Browsing by Subject "Dose-Response Relationship, Drug"
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Item Open Access A constitutively active mutant beta 2-adrenergic receptor is constitutively desensitized and phosphorylated.(Proc Natl Acad Sci U S A, 1994-03-29) Pei, G; Samama, P; Lohse, M; Wang, M; Codina, J; Lefkowitz, RJThe beta 2-adrenergic receptor (beta 2AR) can be constitutively activated by mutations in the third intracellular loop. Whereas the wild-type receptor exists predominantly in an inactive conformation (R) in the absence of agonist, the mutant receptor appears to spontaneously adopt an active conformation (R*). We now demonstrate that not only is the mutant beta 2AR constitutively active, it is also constitutively desensitized and down-regulated. To assess whether the mutant receptor can constitutively engage a known element of the cellular desensitization machinery, the receptor was purified and reconstituted into phospholipid vesicles. These preparations retained the essential properties of the constitutively active mutant receptor: agonist-independent activity [to stimulate guanine nucleotide-binding protein (Gs)-GTPase] and agonist-specific increase in binding affinity. Moreover, the purified mutant receptor, in the absence of agonist, was phosphorylated by recombinant beta AR-specific kinase (beta ARK) in a fashion comparable to the agonist-occupied wild-type receptor. Thus, the conformation of the mutated receptor is equivalent to the active conformation (R*), which stimulates Gs protein and is identical to the beta ARK substrate.Item Open Access A curative combination cancer therapy achieves high fractional cell killing through low cross-resistance and drug additivity.(eLife, 2019-11) Palmer, Adam C; Chidley, Christopher; Sorger, Peter KCurative cancer therapies are uncommon and nearly always involve multi-drug combinations developed by experimentation in humans; unfortunately, the mechanistic basis for the success of such combinations has rarely been investigated in detail, obscuring lessons learned. Here, we use isobologram analysis to score pharmacological interaction, and clone tracing and CRISPR screening to measure cross-resistance among the five drugs comprising R-CHOP, a combination therapy that frequently cures Diffuse Large B-Cell Lymphomas. We find that drugs in R-CHOP exhibit very low cross-resistance but not synergistic interaction: together they achieve a greater fractional kill according to the null hypothesis for both the Loewe dose-additivity model and the Bliss effect-independence model. These data provide direct evidence for the 50 year old hypothesis that a curative cancer therapy can be constructed on the basis of independently effective drugs having non-overlapping mechanisms of resistance, without synergistic interaction, which has immediate significance for the design of new drug combinations.Item Open Access A Monoclonal Antibody for Malaria Prevention.(The New England journal of medicine, 2021-08) Gaudinski, Martin R; Berkowitz, Nina M; Idris, Azza H; Coates, Emily E; Holman, LaSonji A; Mendoza, Floreliz; Gordon, Ingelise J; Plummer, Sarah H; Trofymenko, Olga; Hu, Zonghui; Campos Chagas, Andrezza; O'Connell, Sarah; Basappa, Manjula; Douek, Naomi; Narpala, Sandeep R; Barry, Christopher R; Widge, Alicia T; Hicks, Renunda; Awan, Seemal F; Wu, Richard L; Hickman, Somia; Wycuff, Diane; Stein, Judy A; Case, Christopher; Evans, Brian P; Carlton, Kevin; Gall, Jason G; Vazquez, Sandra; Flach, Britta; Chen, Grace L; Francica, Joseph R; Flynn, Barbara J; Kisalu, Neville K; Capparelli, Edmund V; McDermott, Adrian; Mascola, John R; Ledgerwood, Julie E; Seder, Robert A; VRC 612 Study TeamBackground
Additional interventions are needed to reduce the morbidity and mortality caused by malaria.Methods
We conducted a two-part, phase 1 clinical trial to assess the safety and pharmacokinetics of CIS43LS, an antimalarial monoclonal antibody with an extended half-life, and its efficacy against infection with Plasmodium falciparum. Part A of the trial assessed the safety, initial side-effect profile, and pharmacokinetics of CIS43LS in healthy adults who had never had malaria. Participants received CIS43LS subcutaneously or intravenously at one of three escalating dose levels. A subgroup of participants from Part A continued to Part B, and some received a second CIS43LS infusion. Additional participants were enrolled in Part B and received CIS43LS intravenously. To assess the protective efficacy of CIS43LS, some participants underwent controlled human malaria infection in which they were exposed to mosquitoes carrying P. falciparum sporozoites 4 to 36 weeks after administration of CIS43LS.Results
A total of 25 participants received CIS43LS at a dose of 5 mg per kilogram of body weight, 20 mg per kilogram, or 40 mg per kilogram, and 4 of the 25 participants received a second dose (20 mg per kilogram regardless of initial dose). No safety concerns were identified. We observed dose-dependent increases in CIS43LS serum concentrations, with a half-life of 56 days. None of the 9 participants who received CIS43LS, as compared with 5 of 6 control participants who did not receive CIS43LS, had parasitemia according to polymerase-chain-reaction testing through 21 days after controlled human malaria infection. Two participants who received 40 mg per kilogram of CIS43LS and underwent controlled human malaria infection approximately 36 weeks later had no parasitemia, with serum concentrations of CIS43LS of 46 and 57 μg per milliliter at the time of controlled human malaria infection.Conclusions
Among adults who had never had malaria infection or vaccination, administration of the long-acting monoclonal antibody CIS43LS prevented malaria after controlled infection. (Funded by the National Institute of Allergy and Infectious Diseases; VRC 612 ClinicalTrials.gov number, NCT04206332.).Item Open Access A phase I study of ABT-510 plus bevacizumab in advanced solid tumors.(Cancer Med, 2013-06) Uronis, Hope E; Cushman, Stephanie M; Bendell, Johanna C; Blobe, Gerard C; Morse, Michael A; Nixon, Andrew B; Dellinger, Andrew; Starr, Mark D; Li, Haiyan; Meadows, Kellen; Gockerman, Jon; Pang, Herbert; Hurwitz, Herbert ITargeting multiple regulators of tumor angiogenesis have the potential to improve treatment efficacy. Bevacizumab is a monoclonal antibody directed against vascular endothelial growth factor and ABT-510 is a synthetic analog of thrombospondin, an endogenous angiogenesis inhibitor. Dual inhibition may result in additional benefit. We evaluated the safety, tolerability, and efficacy of the combination of bevacizumab plus ABT-510 in patients with refractory solid tumors. We also explored the effects of these agents on plasma-based biomarkers and wound angiogenesis. Thirty-four evaluable subjects were enrolled and received study drug. Therapy was well tolerated; minimal treatment-related grade 3/4 toxicity was observed. One patient treated at dose level 1 had a partial response and five other patients treated at the recommended phase II dose had prolonged stable disease for more than 1 year. Biomarker evaluation revealed increased levels of D-dimer, von Willebrand factor, placental growth factor, and stromal-derived factor 1 in response to treatment with the combination of bevacizumab and ABT-510. Data suggest that continued evaluation of combination antiangiogenesis therapies may be clinically useful.Item Open Access A randomized, double-blind, placebo-controlled trial of pramipexole augmentation in treatment-resistant major depressive disorder.(The Journal of clinical psychiatry, 2013-07) Cusin, Cristina; Iovieno, Nadia; Iosifescu, Dan V; Nierenberg, Andrew A; Fava, Maurizio; Rush, A John; Perlis, Roy HBackground
Multiple treatments for patients with major depressive disorder (MDD) have demonstrated efficacy, but up to one-third of individuals with MDD do not achieve symptomatic remission despite various interventions. Existing augmentation or combination strategies can have substantial safety concerns that may limit their application.Method
This study investigated the antidepressant efficacy of a flexible dose of the dopamine agonist pramipexole as an adjunct to standard antidepressant treatment in an 8-week, randomized, double-blind, placebo-controlled trial conducted in a tertiary-level depression center. We randomized 60 outpatients (aged 18 to 75 years) with treatment-resistant nonpsychotic MDD (diagnosed according to DSM-IV) to either pramipexole (n = 30) or placebo (n = 30). Treatment resistance was defined as continued depression (Montgomery-Asberg Depression Rating Scale [MADRS] score ≥ 18) despite treatment with at least 1 prior antidepressant in the current depressive episode. Patients were recruited between September 2005 and April 2008. The primary outcome measure was the MADRS score.Results
The analyses that used a mixed-effects linear regression model indicated a modest but statistically significant benefit for pramipexole (P = .038). The last-observation-carried-forward analyses indicated that 40% and 33% of patients randomized to augmentation with pramipexole achieved response (χ(2) = 1.2, P = .27) and remission (χ(2) = 0.74, P = .61), respectively, compared to 27% and 23% with placebo; however, those differences were not statistically significant. Augmentation with pramipexole was well-tolerated, with no serious adverse effects identified.Conclusion
For patients who have failed to respond to standard antidepressant therapies, pramipexole is a safe and potentially efficacious augmentation strategy.Trial registration
ClinicalTrials.gov identifier: NCT00231959.Item Open Access A selective inhibitor of eIF2alpha dephosphorylation protects cells from ER stress.(Science (New York, N.Y.), 2005-02) Boyce, Michael; Bryant, Kevin F; Jousse, Céline; Long, Kai; Harding, Heather P; Scheuner, Donalyn; Kaufman, Randal J; Ma, Dawei; Coen, Donald M; Ron, David; Yuan, JunyingMost protein phosphatases have little intrinsic substrate specificity, making selective pharmacological inhibition of specific dephosphorylation reactions a challenging problem. In a screen for small molecules that protect cells from endoplasmic reticulum (ER) stress, we identified salubrinal, a selective inhibitor of cellular complexes that dephosphorylate eukaryotic translation initiation factor 2 subunit alpha (eIF2alpha). Salubrinal also blocks eIF2alpha dephosphorylation mediated by a herpes simplex virus protein and inhibits viral replication. These results suggest that selective chemical inhibitors of eIF2alpha dephosphorylation may be useful in diseases involving ER stress or viral infection. More broadly, salubrinal demonstrates the feasibility of selective pharmacological targeting of cellular dephosphorylation events.Item Open Access Adenosine-induced flow arrest to facilitate intracranial aneurysm clip ligation: dose-response data and safety profile.(Anesth Analg, 2010-05-01) Bebawy, John F; Gupta, Dhanesh K; Bendok, Bernard R; Hemmer, Laura B; Zeeni, Carine; Avram, Michael J; Batjer, H Hunt; Koht, AntounBACKGROUND: Adenosine-induced transient flow arrest has been used to facilitate clip ligation of intracranial aneurysms. However, the starting dose that is most likely to produce an adequate duration of profound hypotension remains unclear. We reviewed our experience to determine the dose-response relationship and apparent perioperative safety profile of adenosine in intracranial aneurysm patients. METHODS: This case series describes 24 aneurysm clip ligation procedures performed under an anesthetic consisting of remifentanil, low-dose volatile anesthetic, and propofol in which adenosine was used. The report focuses on the doses administered; duration of systolic blood pressure <60 mm Hg (SBP(<60 mm Hg)); and any cardiovascular, neurologic, or pulmonary complications observed in the perioperative period. RESULTS: A median dose of 0.34 mg/kg ideal body weight (range: 0.29-0.44 mg/kg) resulted in a SBP(<60 mm Hg) for a median of 57 seconds (range: 26-105 seconds). There was a linear relationship between the log-transformed dose of adenosine and the duration of a SBP(<60 mm Hg) (R(2) = 0.38). Two patients developed transient, hemodynamically stable atrial fibrillation, 2 had postoperative troponin levels >0.03 ng/mL without any evidence of cardiac dysfunction, and 3 had postoperative neurologic changes. CONCLUSIONS: For intracranial aneurysms in which temporary occlusion is impractical or difficult, adenosine is capable of providing brief periods of profound systemic hypotension with low perioperative morbidity. On the basis of these data, a dose of 0.3 to 0.4 mg/kg ideal body weight may be the recommended starting dose to achieve approximately 45 seconds of profound systemic hypotension during a remifentanil/low-dose volatile anesthetic with propofol induced burst suppression.Item Open Access Amitifadine, a triple reuptake inhibitor, reduces self-administration of the opiate remifentanil in rats.(Psychopharmacology, 2020-06) Levin, Edward D; Wells, Corinne; Hawkey, Andrew; Holloway, Zade; Blair, Graham; Vierling, Alexander; Ko, Ashley; Pace, Caroline; Modarres, John; McKinney, Anthony; Rezvani, Amir H; Rose, Jed ERationale
A variety of neural systems are involved in drug addiction, and some of these systems are shared across different addictive drugs. We have found several different types of drug treatments that successfully reduce nicotine self-administration.Objectives
The current set of studies is the first in a series to determine if drug treatments that have been found to significantly reduce nicotine self-administration would reduce opiate self-administration.Methods
Amitifadine, a triple reuptake inhibitor of dopamine, norepinephrine, and serotonin, was assessed in female Sprague-Dawley rats to determine whether it significantly reduces remifentanil self-administration with either acute or chronic treatment.Results
Acutely, amitifadine doses of 5, 10, and 20 mg/kg each significantly reduced remifentanil self-administration. In a chronic study, repeated treatment with 10 mg/kg of amitifadine continued to reduce remifentanil self-administration, even after the cessation of treatment. However, amitifadine was not found to attenuate the rise in remifentanil self-administration with continued access. This study and our earlier one showed that the 10 mg/kg amitifadine dose did not significantly affect food motivated responding. Amitifadine did not attenuate remifentanil-induced antinociception as measured on the hot plate test but extended and maintained antinociceptive effects.Conclusions
These studies show the promise of amitifadine as a treatment for countering opiate self-administration for adjunctive use with opioids for analgesia. Further studies are needed to determine the possible efficacy of amitifadine for combating opiate addiction or preventing it in humans during adjunctive use with opioids for chronic pain.Item Open Access An evaluation of remifentanil-sevoflurane response surface models in patients emerging from anesthesia: model improvement using effect-site sevoflurane concentrations.(Anesth Analg, 2010-08) Johnson, Ken B; Syroid, Noah D; Gupta, Dhanesh K; Manyam, Sandeep C; Pace, Nathan L; LaPierre, Cris D; Egan, Talmage D; White, Julia L; Tyler, Diane; Westenskow, Dwayne RINTRODUCTION: We previously reported models that characterized the synergistic interaction between remifentanil and sevoflurane in blunting responses to verbal and painful stimuli. This preliminary study evaluated the ability of these models to predict a return of responsiveness during emergence from anesthesia and a response to tibial pressure when patients required analgesics in the recovery room. We hypothesized that model predictions would be consistent with observed responses. We also hypothesized that under non-steady-state conditions, accounting for the lag time between sevoflurane effect-site concentration (Ce) and end-tidal (ET) concentration would improve predictions. METHODS: Twenty patients received a sevoflurane, remifentanil, and fentanyl anesthetic. Two model predictions of responsiveness were recorded at emergence: an ET-based and a Ce-based prediction. Similarly, 2 predictions of a response to noxious stimuli were recorded when patients first required analgesics in the recovery room. Model predictions were compared with observations with graphical and temporal analyses. RESULTS: While patients were anesthetized, model predictions indicated a high likelihood that patients would be unresponsive (> or = 99%). However, after termination of the anesthetic, models exhibited a wide range of predictions at emergence (1%-97%). Although wide, the Ce-based predictions of responsiveness were better distributed over a percentage ranking of observations than the ET-based predictions. For the ET-based model, 45% of the patients awoke within 2 min of the 50% model predicted probability of unresponsiveness and 65% awoke within 4 min. For the Ce-based model, 45% of the patients awoke within 1 min of the 50% model predicted probability of unresponsiveness and 85% awoke within 3.2 min. Predictions of a response to a painful stimulus in the recovery room were similar for the Ce- and ET-based models. DISCUSSION: Results confirmed, in part, our study hypothesis; accounting for the lag time between Ce and ET sevoflurane concentrations improved model predictions of responsiveness but had no effect on predicting a response to a noxious stimulus in the recovery room. These models may be useful in predicting events of clinical interest but large-scale evaluations with numerous patients are needed to better characterize model performance.Item Open Access An extensive new literature concerning low-dose effects of bisphenol A shows the need for a new risk assessment.(Environmental health perspectives, 2005-08) vom Saal, Frederick S; Hughes, ClaudeBisphenol A (BPA) is the monomer used to manufacture polycarbonate plastic, the resin lining of cans, and other products, with global capacity in excess of 6.4 billion lb/year. Because the ester bonds in these BPA-based polymers are subject to hydrolysis, leaching of BPA has led to widespread human exposure. A recent report prepared by the Harvard Center for Risk Analysis and funded by the American Plastics Council concluded that evidence for low-dose effects of BPA is weak on the basis of a review of only 19 studies; the report was issued after a delay of 2.5 years. A current comprehensive review of the literature reveals that the opposite is true. As of December 2004, there were 115 published in vivo studies concerning low-dose effects of BPA, and 94 of these report significant effects. In 31 publications with vertebrate and invertebrate animals, significant effects occurred below the predicted "safe" or reference dose of 50 microg/kg/day BPA. An estrogenic mode of action of BPA is confirmed by in vitro experiments, which describe disruption of cell function at 10(-12) M or 0.23 ppt. Nonetheless, chemical manufacturers continue to discount these published findings because no industry-funded studies have reported significant effects of low doses of BPA, although > 90% of government-funded studies have reported significant effects. Some industry-funded studies have ignored the results of positive controls, and many studies reporting no significant effects used a strain of rat that is inappropriate for the study of estrogenic responses. We propose that a new risk assessment for BPA is needed based on a) the extensive new literature reporting adverse effects in animals at doses below the current reference dose; b) the high rate of leaching of BPA from food and beverage containers, leading to widespread human exposure; c) reports that the median BPA level in human blood and tissues, including in human fetal blood, is higher than the level that causes adverse effects in mice; and d) recent epidemiologic evidence that BPA is related to disease in women.Item Open Access Anti-cholinergic load, health care utilization, and survival in people with advanced cancer: a pilot study.(J Palliat Med, 2010-06) Agar, Meera; To, Timothy; Plummer, John; Abernethy, Amy; Currow, DavidINTRODUCTION: Anti-cholinergic medications have been associated with increased risks of cognitive impairment, premature mortality and increased risk of hospitalisation. Anti-cholinergic load associated with medication increases as death approaches in those with advanced cancer, yet little is known about associated adverse outcomes in this setting. METHODS: A substudy of 112 participants in a randomised control trial who had cancer and an Australia modified Karnofsky Performance Scale (AKPS) score (AKPS) of 60 or above, explored survival and health service utilisation; with anti-cholinergic load calculated using the Clinician Rated Anti-cholinergic Scale (modified version) longitudinally to death. A standardised starting point for prospectively calculating survival was an AKPS of 60 or above. RESULTS: Baseline entry to the sub-study was a mean 62 +/- 81 days (median 37, range 1-588) days before death (survival), with mean of 4.8 (median 3, SD 4.18, range 1 - 24) study assessments in this time period. Participants spent 22% of time as an inpatient. There was no significant association between anti-cholinergic score and time spent as an inpatient (adjusted for survival time) (p = 0.94); or survival time. DISCUSSION: No association between anti-cholinergic load and survival or time spent as an inpatient was seen. Future studies need to include cognitively impaired populations where the risks of symptomatic deterioration may be more substantial.Item Open Access Anti-hypotensive treatment and endothelin blockade synergistically antagonize exercise fatigue in rats under simulated high altitude.(PLoS One, 2014) Radiloff, Daniel; Zhao, Yulin; Boico, Alina; Blueschke, Gert; Palmer, Gregory; Fontanella, Andrew; Dewhirst, Mark; Piantadosi, Claude A; Noveck, Robert; Irwin, David; Hamilton, Karyn; Klitzman, Bruce; Schroeder, ThiesRapid ascent to high altitude causes illness and fatigue, and there is a demand for effective acute treatments to alleviate such effects. We hypothesized that increased oxygen delivery to the tissue using a combination of a hypertensive agent and an endothelin receptor A antagonist drugs would limit exercise-induced fatigue at simulated high altitude. Our data showed that the combination of 0.1 mg/kg ambrisentan with either 20 mg/kg ephedrine or 10 mg/kg methylphenidate significantly improved exercise duration in rats at simulated altitude of 4,267 m, whereas the individual compounds did not. In normoxic, anesthetized rats, ephedrine alone and in combination with ambrisentan increased heart rate, peripheral blood flow, carotid and pulmonary arterial pressures, breathing rate, and vastus lateralis muscle oxygenation, but under inspired hypoxia, only the combination treatment significantly enhanced muscle oxygenation. Our results suggest that sympathomimetic agents combined with endothelin-A receptor blockers offset altitude-induced fatigue in rats by synergistically increasing the delivery rate of oxygen to hypoxic muscle by concomitantly augmenting perfusion pressure and improving capillary conductance in the skeletal muscle. Our findings might therefore serve as a basis to develop an effective treatment to prevent high-altitude illness and fatigue in humans.Item Open Access ApoE mimetic ameliorates motor deficit and tissue damage in rat spinal cord injury.(Journal of neuroscience research, 2014-07) Wang, Ruihua; Hong, Jun; Lu, Miaomiao; Neil, Jessica E; Vitek, Michael P; Liu, Xiaozhi; Warner, David S; Li, Fengqiao; Sheng, HuaxinApolipoprotein E (apoE), a plasma protein responsible for transporting lipid and cholesterol, modulates responses of the central nervous system to injury. Small peptides derived from the receptor-binding region of apoE can simulate some important bioactivities of apoE holoprotein and offer neuroprotection against brain injury. We tested whether COG1410, an apoE-mimetic peptide, provides protection in a rat model of spinal cord injury (SCI). Traumatic injury was created at T8 by a cortical impact device. Injured rats were randomized to four treatment groups: vehicle, 0.15, 0.3, or 0.6 mg/kg COG1410; sham surgery rats received vehicle. Basso, Beattie, Bresnahan neurological score was evaluated prior to injury and at 1, 3, 7, and 14 days after injury. Histological changes were evaluated at 14 days. All injured rats lost body weight during the first week following injury. Body weight recovery was significantly improved in rats treated with COG1410. Mechanical impact resulted in severe motor deficit, and most animals had a BBB score of 0-1 at 24 hours postinjury. COG1410-treated rats showed significantly improved functional recovery and ameliorated motor deficit at 14 days postinjury. Histological analysis showed that COG1410 groups had a significantly reduced lesion size at the site of injury, a larger preserved luxol fast blue-stained area, and more visible neurons in the surrounding area of injury. Microglial activation was also significantly suppressed. These findings indicate that this apoE mimetic effectively improved neurological and histological outcome following SCI in rats, and the effect was associated with inhibition of microglial activation.Item Open Access Attenuation of inflammatory events in human intervertebral disc cells with a tumor necrosis factor antagonist.(Spine, 2011-07) Sinclair, S Michael; Shamji, Mohammed F; Chen, Jun; Jing, Liufang; Richardson, William J; Brown, Christopher R; Fitch, Robert D; Setton, Lori AStudy design
The inflammatory responses of primary human intervertebral disc (IVD) cells to tumor necrosis factor α (TNF-α) and an antagonist were evaluated in vitro.Objective
To investigate an ability for soluble TNF receptor type II (sTNFRII) to antagonize TNF-α-induced inflammatory events in primary human IVD cells in vitro.Summary of background data
TNF-α is a known mediator of inflammation and pain associated with radiculopathy and IVD degeneration. sTNFRs and their analogues are of interest for the clinical treatment of these IVD pathologies, although information on the effects of sTNFR on human IVD cells remains unknown.Methods
IVD cells were isolated from surgical tissues procured from 15 patients and cultured with or without 1.4 nmol/L TNF-α (25 ng/mL). Treatment groups were coincubated with varying doses of sTNFRII (12.5-100 nmol/L). Nitric oxide (NO), prostaglandin E₂ (PGE₂), and interleukin-6 (IL6) levels in media were quantified to characterize the inflammatory phenotype of the IVD cells.Results
Across all patients, TNF-α induced large, statistically significant increases in NO, PGE₂, and IL6 secretion from IVD cells compared with controls (60-, 112-, and 4-fold increases, respectively; P < 0.0001). Coincubation of TNF-α with nanomolar doses of sTNFRII significantly attenuated the secretion of NO and PGE₂ in a dose-dependent manner, whereas IL6 levels were unchanged. Mean IC₅₀ values for NO and PGE₂ were found to be 35.1 and 20.5 nmol/L, respectively.Conclusion
Nanomolar concentrations of sTNFRII were able to significantly attenuate the effects of TNF-α on primary human IVD cells in vitro. These results suggest this sTNFR to be a potent TNF antagonist with potential to attenuate inflammation in IVD pathology.Item Open Access Attenuation of inflammatory events in human intervertebral disc cells with a tumor necrosis factor antagonist.(2010) Sinclair, Steven MichaelSTUDY DESIGN: The inflammatory responses of primary human intervertebral disc (IVD) cells to tumor necrosis factor α (TNF-α) and an antagonist were evaluated in vitro. OBJECTIVE: To investigate an ability for soluble TNF receptor type II (sTNFRII) to antagonize TNF-α-induced inflammatory events in primary human IVD cells in vitro. SUMMARY OF BACKGROUND DATA: TNF-α is a known mediator of inflammation and pain associated with radiculopathy and IVD degeneration. sTNFRs and their analogues are of interest for the clinical treatment of these IVD pathologies, although information on the effects of sTNFR on human IVD cells remains unknown. METHODS: IVD cells were isolated from surgical tissues procured from 15 patients and cultured with or without 1.4 nmol/L TNF-α (25 ng/mL). Treatment groups were coincubated with varying doses of sTNFRII (12.5-100 nmol/L). Nitric oxide (NO), prostaglandin E₂ (PGE₂), and interleukin-6 (IL6) levels in media were quantified to characterize the inflammatory phenotype of the IVD cells. RESULTS: Across all patients, TNF-α induced large, statistically significant increases in NO, PGE₂, and IL6 secretion from IVD cells compared with controls (60-, 112-, and 4-fold increases, respectively; P < 0.0001). Coincubation of TNF-α with nanomolar doses of sTNFRII significantly attenuated the secretion of NO and PGE₂ in a dose-dependent manner, whereas IL6 levels were unchanged. Mean IC₅₀ values for NO and PGE₂ were found to be 35.1 and 20.5 nmol/L, respectively. CONCLUSION: Nanomolar concentrations of sTNFRII were able to significantly attenuate the effects of TNF-α on primary human IVD cells in vitro. These results suggest this sTNFR to be a potent TNF antagonist with potential to attenuate inflammation in IVD pathology.Item Open Access Catastrophic antiphospholipid syndrome with concurrent thrombotic and hemorrhagic manifestations.(Lupus, 2013-07) Rangel, ML; Alghamdi, I; Contreras, G; Harrington, T; Thomas, DB; Barisoni, L; Andrews, D; Wolf, M; Asif, A; Nayer, AAntiphospholipid syndrome (APS) is a distinct autoimmune prothrombotic disorder due to pathogenic autoantibodies directed against proteins that bind to phospholipids. APS is characterized by arterial and venous thrombosis and their clinical sequelae. Catastrophic antiphospholipid syndrome (CAPS) is a rare and often fatal form of APS characterized by disseminated intravascular thrombosis and ischemic injury resulting in multiorgan failure. Rarely, intravascular thrombosis in CAPS is accompanied by hemorrhagic manifestations such as diffuse alveolar hemorrhage. Here, we report a 43-year-old woman who presented with anemia, acute gastroenteritis, abnormal liver function tests, bilateral pulmonary infiltrates, and a systemic inflammatory response syndrome. The patient developed respiratory failure as a result of diffuse alveolar hemorrhage followed by acute renal failure. Laboratory tests disclosed hematuria, proteinuria, and reduced platelet count. Microbiologic tests were negative. A renal biopsy demonstrated acute thrombotic microangiopathy and extensive interstitial hemorrhage. Serologic tests disclosed antinuclear antibodies and reduced serum complement C4 concentration. Coagulation studies revealed the lupus anticoagulant and autoantibodies against cardiolipin, beta 2-glycoprotein I, and prothrombin. High-dose glucocorticoids and plasma exchange resulted in rapid resolution of pulmonary, renal, and hematological manifestations. This rare case emphasizes that CAPS can present with concurrent thrombotic and hemorrhagic manifestations. Rapid diagnosis and treatment may result in complete recovery.Item Open Access Chronic memantine decreases nicotine self-administration in rats.(European journal of pharmacology, 2019-10) Levin, Edward D; Wells, Corinne; Yao, Leah; Guo, Wendi; Nangia, Anica; Howard, Sarah; Pippen, Erica; Hawkey, Andrew B; Rose, Jed E; Rezvani, Amir HNeurobehavioral bases of tobacco addiction and nicotine reinforcement are complex, involving more than only nicotinic cholinergic or dopaminergic systems. Memantine is an NMDA glutamate antagonist used to improve cognitive function in people with Alzheimer's disease. Glutamate may be an important component of the reinforcing effects of nicotine, so memantine was evaluated as a potential smoking cessation aid. Two studies were conducted with adult female rats, one testing acute effects of memantine over a range of doses for changing nicotine self-administration and the other testing the chronic effects of memantine to reduce nicotine self-administration. Acute memantine injections slightly, but significantly, increased nicotine self-administration in a dose-related manner. In contrast, chronic memantine treatment significantly reduced nicotine self-administration. During the first day of memantine administration in the chronic study, nicotine self-administration was significantly elevated replicating the acute study. Starting in the second week of treatment there was a significant reduction of nicotine self-administration relative to controls. This was seen because memantine treatment prevented the increase in nicotine self-administration shown by controls. There even continued to be a memantine-induced lowered nicotine self-administration during the week after the cessation of memantine treatment. Memantine or other drugs affecting NMDA glutamate receptors may be useful aids to smoking cessation. Full efficacy for reducing nicotine self-administration was seen as the NMDA drug treatment is given chronically. Importantly, the effect persisted even after treatment is ended, indicating the high potential for NMDA glutamate receptors to impact nicotine addiction.Item Open Access Decongestion strategies and renin-angiotensin-aldosterone system activation in acute heart failure.(JACC Heart Fail, 2015-02) Mentz, Robert J; Stevens, Susanna R; DeVore, Adam D; Lala, Anuradha; Vader, Justin M; AbouEzzeddine, Omar F; Khazanie, Prateeti; Redfield, Margaret M; Stevenson, Lynne W; O'Connor, Christopher M; Goldsmith, Steven R; Bart, Bradley A; Anstrom, Kevin J; Hernandez, Adrian F; Braunwald, Eugene; Felker, G MichaelOBJECTIVES: The purpose of this study was to assess the relationship between biomarkers of renin-angiotensin-aldosterone system (RAAS) activation and decongestion strategies, worsening renal function, and clinical outcomes. BACKGROUND: High-dose diuretic therapy in patients with acute heart failure (AHF) is thought to activate the RAAS; and alternative decongestion strategies, such as ultrafiltration (UF), have been proposed to mitigate this RAAS activation. METHODS: This study analyzed 427 AHF patients enrolled in the DOSE-AHF (Diuretic Optimization Strategies in Acute Heart Failure) and CARRESS-HF (Cardiorenal Rescue Study in Acute Decompensated Heart Failure) trials. We assessed the relationship between 2 markers of RAAS activation (plasma renin activity [PRA] and aldosterone) from baseline to 72 h and 96 h and decongestion strategy: high- versus low-dose and continuous infusion versus bolus furosemide for DOSE-AHF and UF versus stepped pharmacologic care for CARRESS-HF. We determined the relationships between RAAS biomarkers and 60-day outcomes. RESULTS: Patients with greater RAAS activation at baseline had lower blood pressures, lower serum sodium levels, and higher blood urea nitrogen (BUN) concentration. Continuous infusion furosemide and UF were associated with greater PRA increases (median: +1.66 vs. +0.66 ng/ml/h with continuous vs. bolus infusion, respectively, p = 0.021; +4.05 vs. +0.56 ng/ml/h with UF vs. stepped care, respectively, p = 0.014). There were no significant differences in RAAS biomarker changes with high- versus low-dose diuretic therapy (both: p > 0.5). Neither baseline log PRA nor log aldosterone was associated with increased death or HF hospitalization (hazard ratio [HR] for a doubling of 1.05; 95% confidence interval [CI]: 0.98 to 1.13; p = 0.18; and HR: 1.13; 95% CI: 0.99 to 1.28; p = 0.069, respectively). The change in RAAS biomarkers from baseline to 72 and 96 h was not associated with outcomes (both: p > 0.5). CONCLUSIONS: High-dose loop diuretic therapy did not result in RAAS activation greater than that with low-dose diuretic therapy. UF resulted in greater PRA increase than stepped pharmacologic care. Neither PRA nor aldosterone was significantly associated with short-term outcomes in this cohort. (Determining Optimal Dose and Duration of Diuretic Treatment in People With Acute Heart Failure [DOSE-AHF]; NCT00577135; Effectiveness of Ultrafiltration in Treating People With Acute Decompensated Heart Failure and Cardiorenal Syndrome [CARRESS]; NCT00608491).Item Open Access Defibrotide for the treatment of severe hepatic veno-occlusive disease and multiorgan failure after stem cell transplantation: a multicenter, randomized, dose-finding trial.(Biology of blood and marrow transplantation : journal of the American Society for Blood and Marrow Transplantation, 2010-07) Richardson, Paul G; Soiffer, Robert J; Antin, Joseph H; Uno, Hajime; Jin, Zhezhen; Kurtzberg, Joanne; Martin, Paul L; Steinbach, Gideon; Murray, Karen F; Vogelsang, Georgia B; Chen, Allen R; Krishnan, Amrita; Kernan, Nancy A; Avigan, David E; Spitzer, Thomas R; Shulman, Howard M; Di Salvo, Donald N; Revta, Carolyn; Warren, Diane; Momtaz, Parisa; Bradwin, Gary; Wei, LJ; Iacobelli, Massimo; McDonald, George B; Guinan, Eva CTherapeutic options for severe hepatic veno-occlusive disease (VOD) are limited and outcomes are dismal, but early phase I/II studies have suggested promising activity and acceptable toxicity using the novel polydisperse oligonucleotide defibrotide. This randomized phase II dose-finding trial determined the efficacy of defibrotide in patients with severe VOD following hematopoietic stem cell transplantation (HSCT) and identified an appropriate dose for future trials. Adult and pediatric patients received either lower-dose (arm A: 25 mg/kg/day; n = 75) or higher-dose (arm B: 40 mg/kg/day; n = 74) i.v. defibrotide administered in divided doses every 6 hours for > or =14 days or until complete response, VOD progression, or any unacceptable toxicity occurred. Overall complete response and day +100 post-HSCT survival rates were 46% and 42%, respectively, with no significant difference between treatment arms. The incidence of treatment-related adverse events was low (8% overall; 7% in arm A, 10% in arm B); there was no significant difference in the overall rate of adverse events between treatment arms. Early stabilization or decreased bilirubin was associated with better response and day +100 survival, and decreased plasminogen activator inhibitor type 1 (PAI-1) during treatment was associated with better outcome; changes were similar in both treatment arms. Defibrotide 25 or 40 mg/kg/day also appears effective in treating severe VOD following HSCT. In the absence of any differences in activity, toxicity or changes in PAI-1 level, defibrotide 25 mg/kg/day was selected for ongoing phase III trials in VOD.Item Open Access Developmental exposure to a complex PAH mixture causes persistent behavioral effects in naive Fundulus heteroclitus (killifish) but not in a population of PAH-adapted killifish.(Neurotoxicol Teratol, 2016-01) Brown, DR; Bailey, JM; Oliveri, AN; Levin, ED; Di Giulio, RTAcute exposures to some individual polycyclic aromatic hydrocarbons (PAHs) and complex PAH mixtures are known to cause cardiac malformations and edema in the developing fish embryo. However, the heart is not the only organ impacted by developmental PAH exposure. The developing brain is also affected, resulting in lasting behavioral dysfunction. While acute exposures to some PAHs are teratogenically lethal in fish, little is known about the later life consequences of early life, lower dose subteratogenic PAH exposures. We sought to determine and characterize the long-term behavioral consequences of subteratogenic developmental PAH mixture exposure in both naive killifish and PAH-adapted killifish using sediment pore water derived from the Atlantic Wood Industries Superfund Site. Killifish offspring were embryonically treated with two low-level PAH mixture dilutions of Elizabeth River sediment extract (ERSE) (TPAH 5.04 μg/L and 50.4 μg/L) at 24h post fertilization. Following exposure, killifish were raised to larval, juvenile, and adult life stages and subjected to a series of behavioral tests including: a locomotor activity test (4 days post-hatch), a sensorimotor response tap/habituation test (3 months post hatch), and a novel tank diving and exploration test (3months post hatch). Killifish were also monitored for survival at 1, 2, and 5 months over 5-month rearing period. Developmental PAH exposure caused short-term as well as persistent behavioral impairments in naive killifish. In contrast, the PAH-adapted killifish did not show behavioral alterations following PAH exposure. PAH mixture exposure caused increased mortality in reference killifish over time; yet, the PAH-adapted killifish, while demonstrating long-term rearing mortality, had no significant changes in mortality associated with ERSE exposure. This study demonstrated that early embryonic exposure to PAH-contaminated sediment pore water caused long-term locomotor and behavioral alterations in killifish, and that locomotor alterations could be observed in early larval stages. Additionally, our study highlights the resistance to behavioral alterations caused by low-level PAH mixture exposure in the adapted killifish population. Furthermore, this is the first longitudinal behavioral study to use killifish, an environmentally important estuarine teleost fish, and this testing framework can be used for future contaminant assessment.
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