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1.
Cancer Discov ; : OF1-OF22, 2024 Jan 25.
Article in English | MEDLINE | ID: mdl-38270272

ABSTRACT

The limited efficacy of currently approved immunotherapies in EGFR-driven lung adenocarcinoma (LUAD) underscores the need to better understand alternative mechanisms governing local immunosuppression to fuel novel therapies. Elevated surfactant and GM-CSF secretion from the transformed epithelium induces tumor-associated alveolar macrophage (TA-AM) proliferation, which supports tumor growth by rewiring inflammatory functions and lipid metabolism. TA-AM properties are driven by increased GM-CSF-PPARγ signaling and inhibition of airway GM-CSF or PPARγ in TA-AMs suppresses cholesterol efflux to tumor cells, which impairs EGFR phosphorylation and restrains LUAD progression. In the absence of TA-AM metabolic support, LUAD cells compensate by increasing cholesterol synthesis, and blocking PPARγ in TA-AMs simultaneous with statin therapy further suppresses tumor progression and increases proinflammatory immune responses. These results reveal new therapeutic combinations for immunotherapy-resistant EGFR-mutant LUADs and demonstrate how cancer cells can metabolically co-opt TA-AMs through GM-CSF-PPARγ signaling to provide nutrients that promote oncogenic signaling and growth. SIGNIFICANCE: Alternate strategies harnessing anticancer innate immunity are required for lung cancers with poor response rates to T cell-based immunotherapies. This study identifies a targetable, mutually supportive, metabolic relationship between macrophages and transformed epithelium, which is exploited by tumors to obtain metabolic and immunologic support to sustain proliferation and oncogenic signaling.

2.
Cancer Discov ; 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38241033

ABSTRACT

The limited efficacy of currently approved immunotherapies in EGFR-driven lung adenocarcinoma (LUAD) underscores the need to better understand alternative mechanisms governing local immunosuppression to fuel novel therapies. Elevated surfactant and GM-CSF secretion from the transformed epithelium induces tumor-associated alveolar macrophage (TA-AM) proliferation which supports tumor growth by rewiring inflammatory functions and lipid metabolism. TA-AM properties are driven by increased GM-CSF-PPARγ signaling and inhibition of airway GM-CSF or PPARγ in TA-AMs suppresses cholesterol efflux to tumor cells, which impairs EGFR phosphorylation and restrains LUAD progression. In the absence of TA-AM metabolic support, LUAD cells compensate by increasing cholesterol synthesis, and blocking PPARγ in TA-AMs simultaneous with statin therapy further suppresses tumor progression and increases proinflammatory immune responses. These results reveal new therapeutic combinations for immunotherapy resistant EGFR-mutant LUADs and demonstrate how cancer cells can metabolically co-opt TA-AMs through GM-CSF-PPARγ signaling to provide nutrients that promote oncogenic signaling and growth.

3.
bioRxiv ; 2023 Apr 17.
Article in English | MEDLINE | ID: mdl-37131637

ABSTRACT

The limited efficacy of currently approved immunotherapies in EGFR-mutant lung adenocarcinoma (LUAD) underscores the need to better understand mechanisms governing local immunosuppression. Elevated surfactant and GM-CSF secretion from the transformed epithelium induces tumor-associated alveolar macrophages (TA-AM) to proliferate and support tumor growth by rewiring inflammatory functions and lipid metabolism. TA-AM properties are driven by increased GM-CSF-PPARγ signaling and inhibition of airway GM-CSF or PPARγ in TA-AMs suppresses cholesterol efflux to tumor cells, which impairs EGFR phosphorylation and restrains LUAD progression. In the absence of TA-AM metabolic support, LUAD cells compensate by increasing cholesterol synthesis, and blocking PPARγ in TA-AMs simultaneous with statin therapy further suppresses tumor progression and increases T cell effector functions. These results reveal new therapeutic combinations for immunotherapy resistant EGFR-mutant LUADs and demonstrate how such cancer cells can metabolically co-opt TA-AMs through GM-CSF-PPARγ signaling to provide nutrients that promote oncogenic signaling and growth.

4.
bioRxiv ; 2023 Jan 27.
Article in English | MEDLINE | ID: mdl-36747824

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) causes an acute respiratory distress syndrome (ARDS) that resembles surfactant deficient RDS. Using a novel multi-cell type, human induced pluripotent stem cell (hiPSC)-derived lung organoid (LO) system, validated against primary lung cells, we found that inflammatory cytokine/chemokine production and interferon (IFN) responses are dynamically regulated autonomously within the lung following SARS-CoV-2 infection, an intrinsic defense mechanism mediated by surfactant proteins (SP). Single cell RNA sequencing revealed broad infectability of most lung cell types through canonical (ACE2) and non-canonical (endocytotic) viral entry routes. SARS-CoV-2 triggers rapid apoptosis, impairing viral dissemination. In the absence of surfactant protein B (SP-B), resistance to infection was impaired and cytokine/chemokine production and IFN responses were modulated. Exogenous surfactant, recombinant SP-B, or genomic correction of the SP-B deletion restored resistance to SARS-CoV-2 and improved viability.

5.
Stud Health Technol Inform ; 298: 3-7, 2022 Aug 31.
Article in English | MEDLINE | ID: mdl-36073446

ABSTRACT

The relationship between poor EHR training and subsequent poor usability is increasingly being recognized. We utilized objective EHR audit log data to personalize EHR training with the goal of improving EHR usability and to identify changes in physician perceptions pre- and post-intervention. We found that time in the system and Pajama time decreased post-coaching intervention. Different physician perceptions were reported pre- and post-coaching. Overall, personalized EHR coaching improved the usability and perceptions of physicians.


Subject(s)
Mentoring , Physicians , Electronic Health Records , Humans , Perception
6.
BMC Geriatr ; 22(1): 619, 2022 07 26.
Article in English | MEDLINE | ID: mdl-35883050

ABSTRACT

BACKGROUND: Improving health-related quality of life (HRQOL) is becoming a major focus of old age care and social policy. Researchers have been increasingly examining subjective social status (SSS), one's self-perceived social position, as a predictor of various health conditions. SSS encompasses not only concrete socio-economic (SES) factors but also intangible aspects of status. This study's main objective was to examine the association between SSS and long-term change in HRQOL in older Chinese adults. METHODS: A longitudinal Hong Kong study recruited 2934 community-dwelling adults (age > 65 years). Participants completed SF-12 physical health (PCS) and mental health (MCS) HRQOL scales. This study analyzed baseline SSS-Society (self-perceived social status within Hong Kong) and SSS-Community (self-perceived status within one's own social network) as predictors of long-term HRQOL decline. After stratifying for sex, multiple-linear-regression was performed on 4-year follow-up SF-12 PCS and MCS scores after adjusting for baseline SF-12 scores, traditional SES indicators, demographic variables, clinical conditions, and lifestyle variables. RESULTS: In the multivariable analyses, lower SSS-Society was associated with declines in MCS in males (ßstandardized = 0.08, p = 0.001) and declines in PCS (ßstandardized = 0.07, p = 0.006) and MCS (ßstandardized = 0.12, p < 0.001) in females. SSS-Community was associated with declines in PCS in males (ßstandardized = 0.07, p = 0.005) and MCS in females (ßstandardized = 0.14, p < 0.001). CONCLUSIONS: SSS may be a useful supplementary tool for predicting risk of long-term HRQOL decline in older Chinese adults. Strategies to reduce perceived social inequalities may improve HRQOL in older adults.


Subject(s)
Quality of Life , Social Status , Aged , Female , Hong Kong/epidemiology , Humans , Longitudinal Studies , Male , Middle Aged , Quality of Life/psychology , Socioeconomic Factors
7.
Stud Health Technol Inform ; 294: 905-909, 2022 May 25.
Article in English | MEDLINE | ID: mdl-35612240

ABSTRACT

There is limited knowledge on whether increased telehealth usage may enhance health access to communities during natural disasters, particularly for emergency medical services. This study aimed to elucidate telehealth usage during three hurricanes in NC between 2018 and 2020 and assessed demographics of users including gender and age, insurance status, and daily rate of visits in relation to respective hurricanes. From 10,056 telehealth visits, we found that age and insurance coverage were significantly different between crisis and non-crisis times. Patients found comparative satisfaction during both times. This study suggests the use of phone and video visits to enable better access to parents with children under the age of 18 years and uninsured patients.


Subject(s)
COVID-19 , Telemedicine , Adolescent , Child , Humans
8.
Res Sq ; 2022 Mar 17.
Article in English | MEDLINE | ID: mdl-35313591

ABSTRACT

The COVID-19 pandemic is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The betacoronvirus has a positive sense RNA genome which encodes for several RNA binding proteins. Here, we use enhanced crosslinking and immunoprecipitation to investigate SARS-CoV-2 protein interactions with viral and host RNAs in authentic virus-infected cells. SARS-CoV-2 proteins, NSP8, NSP12, and nucleocapsid display distinct preferences to specific regions in the RNA viral genome, providing evidence for their shared and separate roles in replication, transcription, and viral packaging. SARS-CoV-2 proteins expressed in human lung epithelial cells bind to 4773 unique host coding RNAs. Nine SARS-CoV-2 proteins upregulate target gene expression, including NSP12 and ORF9c, whose RNA substrates are associated with pathways in protein N-linked glycosylation ER processing and mitochondrial processes. Furthermore, siRNA knockdown of host genes targeted by viral proteins in human lung organoid cells identify potential antiviral host targets across different SARS-CoV-2 variants. Conversely, NSP9 inhibits host gene expression by blocking mRNA export and dampens cytokine productions, including interleukin-1α/ß. Our viral protein-RNA interactome provides a catalog of potential therapeutic targets and offers insight into the etiology of COVID-19 as a safeguard against future pandemics.

9.
bioRxiv ; 2022 Feb 23.
Article in English | MEDLINE | ID: mdl-35233578

ABSTRACT

The COVID-19 pandemic is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The betacoronvirus has a positive sense RNA genome which encodes for several RNA binding proteins. Here, we use enhanced crosslinking and immunoprecipitation to investigate SARS-CoV-2 protein interactions with viral and host RNAs in authentic virus-infected cells. SARS-CoV-2 proteins, NSP8, NSP12, and nucleocapsid display distinct preferences to specific regions in the RNA viral genome, providing evidence for their shared and separate roles in replication, transcription, and viral packaging. SARS-CoV-2 proteins expressed in human lung epithelial cells bind to 4773 unique host coding RNAs. Nine SARS-CoV-2 proteins upregulate target gene expression, including NSP12 and ORF9c, whose RNA substrates are associated with pathways in protein N-linked glycosylation ER processing and mitochondrial processes. Furthermore, siRNA knockdown of host genes targeted by viral proteins in human lung organoid cells identify potential antiviral host targets across different SARS-CoV-2 variants. Conversely, NSP9 inhibits host gene expression by blocking mRNA export and dampens cytokine productions, including interleukin-1α/ß. Our viral protein-RNA interactome provides a catalog of potential therapeutic targets and offers insight into the etiology of COVID-19 as a safeguard against future pandemics.

10.
Cell Signal ; 89: 110170, 2022 01.
Article in English | MEDLINE | ID: mdl-34673141

ABSTRACT

Autophagy is a multi-step process regulated in part by AMP-activated protein kinase (AMPK). Phosphorylation of threonine 172 on the AMPK α-subunit enhances AMPK kinase activity, resulting in activation of downstream signaling. Integrin-mediated cell adhesion activates Src/ Focal Adhesion Kinase (FAK) signaling complex, which regulates multiple cellular processes including cell survival. We show here that Src signaling leads to direct phosphorylation of the AMPK-α subunit on a novel site, tyrosine 179, resulting in suppression of AMPK-T172 phosphorylation and autophagy upon integrin-mediated cell adhesion. By using chemical inhibitors, genetic cell models and targeted mutagenesis, we confirm an important role for Src and FAK in suppressing AMPK signaling and autophagy induced by various additional stimuli, including glucose starvation. Furthermore, we found that autophagy suppression by hydroxychloroquine promotes apoptosis in a cancer cell model that had been treated with Src inhibitors. Our findings reveal a link between the Src/ FAK complex and AMPK/ autophagy regulation, which may play an important role in the maintenance of normal cellular homeostasis and tumor progression.


Subject(s)
AMP-Activated Protein Kinases , src-Family Kinases , AMP-Activated Protein Kinases/metabolism , Autophagy , Cell Adhesion , Focal Adhesion Kinase 1/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Phosphorylation , src-Family Kinases/metabolism
11.
J Biol Chem ; 298(1): 101477, 2022 01.
Article in English | MEDLINE | ID: mdl-34896393

ABSTRACT

Disturbance of the dynamic balance between tyrosine phosphorylation and dephosphorylation of signaling molecules, controlled by protein tyrosine kinases and protein tyrosine phosphatases (PTPs), is known to lead to the development of cancer. While most approved targeted cancer therapies are tyrosine kinase inhibitors, PTPs have long been stigmatized as undruggable and have only recently gained renewed attention in drug discovery. One PTP target is the Src-homology 2 domain-containing phosphatase 2 (SHP2). SHP2 is implicated in tumor initiation, progression, metastasis, and treatment resistance, primarily because of its role as a signaling nexus of the extracellular signal-regulated kinase pathway, acting upstream of the small GTPase Ras. Efforts to develop small molecules that target SHP2 are ongoing, and several SHP2 allosteric inhibitors are currently in clinical trials for the treatment of solid tumors. However, while the reported allosteric inhibitors are highly effective against cells expressing WT SHP2, none have significant activity against the most frequent oncogenic SHP2 variants that drive leukemogenesis in several juvenile and acute leukemias. Here, we report the discovery of novel furanylbenzamide molecules as inhibitors of both WT and oncogenic SHP2. Importantly, these inhibitors readily cross cell membranes, bind and inhibit SHP2 under physiological conditions, and effectively decrease the growth of cancer cells, including triple-negative breast cancer cells, acute myeloid leukemia cells expressing either WT or oncogenic SHP2, and patient-derived acute myeloid leukemia cells. These novel compounds are effective chemical probes of active SHP2 and may serve as starting points for therapeutics targeting WT or mutant SHP2 in cancer.


Subject(s)
Benzamides , Enzyme Inhibitors , Leukemia, Myeloid, Acute , Protein Tyrosine Phosphatase, Non-Receptor Type 11 , Benzamides/pharmacology , Carcinogenesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/enzymology , Oncogenes , Protein Tyrosine Phosphatase, Non-Receptor Type 11/antagonists & inhibitors , Protein Tyrosine Phosphatase, Non-Receptor Type 11/metabolism
12.
bioRxiv ; 2021 Mar 26.
Article in English | MEDLINE | ID: mdl-33791697

ABSTRACT

We identify the prolyl-tRNA synthetase (PRS) inhibitor halofuginone 1 , a compound in clinical trials for anti-fibrotic and anti-inflammatory applications 2 , as a potent inhibitor of SARS-CoV-2 infection and replication. The interaction of SARS-CoV-2 spike protein with cell surface heparan sulfate (HS) promotes viral entry 3 . We find that halofuginone reduces HS biosynthesis, thereby reducing spike protein binding, SARS-CoV-2 pseudotyped virus, and authentic SARS-CoV-2 infection. Halofuginone also potently suppresses SARS-CoV-2 replication post-entry and is 1,000-fold more potent than Remdesivir 4 . Inhibition of HS biosynthesis and SARS-CoV-2 infection depends on specific inhibition of PRS, possibly due to translational suppression of proline-rich proteins. We find that pp1a and pp1ab polyproteins of SARS-CoV-2, as well as several HS proteoglycans, are proline-rich, which may make them particularly vulnerable to halofuginone's translational suppression. Halofuginone is orally bioavailable, has been evaluated in a phase I clinical trial in humans and distributes to SARS-CoV-2 target organs, including the lung, making it a near-term clinical trial candidate for the treatment of COVID-19.

13.
Am J Geriatr Psychiatry ; 29(11): 1140-1151, 2021 11.
Article in English | MEDLINE | ID: mdl-33563520

ABSTRACT

OBJECTIVE: Subjective social status (SSS), one's self-perceived social position, encompasses not only concrete socio-economic (SES) factors (e.g., income) but also intangible aspects of status (e.g., social capital). In recent years, there has been increasing research interest in SSS as a predictor of a vast array of health outcomes but very few studies examining effects on cognitive functioning. This study's main objective was to examine the association between SSS and long-term cognitive decline in older Chinese adults. DESIGN: A 4-year longitudinal study. SETTING: Hong Kong, China. PARTICIPANTS: Chinese adults (aged ≥65) (n = 3,153). MEASUREMENTS: This study analyzed baseline SSS-Hong Kong (self-perceived social status within Hong Kong) and SSS-Community (self-perceived status within one's own social network) as predictors of long-term cognitive decline. Multiple-linear-regression was performed on 4-year follow-up Mini-Mental-Status-Examination (MMSE) cognitive function score (score range: 0-30) after adjusting for baseline MMSE scores, traditional SES indicators (e.g., education), demographic variables (e.g., sex), clinical conditions (e.g., stroke history, depression), and lifestyle variables (e.g., physical activity levels). RESULTS: Lower SSS-Community but not SSS-Hong Kong was associated with greater cognitive decline (unstandardized coefficient (95% CI) = 0.13 (0.07, 0.19) standardized ß-coefficient = 0.08, after adjusting for objective SES measures and other background and clinical factors. The standardized ß-coefficients for the SSS-Community variable were similar in magnitude to those for depression and diabetes. CONCLUSION: Cognitive decline is influenced by self-perceived rank in proximal reference groups rather than socioeconomic comparison with society at-large. SSS-Community is a useful, single-item supplementary instrument to improve prediction of cognitive decline in elderly Chinese.


Subject(s)
Cognitive Dysfunction , Psychological Distance , Aged , China/epidemiology , Cognitive Dysfunction/diagnosis , Cognitive Dysfunction/epidemiology , Hong Kong/epidemiology , Humans , Longitudinal Studies , Middle Aged , Social Class
14.
Cell ; 183(4): 1043-1057.e15, 2020 11 12.
Article in English | MEDLINE | ID: mdl-32970989

ABSTRACT

We show that SARS-CoV-2 spike protein interacts with both cellular heparan sulfate and angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain (RBD). Docking studies suggest a heparin/heparan sulfate-binding site adjacent to the ACE2-binding site. Both ACE2 and heparin can bind independently to spike protein in vitro, and a ternary complex can be generated using heparin as a scaffold. Electron micrographs of spike protein suggests that heparin enhances the open conformation of the RBD that binds ACE2. On cells, spike protein binding depends on both heparan sulfate and ACE2. Unfractionated heparin, non-anticoagulant heparin, heparin lyases, and lung heparan sulfate potently block spike protein binding and/or infection by pseudotyped virus and authentic SARS-CoV-2 virus. We suggest a model in which viral attachment and infection involves heparan sulfate-dependent enhancement of binding to ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin presents new therapeutic opportunities.


Subject(s)
Betacoronavirus/physiology , Heparitin Sulfate/metabolism , Peptidyl-Dipeptidase A/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Amino Acid Sequence , Angiotensin-Converting Enzyme 2 , Betacoronavirus/isolation & purification , Binding Sites , COVID-19 , Cell Line , Coronavirus Infections/pathology , Coronavirus Infections/virology , Heparin/chemistry , Heparin/metabolism , Heparitin Sulfate/chemistry , Humans , Kidney/metabolism , Lung/metabolism , Molecular Dynamics Simulation , Pandemics , Peptidyl-Dipeptidase A/chemistry , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protein Binding , Protein Domains , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Virus Internalization
15.
J Epidemiol Community Health ; 74(11): 882-891, 2020 11.
Article in English | MEDLINE | ID: mdl-32631845

ABSTRACT

BACKGROUND: Subjective social status (SSS), one's self-perceived social status, has been gaining interest among researchers as a risk/protective factor of many health outcomes. SSS encompasses both socio-economic factors (eg, income) and intangible aspects of status (eg, esteem from peers). This study's main objective was to examine the association between SSS and future risk of depression in elderly Chinese. METHODS: Using data from the ongoing Mr/Mrs Os study, a longitudinal study of Hong Kong Chinese elderly, this study analysed baseline SSS-Hong Kong (self-perceived social status within Hong Kong) and SSS-Community (self-perceived status within one's own social network) as predictors of Geriatric Depression Scale (GDS) score at year 4 (n=3153). The models adjusted for baseline depression scores, socio-economic status indicators, demographic variables, clinical conditions and functional status variables. RESULTS: Higher depression scores at follow-up were independently associated with lower SSS-Hong Kong (standardised ß-coefficient= -0.040, p=0.017), lower SSS-Community (standardised ß-coefficient= -0.057, p=0.001), in addition to older age, female gender and stroke history. After stratifying by dementia status, higher baseline SSS was associated with less depressive symptoms only in the non-dementia group. In the multivariable models that included both SSS variables, only SSS-Community was significantly associated with year 4 GDS score. However, both SSS variables were independently associated with year 4 depression status in the logistic regression analysis. CONCLUSION: In Chinese elderly, SSS captures aspects of social status that are not captured by traditional socio-economic indicators. SSS can be a useful supplementary tool for assessing future risk of developing mental health conditions.


Subject(s)
Depression , Psychological Distance , Social Class , Aged , Depression/epidemiology , Female , Hong Kong/epidemiology , Humans , Longitudinal Studies , Male
16.
J Pharm Sci ; 104(3): 865-71, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25482223

ABSTRACT

Current industry perspective of how discovery is conducted seems to be fragmented and does not have a unified overall outlook of how discovery challenges are being addressed. Consequently, well-defined processes and drug-likeness criteria are being viewed as "broken" and will not maintain future R&D productivity. In this commentary, an analysis of existing practices for defining successful development candidates resulted in a 5 "must do" list to help advance Drug Discovery as presented from a Pharmaceutics perspective. The 5 "must do" list includes: what an ideal discovery team model should look like, what criteria should be considered for the desired development candidate profile, what the building blocks of the development candidate should look like, and how to assess the development risks of the candidate.


Subject(s)
Drug Discovery/trends , Drug Industry/trends , Pharmaceutical Preparations/chemistry , Animals , Consumer Product Safety , Cooperative Behavior , Humans , Interdisciplinary Communication , Patient Safety , Pharmaceutical Preparations/metabolism , Pharmacokinetics , Risk Assessment , Solubility , Workflow
17.
Mol Pharm ; 11(11): 4228-37, 2014 Nov 03.
Article in English | MEDLINE | ID: mdl-25325389

ABSTRACT

Physical instability of amorphous solid dispersions can be a major impediment to their widespread use. We characterized the molecular mobility in amorphous solid dispersions of itraconazole (ITZ) with each polyvinylpyrrolidone (PVP) and hydroxypropylmethylcellulose acetate succinate (HPMCAS) with the goal of investigating the correlation between molecular mobility and physical stability. Dielectric spectra showed two mobility modes: α-relaxation at temperatures above the glass transition temperature (Tg) and ß-relaxation in the sub-Tg range. HPMCAS substantially increased the α-relaxation time, with an attendant increase in crystallization onset time and a decrease in crystallization rate constant, demonstrating the correlation between α-relaxation and stability. The inhibitory effect on α-relaxation as well as stability was temperature dependent and diminished as the temperature was increased above Tg. PVP, on the other hand, affected neither the α-relaxation time nor the crystallization onset time, further establishing the link between α-relaxation and crystallization onset in solid dispersions. However, it inhibited the crystallization rate, an effect attributed to factors other than mobility. Interestingly, both of the polymers acted as plasticizers of ß-relaxation, ruling out the latter's involvement in physical stability.


Subject(s)
Drug Stability , Itraconazole/chemistry , Methylcellulose/analogs & derivatives , Povidone/chemistry , Crystallization , Kinetics , Methylcellulose/chemistry , Synchrotrons , Temperature , X-Ray Diffraction
18.
Int J Pharm ; 473(1-2): 10-9, 2014 Oct 01.
Article in English | MEDLINE | ID: mdl-24984068

ABSTRACT

Drug discovery and development is a challenging area. During the drug optimization process, available drug compounds often have poor physicochemical and biopharmaceutical properties, making the proper in vivo evaluation of these compounds difficult. To address these challenges, drug nanoparticles of poorly soluble compounds have emerged as a promising formulation approach. Herein, we report on a new drug sparing technology utilizing low shear acoustic mixing to rapidly identify optimized nanosuspension formulations for a wide range of compounds with dramatically improved material and time efficiencies. This approach has several key advantages over typical methods of preparing nanoparticles, including miniaturization of the milling process, the ability to evaluate multiple formulation conditions in a high throughput manner, and direct translation to optimized formulation scale-up for in vivo studies. Furthermore, there are additional benefits obtained with this new approach resulting in nanosuspension formulations with significant stability and physical property enhancements over those obtained using traditional media milling techniques. These advantages make this approach highly suitable for the rapid evaluation of potential drug candidates in the discovery and development space.


Subject(s)
Drug Compounding/methods , Acoustics , Computer Simulation , Drug Stability , Hydrodynamics , Nanoparticles/chemistry , Naproxen/chemistry , Particle Size , Polymers/chemistry , Surface-Active Agents/chemistry , Suspensions , Viscosity
19.
BMC Complement Altern Med ; 13: 336, 2013 Nov 27.
Article in English | MEDLINE | ID: mdl-24279604

ABSTRACT

BACKGROUND: Although over-the-counter traditional Chinese herbal medicine (COTC) is commonly used to treat everyday illness in many parts of the world, no population-based study has been done to examine the prevalence and factors associated with COTC-related adverse events. METHODS: A cross-sectional telephone survey was conducted among Hong Kong Chinese adults in 2011 (n = 1100) with informed verbal consent. Stepwise logistic regression of demographic, attitudinal and behavioral variables was used to determine factors associated with past-year adverse events. RESULTS: Of study respondents, 71.7% (789/1100) reported past-year COTC use and 2.3% (25/1100) reported at least one COTC-related adverse event in the past year. Of the 27 adverse events cases reported among COTC users, the most common were allergic reactions (n = 11) dizziness (n = 5), and gastro-intestinal problems (n = 4). Pills/capsules were the dosage form that caused the highest proportion of adverse events (n = 10), followed by plasters (n = 7), creams/ointments (n = 5), and ingestible powders (n = 2).Although COTC users reporting adverse events were more likely to report greater practices to avoid adverse events (OR = 6.47; 95% CI: 1.38-30.3); they were also more likely to possess lower education levels (OR = 9.64, 95% CI: 2.20-42.3) and to have received COTC information from non-reliable, mass-media information sources such as magazines (OR = 3.32; 95% CI: 1.01-8.50) or television (OR = 2.93; 95% CI: 1.03-10.7). Package labels were also felt to be unclear by 42.9% of COTC users. A large proportion of COTC users demonstrated low levels of COTC-related knowledge, while the main impediment to greater information-seeking was the belief that reliable COTC information is not obtainable from Western health professionals. CONCLUSIONS: Despite global movements toward more stringent complementary medicine regulation, the limited accessibility of reliable information and widespread misperceptions among consumers present major challenges for the safe use of complementary medicine.


Subject(s)
Drugs, Chinese Herbal/adverse effects , Nonprescription Drugs/adverse effects , Adolescent , Adult , Aged , Female , Health Knowledge, Attitudes, Practice , Hong Kong/epidemiology , Humans , Male , Medicine, Chinese Traditional , Middle Aged , Socioeconomic Factors
20.
Mol Pharm ; 10(2): 694-700, 2013 Feb 04.
Article in English | MEDLINE | ID: mdl-23198856

ABSTRACT

The goal was to investigate the correlation between molecular mobility and physical stability in amorphous itraconazole and identify the specific mobility mode responsible for its instability. The molecular mobility of amorphous itraconazole, in the glassy as well as the supercooled liquid state, was comprehensively characterized using dynamic dielectric spectroscopy. Isothermal frequency sweeps in the 5-40 °C temperature range revealed a ß-relaxation which exhibited Arrhenius temperature dependence. As the temperature approached T(g), ß-relaxation became progressively less resolved due to interference from the high frequency tail of the α-relaxation and then transformed into an excess wing. Above T(g), nonlinear temperature dependence of the α-relaxation was described by the Vogel-Tammann-Fulcher (VTF) model. Itraconazole was found to be a fragile glass former with a VTF strength parameter of ∼4. Isothermal crystallization kinetics, at several temperatures over the range of 75 to 95 °C, was best described by the 3-dimensional nucleation and growth model. Primary relaxation appeared to be the mobility responsible for the observed physical instability at temperatures above T(g) as indicated by the linear correlation of α-relaxation with both crystallization onset and kinetics (represented by the inverse of the crystallization rate constant). A strong coupling between global mobility and crystallization onset was evident. However, for growth kinetics, the coupling was less pronounced, indicating the involvement of factors other than global mobility.


Subject(s)
Itraconazole/chemistry , Crystallization , Kinetics
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