites, Antineoplastic/chemistry , Antimetabolites, Antineoplastic/pharmacokinetics , Brain Neoplasms/chemistry , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Survival/drug effects , Deoxycytidine/administration & dosage , Deoxycytidine/chemistry , Deoxycytidine/pharmacokinetics , Diffusion , Dose-Response Relationship, Drug , Glioblastoma/pathology , Humans , Molecular Imaging/methods , Nanocapsules/chemistry , Rats , Squalene/administration & dosage , Squalene/chemistry , Squalene/pharmacokinetics , Treatment Outcome , Gemcitabine
15.
J Control Release ; 232: 103-12, 2016 06 28.
Article in English | MEDLINE | ID: mdl-27063424

ABSTRACT

Glioblastoma multiforme (GBM) is a fatal brain tumor characterized by infiltration beyond the margins of the main tumor mass and local recurrence after surgery. The blood-brain barrier (BBB) poses the most significant hurdle to brain tumor treatment. Convection-enhanced delivery (CED) allows for local administration of agents, overcoming the restrictions of the BBB. Recently, polymer nanoparticles have been demonstrated to penetrate readily through the healthy brain when delivered by CED, and size has been shown to be a critical factor for nanoparticle penetration. Because these brain-penetrating nanoparticles (BPNPs) have high potential for treatment of intracranial tumors since they offer the potential for cell targeting and controlled drug release after administration, here we investigated the intratumoral CED infusions of PLGA BPNPs in animals bearing either U87 or RG2 intracranial tumors. We demonstrate that the overall volume of distribution of these BPNPs was similar to that observed in healthy brains; however, the presence of tumors resulted in asymmetric and heterogeneous distribution patterns, with substantial leakage into the peritumoral tissue. Together, our results suggest that CED of BPNPs should be optimized by accounting for tumor geometry, in terms of location, size and presence of necrotic regions, to determine the ideal infusion site and parameters for individual tumors.


Subject(s)
Brain Neoplasms/metabolism , Convection , Drug Delivery Systems , Lactic Acid/administration & dosage , Nanoparticles/administration & dosage , Polyglycolic Acid/administration & dosage , Animals , Brain/metabolism , Brain/pathology , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Cell Line, Tumor , Glioblastoma/drug therapy , Glioblastoma/metabolism , Green Fluorescent Proteins/administration & dosage , Green Fluorescent Proteins/pharmacokinetics , Humans , Male , Polylactic Acid-Polyglycolic Acid Copolymer , Rats, Inbred F344 , Rats, Nude , Rats, Sprague-Dawley , Tumor Burden
16.
Biomaterials ; 89: 127-35, 2016 May.
Article in English | MEDLINE | ID: mdl-26967647

ABSTRACT

The foreign body response (FBR) begins with injury acquired during implantation of a biomaterial (BM) and is detrimental due to the eventual encapsulation of the implant. Fusion of macrophages to form foreign body giant cells (FBGC), a hallmark of the FBR, is the consequence of a multistep mechanism induced by interleukin (IL)-4 that includes the acquisition of a fusion competent state and subsequent cytoskeletal rearrangements. However, the precise mechanism, regulation, and interplay among molecular mediators to generate FBGCs are insufficiently understood. Seeking novel mediators of fusion that might be regulated at the post-transcriptional level, we examined the role of microRNAs (miRs) in this process. A miR microarray was screened and identified miR-223 as a negative regulator of macrophage fusion. In addition, transfection of primary macrophages with a mir-223 mimic attenuated IL-4-induced fusion. Furthermore, miR-223 KO mice and mir-223 deficient cells displayed increased fusion in vivo and in vitro, respectively. Finally, we developed a method for in vivo delivery of miR-223 mimic utilizing PLGA nanoparticles, which inhibited FBGC formation in a biomaterial implant model. Our results identify miR-223 as a negative regulator of fusion and demonstrate miR-223 mimic-loaded nanoparticles as a therapeutic inhibitor of macrophage fusion.


Subject(s)
Giant Cells, Foreign-Body/metabolism , Macrophages/metabolism , MicroRNAs/genetics , Animals , Cell Fusion , Cells, Cultured , Gene Expression Regulation , Giant Cells, Foreign-Body/cytology , Lactic Acid/chemistry , Macrophages/cytology , Mice , Mice, Knockout , MicroRNAs/administration & dosage , Nanoparticles/chemistry , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer
17.
J Drug Target ; 23(7-8): 736-49, 2015.
Article in English | MEDLINE | ID: mdl-26453169

ABSTRACT

Delivery of therapeutic agents to the central nervous system is a significant challenge, hindering progress in the treatment of diseases such as glioblastoma. Due to the presence of the blood-brain barrier (BBB), therapeutic agents do not readily transverse the brain endothelium to enter the parenchyma. Previous reports suggest that surface modification of polymer nanoparticles (NPs) can improve their ability to cross the BBB, but it is unclear whether the observed enhancements in transport are large enough to enhance therapy. In this study, we synthesized two degradable polymer NP systems surface-modified with ligands previously suggested to improve BBB transport, and tested their ability to cross the BBB after intravenous injection in mice. All the NP preparations were able to cross the BBB, although generally in low amounts (<0.5% of the injected dose), which was consistent with prior reports. One NP produced significantly higher brain uptake (∼0.8% of the injected dose): a block copolymer of polylactic acid and hyperbranched polyglycerol, surface modified with adenosine (PLA-HPG-Ad). PLA-HPG-Ad NPs provided controlled release of camptothecin, killing U87 glioma cells in culture. When administered intravenously in mice with intracranial U87 tumors, they failed to increase survival. These results suggest that enhancing NP transport across the BBB does not necessarily yield proportional pharmacological effects.


Subject(s)
Brain/metabolism , Camptothecin/administration & dosage , Drug Delivery Systems , Nanoparticles , Animals , Antineoplastic Agents, Phytogenic/administration & dosage , Antineoplastic Agents, Phytogenic/pharmacokinetics , Antineoplastic Agents, Phytogenic/pharmacology , Biological Transport , Blood-Brain Barrier/metabolism , Brain/pathology , Brain Neoplasms/drug therapy , Brain Neoplasms/pathology , Camptothecin/pharmacokinetics , Camptothecin/pharmacology , Cell Line, Tumor , Delayed-Action Preparations , Drug Carriers/chemistry , Glioma/drug therapy , Glioma/pathology , Humans , Injections, Intravenous , Mice , Mice, Inbred BALB C , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/pathology , Polymers/chemistry , Tissue Distribution
18.
Nat Rev Drug Discov ; 14(4): 239-47, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25598505

ABSTRACT

The primary goal of nanomedicine is to improve clinical outcomes. To this end, targeted nanoparticles are engineered to reduce non-productive distribution while improving diagnostic and therapeutic efficacy. Paradoxically, as this field has matured, the notion of targeting has been minimized to the concept of increasing the affinity of a nanoparticle for its target. This Opinion article outlines a holistic view of nanoparticle targeting, in which the route of administration, molecular characteristics and temporal control of the nanoparticles are potential design variables that must be considered simultaneously. This comprehensive vision for nanoparticle targeting will facilitate the integration of nanomedicines into clinical practice.


Subject(s)
Drug Delivery Systems/methods , Nanoparticles/chemistry , Polymers/chemistry , Animals , Humans , Nanomedicine
19.
Br J Haematol ; 168(6): 845-53, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25382494

ABSTRACT

(18) F-labelled-fluorodeoxyglucose positron emission tomography (FDG-PET) findings are challenging to interpret for residual disease versus complete response in paediatric patients with non-Hodgkin lymphoma (NHL). A biopsy is often warranted to confirm the presence or absence of viable tumour if there is clinical or radiographic evidence of residual disease. In this study, we compared conventional imaging and FDG-PET/computerized tomography (CT) findings with biopsy results in 18 children with NHL. Our goal was to provide additional data to establish more reliable criteria for response evaluation. Residual disease was suspected after conventional imaging alone in eight patients, after FDG-PET/CT alone in three and after both modalities in seven patients. Biopsy confirmed the presence of viable tumour in two patients. Two additional patients experienced progressive disease or relapse. The sensitivity and negative predictive value of FDG-PET/CT using the London criteria to indicate residual tumour detectable by biopsy were 100%, but specificity was low (60%), as was the positive predictive value (25%). Thus, in this study, a negative FDG-PET/CT finding was a good indicator of complete remission. However, because false-positive FDG-PET/CT findings are common, biopsy and close monitoring are required for accurate determination of residual disease in individual patients.


Subject(s)
Lymphoma, Non-Hodgkin/diagnosis , Adolescent , Biopsy , Child , Child, Preschool , Disease Progression , Fluorodeoxyglucose F18 , Humans , Lymphoma, Non-Hodgkin/pathology , Multimodal Imaging/methods , Neoplasm, Residual , Positron-Emission Tomography/methods , Predictive Value of Tests , Prognosis , Radiopharmaceuticals , Retrospective Studies , Sensitivity and Specificity , Tomography, X-Ray Computed/methods , Young Adult
20.
Biomaterials ; 35(25): 6698-706, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24881026

ABSTRACT

Intracranial implants elicit neurodegeneration via the foreign body response (FBR) that includes BBB leakage, macrophage/microglia accumulation, and reactive astrogliosis, in addition to neuronal degradation that limit their useful lifespan. Previously, monocyte chemoattractant protein 1 (MCP-1, also CCL2), which plays an important role in monocyte recruitment and propagation of inflammation, was shown to be critical for various aspects of the FBR in a tissue-specific manner. However, participation of MCP-1 in the brain FBR has not been evaluated. Here we examined the FBR to intracortical silicon implants in MCP-1 KO mice at 1, 2, and 8 weeks after implantation. MCP-1 KO mice had a diminished FBR compared to WT mice, characterized by reductions in BBB leakage, macrophage/microglia accumulation, and astrogliosis, and an increased neuronal density. Moreover, pharmacological inhibition of MCP-1 in implant-bearing WT mice maintained the increased neuronal density. To elucidate the relative contribution of microglia and macrophages, bone marrow chimeras were generated between MCP-1 KO and WT mice. Increased neuronal density was observed only in MCP-1 knockout mice transplanted with MCP-1 knockout marrow, which indicates that resident cells in the brain are major contributors. We hypothesized that these improvements are the result of a phenotypic switch of the macrophages/microglia polarization state, which we confirmed using PCR for common activation markers. Our observations suggest that MCP-1 influences neuronal loss, which is integral to the progression of neurological disorders like Alzheimer's and Parkinson disease, via BBB leakage and macrophage polarization.


Subject(s)
Chemokine CCL2/metabolism , Foreign-Body Reaction/therapy , Neurodegenerative Diseases/therapy , Neurons/metabolism , Animals , Benzoxazines/pharmacology , Blood-Brain Barrier/metabolism , Brain/metabolism , Cell Survival/drug effects , Chronic Disease , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Microglia/metabolism , Piperidines/pharmacology , Prostheses and Implants , Receptors, CCR2/antagonists & inhibitors , Receptors, CCR2/metabolism , Tissue Engineering
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