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1.  Cannabinoids Inhibit T-cells via Cannabinoid Receptor 2 in an in vitro Assay for Graft Rejection, the Mixed Lymphocyte Reaction 
Cannabinoids are known to have anti-inflammatory and immunomodulatory properties. Cannabinoid receptor 2 (CB2) is expressed mainly on leukocytes and is the receptor implicated in mediating many of the effects of cannabinoids on immune processes. This study tested the capacity of Δ9-tetrahydrocannabinol (Δ9-THC) and of two CB2-selective agonists to inhibit the murine Mixed Lymphocyte Reaction (MLR), an in vitro correlate of graft rejection following skin and organ transplantation. Both CB2-selective agonists and Δ9-THC significantly suppressed the MLR in a dose dependent fashion. The inhibition was via CB2, as suppression could be blocked by pretreatment with a CB2-selective antagonist, but not by a CB1 antagonist, and none of the compounds suppressed the MLR when splenocytes from CB2 deficient mice were used. The CB2 agonists were shown to act directly on T-cells, as exposure of CD3+ cells to these compounds completely inhibited their action in a reconstituted MLR. Further, the CB2-selective agonists completely inhibited proliferation of purified T-cells activated by anti-CD3 and anti-CD28 antibodies. T-cell function was decreased by the CB2 agonists, as an ELISA of MLR culture supernatants revealed IL-2 release was significantly decreased in the cannabinoid treated cells. Together, these data support the potential of this class of compounds as useful therapies to prolong graft survival in transplant patients.
doi:10.1007/s11481-013-9485-1
PMCID: PMC3864984  PMID: 23824763
Cannabinoids; Cannabinoid Receptor 2; Mixed Lymphocyte Reaction; T-cells; Immunosuppression
2.  A tunable synthetic hydrogel system for culture of retinal ganglion cells and amacrine cells 
Acta biomaterialia  2013;9(8):7622-7629.
The central nervous system (CNS) consists of complex groups of individual cells that receive electrical, chemical, and physical signals from their local environment. Standard in vitro cell culture methods rely on two-dimensional (2D) substrates that poorly simulate in vivo neural architecture. Neural cells grown in three-dimensional (3D) culture systems may provide an opportunity to study more accurate representations of the in vivo environment than 2D cultures. Furthermore, each specific type of neuron depends on discrete compositions and physical properties of their local environment. Previously, we developed a library of hydrogels composed of poly(ethylene glycol) (PEG) and poly(L-lysine) (PLL) which exhibit a wide range of mechanical properties. Here, we identified specific scaffolds from this library that readily support the survival, migration and neurite outgrowth of purified retinal ganglion cells (RGCs) and amacrine cells (ACs). These data address important biological questions about the interaction of neurons with the physical and chemical properties of their local environment and provide further insight for engineering neural tissue for cell-replacement therapies following injury.
doi:10.1016/j.actbio.2013.04.048
PMCID: PMC3722500  PMID: 23648573
ECM (extracellular matrix); Protein adsorption; Elasticity; Retina
3.  The Alcohol Clinical Trials Initiative (ACTIVE): Purpose and Goals for Assessing Important and Salient Issues for Medications Development in Alcohol Use Disorders 
Neuropsychopharmacology  2011;37(2):402-411.
Although progress has been made in the treatment of alcohol use disorders, more effective treatments are needed. In the last 15 years, several medications have been approved for use in alcohol dependence but have only limited effectiveness and clinical acceptance. While academics have developed some ‘standards' for the performance of clinical trials for alcohol dependence, they vary considerably, in the type of populations to be studied, the length of trials, salient outcome measures, and data analyses to be used (especially in the treatment of missing data). This variability impedes the commercial development of medications to treat alcohol dependence. Using a model similar to that used to develop an expert consensus for medications to improve cognitive aspects of schizophrenia (MATRICS) and in the treatment of pain (IMMPACT), a workgroup has been formed under the auspices of ACNP, known as the ACTIVE (Alcohol Clinical Trials Initiative) group, to evaluate data from completed clinical trials to develop a consensus on key issues in the conduct of clinical trials in alcohol dependence. ACTIVE consists of academic experts, industry representatives, and staff from the Food and Drug Administration, the National Institute on Alcohol Abuse and Alcoholism, and the National Institute on Drug Abuse. This paper describes the rationale behind the effort, its history and organization, and initial key questions that have been identified as the primary focus of the workgroup. Future papers will focus on knowledge gained from the re-analysis of completed trials and provide consensus opinions regarding the performance of clinical trials that might be undertaken in the future.
doi:10.1038/npp.2011.182
PMCID: PMC3242301  PMID: 21900883
addiction and substance abuse; clinical pharmacology/clinical trials; alcohol and alcoholism; drug discovery/development; neuropharmacology; addiction and substance abuse; clinical pharmacology/clinical trials; alcohol and alcoholism; drug discovery/development; alcohol
4.  Short Term Interactions with Long Term Consequences: Modulation of Chimeric Vessels by Neural Progenitors 
PLoS ONE  2012;7(12):e53208.
Vessels are a critical and necessary component of most tissues, and there has been substantial research investigating vessel formation and stabilization. Several groups have investigated coculturing endothelial cells with a second cell type to promote formation and stabilization of vessels. Some have noted that long-term vessels derived from implanted cocultures are often chimeric consisting of both host and donor cells. The questions arise as to whether the coculture cell might impact the chimeric nature of the microvessels and can modulate the density of donor cells over time. If long-term engineered microvessels are primarily of host origin, any impairment of the host's angiogenic ability has significant implications for the long-term success of the implant. If one can modulate the host versus donor response, one may be able to overcome a host's angiogenic impairment. Furthermore, if one can modulate the donor contribution, one may be able to engineer microvascular networks to deliver molecules a patient lacks systemically for long times. To investigate the impact of the cocultured cell on the host versus donor contributions of endothelial cells in engineered microvascular networks, we varied the ratio of the neural progenitors to endothelial cells in subcutaneously implanted poly(ethylene glycol)/poly-L-lysine hydrogels. We found that the coculture of neural progenitors with endothelial cells led to the formation of chimeric host-donor vessels, and the ratio of neural progenitors has a significant impact on the long term residence of donor endothelial cells in engineered microvascular networks in vivo even though the neural progenitors are only present transiently in the system. We attribute this to the short term paracrine signaling between the two cell types. This suggests that one can modulate the host versus donor contributions using short-term paracrine signaling which has broad implications for the application of engineered microvascular networks and cellular therapy more broadly.
doi:10.1371/journal.pone.0053208
PMCID: PMC3531360  PMID: 23300890
5.  Nanospheres Delivering the EGFR TKI AG1478 Promote Optic Nerve Regeneration: The Role of Size For Intraocular Drug Delivery 
ACS nano  2011;5(6):4392-4400.
Promoting nerve regeneration involves not only modulating the post-injury microenvironment but also ensuring survival of injured neurons. Sustained delivery of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has been shown to promote the survival and regeneration of neurons, but systemic administration is associated with significant side effects. We fabricated poly(lactic-co-glycolic acid) (PLGA) microspheres and nanospheres containing the EGFR TKI 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG1478) for intravitreal administration in a rat optic nerve crush injury model. Upon administration, less backflow from the injection site was observed when injecting nanospheres compared to microspheres. Two weeks after intravitreal delivery, we were able to detect microspheres and nanospheres in the vitreous using coumarin-6 fluorescence, but fewer microspheres were observed compared to the nanospheres. At four weeks only nanospheres could be detected. AG1478 microspheres and nanospheres promoted optic nerve regeneration at two weeks, and at four weeks evidence of regeneration was found only in the nanosphere-injected animals. This observation could be attributed to the ease of administration of the nanospheres versus the microspheres, which in turn led to an increased amount of spheres delivered to the vitreous in the nanosphere group compared to the microsphere group. These data provide evidence for use of PLGA nanospheres to deliver AG1478 intravitreally in a single administration to promote nerve regeneration.
doi:10.1021/nn103146p
PMCID: PMC3136352  PMID: 21619059
optic nerve regeneration; nanospheres; microspheres; PLGA; epidermal growth factor receptor; AG1478
6.  Incidence and impact of pain conditions and comorbid illnesses 
Journal of Pain Research  2011;4:331-345.
Background
Individuals with pain often present with more than one painful condition. The purpose of this study was to characterize the rates of comorbidity, pain medication use, and health care costs for 23 selected pain conditions in a large health plan using administrative claims data from 2005 to 2007.
Methods
Eligible patients included 1,211,483 adults with at least one pain condition during the one-year study period. Pain condition cohorts were classified based on the first diagnosis present in the claims during the study period.
Results
Musculoskeletal pain conditions were among the most prevalent cohorts including low back pain, osteoarthritis, and fibromyalgia. Cancer pain was the least prevalent cohort. Conditions with the lowest illness severity included migraine and painful bladder syndrome cohorts, while cohorts with diabetic neuropathy, human immunodeficiency virus (HIV)-associated pain, and cancer pain were the most severe. Across cohorts, the mean number of comorbid pain conditions ranged from 1.39 (for cancer pain and migraine) to 2.65 (for multiple sclerosis pain). High rates of mental health conditions were found in cohorts with HIV-associated pain and multiple sclerosis pain (42.59% and 34.78%) and were lowest among cohorts with rheumatoid arthritis and psoriatic arthropathy (12.73% and 13.31%), respectively. Rates of sleep disorders ranged from 5.47% (for painful bladder syndrome) to 11.59% (for multiple sclerosis pain). Overall, patients averaged 3.53 unique pain medications during the study period. Considerable annual total health care costs were observed in the cancer pain cohort and the lowest costs were observed in the postherpetic neuropathy, surgically-induced pain, migraine, and irritable bowel syndrome cohorts. Costs attributed to pain were highest among the multiple sclerosis, HIV, and cancer pain cohorts. The highest pharmaceutical costs were observed in the HIV cohort.
Conclusion
These findings underscore the heterogeneity of patients with pain in terms of burden of illness, costs to the health care system, and the complexity of commonly co-occurring disorders.
doi:10.2147/JPR.S24170
PMCID: PMC3215513  PMID: 22090802
retrospective; health care costs; pain medication use; chronic pain; neuropathic pain
7.  Treatment patterns associated with Duloxetine and Venlafaxine use for Major Depressive Disorder 
BMC Psychiatry  2011;11:19.
Background
Duloxetine and venlafaxine extended release (venlafaxine XR) are SNRIs indicated for the treatment of MDD. This study addresses whether duloxetine and venlafaxine XR are interchangeable in their patterns of use with patients who are depressed or are used more selectively based on treatment history, background characteristics, and presenting symptoms.
Methods
This was a retrospective analysis of an administrative insurance claims database. We studied patients in managed care with major depressive disorder (MDD) treated with duloxetine or venlafaxine XR. Predictors of treatment and cost were assessed using Chi-square and logistic regression analyses of demographics and past-year medication use and comorbidities.
Results
Patients with MDD treated with duloxetine (n = 9,641) versus venlafaxine XR (n = 8,514) tended to be older, slightly more likely to be female, and treated by a psychiatrist (P < 0.0001). In the prior year, more duloxetine patients (vs. venlafaxine XR) received ≥3 unique antidepressants (20.8% vs. 16.6%), ≥3 unique pain medications (25.5% vs. 15.6%), and had ≥8 unique diagnosed comorbid medical and psychiatric conditions (38.6% vs. 29.1%). The prior 6-month total health care costs were $1,731 higher for duloxetine than for venlafaxine XR and declined for both medications in the 6 months after treatment began. Logistic regression analysis revealed that 61% of duloxetine patients and 61% of venlafaxine XR patients were predictable from prior patient and treatment factors.
Conclusions
Patients with MDD treated with duloxetine tended to have a more complex and costly antecedent clinical presentation compared with venlafaxine XR patients, suggesting that physicians do not use the medications interchangeably.
doi:10.1186/1471-244X-11-19
PMCID: PMC3044657  PMID: 21281479
8.  Up Regulation of the Maternal Immune Response in the Placenta of Cattle Naturally Infected with Neospora caninum 
PLoS ONE  2011;6(1):e15799.
Neospora caninum is an intracellular protozoan parasite which is a major cause of abortion in cattle worldwide. It forms persistent infections which recrudesce during pregnancy leading to foetal infection and in a proportion of cases, abortion. The mechanisms underlying abortion are not understood. In this study, recrudescence of a persistent infection in eight naturally infected cows occurred between 20 and 33 weeks of gestation. Animals were killed at the time of recrudescence and parasites were detected in the placentae and foetuses. An active maternal immune response consisting of an infiltration of CD4+ and CD8+ T cells and a 46–49 fold increase in interferon-γ and interleukin-4 mRNA was detected. Other cytokines, notably interleukin-12 p40, interleukin-10 and tumour necrosis factor-α were also significantly increased and Major Histocompatibility Class II antigen was expressed on maternal and foetal epithelial and stromal fibroblastoid cells. Significantly, despite the presence of an active maternal immune response in the placenta, all the foetuses were alive at the time of maternal euthanasia. There was evidence of parasites within foetal tissues; their distribution was restricted to the central nervous system and skeletal muscle and their presence was associated with tissue necrosis and a non-suppurative inflammatory response involving lymphocytes and macrophages, irrespective of the gestational age of the foetus. Whilst an active maternal immune response to a pathogen in the placenta is generally considered to be damaging to the foetal trophoblast, our findings suggest that the presence of a parasite-induced maternal immune response in the placenta is not detrimental to foetal survival but may contribute to the control of placental parasitosis.
doi:10.1371/journal.pone.0015799
PMCID: PMC3023762  PMID: 21283810
9.  Synthetic Platelets: Nanotechnology to Halt Bleeding 
Science translational medicine  2009;1(11):11ra22.
Blood loss is the major cause of death in both civilian and battlefield traumas. Methods to staunch bleeding include pressure dressings and absorbent materials. For example, Quik-clot effectively halts bleeding by absorbing large quantities of fluid and concentrating platelets to augment clotting, but these treatments are limited to compressible and exposed wounds. An ideal treatment would halt bleeding only at the injury site, be stable at room temperature, be administered easily, and work effectively for internal injuries. We have developed synthetic platelets, based on Arg-Gly-Asp functionalized nanoparticles, that halve bleeding time after intravenous administration in a rat model of major trauma. The effects of these synthetic platelets surpass other treatments including recombinant factor VIIa, which is used clinically for uncontrolled bleeding. Synthetic platelets were cleared within 24 hours at a dose of 20 mg/ml, and no complications were seen out to 7 days after infusion, the longest time point studied. These synthetic platelets may be useful for early intervention in trauma and demonstrate the role that nanotechnology can have in addressing unmet medical needs.
doi:10.1126/scitranslmed.3000397
PMCID: PMC2992987  PMID: 20371456
PLGA; nanoparticles; PEG; hemostasis; coagulation cascade; trauma
10.  Functionalized Poly(lactic-co-glycolic acid) Enhances Drug Delivery and Provides Chemical Moieties for Surface Engineering while Preserving Biocompatibility 
Acta biomaterialia  2009;5(8):2860-2871.
Poly(lactic-co-glycolic acid) (PLGA) is one of the more widely used polymers for biomedical applications. Nonetheless, PLGA lacks chemical moieties that facilitate cellular interactions and surface chemistries. Furthermore, incorporation of hydrophilic molecules is often problematic. The integration of polymer functionalities would afford the opportunity to alter device characteristics, thereby enabling control over drug interactions, conjugations, and cellular phenomena. In an effort to introduce amine functionalities and improve polymer versatility, we synthesized two block copolymers (PLGA-PLL 502H and PLGA-PLL 503H) comprised of PLGA and Poly(ε-carbobenzoxy-L-lysine) utilizing dicyclohexyl carbodiimide (DCC) coupling. PLGA-PLL micropsheres encapsulated approximately six-fold (502H) and three-fold (503H) more vascular endothelial growth factor (VEGF), and 41% (503H) more ciliary neurotrophic factor (CNTF) than their PLGA counterparts. While the amine functionalities were amenable to the delivery of large molecules and surface conjugations, they did not comprise polymer biocompatibility. With the versatile combination of properties, biocompatibility, and ease of synthesis, these block copolymers have the potential for diverse utility in the fields of drug delivery and tissue engineering.
doi:10.1016/j.actbio.2009.04.012
PMCID: PMC2749076  PMID: 19433141
Block Copolymers; PLGA; Poly(amino acid); CNTF; VEGF
11.  Engineering angiogenesis following spinal cord injury: A coculture of neural progenitor and endothelial cells in a degradable polymer implant leads to an increase in vessel density and formation of the blood-spinal cord barrier 
Angiogenesis precedes recovery following spinal cord injury (SCI), and its extent correlates with neural regeneration suggesting that angiogenesis may play a role in repair. An important precondition for studying the role of angiogenesis is the ability to induce it in a controlled manner. Previously, we showed that a coculture of endothelial cells (ECs) and neural progenitor cells (NPCs) promoted the formation of stable tubes in vitro and stable, functional vascular networks in vivo in a subcutaneous model. We sought to test whether a similar coculture would lead to formation of stable functional vessels in the spinal cord following injury. We created microvascular networks in a biodegradable two component implant system and tested the ability of the coculture or controls (lesion control, implant alone, implant plus ECs, or implant plus NPCs) to promote angiogenesis in a rat hemisection model of spinal cord injury. The coculture implant led to a four fold increase in functional vessels compared to the lesion control, implant alone, or implant plus NPCs groups and a 2 fold increase in functional vessels over the implant plus ECs group. Furthermore, half of the vessels in the coculture implant exhibited positive staining for the endothelial barrier antigen, a marker for formation of the blood spinal cord barrier (BSB). No other groups showed positive staining for the BSB in the injury epicenter. This work provides a novel method to induce angiogenesis following SCI and a foundation for studying its role in repair.
doi:10.1111/j.1460-9568.2008.06567.x
PMCID: PMC2764251  PMID: 19120441
rat; microvasculature; neural progenitor cells; endothelial cells; hydrogel; scaffold; PLGA; blood-spinal cord barrier
12.  Vibratory Regime Classification of Infant Phonation 
Infant phonation is highly variable in many respects, including the basic vibratory patterns by which the vocal tissues create acoustic signals. Previous studies have identified the regular occurrence of non-modal phonation types in normal infant phonation. The glottis is like many oscillating systems that, because of non-linear relationships among the elements, may vibrate in ways representing the deterministic patterns classified theoretically within the mathematical framework of non-linear dynamics. The infant’s pre-verbal vocal explorations present such a variety of phonations that it may be possible to find effectively all the classes of vibration predicted by non-linear dynamic theory. The current report defines acoustic criteria for an important subset of such vibratory regimes, and demonstrates that analysts can be trained to reliably use these criteria for a classification that includes all instances of infant phonation in the recorded corpora. The method is thus internally comprehensive in the sense that all phonations are classified, but it is not exhaustive in the sense that all vocal qualities are thereby represented. Using the methods thus developed, this study also demonstrates that the distributions of these phonation types vary significantly across sessions of recording in the first year of life, suggesting developmental changes. The method of regime classification is thus capable of tracking changes that may be indicative of maturation of the mechanism, the learning of categories of phonatory control, and the possibly varying use of vocalizations across social contexts.
doi:10.1016/j.jvoice.2006.12.009
PMCID: PMC2575878  PMID: 17509829

Results 1-12 (12)