Residence near power lines and mortality from neurodegenerative diseases: longitudinal study of the Swiss population

The relation between residential magnetic field exposure from power lines and mortality from neurodegenerative conditions was analyzed among 4.7 million persons of the Swiss National Cohort (linking mortality and census data), covering the period 2000-2005. Cox proportional hazard models were used to analyze the relation of living in the proximity of 220-380 kV power lines and the risk of death from neurodegenerative diseases, with adjustment for a range of potential confounders. Overall, the adjusted hazard ratio for Alzheimer's disease in persons living within 50 m of a 220-380 kV power line was 1.24 (95% confidence interval (CI): 0.80, 1.92) compared with persons who lived at a distance of 600 m or more. There was a dose-response relation with respect to years of residence in the immediate vicinity of power lines and Alzheimer's disease: Persons living at least 5 years within 50 m had an adjusted hazard ratio of 1.51 (95% CI: 0.91, 2.51), increasing to 1.78 (95% CI: 1.07, 2.96) with at least 10 years and to 2.00 (95% CI: 1.21, 3.33) with at least 15 years. The pattern was similar for senile dementia. There was little evidence for an increased risk of amyotrophic lateral sclerosis, Parkinson's disease, or multiple sclerosis.

Minimally invasive strabismus surgery (MISS) for inferior obliquus recession

PURPOSE: To present a novel, minimally invasive strabismus surgery (MISS) technique for inferior obliquus recessions. METHODS: Graded MISS inferior obliquus recessions were performed in 20 eyes of 15 patients by applying two small conjunctival cuts, one at the insertion of inferior obliquus and another where the scleral anchoring of the muscle occurred. RESULTS: The amount of recession was 12.2 +/- 2.3 mm (range 6 to 14 mm). The vertical deviation, which was measured in 25 degrees of adduction, decreased from preoperatively 12.8 degrees +/- 5.6 degrees to 2.7 degrees +/- 2.2 degrees (p < 0.0001) at 6 months. LogMAR visual acuity was preoperatively -0.10 +/- 0.17 and at 6 months -0.14 +/- 0.22 (p > 0.1). In one eye (2.5%) the two cuts had to be joined because of excessive bleeding. Binocular vision improved in eight patients, remained unchanged in six patients, and decreased from 30 to 60 arcsec in one patient (p > 0.1). Conjunctival and lid swelling were hardly visible on the first postoperative day in primary gaze position in 10/20 (50%) of eyes. Five of the eyes (25%) had mild and five (25%) moderate visibility of surgery. One patient out of 15 (7%) needed repeat surgery because of insufficient reduction of the sursoadduction within the first 6 months. The dose-effect relationship 6 months postoperatively for an accommodative near target at 25 degrees adduction was 0.83 degrees +/- 0.43 degrees per mm of recession. CONCLUSIONS: This study demonstrates that small-incision, minimal dissection inferior obliquus graded recessions are feasible and effective to improve ocular alignment in patients with strabismus sursoadductorius.

Radiation metabolomics. 1. Identification of minimally invasive urine biomarkers for gamma-radiation exposure in mice

Gamma-radiation exposure has both short- and long-term adverse health effects. The threat of modern terrorism places human populations at risk for radiological exposures, yet current medical countermeasures to radiation exposure are limited. Here we describe metabolomics for gamma-radiation biodosimetry in a mouse model. Mice were gamma-irradiated at doses of 0, 3 and 8 Gy (2.57 Gy/min), and urine samples collected over the first 24 h after exposure were analyzed by ultra-performance liquid chromatography-time-of-flight mass spectrometry (UPLC-TOFMS). Multivariate data were analyzed by orthogonal partial least squares (OPLS). Both 3- and 8-Gy exposures yielded distinct urine metabolomic phenotypes. The top 22 ions for 3 and 8 Gy were analyzed further, including tandem mass spectrometric comparison with authentic standards, revealing that N-hexanoylglycine and beta-thymidine are urinary biomarkers of exposure to 3 and 8 Gy, 3-hydroxy-2-methylbenzoic acid 3-O-sulfate is elevated in urine of mice exposed to 3 but not 8 Gy, and taurine is elevated after 8 but not 3 Gy. Gene Expression Dynamics Inspector (GEDI) self-organizing maps showed clear dose-response relationships for subsets of the urine metabolome. This approach is useful for identifying mice exposed to gamma radiation and for developing metabolomic strategies for noninvasive radiation biodosimetry in humans.

Serum metabolomics reveals irreversible inhibition of fatty acid beta-oxidation through the suppression of PPARalpha activation as a contributing mechanism of acetaminophen-induced hepatotoxicity

Metabolic bioactivation, glutathione depletion, and covalent binding are the early hallmark events after acetaminophen (APAP) overdose. However, the subsequent metabolic consequences contributing to APAP-induced hepatic necrosis and apoptosis have not been fully elucidated. In this study, serum metabolomes of control and APAP-treated wild-type and Cyp2e1-null mice were examined by liquid chromatography-mass spectrometry (LC-MS) and multivariate data analysis. A dose-response study showed that the accumulation of long-chain acylcarnitines in serum contributes to the separation of wild-type mice undergoing APAP-induced hepatotoxicity from other mouse groups in a multivariate model. This observation, in conjunction with the increase of triglycerides and free fatty acids in the serum of APAP-treated wild-type mice, suggested that APAP treatment can disrupt fatty acid beta-oxidation. A time-course study further indicated that both wild-type and Cyp2e1-null mice had their serum acylcarnitine levels markedly elevated within the early hours of APAP treatment. While remaining high in wild-type mice, serum acylcarnitine levels gradually returned to normal in Cyp2e1-null mice at the end of the 24 h treatment. Distinct from serum aminotransferase activity and hepatic glutathione levels, the pattern of serum acylcarnitine accumulation suggested that acylcarnitines can function as complementary biomarkers for monitoring the APAP-induced hepatotoxicity. An essential role for peroxisome proliferator-activated receptor alpha (PPARalpha) in the regulation of serum acylcarnitine levels was established by comparing the metabolomic responses of wild-type and Ppara-null mice to a fasting challenge. The upregulation of PPARalpha activity following APAP treatment was transient in wild-type mice but was much more prolonged in Cyp2e1-null mice. Overall, serum metabolomics of APAP-induced hepatotoxicity revealed that the CYP2E1-mediated metabolic activation and oxidative stress following APAP treatment can cause irreversible inhibition of fatty acid oxidation, potentially through suppression of PPARalpha-regulated pathways.

Unanticipated structural and functional properties of delta-subunit-containing GABAA receptors

GABA(A) receptors mediate inhibitory neurotransmission in the mammalian brain via synaptic and extrasynaptic receptors. The delta (delta)-subunit-containing receptors are expressed exclusively extra-synaptically and mediate tonic inhibition. In the present study, we were interested in determining the architecture of receptors containing the delta-subunit. To investigate this, we predefined the subunit arrangement by concatenation. We prepared five dual and three triple concatenated subunit constructs. These concatenated dual and triple constructs were used to predefine nine different GABA(A) receptor pentamers. These pentamers composed of alpha(1)-, beta(3)-, and delta-subunits were expressed in Xenopus oocytes and maximal currents elicited in response to 1 mm GABA were determined in the presence and absence of THDOC (3alpha, 21-dihydroxy-5alpha-pregnane-20-one). beta(3)-alpha(1)-delta/alpha(1)-beta(3) and beta(3)-alpha(1)-delta/beta(3)-alpha(1) resulted in the expression of large currents in response to GABA. Interestingly, the presence of the neurosteroid THDOC uncovered alpha(1)-beta(3)-alpha(1)/beta(3)-delta receptors, additionally. The functional receptors were characterized in detail using the agonist GABA, THDOC, Zn(2+), and ethanol and their properties were compared with those of non-concatenated alpha(1)beta(3) and alpha(1)beta(3)delta receptors. Each concatenated receptor isoform displayed a specific set of properties, but none of them responded to 30 mm ethanol. We conclude from the investigated receptors that delta can assume multiple positions in the receptor pentamer. The GABA dose-response properties of alpha(1)-beta(3)-alpha(1)/beta(3)-delta and beta(3)-alpha(1)-delta/alpha(1)-beta(3) match most closely the properties of non-concatenated alpha(1)beta(3)delta receptors. Furthermore, we show that the delta-subunit can contribute to the formation of an agonist site in alpha(1)-beta(3)-alpha(1)/beta(3)-delta receptors.

ATG5 is induced by DNA-damaging agents and promotes mitotic catastrophe independent of autophagy

Anticancer drug therapy activates both molecular cell death and autophagy pathways. Here we show that even sublethal concentrations of DNA-damaging drugs, such as etoposide and cisplatin, induce the expression of autophagy-related protein 5 (ATG5), which is both necessary and sufficient for the subsequent induction of mitotic catastrophe. We demonstrate that ATG5 translocates to the nucleus, where it physically interacts with survivin in response to DNA-damaging agents both in vitro and in carcinoma tissues obtained from patients who had undergone radiotherapy and/or chemotherapy. As a consequence, elements of the chromosomal passenger complex are displaced during mitosis, resulting in chromosome misalignment and segregation defects. Pharmacological inhibition of autophagy does not prevent ATG5-dependent mitotic catastrophe, but shifts the balance to an early caspase-dependent cell death. Our data suggest a dual role for ATG5 in response to drug-induced DNA damage, where it acts in two signalling pathways in two distinct cellular compartments, the cytosol and the nucleus.

Anaemia may add information to standardised disease activity assessment to predict radiographic damage in rheumatoid arthritis: a prospective cohort study

OBJECTIVE: Anaemia in rheumatoid arthritis (RA) is prototypical of the chronic disease type and is often neglected in clinical practice. We studied anaemia in relation to disease activity, medications and radiographic progression. METHODS: Data were collected between 1996 and 2007 over a mean follow-up of 2.2 years. Anaemia was defined according to WHO (♀ haemoglobin<12 g/dl, ♂: haemoglobin<13 g/dl), or alternative criteria. Anaemia prevalence was studied in relation to disease parameters and pharmacological therapy. Radiographic progression was analysed in 9731 radiograph sets from 2681 patients in crude longitudinal regression models and after adjusting for potential confounding factors, including the clinical disease activity score with the 28-joint count for tender and swollen joints and erythrocyte sedimentation rate (DAS28ESR) or the clinical disease activity index (cDAI), synthetic antirheumatic drugs and antitumour necrosis factor (TNF) therapy. RESULTS: Anaemia prevalence decreased from more than 24% in years before 2001 to 15% in 2007. Erosions progressed significantly faster in patients with anaemia (p<0.001). Adjusted models showed these effects independently of clinical disease activity and other indicators of disease severity. Radiographic damage progression rates were increasing with severity of anaemia, suggesting a 'dose-response effect'. The effect of anaemia on damage progression was maintained in subgroups of patients treated with TNF blockade or corticosteroids, and without non-selective nonsteroidal anti-inflammatory drugs (NSAIDs). CONCLUSIONS: Anaemia in RA appears to capture disease processes that remain unmeasured by established disease activity measures in patients with or without TNF blockade, and may help to identify patients with more rapid erosive disease.

Investigation of the inhibitory effects of the benzodiazepine derivative, 5-BDBD on P2X4 purinergic receptors by two complementary methods

BACKGROUND/AIMS ATP-gated P2X4 purinergic receptors (P2X4Rs) are cation channels with important roles in diverse cell types. To date, lack of specific inhibitors has hampered investigations on P2X4Rs. Recently, the benzodiazepine derivative, 5-BDBD has been proposed to selectively inhibit P2X4Rs. However, limited evidences are currently available on its inhibitory properties. Thus, we aimed to characterize the inhibitory effects of 5-BDBD on recombinant human P2X4Rs. METHODS We investigated ATP-induced intracellular Ca(2+) signals and whole cell ion currents in HEK 293 cells that were either transiently or stably transfected with hP2X4Rs. RESULTS Our data show that ATP (< 1 μM) stimulates P2X4R-mediated Ca(2+) influx while endogenously expressed P2Y receptors are not activated to any significant extent. Both 5-BDBD and TNP-ATP inhibit ATP-induced Ca(2+) signals and inward ion currents in a concentration-dependent manner. Application of two different concentrations of 5-BDBD causes a rightward shift in ATP dose-response curve. Since the magnitude of maximal stimulation does not change, these data suggest that 5-BDBD may competitively inhibit the P2X4Rs. CONCLUSIONS Our results demonstrate that application of submicromolar ATP concentrations allows reliable assessment of recombinant P2XR functions in HEK 293 cells. Furthermore, 5-BDBD and TNP-ATP have similar inhibitory potencies on the P2X4Rs although their mechanisms of actions are different.

Nano Aerosol Chamber for In-Vitro Toxicity (NACIVT) studies.

Abstract Inhalation of ambient air particles or engineered nanoparticles (NP) handled as powders, dispersions or sprays in industrial processes and contained in consumer products pose a potential and largely unknown risk for incidental exposure. For efficient, economical and ethically sound evaluation of health hazards by inhaled nanomaterials, animal-free and realistic in vitro test systems are desirable. The new Nano Aerosol Chamber for in-vitro Toxicity studies (NACIVT) has been developed and fully characterized regarding its performance. NACIVT features a computer-controlled temperature and humidity conditioning, preventing cellular stress during exposure and allowing long-term exposures. Airborne NP are deposited out of a continuous air stream simultaneously on up to 24 cell cultures on Transwell® inserts, allowing high-throughput screening. In NACIVT, polystyrene as well as silver particles were deposited uniformly and efficiently on all 24 Transwell® inserts. Particle-cell interaction studies confirmed that deposited particles reach the cell surface and can be taken up by cells. As demonstrated in control experiments, there was no evidence for any adverse effects on human bronchial epithelial cells (BEAS-2B) due to the exposure treatment in NACIVT. The new, fully integrated and transportable deposition chamber NACIVT provides a promising tool for reliable, acute and sub-acute dose-response studies of (nano)particles in air-exposed tissues cultured at the air-liquid interface.

Cement volume is the most important modifiable predictor for pain relief in BKP: results from SWISSspine, a nationwide registry

Purpose The effectiveness of vertebral augmentation techniques is a currently highly debated issue. The biomechanical literature suggests that cement filling volumes may play an important role in the ‘‘dosage’’ of vertebral augmentation and its pain alleviating effect. Good clinical data about filling volumes are scarce and most patient series are small. Therefore, we investigated the predictors of pain alleviation after balloon kyphoplasty in the nationwide SWISSspine registry where cement volumes are also recorded. Methods All single-level vertebral fractures with no additional fracture stabilization and availability of at least one follow-up within 6 months after surgery were included. The following potential predictors were assessed in a multivariate logistic regression model with the group’s average pain alleviation of 41 points on VAS as the desired outcome: patient age, patient sex, diagnosis, preoperative pain, level of fracture, type of fracture, age of fracture, segmental kyphotic deformity, cement volume, vertebral body filling volume, and cement extrusions. Results There were 194 female and 82 males with an average age of 70.4 and 65.3 years, respectively. Female patients were about twice as likely for achieving the average pain relief compared to males (p = 0.04). The preoperative pain level was the strongest predictor in that the likelihood for achieving an at least 41-point pain relief increased by about 8 % with each additional point of preoperative pain (p\0.001). A thoraco-lumbar fracture had a three times higher odds for the average pain relief compared with a lumbar fracture (p = 0.03). An A.3.1 fracture only had about a third of the probability for average pain relief compared with an A.1.1 fracture (p = 0.004). Cement volumes up to 4.5 ml only had an approximately 40 % chance for a minimum 41-point pain alleviation as compared with cement volumes of at least 4.5 ml (p = 0.007). In addition, the relationship between cement volume and pain alleviation followed a dose-dependent pattern. Conclusions Cement volume was revealed as a significant predictor for pain relief in BKP. Cement volume was the third most important influential covariate and the most important modifiable and operator dependent one. The clear dose-outcome relationship between cement filling volumes and pain relief additionally supports these findings. Cement volumes of [4.5 ml seem to be recommendable for achieving relevant pain alleviation. Patient sex and fracture type and location were further significant predictors and all these covariates should be recorded and reported in future studies about the pain alleviating effectiveness of vertebral augmentation procedures.

Apoptosis of hippocampal neurons in organotypic slice culture models: direct effect of bacteria revisited

Neurons of the hippocampal dentate gyrus selectively undergo programmed cell death in patients suffering from bacterial meningitis and in experimental models of pneumococcal meningitis in infant rats. In the present study, a membrane-based organotypic slice culture system of rat hippocampus was used to test whether this selective vulnerability of neurons of the dentate gyrus could be reproduced in vitro. Apoptosis was assessed by nuclear morphology (condensed and fragmented nuclei), by immunochemistry for active caspase-3 and deltaC-APP, and by proteolytic caspase-3 activity. Co-incubation of the cultures with live pneumococci did not induce neuronal apoptosis unless cultures were kept in partially nutrient-deprived medium. Complete nutrient deprivation alone and staurosporine independently induced significant apoptosis, the latter in a dose-response way. In all experimental settings, apoptosis occurred preferentially in the dentate gyrus. Our data demonstrate that factors released by pneumococci per se failed to induce significant apoptosis in vitro. Thus, these factors appear to contribute to a multifactorial pathway, which ultimately leads to neuronal apoptosis in bacterial meningitis.

Aluminum toxicity in a tropical montane forest ecosystem in southern Ecuador

Aluminum phytotoxicity frequently occurs in acid soils (pH < 5.5) and was therefore discussed to affect ecosystem functioning of tropical montane forests. The susceptibility to Al toxicity depends on the sensitivity of the plant species and the Al speciation in soil solution, which can vary highly depending e.g., on pH, ionic strength, and dissolved organic matter. An acidification of the ecosystem and periodic base metal deposition from Saharan dust may control plant available Al concentrations in the soil solutions of tropical montane rainforests in south Ecuador. The overall objective of my study was to assess a potential Al phytotoxicity in the tropical montane forests in south Ecuador. For this purpose, I exposed three native Al non-accumulating tree species (Cedrela odorata L., Heliocarpus americanus L., and Tabebuia chrysantha (Jacq.) G. Nicholson) to increased Al concentrations (0 – 2400 μM Al) in a hydroponic experiment, I established dose-response curves to estimate the sensitivity of the tree species to increased Al concentrations, and I investigated the mechanisms behind the observed effects induced by elevated Al concentrations. Furthermore, the response of Al concentrations and the speciation in soil solution to Ca amendment in the study area were determined. In a final step, I assessed all major Al fluxes, drivers of Al concentrations in ecosystem solutions, and indicators of Al toxicity in the tropical montane rainforest in Ecuador in order to test for indications of Al toxicity. In the hydroponic experiment, a 10 % reduction in aboveground biomass production occurred at 126 to 376 μM Al (EC10 values), probably attributable to decreased Mg concentrations in leaves and reduced potosynthesis. At 300 μM Al, increased root biomass production of T. chrysantha was observed. Phosphorus concentrations in roots of C. odorata and T. chrysantha were significantly highest in the treatment with 300 μM Al and correlated significantly with root biomass, being a likely reason for stimulated root biomass production. The degree of organic complexation of Al in the organic layer leachate, which is central to plant nutrition because of the high root density, and soil solution from the study area was very high (mean > 99 %). The resulting low free Al concentrations are not likely to affect plant growth, although the concentrations of potentially toxic Al3+ increased with soil depth due to higher total Al and lower dissolved organic matter concentrations in soil solutions. The Ca additions caused an increase of Al in the organic layer leachate, probably because Al3+ was exchanged against the added Ca2+ ions while pH remained constant. The free ion molar ratios of Ca2+:Al3+ (mean ratio ca. 400) were far above the threshold (≤ 1) for Al toxicity, because of a much higher degree of organo-complexation of Al than Ca. High Al fluxes in litterfall (8.8 – 14.2 kg ha−1 yr−1) indicate a high Al circulation through the ecosystem. The Al concentrations in the organic layer leachate were driven by the acidification of the ecosystem and increased significantly between 1999 and 2008. However, the Ca:Al molar ratios in organic layer leachate and all aboveground ecosystem solutions were above the threshold for Al toxicity. Except for two Al accumulating and one non-accumulating tree species, the Ca:Al molar ratios in tree leaves from the study area were above the Al toxicity threshold of 12.5. I conclude that toxic effects in the hydroponic experiment occurred at Al concentrations far above those in native organic layer leachate, shoot biomass production was likely inhibited by reduced Mg uptake, impairing photosynthesis, and the stimulation of root growth at low Al concentrations can be possibly attributed to improved P uptake. Dissolved organic matter in soil solutions detoxifies Al in acidic tropical forest soils and a wide distribution of Al accumulating tree species and high Al fluxes in the ecosystem do not necessarily imply a general Al phytotoxicity.

p.L1612P, a Novel Voltage-gated Sodium Channel Nav1.7 Mutation Inducing a Cold Sensitive Paroxysmal Extreme Pain Disorder

BACKGROUND Mutations in the SCN9A gene cause chronic pain and pain insensitivity syndromes. We aimed to study clinical, genetic, and electrophysiological features of paroxysmal extreme pain disorder (PEPD) caused by a novel SCN9A mutation. METHODS Description of a 4-generation family suffering from PEPD with clinical, genetic and electrophysiological studies including patch clamp experiments assessing response to drug and temperature. RESULTS The family was clinically comparable to those reported previously with the exception of a favorable effect of cold exposure and a lack of drug efficacy including with carbamazepine, a proposed treatment for PEPD. A novel p.L1612P mutation in the Nav1.7 voltage-gated sodium channel was found in the four affected family members tested. Electrophysiologically the mutation substantially depolarized the steady-state inactivation curve (V1/2 from -61.8 ± 4.5 mV to -30.9 ± 2.2 mV, n = 4 and 7, P < 0.001), significantly increased ramp current (from 1.8% to 3.4%, n = 10 and 12) and shortened recovery from inactivation (from 7.2 ± 5.6 ms to 2.2 ± 1.5 ms, n = 11 and 10). However, there was no persistent current. Cold exposure reduced peak current and prolonged recovery from inactivation in wild-type and mutated channels. Amitriptyline only slightly corrected the steady-state inactivation shift of the mutated channel, which is consistent with the lack of clinical benefit. CONCLUSIONS The novel p.L1612P Nav1.7 mutation expands the PEPD spectrum with a unique combination of clinical symptoms and electrophysiological properties. Symptoms are partially responsive to temperature but not to drug therapy. In vitro trials of sodium channel blockers or temperature dependence might help predict treatment efficacy in PEPD.

The impact of smoking on HPV infection and the development of anogenital warts

PURPOSE: The worldwide prevalence of human papillomavirus (HPV) infection is estimated at 9-13 %. Persistent infection can lead to the development of malignant and nonmalignant diseases. Low-risk HPV types are mostly associated with benign lesions such as anogenital warts. In the present systematic review, we examined the impact of smoking on HPV infection and the development of anogenital warts, respectively. METHODS: A systematic literature search was performed using MEDLINE database for peer-reviewed articles published from January 01, 1985 to November 30, 2013. Pooled rates of HPV prevalence were compared using the χ (2) test. RESULTS: In both genders, smoking is associated with higher incidence and prevalence rates for HPV infection, whereas the latter responds to a dose-effect relationship. The overall HPV prevalence for smoking patients was 48.2 versus 37. 5 % for nonsmoking patients (p < 0.001) (odds ratio (OR) = 1.5, 95 % confidence interval (CI) 1.4-1.7). Smoking does also increase persistence rates for high-risk HPV infection, while this correlation is debatable for low-risk HPV. The incidence and recurrence rates of anogenital warts are significantly increased in smokers. CONCLUSIONS: Most current data demonstrate an association between smoking, increased anogenital HPV infection, and development of anogenital warts. These data add to the long list of reasons for making smoking cessation a keystone of patient health.

Older patients with chronic myeloid leukemia (≥65 years) profit more from higher imatinib doses than younger patients: a subanalysis of the randomized CML-Study IV

The impact of imatinib dose on response rates and survival in older patients with chronic myeloid leukemia in chronic phase has not been studied well. We analyzed data from the German CML-Study IV, a randomized five-arm treatment optimization study in newly diagnosed BCR-ABL-positive chronic myeloid leukemia in chronic phase. Patients randomized to imatinib 400 mg/day (IM400) or imatinib 800 mg/day (IM800) and stratified according to age (≥65 years vs. <65 years) were compared regarding dose, response, adverse events, rates of progression, and survival. The full 800 mg dose was given after a 6-week run-in period with imatinib 400 mg/day. The dose could then be reduced according to tolerability. A total of 828 patients were randomized to IM400 or IM800. Seven hundred eighty-four patients were evaluable (IM400, 382; IM800, 402). One hundred ten patients (29 %) on IM400 and 83 (21 %) on IM800 were ≥65 years. The median dose per day was lower for patients ≥65 years on IM800, with the highest median dose in the first year (466 mg/day for patients ≥65 years vs. 630 mg/day for patients <65 years). Older patients on IM800 achieved major molecular remission and deep molecular remission as fast as younger patients, in contrast to standard dose imatinib with which older patients achieved remissions much later than younger patients. Grades 3 and 4 adverse events were similar in both age groups. Five-year relative survival for older patients was comparable to that of younger patients. We suggest that the optimal dose for older patients is higher than 400 mg/day. ClinicalTrials.gov identifier: NCT00055874