Charles University in Prague

About: Charles University in Prague is a education organization based out in Prague, Czechia. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 32392 authors who have published 74435 publications receiving 1804208 citations.

Elevated anti-streptococcal antibodies in patients with recent narcolepsy onset

Abstract: NARCOLEPSY-CATAPLEXY IS A LIFELONG, DISABLING NEUROLOGICAL DISORDER, AFFECTING 1 IN 2000. CHARACTERISTIC SYMPTOMS INCLUDE EXCESSIVE daytime sleepiness and episodes of sudden loss of muscle tone, triggered by strong emotions (cataplexy). Onset is typically during adolescence, and predisposition involves both genetic and non-genetic factors, as suggested by the low monozygotic concordance but increased familial predisposition.1 The disorder is unique because of its extremely tight association with HLA-DQB1*0602 and hypocretin cell loss, suggesting autoimmune destruction; only 5 patients in the world have been described with low CSF hypocretin-1, a marker of hypocretin cell destruction, and DQB1*0602 negativity.2 Recently, using a Genome Wide Association, we found association with polymorphisms in the T-cell receptor α (TCR) loci.3 TCR is the major receptor of HLA-peptide presentation, and plays a critical role in mediating immune responses in normal (e.g., infectious) or abnormal (e.g., autoimmune) responses. Whereas much progress has been made toward understanding genetic predisposition in narcolepsy, little is known regarding environmental triggers. Retrospective questionnaire studies have found increased stress and decreased sleep amounts prior to narcolepsy onset.4 Case reports, describing a few unusual cases, have found sudden onset of narcolepsy 3 days after head trauma5 or various other unusual triggers (bee sting, etc). In all these cases, however, findings may be coincidental and are likely confounded by bias recall. More recently, a well-designed population based study of narcolepsy has been initiated and found increased smoking exposure in patients with narcolepsy as a risk factor6; the authors suggested the effect to be secondary to increased upper respiratory tract infections in secondary smoking. This, together with the report more than 20 years ago of increased ASO and ADB titers in a small number of narcoleptic patients regardless of disease duration,7,8 a finding that was later refuted,9 led us to reexamine the topic of infectious trigger in narcolepsy. It has been our clinical experience that narcolepsy is increasingly recognized close to onset, whereas 10-20 years ago, the disorder was diagnosed more than 10 years after onset (median time).10 We reasoned that a possible infectious trigger would not be detectable long after onset of narcolepsy, thus explaining variable results obtained in these first studies. Indeed, we also ourselves attempted to duplicate these anti-streptococcal findings in long standing narcolepsy cases, but could not find any differences with controls (Scott Fromhertz, unpublished results). We hypothesized that if streptococcal infections were indeed a trigger for narcolepsy onset, it would be best detected in newly identified patients, many of which had recent onset.

Chemistry and the Linkages between Air Quality and Climate Change.

Abstract: Climate change and air pollution are critical environmental issues both in the here and now and for the coming decades. A recent OECD report found that unless action is taken, air pollution will be the largest environmental cause of premature death worldwide by 2050. Already, air pollution levels in Asia are far above acceptable levels for human health, and even in Europe, the vast majority of the urban population was exposed to air pollution concentrations exceeding the EU daily limit values, and especially the stricter WHO air quality guidelines in the past decade. The most recent synthesis of climate change research as presented in the fifth IPCC Assessment Report (AR5) states that the warming of the climate system is unequivocal, recognizing the dominant cause as human influence, and providing evidence for a 43% higher total (from 1750 to the present) anthropogenic radiative forcing (RF) than was reported in 2005 from the previous assessment report.