Quantifying drug-drug interactions in pharmaco-EEG.

A drug interaction refers to an event in which the usual pharmacological effect of a drug is modified by other factors, most frequently additional drugs. When two drugs are administered simultaneously, or within a short time of each other, an interaction can occur that may increase or decrease the intended magnitude or duration of the effect of one or both drugs. Drugs may interact on a pharmaceutical, pharmacokinetic or pharmacodynamic basis. Pharmacodynamic interactions arise when the alteration of the effects occurs at the site of action. This is a wide field where not only interactions between different drugs are considered but also drug and metabolites (midazolam/alpha-hydroxy-midazolam), enantiomers (ketamine), as well as phenomena such as tolerance (nordiazepam) and sensitization (diazepam). Pharmacodynamic interactions can result in antagonism or synergism and can originate at a receptor level (antagonism, partial agonism, down-regulation, up-regulation), at an intraneuronal level (transduction, uptake), or at an interneuronal level (physiological pathways). Alternatively, psychotropic drug interactions assessed through quantitative pharmaco-EEG can be viewed according to the broad underlying objective of the study: safety-oriented (ketoprofen/theophylline, lorazepam/diphenhydramine, granisetron/haloperidol), strictly pharmacologically-oriented (benzodiazepine receptors), or broadly neuro-physiologically-oriented (diazepam/buspirone). Methodological issues are stressed, particularly drug plasma concentrations, dose-response relationships and time-course of effects (fluoxetine/buspirone), and unsolved questions are addressed (yohimbine/caffeine, hydroxizyne/alcohol).     

Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release.

OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility.     

Altered apoptosis in bronchoalveolar lavage lymphocytes after allergen exposure of atopic asthmatic subjects.

The increased number of lymphocytes in airways during an asthmatic response is believed to be the result of increased recruitment of these cells. However, it is possible that a decreased apoptotic rate could also contribute to the increased number. The aim of the present study was to investigate whether allergen airway provocation influences the apoptotic phenotype of lung and peripheral blood lymphocytes (PBL) in subjects with atopic asthma. Bronchoalveolar lavage (BAL) lymphocytes and PBL from 12 asthmatic subjects previously challenged with allergen (n = 7) or saline (n = 5) were exposed to the apoptotic stimulus tributyltin (TBT) in vitro and assayed for apoptosis. Airway allergen provocation resulted in decreased sensitivity of BAL lymphocytes to TBT-induced apoptosis, with 42.2% (range 33.9-62.5%) apoptotic cells before challenge versus 23.5% (range 15.3-42.4%) after challenge, while PBL were unaffected. The increased apoptosis resistance correlated with higher numbers of Bcl-2-expressing lymphocytes. Interestingly, baseline caspase-3-like activity was significantly elevated in viable BAL lymphocytes compared with viable PBL, and was unaltered by allergen exposure. In conclusion, allergen inhalation renders bronchoalveolar lavage lymphocytes more resistant to apoptosis while peripheral blood lymphocytes were not influenced at all, indicating that the apoptotic phenotype of airway lymphocytes may play a role in asthmatic inflammation.     

Fixed exanthema from systemic tobramycin.

Eye drops contain several ophthalmic medications which can produce allergic reactions. We report the case of a patient with contact dermatitis from neomycin and a probable fixed exanthema after parenteral administration of tobramycin who tolerated topical tobramycin and other aminoglycosides.     

Meta-analysis of drop-out rates in randomised clinical trials, comparing typical and atypical antipsychotics in the treatment of schizophrenia.

OBJECTIVE: To assess antipsychotic medication in the treatment of schizophrenia, based on trial drop-out rates. METHOD: The studies included were randomised controlled trials that compared any of the four clinically best-established atypical antipsychotics (quetiapine, olanzapine, risperidone or clozapine) against either of two typical antipsychotics regarded as the gold standard (haloperidol or chlorpromazine). RESULTS: Meta-analysis indicated less risk of all-cause patient withdrawal from atypical medication trials where dosage was flexible, in both the short, relative risk (RR) 0.70 (95% CI 0.64-0.76), P<0.00001, and long term, RR 0.72 (0.65-0.80), P<0.00001. Similar results were observed for withdrawal due to adverse events, RR: 0.54 (0.41-0.72), P<0.0001. Nevertheless, the favourable effects of atypical medication disappeared in trials relying on fixed dosage. CONCLUSIONS: We detected a significant positive effect in terms of the outcome of treatment discontinuation for atypical versus typical medication, though only where the use of flexible rather than fixed doses (closer to an experimental control situation) was possible.     

Lipid peroxidation, occupational stress and aging in workers of a prehospital emergency service.

BACKGROUND: Stressful conditions lead to formation of excessive free radicals, and lipid peroxidation is one of the major outcomes of free radical-mediated injury that directly damages membranes and generates a number of secondary products. OBJECTIVES: To determine the levels of malondialdehyde, an end product of lipid peroxidation, according to demographic and occupational variables in workers of a prehospital emergency service and to analyse the relationship between malondialdehyde levels and burnout. MATERIAL AND METHODS: One hundred and eleven healthy workers of a prehospital emergency service and eighty aged-matched healthy individuals of both sexes as a control group were surveyed. Malondialdehyde levels were measured by the Bull and Marnett method. To measure burnout, the Maslach Burnout Inventory was used. RESULTS: Professional category is associated with lipid peroxidation and burnout levels (Malondialdehyde levels were: physicians 338.10+/-14.47, nurses 329.17+/-12.62 and technicians 296.74+/-14.28; burnout levels were: physicians 41.29+/-3.59, nurses 37.38+/-6.05 and technicians 35.33+/-5.87). Working at night and in the evening increased malondialdehyde and burnout levels. Malondialdehyde levels increase with age. No significant variations with respect to sex were detected. Significant variations in malondialdehyde levels were detected between singles (303.13+/-12.74) and married people (344.43+/-13.43) but not with respect to divorcees (326.44+/-11.74). Significant differences were detected in erythrocyte malondialdehyde levels between smokers (341.37+/-17.09) and nonsmokers (302.21+/-12.38), but not for alcohol consumption. CONCLUSIONS: These findings suggest a positive correlation between malondialdehyde, a biomarker of lipid peroxidation and occupational stress, as estimated by elements of the Maslach Burnout Inventory, and oxidative stress.     

Predictive factors of stroke in patients undergoing coronary bypass grafting: statins are protective.

BACKGROUND: Despite major improvement in surgical techniques and intensive care management, stroke remains one of the most devastating complications of coronary artery bypass grafting (CABG). We aimed to determine factors predicting the occurrence of stroke during CABG. A special interest was focused on preoperative therapies. METHODS: We prospectively enrolled 810 consecutive candidates for CABG alone in a specific database, including all pre- and perioperative data (history, clinical, therapeutic, cardiac catheterization, surgical and intensive care data). Univariate tests and then multiple logistic regression analysis were used to determine independent predictive factors. RESULTS: During the first postoperative month, stroke occurred in 11 cases and transient ischemic attack (TIA) in 4 additive cases (cumulative rate: 1.85%). After the multivariate analysis, the following factors remained significant (p<0.05) in the predictive model, with corresponding odds ratios between brackets: redo cardiac surgery (7.45), unstable cardiac status (4.74), past history of cerebrovascular disease (4.14), past history of peripheral arterial disease (3.55), whereas the presence of preoperative statins was protective (0.24, 95% IC: 0.07-0.78). The addition of perioperative data (aortic calcification, postoperative arrhythmia, on/off-pump surgery) did not change the final predictive model. CONCLUSION: To our knowledge, this is the first real-world observational report highlighting the interest of statins for the prevention of stroke in the very special situation of CABG. Even though according to randomized trials coronary patients have a benefit from these drugs, a special level of interest should be directed towards those presenting the above-mentioned risk factors.