Severe Hypotony Maculopathy in Anterior Uveitis Associated with Hodgkin Lymphoma.

Purpose: To describe the clinical course and management of anterior uveitis complicated by ocular hypotony associated with Hodgkin lymphoma.Design: Case report.Methods: Chart and multimodal imaging review, including ultrasound biomicroscopy, widefield fundus pictures, fundus autofluorescence, fluorescein angiography, and indocyanine green angiography.Results: A 44-year-old female with progressive visual deterioration and history of low-grade fever developed bilateral granulomatous anterior uveitis complicated by severe hypotony maculopathy, not improving with systemic and topical steroids. After starting ibopamine 2% eye drops, ocular hypotony progressively resolved with visual recovery. Histologic examination of a biopsied enlarged lymph node of the neck revealed the presence of Hodgkin lymphoma, for which the patient underwent systemic chemotherapy.Conclusion: Severe hypotony maculopathy complicating anterior uveitis can be associated with Hodgkin lymphoma. Topical ipobamine 2% was safe and effective in the treatment of ocular hypotony in this case.

Ibopamine challenge testing becomes negative following successful trabeculectomy surgery.

BACKGROUND: The ibopamine challenge test correlates well with a patient's peak diurnal intraocular pressure (IOP) measurement. We aimed to investigate the effect that a functioning trabeculectomy has on the ibopamine challenge test. DESIGN: Non-randomized prospective clinical trial evaluating a diagnostic test. PARTICIPANTS: Thirteen patients were recruited through glaucoma clinics at the Flinders Medical Centre. Of these, seven required surgical management with trabeculectomy surgery, whilst the remainder were managed medically. METHODS: Patients underwent IOP measurement, and then two drops of Ibopamine 2% solution were instilled into the study eye of each patient. After 45 min, IOP was reassesed. A positive challenge test was considered to be a rise in IOP of greater than 3 mmHg. Changes from baseline were determined and compared between groups. Twelve months later, this test was then repeated in all patients. MAIN OUTCOME MEASURE: Change in IOP after ibopamine challenge. RESULTS: Following the ibopamine challenge, IOP increased by 9.2 mmHg (SD 2.8) (100% positive) for medically managed patients and 7.2 mmHg (SD 2.0) (100% positive) for surgically managed patients (P = 0.18). The surgically managed group then underwent trabeculectomy surgery. Twelve months later, the ibopamine challenge was repeated. Following the repeat ibopamine challenge, IOP increased by 7.2 mmHg (SD 2.3) for medically managed patients and 0.3 mmHg (SD 1.3) for surgically managed patients (P < 0.0001). The medically managed group remained 100% positive, whilst the surgically manage group became 0% positive (Fisher Exact P = 0.044). CONCLUSIONS: A glaucoma patient with a positive ibopamine challenge will show a negative challenge result when re-tested following trabeculectomy surgery.

Treatment with a novel oleic-acid-dihydroxyamphetamine conjugation ameliorates non-alcoholic fatty liver disease in obese Zucker rats.

Fatty liver disease is one of the main hepatic complications associated with obesity. To date, there are no effective treatments for this pathology apart from the use of classical fibrates. In this study, we have characterized the in vivo effects of a novel conjugation of oleic acid with an amphetamine derivative (OLHHA) in an animal model of genetic obesity. Lean and obese Zucker rats received a daily intraperitoneal administration of OLHHA (5 mg kg(-1)) for 15 days. Plasma and liver samples were collected for the biochemical and molecular biological analyses, including both immunohistochemical and histological studies. The expression of key enzymes and proteins that are involved in lipid metabolism and energy homeostasis was evaluated in the liver samples. The potential of OLHHA to produce adverse drug reactions or toxicity was also evaluated through the monitoring of interactions with hERG channel and liver cytochrome. We found that OLHHA is a drug with a safe pharmacological profile. Treatment for 15 days with OLHHA reduced the liver fat content and plasma triglyceride levels, and this was accompanied by a general improvement in the profile of plasma parameters related to liver damage in the obese rats. A decrease in fat accumulation in the liver was confirmed using histological staining. Additionally, OLHHA was observed to exert anti-apoptotic effects. This hepatoprotective activity in obese rats was associated with an increase in the mRNA and protein expression of the cannabinoid type 1 receptor and a decrease in the expression of the lipogenic enzymes FAS and HMGCR primarily. However, changes in the mRNA expression of certain proteins were not associated with changes in the protein expression (i.e. L-FABP and INSIG2). The present results demonstrate that OLHHA is a potential anti-steatotic drug that ameliorates the obesity-associated fatty liver and suggest the potential use of this new drug for the treatment of non-alcoholic fatty liver disease.

Methylenedioxy designer drugs: mass spectrometric characterization of their glutathione conjugates by means of liquid chromatography-high-resolution mass spectrometry/mass spectrometry and studies on their glutathionyl transferase inhibition potency.

Methylenedioxy designer drugs of abuse such as 3,4-methylenedioxymethamphetamine (MDMA) can be selectively toxic to serotonergic neurons and glutathione (GSH) adducts have been implicated in its neurotoxicity. The catecholic demethylenyl metabolites of MDMA, 3,4-dihydroxymethamphetamine and 3,4-dihydroxyamphetamine, are metabolically oxidized to the corresponding ortho-quinones, which are highly reactive intermediates. These intermediates can then be conjugated with GSH preventing cellular damage. Furthermore, glutathionyl transferase (GST) activity was described to be irreversibly inhibited by the catechols dopamine, α-methyldopa and their GSH conjugates. Therefore, the aims of the present work were the detection and characterization of GSH conjugates of ten methylenedioxy drugs of abuse and their phase I metabolites as well as to assess their inhibition potency on GST activity. The substrates were incubated using human placental GST with or without preincubation by cytochrome P450 enzymes preparations. GST inhibition was tested using chlorodinitrobenzene GSH conjugation as marker reaction. GSH conjugates were analyzed and characterized using LC-high-resolution-MS/MS. For confirmation of postulated fragmentation patterns, formation of GSH conjugates of selected deuterated analogs (deuterated analogue approach, DAA) of the investigated drugs was explored. For the methylenedioxy amphetamines the following steps could be identified: conjugation of the parent compounds at position 2, 5, 6, of the demethylenyl metabolites at position 2 and 5, and of the further deaminated demethylenyl metabolites at position 2. For the ß-keto-phenylalkylamine and pyrrolidinophenone, conjugation of the demethylenyl metabolites and of the deaminated demethylenyl metabolites at position 2 could be identified. The DAA allowed the differentiation of the 2 and 5/6 isomers by confirmation of the postulated mass spectral fragments. Finally, the tested drugs and phase I metabolites showed no inhibition potency on GST activity.

The mixture of "ecstasy" and its metabolites is toxic to human SH-SY5Y differentiated cells at in vivo relevant concentrations.

The neurotoxicity of "ecstasy" (3,4-methylenedioxymethamphetamine, MDMA) is thought to involve hepatic metabolism, though its real contribution is not completely understood. Most in vitro neurotoxicity studies concern isolated exposures of MDMA or its metabolites, at high concentrations, not considering their mixture, as expected in vivo. Therefore, our postulate is that combined deleterious effects of MDMA and its metabolites, at low micromolar concentrations that may be attained into the brain, may elicit neurotoxicity. Using human SH-SY5Y differentiated cells as dopaminergic neuronal model, we studied the neurotoxicity of MDMA and its MDMA metabolites α-methyldopamine and N-methyl-α-methyldopamine and their correspondent glutathione and N-acetylcysteine monoconjugates, under isolated exposure and as a mixture, at normothermic or hyperthermic conditions. The results showed that the mixture of MDMA and its metabolites was toxic to SH-SY5Y differentiated cells, an effect potentiated by hyperthermia and prevented by N-acetylcysteine. As a mixture, MDMA and its metabolites presented a different toxicity profile, compared to each compound alone, even at equimolar concentrations. Caspase 3 activation, increased reactive oxygen species production, and intracellular Ca(2+) raises were implicated in the toxic effect. The mixture increased intracellular glutathione levels by increasing its de novo synthesis. In conclusion, this study demonstrated, for the first time, that the mixture of MDMA and its metabolites, at low micromolar concentrations, which represents a more realistic approach of the in vivo scenario, elicited toxicity to human SH-SY5Y differentiated cells, thus constituting a new insight into the context of MDMA-related neurotoxicity.

Mixtures of 3,4-methylenedioxymethamphetamine (ecstasy) and its major human metabolites act additively to induce significant toxicity to liver cells when combined at low, non-cytotoxic concentrations.

Hepatic injury after 3,4-methylenedioxymethamphetamine (MDMA; ecstasy) intoxications is highly unpredictable and does not seem to correlate with either dosage or frequency of use. The mechanisms involved include the drug metabolic bioactivation and the hyperthermic state of the liver triggered by its thermogenic action and exacerbated by the environmental circumstances of abuse at hot and crowded venues. We became interested in understanding the interaction between ecstasy and its metabolites generated in vivo as users are always exposed to mixtures of parent drug and metabolites. With this purpose, Hep G2 cells were incubated with MDMA and its main human metabolites methylenedioxyamphetamine (MDA), α-methyldopamine (α-MeDA) and N-methyl-α-methyldopamine (N-Me-α-MeDA), individually and in mixture (drugs combined in proportion to their individual EC01 ), at normal (37 °C) and hyperthermic (40.5 °C) conditions. After 48 h, viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Extensive concentration-response analysis was performed with single drugs and the parameters of the individual non-linear logit fits were used to predict joint effects using the well-founded models of concentration addition (CA) and independent action (IA). Experimental testing revealed that mixture effects on cell viability conformed to CA, for both temperature settings. Additionally, substantial combination effects were attained even when each substance was present at concentrations that individually produced unnoticeable effects. Hyperthermic incubations dramatically increased the toxicity of the tested drug and metabolites, both individually and combined. These outcomes suggest that MDMA metabolism has hazard implications to liver cells even when metabolites are found in low concentrations, as they contribute additively to the overall toxic effect of MDMA.

"Ecstasy"-induced toxicity in SH-SY5Y differentiated cells: role of hyperthermia and metabolites.

3,4-Methylenedioxymethamphetamine (MDMA; "ecstasy") is a recreational hallucinogenic drug of abuse known to elicit neurotoxic properties. Hepatic formation of neurotoxic metabolites is thought to play a major role in MDMA-related neurotoxicity, though the mechanisms involved are still unclear. Here, we studied the neurotoxicity mechanisms and stability of MDMA and 6 of its major human metabolites, namely α-methyldopamine (α-MeDA) and N-methyl-α-methyldopamine (N-Me-α-MeDA) and their correspondent glutathione (GSH) and N-acetyl-cysteine (NAC) conjugates, under normothermic (37 °C) or hyperthermic conditions (40 °C), using cultured SH-SY5Y differentiated cells. We showed that MDMA metabolites exhibited toxicity to SH-SY5Y differentiated cells, being the GSH and NAC conjugates more toxic than their catecholic precursors and MDMA. Furthermore, whereas the toxicity of the catechol metabolites was potentiated by hyperthermia, NAC-conjugated metabolites revealed higher toxicity under normothermia and GSH-conjugated metabolites-induced toxicity was temperature-independent. Moreover, a time-dependent decrease in extracellular concentration of MDMA metabolites was observed, which was potentiated by hyperthermia. The antioxidant NAC significantly protected against the neurotoxic effects of MDMA metabolites. MDMA metabolites increased intracellular glutathione levels, though depletion in thiol content was observed in MDMA-exposed cells. Finally, the neurotoxic effects induced by the MDMA metabolite N-Me-α-MeDA involved caspase 3 activation. In conclusion, this study evaluated the stability of MDMA metabolites in vitro, and demonstrated that the catechol MDMA metabolites and their GSH and NAC conjugates, rather than MDMA itself, exhibited neurotoxic actions in SH-SY5Y differentiated cells, which were differently affected by hyperthermia, thus highlighting a major role for reactive metabolites and hyperthermia in MDMA's neurotoxicity.

Pro-oxidant effects of Ecstasy and its metabolites in mouse brain synaptosomes.

BACKGROUND AND PURPOSE: 3,4-Methylenedioxymethamphetamine (MDMA or 'Ecstasy') is a worldwide major drug of abuse known to elicit neurotoxic effects. The mechanisms underlying the neurotoxic effects of MDMA are not clear at present, but the metabolism of dopamine and 5-HT by monoamine oxidase (MAO), as well as the hepatic biotransformation of MDMA into pro-oxidant reactive metabolites is thought to contribute to its adverse effects. EXPERIMENTAL APPROACH: Using mouse brain synaptosomes, we evaluated the pro-oxidant effects of MDMA and its metabolites, α-methyldopamine (α-MeDA), N-methyl-α-methyldopamine (N-Me-α-MeDA) and 5-(glutathion-S-yl)-α-methyldopamine [5-(GSH)-α-MeDA], as well as those of 5-HT, dopamine, l-DOPA and 3,4-dihydroxyphenylacetic acid (DOPAC). KEY RESULTS: 5-HT, dopamine, l-DOPA, DOPAC and MDMA metabolites α-MeDA, N-Me-α-MeDA and 5-(GSH)-α-MeDA, concentration- and time-dependently increased H(2) O(2 ) production, which was significantly reduced by the antioxidants N-acetyl-l-cysteine (NAC), ascorbic acid and melatonin. From experiments with MAO inhibitors, it was observed that H(2) O(2) generation induced by 5-HT was totally dependent on MAO-related metabolism, while for dopamine, it was a minor pathway. The MDMA metabolites, dopamine, l-DOPA and DOPAC concentration-dependently increased quinoproteins formation and, like 5-HT, altered the synaptosomal glutathione status. Finally, none of the compounds modified the number of polarized mitochondria in the synaptosomal preparations, and the compounds' pro-oxidant effects were unaffected by prior mitochondrial depolarization, excluding a significant role for mitochondrial-dependent mechanisms of toxicity in this experimental model. CONCLUSIONS AND IMPLICATIONS: MDMA metabolites along with high levels of monoamine neurotransmitters can be major effectors of neurotoxicity induced by Ecstasy.

Six months treatment with ibopamine in patients with hypotony after vitreoretinal surgery for retinal detachment, uveitis or penetrating trauma.

PURPOSE: To evaluate the effectiveness of 6 months treatment with ibopamine eye drops in raising the intraocular pressure in patients with therapy-resistant hypotony after vitreoretinal surgery for proliferative vitreoretinopathy secondary to rhegmatogenous retinal detachment or penetrating trauma. METHODS: A 2% ibopamine eye drop was topically administered 3 times daily during 24 weeks. RESULTS: Seventeen patients were included. Nine patients were able to continue their treatment up to 24 weeks; their mean intraocular pressure increase was 2.11 mmHg (SE, 0.56; 95% confidence interval, 0.96 to 3.23; P < 0.0005) in comparison with baseline values. Eight patients stopped using ibopamine before 24 weeks because of complains of follicular conjunctivitis or irritation without clinically observable conjunctivitis. In these patients a comparable increase in intraocular pressure was observed up to treatment discontinuation. CONCLUSION: This study confirms that the use of topical ibopamine may result in a sustained increase in intraocular pressure of >2 mmHg in the majority of patients, but was only well tolerated in half of them. There may only be a few patients, however, who will clinically benefit from this rise in intraocular pressure. A better formulation or method of administration would be needed.

Induction of glutathione synthesis and conjugation by 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-dihydroxymethamphetamine (HHMA) in human and rat liver cells, including the protective role of some antioxidants.

MDMA (3,4-methylenedioxymethamphetamine) metabolism is a major cause of MDMA-mediated hepatotoxicity. In this study the effects of MDMA and its metabolites on the glutathione system were evaluated. Glutathione (GSH/GSSG) levels and gene expression of glutamate cysteine ligase catalytic subunit (GCLC), glutathione-S-transferase (GST) and pregnane X receptor (PXR) were compared in the immortalized human liver epithelial cell line THLE-Neo lacking phase I metabolism and primary rat hepatocytes expressing both phase I and II metabolism. Furthermore, we evaluated the potential protective effects of two antioxidants, N-acetyl-cysteine (NAC) and sulforaphane (SFN) in these cell systems. In THLE-Neo cells, the MDMA metabolite 3,4-dihydroxymetamphetamine (HHMA) significantly decreased cell viability and depleted GSH levels, resulting in an increased expression of GCLC and GST up to 3.4- and 2.2-fold, respectively. In primary rat hepatocytes, cell viability or GSH levels were not significantly affected upon MDMA exposure. GCLC expression levels where not significantly altered either, although GST expression was increased 2.3-fold. NAC counteracted MDMA-induced cytotoxicity and restored GSH levels. Phase II enzyme expression was also reverted. Conversely, SFN increased MDMA-induced cytotoxicity and GSH depletion, while GCLC and GST expression were significantly induced. In addition, PXR expression decreased after HHMA and MDMA exposure, while co-exposure to SFN induced it up to 3.6- and 3.9-fold compared to vehicle-control in the THLE-Neo cells and rat hepatocytes, respectively. Taken together, these data indicate that HHMA is a major factor in the MDMA-mediated hepatotoxicity through interaction with the glutathione system. The results of our study show that for MDMA intoxication the treatment with an antioxidant such as NAC may counteract the potentially hepatotoxicity. However, SFN supplementation should be considered with care because of the indications of possible drug-drug interactions.

Comparative neurochemical profile of 3,4-methylenedioxymethamphetamine and its metabolite alpha-methyldopamine on key targets of MDMA neurotoxicity.

The neurotoxicity of MDMA or "Ecstasy" in rats is selectively serotonergic, while in mice it is both dopaminergic and serotonergic. MDMA metabolism may play a key role in this neurotoxicity. The function of serotonin and dopamine transporter and the effect of MDMA and its metabolites on them are essential to understand MDMA neurotoxicity. The aim of the present study was to investigate and compare the effects of MDMA and its metabolite alpha-methyldopamine (MeDA) on several molecular targets, mainly the dopamine and serotonin transporter functionality, to provide evidence for the role of this metabolite in the neurotoxicity of MDMA in rodents. MeDA had no affinity for the serotonin transporter but competed with serotonin for its uptake. It had no persistent effects on the functionalism of the serotonin transporter, in contrast to the effect of MDMA. Moreover, MeDA inhibited the uptake of dopamine into the serotonergic terminal and also MAO(B) activity. MeDA inhibited dopamine uptake with a lower IC(50) value than MDMA. After drug washout, the inhibition by MeDA persisted while that of MDMA was significantly reduced. The effect of MDMA on the dopamine transporter is related with dopamine release from vesicular stores, as this inhibition disappeared in reserpine-treated animals. However, the effect of MeDA seems to be a persistent conformational change of this transporter. Moreover, in contrast with MDMA, MeDA did not show affinity for nicotinic receptors, so no effects of MeDA derived from these interactions can be expected. The metabolite reduced cell viability at lower concentrations than MDMA. Apoptosis plays a key role in MDMA induced cellular toxicity but necrosis is the major process involved in MeDA cytotoxicity. We conclude that MeDA could protect against the serotonergic lesion induced by MDMA but potentiate the dopaminergic lesion as a result of the persistent blockade of the dopamine transporter induced this metabolite.

Avaliação do comportamento da pressão intraocular em pacientes com glaucoma primário de ângulo aberto assimétrico submetidos ao teste provocativo da ibopamina / Evaluation of the intraocular pressure behavior in patients with assimetric primary open-angle glaucoma submitted to ibopamine provocative test

OBJETIVO: Avaliar o efeito da ibopamina a 2 por cento tópica e comparar a variação na pressão intraocular (PIO) em olhos com glaucoma primário de ângulo aberto assimétrico (GPAA). MÉTODOS: Quinze pacientes (30 olhos) com GPAA com evolução assimétrica da neuropatia entre os dois olhos, onde comparamos em cada paciente a resposta a ibopamina e o defeito perimétrico, caracterizado por uma diferença de pelo menos 5dB de MD entre os olhos. O teste estatístico utilizado foi o t Student bicaudal e para significância estatística estabeleceu-se p <0,05. RESULTADOS: Em 80 por cento dos casos, (12/15 pacientes) o olho mais afetado pelo defeito perimétrico apresentou um aumento da PIO e/ou uma variaçã da PIO pós-ibopamina maior, sendo o resultado estatisticamente significativo (p<0,0001 e p = 0,0006), respectivamente. CONCLUSÃO: Este estudo mostrou que o defeito perimétrico no GPAA é significativamente relacionado com a positividade do teste de ibopamina sendo que olhos com maior defeito no campo visual apresentam maiores picos de PIO (max-PIO) pós-ibopamina e/ou uma maior variação em relação a sua PIO prévia ao teste (v-PIO).

OBJECTIVE: To evaluate the topic 2 percent ibopamine effect in the intraocular pressure (IOP) of eyes with assimetric primary open-angle glaucoma (POAG). METHODS: 15 patients (30 eyes) with primary open-angle glaucoma showing assimetric nerve disease evolution were assessed. We compared in all patients, the ibopamine response and the visual field defect between both eyes. The visual field, to be considered, should have at least 5 dB in MD difference between them. The statistical analysis was done with the Two-Tailed Student Test, with a Statistics significance of p<0.05. RESULTS: In 80 percent of the cases, (12/15 patients), the most affected eye in the visual field presented a greater variation and/or higher intraocular pressure after the ibopamine provocative test. The difference was statistically significant (p<0.00001 and p= 0.0006) respectively. CONCLUSION: This study showed that the visual field defect in GPAA is significantly connected with the positivity of the ibopamine test. The most affected eyes in the visual field presented a higher intraocular pressure (max-PIO) and/or a greater variation (v-PIO) after the ibopamine provocativetest.

Synthesis and in vitro cytotoxicity profile of the R-enantiomer of 3,4-dihydroxymethamphetamine (R-(-)-HHMA): comparison with related catecholamines.

(+/-)-3,4-Methylenedioxymethamphetamine (MDMA, also known as "ecstasy") is a chiral drug that is essentially metabolized in humans through O-demethylenation into 3,4-dihydroxymethamphetamine (HHMA). There has recently been a resurgence of interest in the possibility that MDMA metabolites, especially 5-(N-acetylcystein-S-yl)-N-methyl-alpha-methyldopamine (designated as 5-NAC-HHMA), might play a role in MDMA neurotoxicity. However, the chirality of MDMA was not considered in previously reported in vivo studies because HHMA, the precursor of the 5-NAC-HHMA metabolite, was used as the racemate. Since the stereochemistry of this chiral drug needs to be considered, the first total synthesis of R-(-)-HHMA is reported. Using L-DOPA as the chiral source, the preparation of R-(-)-HHMA is achieved through seven steps, in 30% overall yield and 99.5% enantiomeric excess. The cytotoxicity of R-(-)-HHMA and related catecholamines has been further determined by flow cytometric analysis of propidium iodide uptake in human dopaminergic neuroblastoma SH-SY5Y cells and by an Escherichia coli plate assay, specific for the detection of oxidative toxicity. The good correlation between the toxicities observed in both systems suggests that SH-SY5Y cells are sensitive to oxidative toxicity and that cell death (necrosis) would be mediated by reactive oxygen species mainly generated from redox active quinonoid centers. In contrast, apoptosis was detected for 3,4-dimethoxymethamphetamine (MMMA), the synthetic precursor of HHMA possessing a protected catechol group. MMMA was not toxic in the bacterial assay, indicating that its toxicity is not related to increased oxidative stress. Finally, we can conclude that there is a need to distinguish the toxicity ascribed to MDMA itself, also bearing a protected catechol moiety, from that depending on MDMA biotransformation leading to catechol metabolites such as HHMA and the thioether conjugates.

Efeitos da ibopamina 2 por cento tópica nos resultados da campimetria visual computadorizada / Effects of 2 percent ibopamine eye drops on computerized visual field results

OBJETIVO: Avaliar os efeitos do uso do colírio de ibopamina a 2 por cento nos resultados da campimetria visual computadorizada em indivíduos normais. MÉTODOS: Voluntários oriundos do CEROF-UFG, sem alterações ao exame oftalmológico que pudessem afetar o campo visual foram selecionados. Os indivíduos foram submetidos a exame de perimetria computadorizada SITA-standard 24-2 antes e após dilatação com o colírio de ibopamina a 2 por cento ou ciclopentolato, com intervalo mínimo de 3 dias entre si e em ordem aleatória. Índices globais e número de pontos alterados foram comparados entre os grupos. RESULTADOS: Foram avaliados 30 olhos de 30 indivíduos normais. Não houve diferença estatisticamente significativa entre o "mean deviation" (MD) nos pacientes não dilatados e nos mesmos após a instilação da ibopamina (MD: -1,05 ± 0,26 dB vs. -1,47 ± 0,20 dB, P=0,08), o que ocorreu após cicloplegia (MD: -3,19 ± 0,29 dB), P<0,001 para ambos. Na avaliação entre cicloplegia e pré-dilatação, nota-se significância para o "pattern standard deviation" (P=0,04), o que não ocorreu na avaliação com ibopamina. O número de pontos alterados no "pattern deviation" não apresentou diferença significativa entre todos os pares. Quanto ao número de pontos do "total deviation", houve diferença estatisticamente significativa antes da dilatação e após o uso do cicloplégico (n: 8,86 ± 1,51 vs. 25,72 ± 2,96 pontos, P<0,001) e entre olhos após a instilação do cicloplégico e da ibopamina (ibopamina: 9,75 ± 1,85 pontos, P<001). CONCLUSÃO: O colírio de ibopamina 2 por cento aparentemente não afeta os resultados da perimetria computadorizada em indivíduos normais.

PURPOSE: To evaluate the influence of 2 percent ibopamine eye drops on the results of computerized visual field exams. METHODS: Normal volunteers from CEROF-UFG were selected, with no variance in the ophthalmologic examination that could affect the visual field test. The volunteers underwent computerized visual field test before and after dilation with 2 percent ibopamine eye drop or cyclopentolate, with a minimum interval of three days between them and in a random order. Global indices and number of altered points were compared between the groups. RESULTS: Thirty eyes of 30 normal individuals were selected. There was no statistically significant difference on Mean Deviation (MD) before and after dilation with ibopamine (MD: -1.05 ± 0.26 dB vs. -1.47 ± 0.20 dB, P=0.08). However, after cycloplegia (MD: -3.19 ± 0.29 dB), there was a significant difference on MD (P<0.001 for both ibopamine and pre-dilation). No significant difference was detected in the Pattern Standard Deviation when comparing ibopamine with pre-dilation and cycloplegia values, but it was statistically significant comparing pre-dilation to cycloplegia (P=0.04). The number of altered points in the Pattern Deviation graphic were not significant comparing all pairs. There was a statistically significant difference in the number of altered points in the total deviation graphic before dilation and after cycloplegia (n: 8.86 ± 1.51 vs. 25.72 ± 2.96 points, P<0.001), and comparing cycloplegia with ibopamine (ibopamine: 9.75 ± 1.85 points, P<0.001). CONCLUSION: Ibopamine 2 percent eye drops seem to not modify the results of visual field tests in normal individuals.

Metabolites of MDMA induce oxidative stress and contractile dysfunction in adult rat left ventricular myocytes.

Repeated administration of 3,4-methylenedioxymethamphetamine (MDMA) (ecstasy) produces eccentric left ventricular (LV) dilation and diastolic dysfunction. While the mechanism(s) underlying this toxicity are unknown, oxidative stress plays an important role. MDMA is metabolized into redox cycling metabolites that produce superoxide. In this study, we demonstrated that metabolites of MDMA induce oxidative stress and contractile dysfunction in adult rat left ventricular myocytes. Metabolites of MDMA used in this study included alpha-methyl dopamine, N-methyl alpha-methyl dopamine and 2,5-bis(glutathion-S-yl)-alpha-MeDA. Dihydroethidium was used to detect drug-induced increases in reactive oxygen species (ROS) production in ventricular myocytes. Contractile function and changes in intracellular calcium transients were measured in paced (1 Hz), Fura-2 AM loaded, myocytes using the IonOptix system. Production of ROS in ventricular myocytes treated with MDMA was not different from control. In contrast, all three metabolites of MDMA exhibited time- and concentration-dependent increases in ROS that were prevented by N-acetyl-cysteine (NAC). The metabolites of MDMA, but not MDMA alone, significantly decreased contractility and impaired relaxation in myocytes stimulated at 1 Hz. These effects were prevented by NAC. Together, these data suggest that MDMA-induced oxidative stress in the left ventricle can be due, at least in part, to the metabolism of MDMA to redox active metabolites.

Cross-functioning between the extraneuronal monoamine transporter and multidrug resistance protein 1 in the uptake of adrenaline and export of 5-(glutathion-S-yl)adrenaline in rat cardiomyocytes.

Isolated heart cells are highly susceptible to the toxicity of catecholamine oxidation products, namely, to catecholamine-glutathione adducts. Although cellular uptake and/or efflux of these products may constitute a crucial step, the knowledge about the involvement of transporters is still very scarce. This work aimed to contribute to the characterization of membrane transport mechanisms, namely, extraneuronal monoamine transporter (EMT), the multidrug resistant protein 1 (MRP1), and P-glycoprotein (P-gp) in freshly isolated cardiomyocytes from adult rats. These transporters may be accountable for uptake and/or efflux of adrenaline and an adrenaline oxidation product, 5-(glutathion-S-yl)adrenaline, in cardiomyocyte suspensions. Our results showed that 5-(glutathion-S-yl)adrenaline efflux was mediated by MRP1. Additionally, we demonstrated that the adduct formation occurs within the cardiomyocytes, since EMT inhibition reduced the intracellular adduct levels. The classical uptake2 transport in rat myocardial cells was inhibited by the typical EMT inhibitor, corticosterone, and surprisingly was also inhibited by low concentrations of another drug, a well-known P-gp inhibitor, GF120918. The P-gp activity was absent in the cells since P-gp-mediated efflux of quinidine was not blocked by GF120918. In conclusion, this work showed that freshly isolated cardiomyocytes from adult rats constitute a good model for the study of catecholamines and catecholamines metabolites membrane transport. The cardiomyocytes maintain EMT and MRP1 fully active, and these transporters contribute to the formation and efflux of 5-(glutathion-S-yl)adrenaline. In the present experimental conditions, P-gp activity is absent in the isolated cardiomyocytes.

Ibopamina 2 por cento vs. sobrecarga hídrica como teste provocativo para glaucoma / 2 percent ibopamine vs. water-drinking test as a provocative test for glaucoma

OBJETIVO: Comparar o teste da ibopamina 2 por cento com o teste de sobrecarga hídrica como testes provocativos para glaucoma. MÉTODOS: Pacientes com glaucoma primário de ângulo aberto, e indivíduos normais foram selecionados do CEROF-Universidade Federal de Goiás - UFG, e submetidos, de forma randomizada, e com intervalo mínimo de 1 semana, aos testes provocativos da ibopamina 2 por cento, e sobrecarga hídrica. A pressão intra-ocular (Pio) antes e após os testes, confrontação entre os métodos (gráfico de Bland-Altman) além da melhor relação sensibilidade/especificidade (realizados por meio de curvas ROC) foram obtidos. RESULTADOS: Foram incluídos 47 olhos de 25 pacientes (27 olhos de 15 pacientes com glaucoma e 20 olhos de 10 pacientes normais), com idade média de 54,2 ± 12,7 anos. O MD médio dos pacientes com glaucoma foi de -2,8 ± 2,11 dB. Nos pacientes com glaucoma, não houve diferença estatisticamente significativa na Pio basal (p=0,8), ao passo que se notou diferença na Pio após os testes provocativos (p=0,03), e na variação da Pio após os testes (4,4 ± 1,3 mmHg para ibopamina e 3,2 ± 2,2 mmHg para ingestão hídrica, p=0,01). Nos pacientes normais, não houve diferença estatisticamente significativa entre os grupos para todos os parâmetros avaliados. O gráfico de Bland-Altman mostrou grande dispersão dos resultados. Finalmente, obteve-se áreas abaixo das curvas ROC de 0,987 para o teste da ibopamina e 0,807 para a ingestão hídrica. CONCLUSÃO: O teste provocativo da ibopamina apresentou melhor relação sensibilidade/especificidade que o teste de ingestão hídrica nesse subgrupo selecionado de pacientes com glaucoma com dano perimétrico inicial.

PURPOSE: To compare the 2 percent ibopamine provocative test with the water drinking test as a provocative test for glaucoma. METHODS: Primary open-angle glaucoma patients and normal individuals were selected from CEROF-Universidade Federal de Goiânia UFG, and underwent the 2 percent ibopamine provocative test and the water drinking test in a randomized fashion, at least 1 week apart. Intraocular pressure (IOP) before and after both tests, Bland-Altman graph, sensitivity and specificity (as mesured by ROC curves) were obtained for both methods. RESULTS: Forty-seven eyes from 25 patients were included (27 eyes from 15 glaucoma patients and 20 eyes from 10 normal individuals), with a mean age of 54.2 ± 12.7 years. The mean MD of glaucoma patients was -2.8 ± 2.11 dB. There was no statistically difference in the baseline IOP (p=0.8) comparing glaucoma patients, but positive after the provocative tests (p=0.03), and in the IOP variation (4.4 ± 1.3 mmHg for ibopamine and 3.2 ± 2.2 mmHg for water drinking test, p=0.01). There was no difference in all studied parameters for normal individuals. The Bland-Altman graph showed high dispersion comparing both methods. The areas under the ROC curve were 0.987 for the ibopamine provocative test, and 0.807 for the water-drinking test. CONCLUSION: In this selected subgroup of glaucoma patients with early visual field defect, the ibopamine provocative test has shown better sensitivity/specificity than the water drinking test.

Neurotoxicity mechanisms of thioether ecstasy metabolites.

3,4-Methylenedioxymethamphetamine (MDMA or "ecstasy"), is a widely abused, psychoactive recreational drug that is known to induce neurotoxic effects. Human and rat hepatic metabolism of MDMA involves N-demethylation to 3,4-methylenedioxyamphetamine (MDA), which is also a drug of abuse. MDMA and MDA are O-demethylenated to N-methyl-alpha-methyldopamine (N-Me-alpha-MeDA) and alpha-methyldopamine (alpha-MeDA), respectively, which are both catechols that can undergo oxidation to the corresponding ortho-quinones. Ortho-quinones may be conjugated with glutathione (GSH) to form glutathionyl adducts, which can be transported into the brain and metabolized to the correspondent N-acetylcysteine (NAC) adducts. In this study we evaluated the neurotoxicity of nine MDMA metabolites, obtained by synthesis: N-Me-alpha-MeDA, alpha-MeDA and their correspondent GSH and NAC adducts. The studies were conducted in rat cortical neuronal cultures, for a 6 h of exposure period, under normal (36.5 degrees C) and hyperthermic (40 degrees C) conditions. Our findings show that thioether MDMA metabolites are strong neurotoxins, significantly more than their correspondent parent catechols. On the other hand, N-Me-alpha-MeDA and alpha-MeDA are more neurotoxic than MDMA. GSH and NAC conjugates of N-Me-alpha-MeDA and alpha-MeDA induced a concentration dependent delayed neuronal death, accompanied by activation of caspase 3, which occurred earlier in hyperthermic conditions. Furthermore, thioether MDMA metabolites time-dependently increased the production of reactive species, concentration-dependently depleted intracellular GSH and increased protein bound quinones. Finally, thioether MDMA metabolites induced neuronal death and oxidative stress was prevented by NAC, an antioxidant and GSH precursor. This study provides new insights into the neurotoxicity mechanisms of thioether MDMA metabolites and highlights their importance in "ecstasy" neurotoxicity.

Comparison between the 1 percent and 2 percent ibopamine provocative test in primary open-angle glaucoma patients: sensitivity, specificity and tolerability / Comparação entre o teste de ibopamina a 1 por cento e a 2 por cento no glaucoma primário de ângulo aberto: sensibilidade, especificidade e tolerabilidade

PURPOSE: To compare intraocular pressure (IOP) rise in normal individuals and primary open-angle glaucoma patients and the safety and efficacy of ibopamine eye drops in different concentrations as a provocative test for glaucoma. METHODS: Glaucoma patients underwent (same eye) the ibopamine provocative test with two concentrations, 1 percent and 2 percent, in a random sequence at least 3 weeks apart, but not more than 3 months. The normal individuals were randomly submitted to one of the concentrations of ibopamine (1 percent and 2 percent). The test was considered positive if there was an IOP rise greater than 3 or 4 mmHg at 30 or 45 minutes to test which subset of the test has the best sensitivity (Se)/specificity (Sp). RESULTS: There was no statistically significant difference in any of the IOP measurements, comparing 1 percent with 2 percent ibopamine. The IOP was significantly higher at 30 and 45 minutes with both concentrations (p<0.001). The best sensitivity/specificity ratio was achieved with the cutoff point set as greater than 3 mmHg at 45 minutes with 2 percent ibopamine (area under the ROC curve: 0.864, Se: 84.6 percent; Sp:73.3 percent). All patients described a slight burning after ibopamine's instillation. CONCLUSION: 2 percent ibopamine is recommended as a provocative test for glaucoma. Because both concentrations have similar ability to rise IOP, 1 percent ibopamine may be used to treat ocular hypotony.

OBJETIVO: Comparar a tolerabilidade e a eficácia do teste provocativo da ibopamina com diferentes concentrações em pacientes com glaucoma primário de ângulo aberto. MÉTODOS: Pacientes com glaucoma (mesmo olho) foram aleatoriamente submetidos ao teste provocativo da ibopamina com as duas concentrações comercialmente disponíveis: 1 por cento e 2 por cento com pelo menos 3 semanas de intervalo, mas não superior a 3 meses. Os indivíduos normais foram randomizados a uma das concentrações utilizadas. O teste era considerado positivo se houvesse elevação da pressão intra-ocular (Pio) superior a 3 ou 4 mmHg 30 ou 45 minutos após o início do teste para se estabelecer a melhor relação sensibilidade (Se)/especificidade (Es) do teste. RESULTADOS: Treze pacientes com glaucoma, 15 indivíduos normais com a ibopamina a 2 por cento e 13 com a ibopamina a 1 por cento foram incluídos. Não houve diferença estatisticamente significativa em qualquer uma das médias da Pio entre a ibopamina a 1 por cento ou a 2 por cento. A Pio foi significativamente maior aos 30 e 45 minutos com ambas as concentrações (p<0,001). A melhor relação Se/Es foi obtida com o aumento da Pio >3 mmHg, 45 minutos após o teste com a ibopamina a 2 por cento (área abaixo da curva ROC: 0,864, Se: 84,6 por cento; Es: 73,3 por cento). Todos os pacientes referiram leve ardência à instilação da ibopamina. CONCLUSÃO: Sugere-se a utilização da ibopamina a 2 por cento como teste provocativo para o glaucoma. Como ambas as concentrações apresentaram capacidade similar em elevar a Pio, a Ibopamina a 1 por cento (menor concentração da droga) pode ser utilizada por períodos prolongados, como na hipotonia ocular.

Correlation between the ibopamine provocative test and the diurnal tension curve in glaucoma patients / Correlação entre o teste provocativo da ibopamina e a curva diurna de pressão intra-ocular em pacientes com glaucoma

PURPOSE: To correlate the ibopamine provocative test with the diurnal tension curve (highest intraocular pressure-IOP and range) in glaucoma. METHODS: This is a prospective case series including glaucoma patients from the Federal University of Goiás, Glaucoma Service. Two 2 percent ibopamine eyedrops were instilled into one or both eyes of each patient, 5 minutes apart. Intraocular pressure was checked before and 30 and 45 minutes after the second ibopamine instillation. Thereafter, the diurnal tension curve of each patient was assessed with five independent measurements (at every 2:30 hours), from 8:00 o'clock AM to 6:00 o'clock PM. Pearson's correlation coefficient was used to test the linear relation between the intraocular pressure after the ibopamine instillation with the highest intraocular pressure value and the intraocular pressure range in the diurnal curve. RESULTS: Thirty-one eyes from 22 patients were included. There was a significant correlation between the intraocular pressure 30 and 45 minutes after ibopamine instillation and the highest intraocular pressure assessed in the diurnal curve (r=0.356, p=0.04 and r=0.429, p=0.01, respectively). However, no correlation between IOP after the use of ibopamine and the diurnal intraocular pressure range at 30 (r=0.046, p=0.8) and 45 minutes (r=0.109, p=0.5) was observed. CONCLUSION: The ibopamine provocative test shows a significant correlation with the highest intraocular pressure in the diurnal tension curve in glaucoma patients. However, no correlation was observed with the intraocular pressure range.

OBJETIVO: Correlacionar o teste provocativo da ibopamina com a curva diurna de pressão intra-ocular (Pio máxima e flutuação da mesma) em pacientes com glaucoma. MÉTODOS: Estudo prospectivo incluindo pacientes com glaucoma provenientes do CEROF-UFG. Duas gotas de ibopamina a 2 por cento foram instiladas em um ou ambos os olhos dos pacientes com intervalo de 5 minutos entre elas. A pressão intra-ocular foi checada antes, 30 e 45 minutos após a segunda gota de ibopamina. Após, a curva diurna de pressão intra-ocular foi realizada com 5 medidas independentes (a cada 2:30 horas) entre 8:00 e 18:00 horas. A correlação de Pearson foi utilizada para se testar a relação linear entre a pressão intra-ocular após o uso da ibopamina, a pressão intra-ocular máxima e a flutuação diurna da pressão intra-ocular. RESULTADOS: Trinta e um olhos de 22 pacientes foram incluídos. Notou-se correlação estatisticamente significativa entre a Pio 30 e 45 minutos após a instilação da ibopamina e a máxima pressão intra-ocular obtida na curva diurna (r=0,356, p=0,04 e r=0,429, p=0,01, respectivamente). Entretanto, não foi observada correlação positiva com a flutuação diurna da pressão intra-ocular aos 30 (r=0,046, p=0,8) e 45 minutos (r=0,109, p=0,5). CONCLUSÃO: O teste provocativo da ibopamina apresentou alta correlação com a pressão intra-ocular máxima na curva diurna em pacientes com glaucoma. Entretanto, não foi notado relação linear direta com a flutuação diurna da pressão intra-ocular.