Dietary exposure assessment of cyadox based on tissue depletion of cyadox and its major metabolites in pigs, chickens, and carp.

The tissue kinetics of cyadox, an antibacterial agent used in food animals, and its major metabolites in pigs, chickens, and carp were investigated followed by a complete dietary exposure assessment to evaluate the food safety of cyadox. Cyadox and its major metabolites, bisdeoxycyadox (Cy1), 4-desoxycyadox (Cy2), N-(quinoxaline-2-methyl)-cyanide acetyl hydrazine (Cy4), quinoxaline-2-carboxylic acid (Cy6), and 2-hydromethyl-3-hydroxy-quinoxaline (Cy12), were simultaneously quantitated with a high-performance liquid chromatography-ultraviolet (HPLC-UV) method. Pigs, chickens, and carp were fed with 150 mg/kg cyadox in feed for consecutive 60, 40, and 30 days, respectively. The residue amount of cyadox and its major metabolites in liver, kidney, muscle, and fat (skin) tissues was determined. Cy2 was below the limit of quantitation even at the withdrawal time of 6 hr, cyadox, Cy4, Cy6, and Cy12 could be detected at 6-24 hr with low level less than 50 µg/kg. By contrast, Cy1 persisted for 3 days in the kidney of pigs and chickens, and in the liver of carp. Based on these residue depletion data and previous toxicology results, the global estimated chronic dietary exposure assessment of cyadox for general population was conducted, indicating a zero withdrawal time (WDT) may be appropriate for cyadox in food animals when used in feed for prolonged administration. These results provide analytical techniques and safety standards suitable for residue monitoring of cyadox in food animals.

Ginsenoside Rg1 Attenuates Cigarette Smoke-Induced Pulmonary Epithelial-Mesenchymal Transition via Inhibition of the TGF-ß1/Smad Pathway.

Epithelial-mesenchymal transition (EMT) is a process associated with airway remodeling in chronic obstructive pulmonary disease (COPD), which leads to progressive pulmonary destruction. Panax ginseng is a traditional herbal medicine that has been shown to improve pulmonary function and exercise capacity in patients with COPD. Ginsenoside Rg1 is one of the main active components and was shown to inhibit oxidative stress and inflammation. The present study investigated the hypothesis that ginsenoside Rg1 attenuates EMT in COPD rats induced by cigarette smoke (CS) and human bronchial epithelial (HBE) cells exposed to cigarette smoke extract (CSE). Our data showed that CS or CSE exposure increased expression of the mesenchymal marker α-smooth muscle actin (α-SMA) and decreased expression of the epithelial marker epithelial cadherin (E-cad) in both lung tissues and HBE cells, which was markedly suppressed by ginsenoside Rg1. Importantly, CS-induced upregulation of TGF-ß1/Smad pathway components, including TGF-ß1, TGF-ßR1, phospho-Smad2, and phospho-Smad3, was also inhibited by ginsenoside Rg1. Additionally, ginsenoside Rg1 mimicked the effect of SB525334, a TGF-ßR1-Smad2/3 inhibitor, on suppression of EMT in CSE-induced HBE cells. Collectively, we concluded that ginsenoside Rg1 alleviates CS-induced pulmonary EMT, in both COPD rats and HBE cells, via inhibition of the TGF-ß1/Smad pathway.

Efficacy of 12 or 18 weeks of elbasvir plus grazoprevir with ribavirin in treatment-naïve, noncirrhotic HCV genotype 3-infected patients.

Elbasvir (EBR; HCV NS5A inhibitor) and grazoprevir (GZR; HCV NS3/4A protease inhibitor) are approved as a fixed-dose combination to treat patients chronically infected with HCV genotypes 1 and 4. During the development programme and supported by in vitro potency, the efficacy of EBR+GZR was assessed in HCV GT3-infected patients. This study's aim was to determine the efficacy and tolerability of 12 or 18 weeks of EBR+GZR with ribavirin (RBV) in treatment-naïve, noncirrhotic HCV GT3-infected patients. Randomized patients received open-label EBR (50 mg once daily) + GZR (100 mg once daily) + RBV. The primary efficacy objective was to evaluate the sustained virologic response rates 12 weeks after the end of all study therapy (SVR12). SVR12 rates (95% confidence interval) were 45.0% (23.1, 68.5) and 57.1% (34.0, 78.2) after treatment with EBR+GZR+RBV for 12 weeks or 18 weeks, respectively. On-treatment virologic failure was observed in 41% (17 of 41) of patients. At virologic failure, resistance-associated substitutions (RASs) with a >five-fold shift in potency occurred in the NS3 region in six (35%) patients and in the NS5A region in 16 (94%) patients. The most common RAS at virologic failure was Y93H in NS5A which was identified in 13 of 17 (76%) patients. The efficacy of EBR+GZR+RBV was suboptimal in HCV GT3-infected patients due to a high rate of on-treatment virologic failure and treatment-emergent RASs which demonstrates an inadequate barrier to the development of GT3 resistance. However, rapid viral clearance demonstrated the antiviral activity of EBR+GZR+RBV in GT3-infected patients.clinicaltrials.gov: NCT01717326.

An Orally Active Allosteric GLP-1 Receptor Agonist Is Neuroprotective in Cellular and Rodent Models of Stroke.

Diabetes is a major risk factor for the development of stroke. Glucagon-like peptide-1 receptor (GLP-1R) agonists have been in clinical use for the treatment of diabetes and also been reported to be neuroprotective in ischemic stroke. The quinoxaline 6,7-dichloro-2-methylsulfonyl-3-N-tert- butylaminoquinoxaline (DMB) is an agonist and allosteric modulator of the GLP-1R with the potential to increase the affinity of GLP-1 for its receptor. The aim of this study was to evaluate the neuroprotective effects of DMB on transient focal cerebral ischemia. In cultured cortical neurons, DMB activated the GLP-1R, leading to increased intracellular cAMP levels with an EC50 value about 100 fold that of exendin-4. Pretreatment of neurons with DMB protected against necrotic and apoptotic cell death was induced by oxygen-glucose deprivation (OGD). The neuroprotective effects of DMB were blocked by GLP-1R knockdown with shRNA but not by GLP-1R antagonism. In C57BL/6 mice, DMB was orally administered 30 min prior to middle cerebral artery occlusion (MCAO) surgery. DMB markedly reduced the cerebral infarct size and neurological deficits caused by MCAO and reperfusion. The neuroprotective effects were mediated by activation of the GLP-1R through the cAMP-PKA-CREB signaling pathway. DMB exhibited anti-apoptotic effects by modulating Bcl-2 family members. These results provide evidence that DMB, a small molecular GLP-1R agonist, attenuates transient focal cerebral ischemia injury and inhibits neuronal apoptosis induced by MCAO. Taken together, these data suggest that DMB is a potential neuroprotective agent against cerebral ischemia.

Dynamic changes in metabolic profiles of rats subchronically exposed to mequindox.

Mequindox is widely used as an antibacterial veterinary drug and a feeding additive for farm animals in China. Although its toxicity has been widely studied, little is known regarding the metabolic effects of subchronic exposure to mequindox, which is vital for the health of meat producing livestock. Here, we characterized the dose- and time-dependent metabolic alterations in female Wistar rats subchronically exposed to mequindox through dietary supplementation at the level of 40, 110 and 280 mg kg(-1) for 13 weeks, employing a NMR based metabonomics approach with supplementary information from serum clinical chemistry. We found that urinary metabolic profiles were significantly affected in all dosed groups during the supplementation period; plasma and hepatic metabolic profiles were significantly affected only in rats dosed with moderate and high levels of mequindox. We also observed a return to control levels, for the profiles of urine and liver, at all dose levels after a two weeks washout period. However, this was not the case for the metabolic profiles of plasma from rats dosed at high levels. At the molecular level, we showed that subchronic exposure to mequindox resulted in tricarboxylic acid cycle (TCA cycle) stimulation, suppression of glycolysis, and promotion of gluconeogenesis and lipid oxidation in rats. In addition, subchronic exposure to mequindox induced oxidative stress in rats. Furthermore, a disturbance of gut microbiota, manifested by alterations in the urinary excretion of hippurate, phenylacetylglycine, 3-(3-hydroxyphenyl)propionate, p-cresol glucuronide, methylamine, dimethylamine, and formate, was associated with mequindox exposure. The present study provided important holistic metabolic information on the effects of subchronic dosage of mequindox on rats, which is useful for evaluating the safety of mequindox usage in meat producing animals.

Short-term, low-dose varenicline administration enhances information processing speed in methamphetamine-dependent users.

UNLABELLED: Long-term, high-dose methamphetamine (METH) use is associated with decrements in neurocognition and, given the association between impaired neurocognition and poorer treatment outcomes in individuals dependent on alcohol and drugs, it is considered to be a neglected area of critical concern. The objective of this study was to determine whether varenicline, a partial agonist at α4ß2- and a full agonist at α7-nicotinic acetylcholine receptors, enhances attention/information processing speed, episodic memory, and working memory in non-treatment seeking METH-dependent participants. Twenty-six participants were randomly assigned to receive oral placebo or oral varenicline (titrated up to 1 mg) over 5 days during three separate inpatient phases, and 17 completed each inpatient phase. Participants were predominately male (71%) and Caucasian (71%). Varenicline significantly improved reaction time on the n-back for visual stimuli (F(1,47)=5.369, p=0.025, η2=0.103), and a trend was observed for improvement in reaction time for auditory stimuli (F(1,47)=3.141, p=0.083, η2=0.063). For those study participants whose reaction time was in the lower half of the distribution at baseline, the effect was even more pronounced for auditory (F(1,22)=5.287, p=0.031, η2=0.194) and visual (F(1,22)=11.981, p=0.002, η2=0.353) stimuli relative to placebo. In contrast, varenicline did not modulate mean or maximum span of working memory or performance on tests of episodic memory or attention (p's>0.05). Given the potential importance of this finding, it should be replicated in a larger sample over a longer treatment period with a higher dose of varenicline (2 mg). TRIAL REGISTRATION: clinicalTrials.gov Identifier NCT01571167.

Chronic sazetidine-A maintains anxiolytic effects and slower weight gain following chronic nicotine without maintaining increased density of nicotinic receptors in rodent brain.

Chronic nicotine administration increases the density of brain α4ß2* nicotinic acetylcholine receptors (nAChRs), which may contribute to nicotine addiction by exacerbating withdrawal symptoms associated with smoking cessation. Varenicline, a smoking cessation drug, also increases these receptors in rodent brain. The maintenance of this increase by varenicline as well as nicotine replacement may contribute to the high rate of relapse during the first year after smoking cessation. Recently, we found that sazetidine-A (saz-A), a potent partial agonist that desensitizes α4ß2* nAChRs, does not increase the density of these receptors in brain at doses that decrease nicotine self-administration, increase attention in rats, and produce anxiolytic effects in mice. Here, we investigated whether chronic saz-A and varenicline maintain the density of nAChRs after their up-regulation by nicotine. In addition, we examined the effects of these drugs on a measure of anxiety in mice and weight gain in rats. After increasing nAChRs in the rodent brain with chronic nicotine, replacing nicotine with chronic varenicline maintained the increased nAChR binding, as well as the α4ß2 subunit proteins measured by western blots. In contrast, replacing nicotine treatments with chronic saz-A resulted in the return of the density of nAChRs to the levels seen in saline controls. Nicotine, saz-A and varenicline each demonstrated anxiolytic effects in mice, but only saz-A and nicotine attenuated the gain of weight over a 6-week period in rats. These findings suggest that apart from its modest anxiolytic and weight control effects, saz-A, or drugs like it, may be useful in achieving long-term abstinence from smoking.

Chick chorioallantoic membrane model for in ovo evaluation of timolol maleate-brimonidine tartrate ocular inserts.

The main aspire of this study was to develop ocular drug delivery system for dual drug glaucoma therapy by timolol maleate-brimonidine tartrate and endeavor the possibility of biocompatibility studies by in ova studies. Matrix type, both hydrophilic and lipophilic polymers, and reservoir-type ocular inserts of timolol maleate were prepared using hydrophilic polymers like polyvinyl alcohol, hydroxyl propyl methyl cellulose K4M and lipophilic polymers like ethylcellulose and eudragit S100 and were optimized. Based on the optimized formulation, triple-layered ocular inserts (reservoir type) of dual drug were prepared by solvent casting technique with an objective of reducing the frequency of administration, obtaining controlled release and greater therapeutic efficacy, preservative free dosage form for the treatment of glaucoma. FTIR spectral studies revealed no pharmaceutical incompatibility and no drug polymer interactions. Maximum drug release (99.18 ± 1.7) was achieved when PVP and HPMC K4M in 1:1 ratio with PEG 400 (0.3 ml) drug reservoir layer was sandwiched between ethyl cellulose as rate control membrane up to 32 h in a controlled fashion. Drug release was by non-Fickian diffusion mechanism for single drug formulation. But in dual drug insert, timolol maleate best fit into zero order and for brimonidine tartrate to Higuchi model and diffusion of drugs from this by non-Fickian diffusion mechanism. In ovo studies suggested that the optimized formulation was found to be sterile, biocompatible and physicochemically stable and support us to claim that the developed formulation was biocompatible.

Evaluation of extended release brimonidine intravitreal device in normotensive rabbit eyes.

PURPOSE: To evaluate the safety profile of a brimonidine extended release intravitreal implant, in normotensive rabbit eyes. METHODS: Devices were made from hollow poly-l-lactic acid (PLA) tubes and contained hundred micrograms of brimonidine pamoate. Device was injected intravitreally in one eye of 12 New Zealand pigmented rabbits, whereas other eye was injected with a sham implant in masked fashion. Ocular examination was conducted at baseline and months 1, 3 and 6 including dilated fundus examination and electro-retinogram (ERG). Four rabbits were sacrificed at each time-point for retinal histology. ERG data were compared between groups and time-points using anova. RESULTS: No complications were reported from either eye of any rabbits over a 6-month period. Photopic A wave was reduced in the control eye at 1 month compared with baseline (p < 0.01). There was no significant difference in other ERG parameters between the groups at different time-points. Gross retinal histology was normal at all time-points. CONCLUSION: Extended release intravitreal brimonidine device was found to be safe and in normotensive rabbit eyes.

Promoting smoking cessation.

Cigarette smoking causes significant morbidity and mortality in the United States. Physicians can use the five A's framework (ask, advise, assess, assist, arrange) to promote smoking cessation. All patients should be asked about tobacco use and assessed for motivation to quit at every clinical encounter. Physicians should strongly advise patients to quit smoking, and use motivational interviewing techniques for patients who are not yet willing to stop smoking. Clinical contacts with unmotivated patients should emphasize the rewards and relevance of quitting, as well as the risks of smoking and anticipated barriers to abstinence. These messages should be repeated at every opportunity. Appropriate patients should be offered pharmacologic assistance in quitting, such as nicotine replacement therapies, bupropion, and varenicline. Use of pharmacologic support during smoking cessation can double the rate of successful abstinence. Using more than one type of nicotine replacement therapy ("patch plus" method) and combining these therapies with bupropion provide additional benefit. However, special populations pose unique challenges in pharmacotherapy for smoking cessation. Nicotine replacement therapies increase the risk of birth defects and should not be used during pregnancy. They are usually safe in patients with cardiovascular conditions, except for those with unstable angina or within two weeks of a coronary event. Varenicline may increase the risk of coronary events. Nicotine replacement therapies are safe for use in adolescents; however, they are less effective than in adults. Physicians also should arrange to have repeated contact with smokers around their quit date to reinforce cessation messages.

The long-term outcomes of four alternative treatment strategies for primary open-angle glaucoma.

PURPOSE: To evaluate the long-term effects and costs of four treatment strategies for primary open-angle glaucoma compared to usual care. METHODS: Cost-effectiveness analyses with a lifelong horizon were made from a societal perspective. Data were generated with a patient-level model based on discrete event simulation. The model structure and parameter estimates were based on literature, particularly clinical studies on the natural course of glaucoma and the effect of treatment. We simulated heterogeneous cohorts of 3000 patients and explored the impact of uncertainty with sensitivity analyses. RESULTS: The incremental cost-effectiveness ratio (ICER) of initial treatment with a prostaglandin analogue compared with a ß-blocker was €12.931 per quality-adjusted life year (QALY) gained. A low initial target pressure (15 mmHg) resulted in 0.115 QALYs gained and €1550 saved compared to a gradual decrease from 21 to 15 mmHg upon progression. Visual field (VF) measurements every 6 rather than 12 months lead to health gains at increased costs (ICER €173,486 per QALY gained), whereas measurements every 24 months lead to health losses at reduced costs (ICER €21,516 per QALY lost). All treatment strategies were dominant over 'withholding treatment'. CONCLUSIONS: From a cost-effectiveness point of view, it seems advantageous to aim for a low intraocular pressure in all glaucoma patients. The feasibility of this strategy should therefore be investigated. Additionally, the cost-effectiveness outcomes of initiating monotherapy with a prostaglandin analogue and reducing the frequency of VF testing may be acceptable.

Pu-erh black tea extract supplementation attenuates the oxidative DNA damage and oxidative stress in Sprague-Dawley rats with renal dysfunction induced by subchronic 3-methyl-2-quinoxalin benzenevinylketo-1,4-dioxide exposure.

3-Methyl-2-quinoxalin benzenevinylketo-1,4-dioxide (Quinocetone, QCT), has been used to treat dysentery and promote growth in animal feeding. However, available data show that QCT has potential nephrotoxicity. The present study was designed to investigate the protective effects of Pu-erh black tea extract (PBTE) which is a traditional remedy in China with antioxidant properties against oxidative DNA damage and oxidative stress in a rat model of QCT-induced renal dysfunction. Increased serum creatinine, blood urea nitrogen, pathological lesions, urinary 8-hydroxy 2-deoxyguanosine (8-OHdG) and renal DNA damage were observed in the QCT-fed rats. These were accompanied by intracellular reactive oxygen species accumulation, enhanced lipid peroxidation, and inhibited antioxidant system, i.e., glutathione glutathione S-transferase, glutathione peroxidase and glutathione reductase. Oral administration of PBTE effectively suppressed QCT-induced renal dysfunction, as evidenced by reduced serum creatinine, urinary 8-OHdG and DNA damage in isolated renal cells, amelioration of oxidative stress and modulation of antioxidative system. In conclusion, PBTE administration ameliorated QCT-induced nephrotoxicity by maintaining DNA's double-helix architecture and mitigating oxidative stress.

An immunohistochemical analysis of the neuroprotective effects of memantine, hyperbaric oxygen therapy, and brimonidine after acute ischemia reperfusion injury.

PURPOSE: This study applies treatment methods to rat retinas subjected to acute ischemia reperfusion injury and compares the efficacy of memantine, hyperbaric oxygen (HBO) therapy, and brimonidine by histopathological examination. METHODS: Thirty adult Wistar albino rats were divided into five groups after retinal ischemia was induced by elevating the intraocular pressure to 120 mmHg. The groups were as follows: group 1: control; group 2: acute retinal ischemia (ARI) model but without treatment group; group 3: memantine (MEM) treatment group; group 4: HBO therapy group; and group 5: brimonidine treatment (BRI) group. In the control group, right eyes were cannulated with a 30-gauge needle and removed without causing any intraocular pressure change. The ARI group was an acute retinal ischemia model, but without treatment. In the MEM group, animals were given a unique dose of intravenous 25 mg/kg memantine by the tail vein route after inducing ARI. In the HBO group, at 2 h following ARI, HBO treatment was applied for nine days. In the BRI group, a 0.15% brimonidine tartrate eye drop treatment was applied twice a day (BID) for seven days before ARI. Twenty-one days after establishing ischemia reperfusion, the right eyes were enucleated after the cardiac gluteraldehyde perfusion method, and then submitted to histological evaluation. RESULTS: On average, the total retinal ganglion cell number was 239.93 ± 8.60 in the control group, 125.14 ± 7.18 in the ARI group, 215.89 ± 8.36 in the MEM group, 208.69 ± 2.05 in the HBO group, and 172.27 ± 8.16 in the BRI group. Mean apoptotic indexes in the groups were 1.1 ± 0.35%, 57.71 ± 0.58%, 23.57 ± 1.73%, 15.63 ± 0.58%, and 29.37 ± 2.55%, respectively. CONCLUSIONS: The present study shows that memantine, HBO, and brimonidine therapies were effective in reducing the damage induced by acute ischemia reperfusion in the rat retina. Our study suggests that these treatments had beneficial effects due to neuroprotection, and therefore may be applied in clinical practice.

Molecular determinants of melanoma malignancy: selecting targets for improved efficacy of chemotherapy.

The BRAFV600E mutation is common in human melanoma. This mutation enhances IkappaB kinase (IKK)/nuclear factor-kappaB (NF-kappaB) and extracellular signal-regulated kinase/activator protein signaling cascades. In this study, we evaluated the efficacy of targeting either B-Raf or IKKbeta in combination with the DNA alkylating agent temozolomide for treatment of advanced metastatic melanoma. Xenografts of Hs294T human metastatic melanoma cells exhibiting the BRAFV600E mutation were treated with inhibitors of IKKbeta (BMS-345541), B-Raf (BAY 54-9085), and/or temozolomide. Drug response was mechanistically analyzed in vitro and in vivo. In this study, we determined that the antitumor activity of all three drugs depends on inhibition of NF-kappaB. BMS-345541 inhibits IKKbeta-mediated phosphorylation of IkappaBalpha and thus blocks the nuclear localization of NF-kappaB, whereas BAY 54-9085 inhibits activation of NF-kappaB through a mechanism that does not involve stabilization of IkappaBalpha. Moreover, BMS-345541, but not BAY 54-9085, activates the death pathways of p53 and c-Jun-NH2-kinase, contributing to the killing of melanoma cells. Temozolomide inhibits both NF-kappaB and extracellular signal-regulated kinase activity, conferring effective in vivo antitumor activity. Thus, temozolomide, but not BAY 54-9085, has a synergistic in vivo antitumor effect with BMS-345541. We conclude that the efficacy of antimelanoma therapy depends on inhibition of expression of antiapoptotic genes transcriptionally regulated by NF-kappaB. In contrast, drug targeting of the extracellular signal-regulated kinase/mitogen-activated protein kinase pathway alone in melanoma cells is ineffective for melanoma therapy in cases where NF-kappaB is not also targeted.

Suppressive effects of a quinoxaline-analogue (Rob 803) on pathogenic immune mechanisms in collagen-induced arthritis.

The anti-arthritic effects of the synthetic compound 9-chloro-2,3 dimethyl-6-(N,N-dimetylamino-2-oxoethyl)-6H-indolo[2,3-b] quinoxaline (Rob 803) was evaluated by treating Dark Agouti rats with collagen-induced arthritis using three different protocols. Daily subcutaneous treatment with 40 mg/kg/day of Rob 803 from the day of immunization and 14 days forward suppressed arthritis severity significantly and delayed the onset of clinical arthritis. In contrast, similar treatment initiated when individual rats had developed clinical disease (at a score of 2 points) did not suppress disease. Oral treatment with 35 mg/kg/day of Rob 803 from the day of immunization and 21 days forward resulted in a trend towards disease suppression. In vitro analysis of rats treated subcutaneously with Rob 803 revealed an inhibition of T cell proliferation but no effect on the generation of an anti-CII immunoglobulin G response. Further in vitro analysis demonstrated that Rob 803 also inhibited the generation of nitric oxide in macrophages, although at higher concentrations than needed for inhibitory effects on T cell proliferation. Thus we report that early subcutaneous administration of the synthetic substance Rob 803 has anti-rheumatic effects that are probably mediated by affecting the proliferative capacity of lymph node T cells. Rob 803 should be considered as a new candidate substance for anti-rheumatic treatment.

Neuroprotective effects of brimonidine treatment in a rodent model of ischemic optic neuropathy.

Ischemic optic neuropathy (ION) is a common disorder caused by disruption of the arterial blood supply to the optic nerve. It can result in significant loss of visual acuity and/or visual field. An ischemic optic nerve injury was produced in rats by intravenous injection of Rose Bengal dye followed by argon green laser application to the retinal arteries overlying the optic nerve, causing a coagulopathy within the blood vessels and disruption of optic nerve and retinal perfusion. The effect of brimonidine tartrate eye drops on survival of retinal ganglion cell axons in this experimental paradigm was studied. One eye was treated and the contralateral eye served as a control. Four groups of animals were used for this study. Group 1 received 7 days of treatment with 0.15% brimonidine tartrate eye drops twice a day prior to the ischemic injury. Group 2 animals received 0.15% brimonidine tartrate eye drops twice a day for 14 days after photocoagulation injury. Animal groups 3 and 4 received eye drops of 0.9% NaCl twice a day either daily for 7 days before injury or daily for 14 days, respectively. All rats were sacrificed 5 months after the injury to ascertain long-term optic axon survival. Coagulopathy-induced optic nerve ischemia resulted in a 71% loss of optic axons. Treatment with brimonidine daily for the 7 days prior to the injury resulted in a greater survival of optic axons, with only a 56.1% loss compared to control. Brimonidine treatment every day for 14 days after the ischemic injury did not result in a significant rescue of optic axons compared to injury alone. In summary, the application of brimonidine eye drops for one week prior to an ischemic injury resulted in a statistically significant increase in survival of optic axons within the injured optic nerves. Brimonidine treatment of the eye after the ischemic injury did not result in axon rescue, and axon loss was similar to the injured optic nerves treated with saline only. These results suggest that brimonidine may have potential use for prevention of ION in at-risk patients.

BMS-345541 targets inhibitor of kappaB kinase and induces apoptosis in melanoma: involvement of nuclear factor kappaB and mitochondria pathways.

PURPOSE: Constitutive activation of inhibitor of kappaB kinase (IKK) confers melanoma resistance to apoptosis and chemotherapy. Whether IKK is able to serve as a therapeutic target in melanoma is unknown. We explored the possibility of exploiting IKK as a therapeutic target in melanoma by using BMS-345541, a novel compound with a highly selective IKKbeta inhibitory activity, to trigger melanoma cell apoptosis. EXPERIMENTAL DESIGN: Three human melanoma cell lines (SK-MEL-5, Hs 294T, and A375), all of which have high constitutive IKK activities, served as in vitro and in vivo melanoma models for treatment with BMS-345541. Two known antitumor drugs (temozolomide and bortezomib) were used as parallel controls for evaluation of the therapeutic efficiency and toxicity of BMS-345541. The effects of BMS-345541 on nuclear factor kappaB (NF-kappaB) signaling and on the apoptosis machinery were investigated. RESULTS: Inhibition of constitutive IKK activity by BMS-345541 resulted in the reduction of NF-kappaB activity, CXCL1 chemokine secretion by cultured melanoma cells and melanoma cell survival in vitro and in vivo. The effect of BMS-345541 on tumor cell growth was through mitochondria-mediated apoptosis, based on the release of apoptosis-inducing factor, dissipation of mitochondrial membrane potential, and reduced ratio of B cell lymphoma gene-2 (Bcl-2)/Bcl-associated X protein (Bax) in mitochondria. The BMS-345541 execution of apoptosis was apoptosis-inducing factor-dependent, but largely caspase-independent. CONCLUSION: BMS-345541 down-regulation of IKK activity results in mitochondria-mediated apoptosis of tumor cells because the programmed cell death machinery in melanoma cells is highly regulated by NF-kappaB signaling. Therefore, IKK may serve as a potential target for melanoma therapy.

Comparison of the clinical success rates and quality of life effects of brimonidine tartrate 0.2% and betaxolol 0.25% suspension in patients with open-angle glaucoma and ocular hypertension. Brimonidine Outcomes Study Group II.

PURPOSE: To compare the clinical effectiveness and the impact on quality of life of twice-daily brimonidine 0.2% with those of twice-daily betaxolol 0.25% in patients with glaucoma or ocular hypertension. METHODS: A prospective, double-masked, randomized, comparative, multicenter, 4-month "real-life" clinical trial involving 188 patients. Medications were instilled twice daily. Efficacy was determined through measurement of intraocular pressure; safety and tolerability were measured using reports of adverse events, a quality of life survey (Glaucoma Disability Index), heart rate, and blood pressure. Patients with an inadequate response in intraocular pressure after 1 month or those who experienced significant adverse events in the first month were switched to the alternative study arm and remained taking the alternative medication for a total of 4 months or left the study. The main outcome measure was clinical success, as determined by evaluation of the efficacy, safety, and tolerability of drug treatment, and was achieved when the investigator recommended that the patient continue the treatment after completion of the study. RESULTS: As initial therapy, clinical success was achieved in 74% of patients treated with brimonidine, as compared with 57% of patients treated with betaxolol (P = 0.027). The overall mean decrease in intraocular pressure from baseline was 5.9 mm Hg with brimonidine and 3.8 mm Hg with betaxolol. Both treatments were well tolerated, and there were no significant between-group differences in the incidence of adverse events or in the quality of life summary scores. CONCLUSIONS: Twice-daily brimonidine 0.2% and betaxolol 0.25% suspension were safe and effective as first-line therapy for glaucoma and ocular hypertension. In this study, brimonidine showed clinical effectiveness superior to that of betaxolol.

Characterization of audiogenic-like seizures in naive rats evoked by activation of AMPA and NMDA receptors in the inferior colliculus.

The role of glutamate receptors in the inferior colliculus (IC) in audiogenic and audiogenic-like seizures was investigated in adult rats with transient neonatal hypothyroidism by 0.02% propylthiouracil (PTU) treatment through mother's milk (PTU rats) and in naive rats treated intracisternally with N-methyl-d-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole-proprionic acid (AMPA), or cyclothiazide, an inhibitor of rapid AMPA receptor desensitization. All rats showed audiogenic or audiogenic-like seizures characterized by running fit (RF) and generalized tonic-clonic seizures (GTCS). While systemically administered MK-801 inhibited GTCS, intracisternally administered NBQX inhibited RF and GTCS in both audiogenic and audiogenic-like seizures. Auditory stimulation shortened the latency to GTCS induced by AMPA, but not NMDA, at a subclinical dose and further elongated the shortened duration of RF, but not GTCS, induced by MK-801 pretreatment. Furthermore, Northern blot analysis was used to evaluate the expression of the immediate-early gene c-fos in the IC following induction of audiogenic or audiogenic-like seizures. The significant induction of c-fos mRNA by audiogenic seizures in PTU rats or by AMPA- or cyclothiazide-induced seizures in naive rats was prominent in the IC. MK-801 suppressed c-fos mRNA expression in the IC induced by audiogenic seizures in PTU rats or by AMPA-induced seizures in naive rats. NBQX suppressed the expression of c-fos mRNA in the IC induced by AMPA-induced seizures but did not suppress c-fos mRNA in PTU rats or rats with cyclothiazide-induced seizures. Auditory stimuli failed to affect c-fos mRNA induction by AMPA. The present study suggests that audiogenic-like seizures can be reproduced by glutamate receptor agonists in which AMPA receptors are primarily linked to the initiation of audiogenic seizures (RF) while NMDA receptors presumably located within the IC are involved in the propagation of GTCS in audiogenic seizures.