Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 13 de 13
Filter
1.
Pulm Ther ; 8(2): 195-208, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35467260

ABSTRACT

INTRODUCTION: Single-inhaler fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) triple therapy was approved by the United States Food and Drug Administration in 2017 as a maintenance therapy for chronic obstructive pulmonary disease (COPD). Patient characteristics and treatment patterns prior to initiating FF/UMEC/VI are currently unknown. This study assessed patient characteristics, exacerbation, and medication history in patients with COPD before the initiation of FF/UMEC/VI or multiple-inhaler triple therapy (MITT). METHODS: This was a retrospective study using the Optum Clinformatics® Data Mart. Patients who initiated FF/UMEC/VI triple therapy or MITT (consisting of a long-acting muscarinic antagonist [LAMA], long-acting ß2-agonist [LABA], and inhaled corticosteroid [ICS]) between October 2017 and September 2018, were enrolled in commercial or Medicare Advantage Prescription Drug plans, were aged > 40 years, and had a COPD diagnosis were eligible. Patient characteristics, comorbidities, COPD medication use, exacerbations, and eosinophil counts were assessed in the 12-month baseline period prior to initiation of FF/UMEC/VI triple therapy or MITT. RESULTS: The study population included 3933 FF/UMEC/VI users and 18,244 MITT users. Mean (standard deviation) patient age was 72.2 (8.6) years in FF/UMEC/VI users and 70.7 (9.7) years in MITT users. Prior to initiating triple therapy, the majority of FF/UMEC/VI (89.1%) and MITT (93.8%) users experienced a moderate or severe exacerbation or used a COPD maintenance therapy during the baseline period. In addition, 41.2% of FF/UMEC/VI users received overlapping ICS/LAMA/LABA, 20.3% received ICS/LABA, and 9.7% received LAMA/LABA. CONCLUSION: In this population of COPD patients, triple therapy was frequently initiated after previous maintenance medication use or an exacerbation, in line with treatment guideline recommendations.

2.
Respir Med ; 197: 106807, 2022 06.
Article in English | MEDLINE | ID: mdl-35429764

ABSTRACT

BACKGROUND: Triple therapy comprising an inhaled corticosteroid, long-acting muscarinic antagonist, and long-acting ß2 agonist (ICS/LAMA/LABA) is recommended for chronic obstructive pulmonary disease (COPD) patients at risk of exacerbation. Multiple-inhaler triple therapy (MITT) is associated with poor adherence and persistence; however, these outcomes have not been evaluated for single-inhaler fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI). METHODS: This retrospective analysis of the IQVIA PharMetrics Plus claims database identified patients with COPD initiating triple therapy between 18 September 2017 and 30 June 2019. The first date of single-inhaler FF/UMEC/VI dispensing, or first day of overlapping ICS, LAMA, and LABA medications for MITT users, defined the index date. Patients were ≥40 years, had ≥12 months of continuous insurance coverage pre-index (baseline) and ≥6 months' coverage post-index; those with MITT during baseline were excluded. Inverse probability weighting was used to balance baseline characteristics. Adherence was assessed using proportion of days covered (PDC) and was evaluated using linear and log-binomial models. Persistence (non-persistence identified as >30-day gap between fills) was evaluated using Cox models. RESULTS: 9942 patients (FF/UMEC/VI: 2782; MITT: 7160) were included. Adherence was significantly higher for FF/UMEC/VI versus MITT users (mean PDC, 0.66 vs. 0.48; p < 0.001), and FF/UMEC/VI users were twice as likely to be adherent (PDC ≥0.8) than MITT users (46.5% vs. 22.3%; risk ratio [95% CI]: 2.08 [1.85-2.30]; p < 0.001). After 12 months, significantly more FF/UMEC/VI users persisted on therapy than MITT users (35.7% vs. 13.9%; hazard ratio [95% CI]: 1.91 [1.81-2.01]; p < 0.001). CONCLUSIONS: COPD patients initiating single-inhaler FF/UMEC/VI had significantly improved adherence and persistence compared with MITT.


Subject(s)
Chlorobenzenes , Pulmonary Disease, Chronic Obstructive , Administration, Inhalation , Benzyl Alcohols/therapeutic use , Bronchodilator Agents/therapeutic use , Chlorobenzenes/therapeutic use , Drug Combinations , Humans , Muscarinic Antagonists/therapeutic use , Nebulizers and Vaporizers , Pulmonary Disease, Chronic Obstructive/drug therapy , Quinuclidines/therapeutic use , Retrospective Studies
3.
Int J Chron Obstruct Pulmon Dis ; 16: 2755-2767, 2021.
Article in English | MEDLINE | ID: mdl-34675501

ABSTRACT

BACKGROUND: There is currently little research describing patient experience and continuity of care immediately prior, during, and following an acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This analysis examined clinical characteristics, chronic obstructive pulmonary disease (COPD)­related medication patterns and outpatient visits before and after an AECOPD. METHODS: This retrospective analysis used electronic health records, medical claims, and pharmacy dispensing data for patients within the Kaiser Permanente Northwest Health System. Patients with ≥1 AECOPD between January 1, 2015 and December 31, 2017 were identified. The most recent AECOPD was considered the index date. An AECOPD was defined as an inpatient hospitalization with a primary diagnosis of COPD, or respiratory failure with a secondary diagnosis of COPD, or an outpatient visit with a primary diagnosis of COPD and dispensing of respiratory-related antibiotics and/or oral corticosteroids ±5 days of the visit. Eligible patients were: ≥40 years old; ≥2 encounters within 12 months of each other or ≥1 hospitalization with primary or secondary COPD diagnosis, chronic bronchitis, or emphysema prior to index; and continuously enrolled ±90 days relative to index. COPD-related inhaled maintenance medication, rescue inhalers, oral corticosteroid use, and ambulatory visits were assessed 90-days pre- and post-index. RESULTS: There were 2829 patients included (mean [standard deviation] age: 69.0 [10.5] years) who had an AECOPD (7% severe; 93% moderate). The percentage of patients on inhaled maintenance therapy increased from 60.6% pre-AECOPD to 68.8% post-AECOPD and increased from 60.0% to 87.4% among patients who experienced a severe AECOPD. COPD-related ambulatory visits increased more than four-fold for primary care and more than doubled for pulmonologist visits in the post-AECOPD period. CONCLUSION: The low proportion of patients observed with changes to controller and rescue medication (particularly following a moderate AECOPD), yet higher utilization of COPD-related ambulatory visits before and after an AECOPD suggests that there is opportunity to improve pharmacotherapy management.


Subject(s)
Bronchitis, Chronic , Delivery of Health Care, Integrated , Pulmonary Disease, Chronic Obstructive , Adult , Aged , Continuity of Patient Care , Disease Progression , Humans , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/drug therapy , Retrospective Studies
4.
Int J Chron Obstruct Pulmon Dis ; 15: 2207-2215, 2020.
Article in English | MEDLINE | ID: mdl-32982213

ABSTRACT

Background: Adherence to inhaled maintenance therapy is critical to managing chronic obstructive pulmonary disease (COPD), while increasing rescue medication usage may indicate worsening symptoms. This study evaluated adherence and rescue medication use in patients with COPD without a history of exacerbation who initiated combination therapy with budesonide/formoterol (B/F) or umeclidinium/vilanterol (UMEC/VI). Methods: Retrospective observational study of commercially insured and Medicare Advantage with Part D enrollees who initiated UMEC/VI or B/F between January 1, 2014 and December 31, 2017 (earliest fill defined as index date). Eligibility criteria included age ≥40 years, 12 months continuous enrollment pre- and post-index, ≥1 pre-index COPD diagnosis, no pre-index asthma diagnosis, COPD-related exacerbations, or medication fills containing inhaled corticosteroids, long-acting ß2-agonists, or long-acting muscarinic antagonists. Inverse probability of treatment weighting (IPTW) was used to balance treatment groups on potential confounders. Medication adherence (primary endpoint) was evaluated by the proportion of days covered (PDC). Rescue medication use (secondary endpoint) was standardized to canister equivalents (1 metered dose inhaler [200 puffs] or ~100 nebulized doses of short-acting ß2-agonist- and/or short-acting muscarinic agonist-containing medication). Results: After IPTW, covariates were balanced between cohorts (UMEC/VI: N=4082; B/F: N=9529). UMEC/VI initiators had a significantly greater mean PDC (UMEC/VI: 0.47 [0.33]; B/F: 0.38 [0.30]; P<0.001) and significantly higher rates of adherence (PDC≥0.80) than B/F initiators (UMEC/VI: n=1004 [25%], B/F: n=1391 [15%]; relative risk: 1.68, 95% CI: 1.57, 1.81; P<0.001). In the year following initiation, UMEC/VI initiators filled significantly fewer rescue medication canister equivalents than B/F initiators (predicted mean [95% CI]: 1.78 [1.69, 1.88] vs 2.15 [2.08, 2.23]; mean difference [95% CI]: -0.37 [-0.50, -0.24]; P<0.001), corresponding to 17% less (estimated) rescue medication use (incidence rate ratio [95% CI]: 0.83 [0.78, 0.88]). Conclusion: Among non-exacerbating patients with COPD initiating dual therapy, UMEC/VI demonstrated improved adherence and reduced rescue medication use compared with B/F.


Subject(s)
Medication Adherence , Pulmonary Disease, Chronic Obstructive , Adrenergic beta-2 Receptor Agonists/adverse effects , Adult , Aged , Benzyl Alcohols/adverse effects , Bronchodilator Agents/adverse effects , Budesonide/adverse effects , Chlorobenzenes/adverse effects , Drug Combinations , Female , Formoterol Fumarate/adverse effects , Humans , Medicare , Pulmonary Disease, Chronic Obstructive/diagnosis , Pulmonary Disease, Chronic Obstructive/drug therapy , Quinuclidines/adverse effects , United States
5.
J Biomed Mater Res B Appl Biomater ; 107(5): 1384-1392, 2019 07.
Article in English | MEDLINE | ID: mdl-30281908

ABSTRACT

Indocyanine green (ICG) is the only FDA-approved near-infrared dye and it is currently used clinically for diagnostic applications. However, there is significant interest in using ICG for triggered drug delivery applications and heat ablation therapy. Unfortunately, free ICG has a short half-life in vivo and is rapidly cleared from circulation. Liposomes have been frequently used to improve ICG's stability and overall time of effectiveness in vivo, but they have limited stability due to the susceptibility of phospholipids to hydrolysis and oxidation. In this study, nonphospholipid liposomes were used to encapsulate ICG, and the resulting liposomes were characterized for size, encapsulation efficiency, stability, and photothermal response. Using the thin-film hydration method, an ICG encapsulation efficiency of 54% was achieved, and the liposomes were stable for up to 12 weeks, with detectable levels of encapsulated ICG up to week 4. Additionally, ICG-loaded liposomes were capable of rapidly producing a significant photothermal response upon exposure to near-infrared light, and this photothermal response was able to induce changes in the mechanical properties of thermally responsive hydrogels. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1384-1392, 2019.


Subject(s)
Cholesterol/chemistry , Hyperthermia, Induced , Indocyanine Green/chemistry , Palmitic Acid/chemistry , Phototherapy , Liposomes
6.
Psychiatr Serv ; 69(6): 716-722, 2018 06 01.
Article in English | MEDLINE | ID: mdl-29540121

ABSTRACT

OBJECTIVE: The study examined differences in psychotropic polypharmacy among youths with serious emotional and behavioral disorders who received coordinated care services (CCS) that used a wraparound model and a matched sample of youths who received traditional services. METHODS: A quasi-experimental design compared psychotropic polypharmacy one year before and one year after discharge from CCS. The cohort was youths with serious emotional and behavioral disorders who were enrolled in CCS from December 2009 through May 2014. The comparison group was youths with serious emotional and behavioral disorders who received outpatient mental health services during the same time. Administrative data from Medicaid, child welfare, and juvenile justice services were used. A difference-in-difference analysis with propensity score matching evaluated the CCS intervention by time effect on psychotropic polypharmacy. RESULTS: In both groups, most youths were male, black, and 10-18 years old, with attention-deficit hyperactivity disorder (54%-55%), mood disorder (39%-42%), depression (26%-27%), and bipolar disorder (25%-26%). About half of each group was taking an antipsychotic. The percentage reduction in polypharmacy from one year before CCS enrollment to one year after discharge was 28% for the CCS group and 29% for the non-CCS group, a nonsignificant difference. CCS youths excluded from the analysis had more complex mental health needs and a greater change in polypharmacy than the CCS youths who were included in the analytic sample. CONCLUSIONS: Mental health care coordination had limited impact in reducing psychotropic polypharmacy for youths with less complex mental health needs. Further research is needed to evaluate the effect on psychotropic polypharmacy among youths with the greatest mental health needs.


Subject(s)
Attention Deficit Disorder with Hyperactivity/drug therapy , Bipolar Disorder/drug therapy , Delivery of Health Care, Integrated/statistics & numerical data , Drug Prescriptions/statistics & numerical data , Medicaid/statistics & numerical data , Mental Health Services/statistics & numerical data , Mood Disorders/drug therapy , Polypharmacy , Psychotropic Drugs/therapeutic use , Adolescent , Child , Female , Humans , Male , Maryland , United States
7.
Oncologist ; 22(7): 780-e65, 2017 07.
Article in English | MEDLINE | ID: mdl-28592620

ABSTRACT

LESSONS LEARNED: Trebananib leveraging anti-angiogenic mechanism that is distinct from the classic sorafenib anti-vascular endothelial growth factor inhibition did not demonstrate improved progression-free survival at 4 months in patients with advanced hepatocellular carcinoma (HCC).In support of previously reported high Ang-2 levels' association with poor outcome in HCC for patients, trebananib treatment with lower baseline Ang-2 at study entry was associated with improved overall survival to 22 months and may suggest future studies to be performed within the context of low baseline Ang-2. BACKGROUND: Ang-1 and Ang-2 are angiopoietins thought to promote neovascularization via activation of the Tie-2 angiopoietin receptor. Trebananib sequesters Ang-1 and Ang-2, preventing interaction with the Tie-2 receptor. Trebananib plus sorafenib combination has acceptable toxicity. Elevated Ang-2 levels are associated with poor prognosis in hepatocellular carcinoma (HCC). METHODS: Patients with HCC, Eastern Cooperative Oncology Group ≤2, and Childs-Pugh A received IV trebananib at 10 mg/kg or 15 mg/kg weekly plus sorafenib 400 mg orally twice daily. The study was planned for ≥78% progression-free survival (PFS) rate at 4 months relative to 62% for sorafenib historical control (power = 80% α = 0.20). Secondary endpoints included safety, tolerability, overall survival (OS), and multiple biomarkers, including serum Ang-2. RESULTS: Thirty patients were enrolled sequentially in each of the two nonrandomized cohorts. Demographics were comparable between the two arms and the historical controls. PFS rates at 4 months were 57% and 54% on the 10 mg/kg and 15 mg/kg trebananib cohorts, respectively. Median OS was 17 and 11 months, respectively. Grade 3 and above events noted in ≥10% of patients included fatigue, hypertension, diarrhea, liver failure, palmar-plantar erythrodysesthesia syndrome, dyspnea, and hypophosphatemia. One death was due to hepatic failure. Serum Ang-2 dichotomized at the median was associated with improved OS in both cohorts. CONCLUSION: There was no improvement in PFS rate at 4 months in either cohort, when compared with sorafenib historical control.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Hepatocellular/drug therapy , Liver Neoplasms/drug therapy , Angiopoietin-2/blood , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Carcinoma, Hepatocellular/mortality , Disease-Free Survival , Female , Humans , Liver Neoplasms/mortality , Male , Middle Aged , Niacinamide/administration & dosage , Niacinamide/analogs & derivatives , Phenylurea Compounds/administration & dosage , Recombinant Fusion Proteins/administration & dosage , Sorafenib , Treatment Outcome
8.
J Biomed Mater Res B Appl Biomater ; 105(2): 272-282, 2017 02.
Article in English | MEDLINE | ID: mdl-26478568

ABSTRACT

Chitosan-alginate (Ch-Al) natural polysaccharide blends have been used for wound healing, tissue engineering, and drug delivery due to their ability to form pH-dependent ionic chain-chain interactions. Yet, the biomechanical properties and growth factor (GF) release kinetics of Ch-Al, which are important in controlling the microenvironment during tissue regeneration, have not been fully explored. This study examines the compressive elastic modulus of many Ch-Al scaffold formulations and crosslinking conditions, and also the strain recovery after compressive deformation of Ch-Al scaffolds, both of which make Ch-Al an attractive composite for reproducing articular cartilage's resistance to and resiliency under compression. Cell viability, proliferation, and in vitro cartilaginous matrix production (collagen type II, glycosaminoglycans, aggrecan) without supplemental GFs are also investigated, demonstrating the polymer blend's inherent chondrogenic properties. Additionally, this study explores the ability of Ch-Al chain functional groups to control and extend GF delivery and minimize GF burst release, using model proteins BSA and histone at high loading dose and chondrogenic protein TGF-ß1 at low loading dose in complete media. Expedited cartilaginous matrix synthesis on Ch-Al with low dose TGF-ß1 release is evaluated, with Ch-Al supporting homogeneous matrix deposition and lacunae formation as early as 3 weeks due to Ch-Al's maintenance of GF bioactivity and sustained GF delivery. These results illustrate the potential to focus the formulational range of Ch-Al to provide enhanced mechanical performance and controlled, bioactive GF release to cooperatively promote cartilage regeneration. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 272-282, 2017.


Subject(s)
Alginates , Cell Proliferation/drug effects , Chitosan , Chondrogenesis/drug effects , Drug Carriers , Transforming Growth Factor beta1 , Alginates/chemistry , Alginates/pharmacology , Animals , Cell Survival/drug effects , Cells, Cultured , Chitosan/chemistry , Chitosan/pharmacology , Drug Carriers/chemistry , Drug Carriers/pharmacology , Glucuronic Acid/chemistry , Glucuronic Acid/pharmacology , Hexuronic Acids/chemistry , Hexuronic Acids/pharmacology , Mice , Rabbits , Transforming Growth Factor beta1/chemistry , Transforming Growth Factor beta1/pharmacology
9.
Nat Commun ; 6: 7362, 2015 Jun 17.
Article in English | MEDLINE | ID: mdl-26082355

ABSTRACT

NELL-1 is a secreted, osteoinductive protein whose expression rheostatically controls skeletal ossification. Overexpression of NELL-1 results in craniosynostosis in humans and mice, whereas lack of Nell-1 expression is associated with skeletal undermineralization. Here we show that Nell-1-haploinsufficient mice have normal skeletal development but undergo age-related osteoporosis, characterized by a reduction in osteoblast:osteoclast (OB:OC) ratio and increased bone fragility. Recombinant NELL-1 binds to integrin ß1 and consequently induces Wnt/ß-catenin signalling, associated with increased OB differentiation and inhibition of OC-directed bone resorption. Systemic delivery of NELL-1 to mice with gonadectomy-induced osteoporosis results in improved bone mineral density. When extended to a large animal model, local delivery of NELL-1 to osteoporotic sheep spine leads to significant increase in bone formation. Altogether, these findings suggest that NELL-1 deficiency plays a role in osteoporosis and demonstrate the potential utility of NELL-1 as a combination anabolic/antiosteoclastic therapeutic for bone loss.


Subject(s)
Bone and Bones/pathology , Nerve Tissue Proteins/administration & dosage , Nerve Tissue Proteins/deficiency , Osteoporosis/drug therapy , Adult , Aged , Aged, 80 and over , Animals , Calcium-Binding Proteins , Cells, Cultured , Drug Evaluation, Preclinical , Female , Haploinsufficiency , Humans , Integrin beta Chains/metabolism , Male , Mice , Middle Aged , Osteoporosis/etiology , Osteoporosis/metabolism , Osteoporosis/pathology , Phenotype , Sheep , Wnt Proteins/metabolism , Young Adult , beta Catenin/metabolism
10.
Clin Genitourin Cancer ; 12(3): 167-177.e2, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24365125

ABSTRACT

BACKGROUND: Trebananib, an investigational peptibody, binds to angiopoietin 1 and 2, thereby blocking their interaction with Tie2. PATIENTS AND METHODS: This open-label phase I study examined trebananib 3 mg/kg or 10 mg/kg intravenous (I.V.) once weekly plus sorafenib 400 mg twice per day or sunitinib 50 mg once per day in advanced RCC. Primary end points were adverse event incidence and pharmacokinetics. RESULTS: Thirty-seven patients were enrolled. During trebananib plus sorafenib administration (n = 17), the most common treatment-related adverse events (TRAEs) included rash (n = 12; 71%), diarrhea (n = 12; 71%), hypertension (n = 11; 65%), and fatigue (n = 11; 65%); grade ≥ 3 TRAEs (n = 7; 41%); and 2 patients (12%) had peripheral edema. During trebananib plus sunitinib administration (n = 19), the most common TRAEs included diarrhea (n = 14; 74%), fatigue (n = 13; 68%), hypertension (n = 11; 58%), and decreased appetite (n = 11; 58%); grade ≥ 3 TRAEs (n = 13; 68%); and 8 (42%) patients had peripheral edema. Trebananib did not appear to alter the pharmacokinetics of sorafenib or sunitinib. No patient developed anti-trebananib antibodies. Objective response rates were 29% (trebananib plus sorafenib) and 53% (trebananib plus sunitinib). CONCLUSION: The toxicities of trebananib 3 mg/kg or 10 mg/kg I.V. plus sorafenib or sunitinib in RCC were similar to those of sorafenib or sunitinib monotherapy, with peripheral edema being likely specific to the combinations. Antitumor activity was observed.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Renal Cell/drug therapy , Kidney Neoplasms/drug therapy , Adult , Aged , Angiogenic Proteins/metabolism , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/pharmacokinetics , Biomarkers, Tumor/metabolism , Carcinoma, Renal Cell/metabolism , Carcinoma, Renal Cell/pathology , Female , Humans , Indoles/administration & dosage , Kidney Neoplasms/metabolism , Kidney Neoplasms/pathology , Male , Middle Aged , Niacinamide/administration & dosage , Niacinamide/analogs & derivatives , Phenylurea Compounds/administration & dosage , Pyrroles/administration & dosage , Recombinant Fusion Proteins/administration & dosage , Sorafenib , Sunitinib , Treatment Outcome
11.
Tissue Eng ; 13(7): 1623-31, 2007 Jul.
Article in English | MEDLINE | ID: mdl-17518707

ABSTRACT

Murine adipose-derived adult stromal cells (ADAS) seeded onto appropriate scaffolds and pre-incubated with retinoic acid have been shown to generate in vivo bone rapidly. Prompt resorption ensues, however, as a result of osteoclastogenesis, likely secondary to retinoic acid carryover. In this study, we determined the effects of abbreviated retinoic acid exposure on ADAS osteogenic differentiation. Histological staining and gene expression analysis revealed that longer retinoic acid exposure resulted in better in vitro bone differentiation. However, significant osteogenesis was observed in ADAS after just 15 days of retinoic acid supplementation, suggesting that continual culture with retinoic acid is unnecessary for initiation of the osteogenic program. This was confirmed using ADAS pre-incubated in monolayer with an abbreviated 15 days of retinoic acid exposure before implantation into critical-sized calvarial defects. Similar rates of regeneration were observed between ADAS exposed to for 15 days or for a full 25-day course of retinoic acid before defect repair. Furthermore, by limiting retinoic acid exposure to ADAS in monolayer without scaffold, accelerated bone formation was observed without concomitant osteoclastic resorption. These data suggest that skeletal regeneration may be improved by modulating retinoic acid exposure before implantation, markedly accelerating the repair of bone defects using ADAS.


Subject(s)
Adipose Tissue/cytology , Cell Differentiation/physiology , Osteoblasts/cytology , Tretinoin/physiology , Adipose Tissue/metabolism , Animals , Cells, Cultured , Mice , Osteoblasts/metabolism , Osteogenesis/physiology , Stromal Cells/cytology , Stromal Cells/metabolism
12.
J Prosthet Dent ; 94(5): 421-9, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16275301

ABSTRACT

STATEMENT OF PROBLEM: Many studies on the strengthening effects of grinding and polishing, as well as heat treatment on ceramics, are not well standardized or use commercially available industrial polishing systems. The reported effectiveness of these strengthening mechanisms on ceramics may not be applicable to clinical dentistry. PURPOSE: The purpose of this study was to evaluate the effects of controlled polishing on the flexural strength of dental ceramics by using a custom-made machine that applied standardized loads and speeds that coincided with the mean loads and speeds used by experienced prosthodontists. MATERIAL AND METHODS: A total of 140 aluminous dental ceramic bar-shaped specimens (Vitadur Alpha Enamel) measuring 1.5 x 2.0 x 25 mm were fabricated and divided into 12 groups (for most groups, n=10). Specimens were untreated, polished with different polishing systems, polished at different speeds, ground and autoglazed, polished and autoglazed, autoglazed and polished, polished with loose (paste) and bonded abrasives, or overglazed. Simulated clinical polishing was performed on the ceramic specimens by using a customized polishing apparatus that allowed independent control over the relevant polishing parameters (abrasive hardness, applied load, linear speed, rotational velocity, and wheel stiffness). Flexural strength (MPa) was measured with a 4-point bending test, and subjective surface roughness was assessed with scanning electron microscopy. Autoglazing was performed at various stages of the polishing sequence to determine the effects of polishing on surface stresses. Mean values, standard deviations, independent-sample t tests, 1-way and 2-way analyses of variance, Dunnett t tests and Kruskal-Wallis tests were applied to the data (alpha=.05). RESULTS: Under a clinical load of 0.6 N for a coarse polishing wheel, 1.0 N for a medium polishing wheel, and 1.3 N for a fine polishing wheel, a linear speed of 499 mm/min, and a rotational velocity of 10,000 rpm, the use of clinical polishing instruments did not affect the flexural strength of the aluminous ceramics studied (P=.274). At higher rotational velocity (20,000 rpm), specimens polished with the diamond polishing system produced statistically weaker specimens compared with those that had been polished at 10,000 rpm (P=.019). Autoglazing treatment of the diamond-polished specimens did not reverse the strength degradation (P=.125). Conversely, diamond polishing of the autoglazed specimens resulted in significant flexural strength reduction (P=.029). Fine-diamond-bonded abrasive significantly reduced flexural strength (P=.025). CONCLUSIONS: Simulated clinical polishing at 10,000 rpm did not appear to substantially strengthen or weaken the ceramic specimens. Polishing at 20,000 rpm reduced flexural strength of the ceramic bars.


Subject(s)
Dental High-Speed Technique , Dental Polishing/instrumentation , Dental Porcelain , Aluminum Oxide , Analysis of Variance , Dental Stress Analysis , Diamond , Elasticity , Materials Testing , Microscopy, Electron, Scanning , Pliability , Statistics, Nonparametric , Surface Properties
13.
Regul Toxicol Pharmacol ; 40(3): 219-26, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15546677

ABSTRACT

Surrogate antibodies are a potential solution to the limited safety testing possible with humanized monoclonal antibodies with restricted species cross-reactivity. However, there are currently no defined criteria by which a potential surrogate antibody should be judged prior to its use in determining safety issues for the clinical agent. We propose that, potential surrogates should undergo rigorous evaluation to assess pharmacological and toxicological activities in comparison to the clinical agent. The current studies evaluated a chimeric mouse/rat anti-mouse CD11a monoclonal antibody (muM17) as a potential surrogate for efalizumab, a humanized anti-CD11a antibody in development for psoriasis. CD11a is a subunit of lymphocyte function associated antigen-1, an integrin involved in cell-cell interactions important to immune responses and inflammation. In vitro pharmacology studies included binding affinity to whole mouse blood and inhibitory activity of muM17 in a mixed lymphocyte response assay. In vivo pharmacology was examined using a delayed type hypersensitivity assay in female CD-1 mice. The toxicology evaluation included a murine tissue cross-reactivity study and in vivo multiple dose studies in female CD-1 mice which were administered muM17 (0.1-30 mg/kg) via subcutaneous injections once a week for 4 weeks. Clinical observations, body weight, clinical pathology, T cell CD11a expression, immunogenicity, toxicokinetics, and lymphoid organ histopathology were evaluated. Finally, since reproductive safety testing would be an important application of the proposed surrogate antibody, a pilot study in pregnant mice was conducted that demonstrated proportional transfer of muM17 into the fetus. These studies demonstrated that muM17 has pharmacological and toxicological activities similar to efalizumab. The selection of dose and regimen for GLP (Good Laboratory Practice) toxicology studies and extrapolation to clinical dose levels was based on pharmacodynamic activity (CD11a downmodulation on T cells).


Subject(s)
Antibodies, Monoclonal/toxicity , CD11a Antigen/immunology , Animals , Antibodies, Monoclonal, Humanized , Antineoplastic Agents/toxicity , Cross Reactions , Drug Evaluation, Preclinical , Enzyme-Linked Immunosorbent Assay , Female , Flow Cytometry , Humans , Hypersensitivity, Delayed/pathology , Immunoglobulin G/immunology , In Vitro Techniques , Leukocyte Count , Lymphocyte Culture Test, Mixed , Male , Mice , Rats , Reproduction/drug effects , T-Lymphocytes/drug effects , T-Lymphocytes/immunology
SELECTION OF CITATIONS
SEARCH DETAIL