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Background Although seizures (other than myoclonus) are frequently reported in Creutzfeldt‐Jakob disease (CJD), their frequency, clinical manifestations, and effect on the disease course is unknown. Objectives To characterize the frequency of seizures in E200K familial and sporadic CJD, to describe its semiology, EEG and MRI findings. Methods In this retrospective study, we reviewed all patients with CJD who were seen in the Sheba Medical Center between the years 2003–2012 and underwent clinical evaluation, genetic testing, EEG and MRI studies. The diagnosis of seizures was carried out based on documentation of episodes consistent with seizures or episode of unresponsiveness correlated with ictal activity in EEG. Results Sixty‐four probable patients with CJD were included in the study, 57 (89%) with E200K familial (fCJD) and 7 (11%) with sporadic (sCJD). Seizures occurred in 8 patients: 3 of 7 (43%) in patients with sCJD compared to 5/57 (9%) in patients with E200K fCJD (P = 0.04, chi‐square test). Two of E200K fCJD patients with seizures had other non‐prion etiologies for seizures (brain metastasis, known history of temporal lobe epilepsy which started 44 years before the diagnosis of CJD). Seizures occurred late in the course of the disease with an average of 12 days between the onset of seizures and death. Conclusion Seizures in E200K fCJD were infrequent and occurred late in the disease course. This difference suggests that E200K fCJD represents a separate subtype of the disease with distinct clinical characteristics. [ABSTRACT FROM AUTHOR]

The photo-oxidation chemistry of isoprene (ISOP; C5H8) was studied in a continuous-flow chamber under conditions such that the reactions of the isoprene-derived peroxyl radicals (RO2) were dominated by the hydroperoxyl (HO2) pathway. A proton-transfer-reaction time-offlight mass spectrometer (PTR-TOF-MS) with switchable H3O+ and NO+ reagent ions was used for product analysis. The products methyl vinyl ketone (MVK; C4H6O) and methacrolein (MACR; C4H6O) were differentiated using NO+ reagent ions. The MVK and MACR yields via the HO2 pathway were (3.8±1.3)% and (2.5±0.9) %, respectively, at +25 °C and <2% relative humidity. The respective yields were (41.4±5.5)% and (29.6±4.2)% via the NO pathway. Production of MVK and MACR via the HO2 pathway implies concomitant production of hydroxyl ((6.3±2.1) %) and hydroperoxyl ((6.3±2.1) %) radicals, meaning a HOx recycling of (12.6±4.2)% given that HO2 was both a reactant and product. Other isoprene oxidation products, believed to be mostly organic hydroperoxides, also contributed to the ion intensity at the same mass-to-charge (m/z) ratios as the MVK and MACR product ions for HO2-dominant conditions. These products were selectively removed from the gas phase by placement of a cold trap (-40 °C) inline prior to the PTR-TOF-MS. When incorporated into regional and global chemical transport models, the yields of MVK and MACR and the concomitant HOx recycling reported in this study can improve the accuracy of the simulation of the HO2 reaction pathway of isoprene, which is believed to be the fate of approximately half of atmospherically produced isoprenederived peroxy radicals on a global scale. [ABSTRACT FROM AUTHOR]

Volatile organic compound (VOC) mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa) during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS), a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS), a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA), a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS) and a Fiber Laser-Induced Fluorescence Instrument (FILIF). The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, sum of the oxygenated hemiterpene 2- methyl-3-buten-2-ol (MBO) and the hemiterpene isoprene, acetaldehyde, sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK) and butanal. Measurements of the above VOCs conducted by different instruments agree within 20 %. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR) is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK +MAC) using PTR-(TOF)- MS at this site. A study-average relative contribution of 85% for MVK+MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOFMS was generally 20-25% higher than the sum of speciated monoterpenes measured by TOGA, which included - pinene, -pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study, and likely points to an offset in calibration, rather than a difference in the ability to measure the sum of terpenes. The contribution of isoprene relative to MBO inferred from PTR-MS and PTR-TOF-MS was smaller than 12% while GC-MS data suggested an average of 21% of isoprene relative to MBO. This comparison demonstrates that the current capability of VOC measurements to account for OH reactivity associated with the measured VOCs is within 20 %. [ABSTRACT FROM AUTHOR]

Biogenic VOC emissions are often dominated by 2-methyl-1,3-butadiene (isoprene) and 2-methyl-3-buten-2-ol (232MBO). Here we explore the possibility to selectively distinguish these species using NO+ as a primary ion in a conventional PTR-MS equipped with an SRI unit. High purity of NO+ (>90%) as a primary ion was utilized in laboratory and field experiments using a conventional PTR-TOF-MS. Isoprene is ionized via charge transfer leading to the major product ion C5H8+ (>99%) (e.g. Spanel and Smith, 1998). 232 MBO undergoes a hydroxide ion transfer reaction resulting in the major product ion channel C5H9+ (>95%) (e.g. Amelynck et al., 2005). We show that both compounds are ionized with little fragmentation (<5%) under standard operating conditions. Typical sensitivities of 11.1 ± 0.1 (isoprene) and 12.9 ± 0.1 (232 MBO) ncps ppbv-1 were achieved, which correspond to limit of detections of 18 and 15 pptv respectively for a 10 s integration time. Sensitivities decreased at higher collisional energies. Calibration experiments showed little humidity dependence. We tested the setup at a field site in Colorado dominated by ponderosa pine, a 232MBO emitting plant species. Our measurements confirm 232 MBO as the dominant biogenic VOC at this site, exhibiting typical average daytime concentrations between 0.2-1.4 ppbv. The method is able to detect the presence of trace levels of isoprene at this field site (90-250 ppt) without any interference from 232 MBO, which would not be feasible using H3O+ ionization chemistry, and which currently also remains a challenge for other analytical techniques (e.g. gas chromatographic methods). [ABSTRACT FROM AUTHOR]

The photo-oxidation chemistry of isoprene (C5H8) was studied in a continuous-flow chamber under conditions such that the reactions of isoprene-derived peroxyl radicals (RO2) were dominated by hydroperoxyl (HO2) pathway. A proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) with switchable H3O+ and NO+ reagent ions was used for product analysis. The products methyl vinyl ketone (MVK; C4H6O) and methacrolein (MACR; C4H6O) were differentiated using NO+ reagent ions. The MVK and MACR yields were 4.3±0.4% and 3.2±0.3 %, respectively, for HO2-dominant conditions at +25 °C and <2% relative humidity. The respective yields were 41.1±2.2% and 28.8±1.2% for NO-dominant conditions. The yields for HO2-dominant conditions imply a concomitant yield (i.e., recycling factor) of hydrogen oxide radicals (HOx) of 15±0.7% from the reaction of isoprene-derived RO2 with HO2. Other isoprene oxidation products, believed to be organic hydroperoxides, also contributed to the ion intensity at the same mass-to-charge (m/z) ratios as the MVK and MACR product ions, and these products were selectively removed from the gas phase using a variable temperature cold trap (-40 °C) in front of the PTR-TOF-MS. These hydroperoxide products were absent for NO-dominant conditions. When incorporated into regional and global chemical transport models, the yields of MVK and MACR and concomitant HOx yields reported in this study will improve the accuracy of simulations of the HO2 reaction pathway of isoprene, which has been shown to make a significant contribution to the total reactivity of isoprene-derived RO2 radicals on a global scale. [ABSTRACT FROM AUTHOR]

Volatile organic compound (VOC) mixing ratios measured by five independent instruments are compared at a forested site dominated by ponderosa pine (Pinus Ponderosa) during the BEACHON-ROCS field study in summer 2010. The instruments included a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS), a Proton Transfer Reaction Quadrupole Mass Spectrometer (PTR-MS), a Fast Online Gas-Chromatograph coupled to a Mass Spectrometer (GC/MS; TOGA), a Thermal Dissociation Chemical Ionization Mass Spectrometer (PAN-CIMS) and a Fiber Laser- Induced Fluorescence Instrument (FILIF). The species discussed in this comparison include the most important biogenic VOCs and a selected suite of oxygenated VOCs that are thought to dominate the VOC reactivity at this particular site as well as typical anthropogenic VOCs that showed low mixing ratios at this site. Good agreement was observed for methanol, the sum of the oxygenated hemiterpene 2-methyl-3-buten-2-ol (MBO) and the hemiterpene isoprene, acetaldehyde, the sum of acetone and propanal, benzene and the sum of methyl ethyl ketone (MEK) and butanal. Measurements of the above VOCs conducted by different instruments agree within 20%. The ability to differentiate the presence of toluene and cymene by PTR-TOF-MS is tested based on a comparison with GC-MS measurements, suggesting a study-average relative contribution of 74% for toluene and 26% for cymene. Similarly, 2-hydroxy-2-methylpropanal (HMPR) is found to interfere with the sum of methyl vinyl ketone and methacrolein (MVK+MAC) using PTR-(TOF)-MS at this site. A study-average relative contribution of 85% for MVK+MAC and 15% for HMPR was determined. The sum of monoterpenes measured by PTR-MS and PTR-TOF-MS was generally 20-25% higher than the sum of speciated monoterpenes measured by TOGA, which included α-pinene, β-pinene, camphene, carene, myrcene, limonene, cineole as well as other terpenes. However, this difference is consistent throughout the study, and likely points to an offset in calibration, rather than a difference in the ability to measure the sum of terpenes. The contribution of isoprene relative to MBO inferred from PTR-MS and PTR-TOF-MS was smaller than 12% while GC-MS data suggested an average of 21% of isoprene relative to MBO. This comparison demonstrates that the current capability of VOC measurements to account for OH reactivity associated with the measured VOCs is within 20%. [ABSTRACT FROM AUTHOR]

Although many types of neurological disorders and events have been described in association with antiphospholipid antibodies (aPL) and the antiphospholipid syndrome (APS), only ischaemic stroke is reasonably well established and accepted as a diagnostic criterion for the syndrome. We propose to evaluate, classify and rank the association of other neurological manifestations as possible, probable, or definite according to the data available from clinical studies and animal models. By these criteria, none of the neurological disorders or events such as epilepsy,psychiatric disease, dementia, transverse myelitis, multiple sclerosis-like disease, chorea, migraine, Guillian-Barrèsyndrome, and sensory-neural hearing loss, can be definitely associated with aPL or APS. [ABSTRACT FROM AUTHOR]

A consecutive series of 30 cases of extracranial medulloblastoma metastases in adults is analysed. The majority of the patients were males with a 3:1 male/female ratio. Bone was the most frequent site of metastases in adults (77%) and children (78%), followed by lymph nodes (33%) in both children and adults. Lung metastases were more common in adults (17%), but liver metastases occurred more frequently in children (15%). Possible routes of spread and development of metastases are discussed, with special emphasis on the role of shunts in tumour seeding. Distant extracranial metastatic spread of medulloblastoma occurs at the rate of 7.1%. Mean interval between operation of the primary tumour and the discovery of metastases was shorter in children (20 months) than in adults (36 months). Survival after the discovery of metastases was also shorter in children (5 months) than in adults (9.5 months). Shunts were associated with an earlier appearance of metastases and with a poorer prognosis. A detailed review of the literature of 119 cases of medulloblastoma with extracranial metastases is provided. [ABSTRACT FROM AUTHOR]

Cogan's syndrome, nonsyphilitic interstitial keratitis with vestibuloauditory dysfunction, is an uncommon disease of young adults, probably a manifestation of vasculitis. A 32 year old woman with this syndrome developed a thalamic syndrome with amnesia and dysphasia due to lacunar infarcts. [ABSTRACT FROM AUTHOR]