Presymptomatic geographical distribution of ALS patients suggests the involvement of environmental factors in the disease pathogenesis

BACKGROUND

Given that the pathogenetic process of ALS begins many years prior to its clinical onset, examining patients' residential histories may offer insights on the disease risk factors. Here, we analyzed the spatial distribution of a large ALS cohort in the 50 years preceding the disease onset.

METHODS

Data from the PARALS register were used. A spatial cluster analysis was performed at the time of disease onset and at 1-year intervals up to 50 years prior to that.

RESULTS

A total of 1124 patients were included. The analysis revealed a higher-incidence cluster in a large area (435,000 inhabitants) west of Turin. From 9 to 2 years before their onset, 105 cases were expected and 150 were observed, resulting in a relative risk of 1.49 (P = 0.04). We also found a surprising high number of patients pairs (51) and trios (3) who lived in the same dwelling while not being related. Noticeably, these occurrences were not observed in large dwellings as we would have expected. The probability of this occurring in smaller buildings only by chance was very low (P = 0.01 and P = 0.04 for pairs and trios, respectively).

CONCLUSIONS

We identified a higher-incidence ALS cluster in the years preceding the disease onset. The cluster area being densely populated, many exposures could have contributed to the high incidence ALS cluster, while we could not find a shared exposure among the dwellings where multiple patients had lived. However, these findings support that exogenous factors are likely involved in the ALS pathogenesis.

The impact of water vapor on the OH reactivity toward CH3CHO at ultra-low temperatures (21.7-135.0 K): Experiments and theory

The role of water vapor (H2O) and its hydrogen-bonded complexes in the gas-phase reactivity of organic compounds with hydroxyl (OH) radicals has been the subject of many recent studies. Contradictory effects have been reported at temperatures between 200 and 400 K. For the OH + acetaldehyde reaction, a slight catalytic effect of H2O was previously reported at temperatures between 60 and 118 K. In this work, we used Laval nozzle expansions to reinvestigate the impact of H2O on the OH-reactivity with acetaldehyde between 21.7 and 135.0 K. The results of this comprehensive study demonstrate that water, instead, slows down the reaction by factors of ∼3 (21.7 K) and ∼2 (36.2-89.5 K), and almost no effect of added H2O was observed at 135.0 K.

Simple quantitative assessment of the outdoor versus indoor airborne transmission of viruses and COVID-19

In this paper we develop a simple model of the inhaled flow rate of aerosol particles of respiratory origin i.e. that have been exhaled by other people. A connection is made between the exposure dose and the probability of developing an airborne disease. This allows a simple assessment of the outdoor versus indoor risk of contamination to be made in a variety of meteorological situations. It is shown quantitatively that for most cases, the outdoor risk is orders of magnitude less than the indoor risk and that it can become comparable only for extremely specific meteorological and topographical situations. It sheds light on various observations of COVID-19 spreading in mountain valleys with temperature inversions while at the same time other areas are much less impacted.

A new instrument for kinetics and branching ratio studies of gas phase collisional processes at very low temperatures

A new instrument dedicated to the kinetic study of low-temperature gas phase neutral-neutral reactions, including clustering processes, is presented. It combines a supersonic flow reactor with vacuum ultra-violet synchrotron photoionization time-of-flight mass spectrometry. A photoion-photoelectron coincidence detection scheme has been adopted to optimize the particle counting efficiency. The characteristics of the instrument are detailed along with its capabilities illustrated through a few results obtained at low temperatures (<100 K) including a photoionization spectrum of n-butane, the detection of formic acid dimer formation, and the observation of diacetylene molecules formed by the reaction between the C₂H radical and C₂H₂.

Correlation between Apolipoprotein E genotype and brain metabolism in amyotrophic lateral sclerosis

BACKGROUND AND PURPOSE

The aim of the study was to evaluate the metabolic correlates of Apolipoprotein E (APOE) genotype in amyotrophic lateral sclerosis (ALS) and to investigate the role of ε2 as a risk factor for cognitive impairment.

METHODS

A total of 159 ALS cases underwent APOE and ALS-related genes analysis, neuropsychological assessment and cerebral ¹⁸ F-2-fluoro-2-deoxy-D-glucose positron emission tomography. The APOE genotype was regressed against whole brain metabolism as assessed by ¹⁸ F-2-fluoro-2-deoxy-D-glucose positron emission tomography, with age, sex, education, type of onset and C9orf72 status as covariates.

RESULTS

Brain metabolism was significantly positively correlated with APOE genotype from ε2/ε2 to ε3/ε4 in the left prefrontal [Brodmann area (BA) 10], orbitofrontal (BAs 11, 45, 47) and anterior cingulate (BA 32) cortices. There was a tendency to a relative hypometabolism going towards the ε2/ε2 extreme.

CONCLUSIONS

We found a highly significant, relatively lower metabolism in association with the ε2 allele in extra-motor areas typically affected in frontotemporal dementia (left prefrontal, orbitofrontal and anterior cingulate cortices), strengthening the finding of a role of ε2 as a risk factor for cognitive impairment in ALS. Our data suggested a link between cholesterol homeostasis and neurodegeneration.

Gas phase kinetics of the OH + CH3CH2OH reaction at temperatures of the interstellar medium (T = 21-107 K)

Ethanol, CH3CH2OH, has been unveiled in the interstellar medium (ISM) by radioastronomy and it is thought to be released into the gas phase after the warm-up phase of the grain surface, where it is formed. Once in the gas phase, it can be destroyed by different reactions with atomic and radical species, such as hydroxyl (OH) radicals. The knowledge of the rate coefficients of all these processes at temperatures of the ISM is essential in the accurate interpretation of the observed abundances. In this work, we have determined the rate coefficient for the reaction of OH with CH3CH2OH (k(T)) between 21 and 107 K by employing the pulsed and continuous CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, which means Reaction Kinetics in a Uniform Supersonic Flow) technique. The pulsed laser photolysis technique was used for generating OH radicals, whose time evolution was monitored by laser induced fluorescence. An increase of approximately 4 times was observed for k(21 K) with respect to k(107 K). With respect to k(300 K), the OH-reactivity at 21 K is enhanced by two orders of magnitude. The obtained T-expression in the investigated temperature range is k(T) = (2.1 ± 0.5) × 10-11 (T/300 K)-(0.71±0.10) cm3 molecule-1 s-1. In addition, the pressure dependence of k(T) has been investigated at several temperatures between 21 K and 90 K. No pressure dependence of k(T) was observed in the investigated ranges. This may imply that this reaction is purely bimolecular or that the high-pressure limit is reached at the lowest total pressure experimentally accessible in our system. From our results, k(T) at usual IS temperatures (∼10-100 K) is confirmed to be very fast. Typical rate coefficients can be considered to range within about 4 × 10-11 cm3 molecule-1 s-1 at 100 K and around 1 × 10-10 cm3 molecule-1 s-1 at 20 K. The extrapolation of k at the lowest temperatures of the dense molecular clouds of ISM is also discussed in this paper.

Spatial epidemiology of amyotrophic lateral sclerosis in Piedmont and Aosta Valley, Italy: a population-based cluster analysis

BACKGROUND AND PURPOSE

The analysis of the spatial distribution of cases could give important cues on putative environmental causes of a disease. Our aim was to perform a spatial analysis of an amyotrophic lateral sclerosis (ALS) cohort from the Piedmont and Aosta Valley ALS register (PARALS) over a 20-year period.

METHODS

The address at the moment of diagnosis was considered for each ALS case. Municipalities' and census divisions' resident populations during the 1995-2014 period were obtained. A cluster analysis was performed adopting both Moran's index and the Kulldorff spatial scan statistic.

RESULTS

A total of 2702 ALS patients were identified. An address was retrieved for 2671 (99%) patients. Moran's index was -0.01 (P value 0.83), thus revealing no clusters. SaTScan identified no statistically significant clusters. When census divisions were considered, Moran's index was 0.13 (P value 0.45); SaTScan revealed one statistically significant small cluster in the province of Alessandria. Here, 0.0099 cases were expected and three cases were observed (relative risk 304.60; 95% confidence interval 109.83-845.88, P value 0.03).

DISCUSSION

Our study showed a substantial homogeneous distribution of ALS cases in Piedmont and Aosta Valley. The population-based setting and the adoption of proper statistical analyses strengthen the validity of our results. Such a finding further suggests the involvement of multiple environmental and genetic factors in ALS pathogenesis.

Comment on “Methanol dimer formation drastically enhances hydrogen abstraction from methanol by OH at low temperature” by W. Siebrand, Z. Smedarchina, E. Martínez-Núñez and A. Fernández-Ramos, Phys. Chem. Chem. Phys., 2016, 18, 22712

A low fraction of methanol dimers is formed in the Laval nozzle used for kinetics studies at very low temperatures.

Is the gas-phase OH+H2CO reaction a source of HCO in interstellar cold dark clouds? A kinetic, dynamic and modelling study

Chemical kinetics of neutral-neutral gas-phase reactions at ultralow temperatures is a fascinating research subject with important implications on the chemistry of complex organic molecules in the interstellar medium (T∼10-100K). Scarce kinetic information is currently available for this kind of reactions at T<200 K. In this work we use the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, which means Reaction Kinetics in a Uniform Supersonic Flow) technique to measure for the first time the rate coefficients (k) of the gas-phase OH+H2CO reaction between 22 and 107 K. k values greatly increase from 2.1×10-11 cm3 s-1 at 107 K to 1.2×10-10 cm3 s-1 at 22 K. This is also confirmed by quasi-classical trajectories (QCT) at collision energies down to 0.1 meV performed using a new full dimension and ab initio potential energy surface, recently developed which generates highly accurate potential and includes long range dipole-dipole interactions. QCT calculations indicate that at low temperatures HCO is the exclusive product for the OH+H2CO reaction. In order to revisit the chemistry of HCO in cold dense clouds, k is reasonably extrapolated from the experimental results at 10K (2.6×10-10 cm3 s-1). The modeled abundances of HCO are in agreement with the observations in cold dark clouds for an evolving time of 105-106 yrs. The different sources of production of HCO are presented and the uncertainties in the chemical networks discussed. This reaction can be expected to be a competitive process in the chemistry of prestellar cores. The present reaction is shown to account for a few percent of the total HCO production rate. Extensions to photodissociation regions and diffuse clouds environments are also commented.

Monocytes of patients with amyotrophic lateral sclerosis linked to gene mutations display altered TDP-43 subcellular distribution

AIMS

Cytoplasmic accumulation of the nuclear protein transactive response DNA-binding protein 43 (TDP-43) is an early determinant of motor neuron degeneration in most amyotrophic lateral sclerosis (ALS) cases. We previously disclosed this accumulation in circulating lymphomonocytes (CLM) of ALS patients with mutant TARDBP, the TDP-43-coding gene, as well as of a healthy individual carrying the parental TARDBP mutation. Here, we investigate TDP-43 subcellular localization in CLM and in the constituent cells, lymphocytes and monocytes, of patients with various ALS-linked mutant genes.

METHODS

TDP-43 subcellular localization was analysed with western immunoblotting and immunocytofluorescence in CLM of healthy controls (n = 10), patients with mutant TARDBP (n = 4, 1 homozygous), valosin-containing protein (VCP; n = 2), fused in sarcoma/translocated in liposarcoma (FUS; n = 2), Cu/Zn superoxide dismutase 1 (SOD1; n = 6), chromosome 9 open reading frame 72 (C9ORF72; n = 4), without mutations (n = 5) and neurologically unaffected subjects with mutant TARDBP (n = 2).

RESULTS

TDP-43 cytoplasmic accumulation was found (P < 0.05 vs. controls) in CLM of patients with mutant TARDBP or VCP, but not FUS, in line with TDP-43 subcellular localization described for motor neurons of corresponding groups. Accumulation also characterized CLM of the healthy individuals with mutant TARDBP and of some patients with mutant SOD1 or C9ORF72. In 5 patients, belonging to categories described to carry TDP-43 mislocalization in motor neurons (3 C9ORF72, 1 TARDBP and 1 without mutations), TDP-43 cytoplasmic accumulation was not detected in CLM or in lymphocytes but was in monocytes.

CONCLUSIONS

In ALS forms characterized by TDP-43 mislocalization in motor neurons, monocytes display this alteration, even when not manifest in CLM. Monocytes may be used to support diagnosis, as well as to identify subjects at risk, of ALS and to develop/monitor targeted treatments.

First evidence of the dramatic enhancement of the reactivity of methyl formate (HC(O)OCH3) with OH at temperatures of the interstellar medium: a gas-phase kinetic study between 22 K and 64 K

The gas phase chemistry of neutral-neutral reactions of interest in the interstellar medium (ISM) is poorly understood.

Development of a pulsed uniform supersonic gas expansion system based on an aerodynamic chopper for gas phase reaction kinetic studies at ultra-low temperatures

A detailed description of a new pulsed supersonic uniform gas expansion system is presented together with the experimental validation of the setup by applying the CRESU (French acronym for Cinétique de Réaction en Ecoulement Supersonique Uniforme or Reaction Kinetics in a Uniform Supersonic Flow) technique to the gas-phase reaction of OH radicals with 1-butene at ca. 23 K and 0.63 millibars of helium (carrier gas). The carrier gas flow, containing negligible mixing ratios of OH-precursor and 1-butene, is expanded from a high pressure reservoir (337 millibars) to a low pressure region (0.63 millibars) through a convergent-divergent nozzle (Laval type). The novelty of this experimental setup is that the uniform supersonic flow is pulsed by means of a Teflon-coated aerodynamic chopper provided with two symmetrical apertures. Under these operational conditions, the designed Laval nozzle achieves a temperature of (22.4 ± 1.4) K in the gas jet. The spatial characterization of the temperature and the total gas density within the pulsed uniform supersonic flow has also been performed by both aerodynamical and spectroscopic methods. The gas consumption with this technique is considerably reduced with respect to a continuous CRESU system. The kinetics of the OH+1-butene reaction was investigated by the pulsed laser photolysis/laser induced fluorescence technique. The rotation speed of the disk is temporally synchronized with the exit of the photolysis and the probe lasers. The rate coefficient (k(OH)) for the reaction under investigation was then obtained and compared with the only available data at this temperature.

Genetic counselling in ALS: facts, uncertainties and clinical suggestions

The clinical approach to patients with amyotrophic lateral sclerosis (ALS) has been largely modified by the identification of novel genes, the detection of gene mutations in apparently sporadic patients, and the discovery of the strict genetic and clinical relation between ALS and frontotemporal dementia (FTD). As a consequence, clinicians are increasingly facing the dilemma on how to handle genetic counselling and testing both for ALS patients and their relatives. On the basis of existing literature on genetics of ALS and of other late-onset life-threatening disorders, we propose clinical suggestions to enable neurologists to provide optimal clinical and genetic counselling to patients and families. Genetic testing should be offered to ALS patients who have a first-degree or second-degree relative with ALS, FTD or both, and should be discussed with, but not offered to, all other ALS patients, with special emphasis on its major uncertainties. Presently, genetic testing should not be proposed to asymptomatic at-risk subjects, unless they request it or are enrolled in research programmes. Genetic counselling in ALS should take into account the uncertainties about the pathogenicity and penetrance of some genetic mutations; the possible presence of mutations of different genes in the same individual; the poor genotypic/phenotypic correlation in most ALS genes; and the phenotypic pleiotropy of some genes. Though psychological, social and ethical implications of genetic testing are still relatively unexplored in ALS, we recommend multidisciplinary counselling that addresses all relevant issues, including disclosure of tests results to family members and the risk for genetic discrimination.

ALS clinical trials: do enrolled patients accurately represent the ALS population?

OBJECTIVE

To assess the effect of eligibility criteria in amyotrophic lateral sclerosis (ALS) clinical trials on the representativeness of the enrolled population.

METHODS

Patients enrolled in 8 placebo-controlled clinical trials in our ALS center from 2003 to 2008 were compared 1) to the patients included a prospective epidemiologic register (Piemonte and Valle d'Aosta register for ALS, PARALS) in the same period and 2) the subset of PARALS patients who met the usual criteria for inclusion in clinical trials (PARALS-ct) (definite, probable, probable laboratory-supported ALS; age between 18 and 75 years; disease duration <36 months; vital capacity at diagnosis ≥70%; score ≥3 at the items swallowing and respiratory insufficiency at the Amyotrophic Lateral Sclerosis Functional Rating Scale-revised scale; riluzole therapy).

RESULTS

A total of 164 patients were enrolled in 8 different clinical trials. The PARALS cohort included 813 patients, of whom 539 (66.3%) met the entry criteria for clinical trials. Patients enrolled in clinical trials were different from both epidemiologic cohorts, since they were younger, had a longer diagnostic delay, and were more likely to have a spinal onset, and to be men. Tracheostomy-free survival was significantly longer in the group of patients enrolled in clinical trials (median survival time, trial patients, 3.9 years [95% confidence interval (CI) 3.4-4.4]; PARALS, 2.6 [2.4-2.8]; PARALS-ct, 2.9 [2.7-3.1]).

CONCLUSIONS

Patients enrolled in clinical trials do not satisfactorily represent the ALS population; consequently, the findings of ALS trials lack of external validity (generalizability). Efforts should be made to improve patients' recruitment in trials, particularly enrolling incident rather than prevalent cases.

Use of poly-beta-hydroxy-butyrate as a slow-release electron donor for the microbial reductive dechlorination of TCE

In situ anaerobic reductive dechlorination, using slow-release electron donors, is emerging as an effective and sustainable (low-cost and low-maintenance) technology to remediate aquifers contaminated by chloroethenes. In the present study, we investigated the use of poly-beta-hydroxy-butyrate (PHB), a fully biodegradable polymer, as a slow-release source of hydrogen and acetate for the reductive dechlorination of trichloroethene (TCE). Results of this study indicated that TCE dechlorination in PHB-amended microcosms was 2.3-times higher than in non-amended controls. This higher activity was explained by a higher H(2) level in PHB-amended microcosms. As usual, acetate was the major sink (approximately 90%) of reducing equivalents available from PHB degradation, whereas no acetotrophic dechlorination was observed.

Urban-rural differences in gynaecological cancer occurrence in a central region of Italy: 1978-1982 and 1998-2002

Differences in gynaecological cancer incidence and mortality in the urban and rural areas of the Umbria region (central Italy) were investigated. All women with primary invasive breast cancers, uterine cervix and uterine corpus, and ovarian cancers diagnosed during the periods 1978-1982 and 1998-2002 were identified and analysed according to place of residence (either urban or rural). Mortality data were supplied by the National Institute of Statistics (ISTAT) for the period 1978 to 1982, whereas for the 1994-2002 period they were supplied by the Regional Nominative Causes of Death Registry (ReNCaM). Incident cases considered were taken from an ad hoc survey for the first period and from the Umbrian Population Cancer Registry database for the second one. For each site the age-adjusted incidence (AAIR) and mortality (AADR) rates were calculated. The expected number of rural cases was obtained from indirect standardisation with urban incidence and mortality rates of several sites. The significance of the observed expected ratios (SIRs for incidence and SMRs for mortality) and the corresponding 95% confidence intervals were based on the Poisson distribution. Urbanisation levels were established following the classification of the Italian Institute of Statistics. For all sites, excluding the ovary during the most recent period, the SIR relative to rural areas was below 1, but the rates were statistically significant only for breast cancer in both periods (SIR 0.81, 95% CI 0.74-0.88 and SIR 0.82, 95% CI 0.77-0.88, respectively) and for cervix uteri in the first period (SIR 0.77, 95% CI 0.59-0.94). The lower breast cancer incidence in the rural area could also be due to lesser compliance with screening procedures which, up until 2002, were not provided in the form of mass-screenings throughout the region by the Regional Health Department. These results underscore the need for continued efforts to provide preventive health services to medically underserved women throughout Umbria, including rural communities. Underutilisation of preventive healthcare services may result in failure to identify healthcare problems that might be successfully managed with medication or lifestyle changes, as well as missed opportunities to prevent potentially life-threatening diseases.

The reaction of anthracene with OH radicals: An experimental study of the kinetics between 58 and 470K

The first direct measurement of the reaction rate constant of a polycyclic aromatic hydrocarbon in the gas phase in the temperature range 58-470 K is reported. The reaction is OH+ anthracene and the experiment has been performed in a continuous flow Cinetique de Reaction en Ecoulement Supersonique Uniforme apparatus, which had to be modified for this purpose. Pulsed laser photolysis of H(2)O(2) has been used to generate OH radicals and laser-induced fluorescence to observe the kinetic decay of the radicals and hence determine the rate coefficients. The reaction is found to be fast, and the rate constant increases monotonically as the temperature is lowered. The rate coefficients match the expression k(cm(3) molecules(-1) s(-1))=1.12 x 10(-10)(T/300)(-0.46).

[Decrease of frequency of male lung cancer in Umbria region. 1978-1982 and 1994-1999]

In Umbria, region of Central Italy, lung cancer is the leading cause of death due to cancer in males. The aim of this work is to highlight decrease of mortality from lung cancer in males in Umbria, in the last 20 years and to describe relationship among incidence, mortality and survival of this cancer. The incidence data derived from an ad hoc survey carried out over the period 1978-1982 and for 1994-1999 from the Umbrian Population Cancer Registry (RTUP). The mortality data were derived from official publications of the Italian Central Institute for Statistics (ISTAT) and covered the entire period 1978-1999. Estimated annual percent change (EAPC) was calculated by joinpoint regression analysis. Decrease of mortality from male lung cancer in Umbria began in the 1990-ies due to reduced quantity of tar in cigarettes, decreasing consumption of tobacco and increasing of survival derived from the quality and the effectiveness of the oncological health care system.

Uniform Supersonic Expansion for FTIR Absorption Spectroscopy: The nu(5) Band of (NO)(2) at 26 K

A high-resolution Fourier transform interferometer (Bruker IFS 120 HR) was combined with a uniform supersonic expansion produced by means of axisymmetric Laval nozzles. The geometry profile of the nozzle enabled us to work under precise thermodynamic and kinetic conditions. The effect of the cooling rate of different nozzles on cluster nucleation is illustrated. The experimental sensitivity was tested by recording the nu(5) band of (NO)(2) at 26 K. Copyright 2000 Academic Press.