Space Microbiology HORNECK, Gerda; KLAUS, David M; MANCINELLI, Rocco L
Microbiology and Molecular Biology Reviews,
03/2010, Letnik:
74, Številka:
1
Journal Article
Life in extreme environments Rothschild, Lynn J; Mancinelli, Rocco L
Nature,
02/2001, Letnik:
409, Številka:
6823
Journal Article
Recenzirano
Odprti dostop
Each recent report of liquid water existing elsewhere in the Solar System has reverberated through the international press and excited the imagination of humankind. Why? Because in the past few ...decades we have come to realize that where there is liquid water on Earth, virtually no matter what the physical conditions, there is life. What we previously thought of as insurmountable physical and chemical barriers to life, we now see as yet another niche harbouring 'extremophiles'. This realization, coupled with new data on the survival of microbes in the space environment and modelling of the potential for transfer of life between celestial bodies, suggests that life could be more common than previously thought. Here we examine critically what it means to be an extremophile, and the implications of this for evolution, biotechnology and especially the search for life in the Universe.
Background and purpose
We systematically reviewed available evidence for reports of neurological signs and symptoms in patients with COVID‐19 to identify cases with severe acute respiratory syndrome ...coronavirus (SARS‐CoV)‐2 infection or immune‐mediated reaction in the nervous system.
Methods
We followed PRISMA guidelines and used the MEDLINE, EMBASE, Google Scholar, MedRxiv and ChinaXiv databases to search for articles on COVID‐19 and nervous system involvement that were published from 1 January to 24 April 2020. Data on design, sample size, neurological assessment and related work‐up were extracted. Biases were assessed with the Newcastle–Ottawa scale.
Results
We analysed 27 publications on potential neuroinvasive or parainfectious neurological complications of COVID‐19. The reports focused on smell and taste (n = 5) and evaluation of neurological symptoms and signs in cohorts (n = 5). There were cases of Guillain‐Barré syndrome/Miller‐Fisher syndrome/cranial neuropathy (seven cases), meningitis/encephalitis (nine cases) and various other conditions (five cases). The number of patients with examination of cerebrospinal fluid and, in particular, SARS‐CoV‐2 polymerase chain reaction was negligible. Two had a positive SARS‐CoV‐2 polymerase chain reaction examination of cerebrospinal fluid specimen. Study of potential parenchymal involvement with magnetic resonance imaging was rare. Only four reports received a rating of the highest quality standards.
Conclusions
This systematic review failed to establish comprehensive insights into nervous system manifestations of COVID‐19 beyond immune‐mediated complications in the aftermath of respiratory symptoms. The authors therefore provide guidance for more careful clinical, diagnostic and epidemiological studies to characterize the manifestations and burden of neurological disease caused by SARS‐CoV‐2 on behalf of the Infectious Disease Panel of the European Academy of Neurology.
Sleep-related disorders have been reported to have a higher prevalence in multiple sclerosis (MS) than in the general population. They are often undervalued for the presence of more severe physical ...problems and the occurrence at night, without a direct observation in common clinical practice, but if not recognized and treated they can negatively affect the quality of life causing daytime drowsiness and worsening fatigue. Sleep related disorders most commonly reported in MS are as follows: insomnia, sleep-related breathing disorders (SRBD), restless legs syndrome (RLS) and periodic limb movement disorders (PLMD). Secondary narcolepsy, REM sleep behavior disorder (RBD) and propriospinal myoclonus have been also described in some case reports or series. The purpose of this review is to correlate the more common sleep disturbances in MS patients to the involvement of specific brain regions, analyzing their relationship with MRI findings. While insomnia is usually secondary to other disabling symptoms such as nocturia or pain, SRBD, RLS, narcolepsy, RBD and propriospinal myoclonus in MS patients can be the consequence of an injury of specific central nervous system (CNS) areas. Lesions in the pontine tegmentum and the dorsal medulla have been associated with SRBD, spinal cord lesions or atrophy with RLS, bilateral lesions in the lateral hypothalamus with narcolepsy-like symptoms, lesions in the dorsal pontine tegmentum with RBD and intramedullary demyelinating plaques in spinal cord with propriospinal myoclonus. MS specialists and general neurologists should be aware of these comorbidities since neuroimaging, which is routinely performed in MS, could provide helpful clinical indications on patients with secondary sleep-related disorders and to categorize symptomatic patients who need to underdo more in-depth sleep studies.
•Insomnia, SRBD, RLS and PLMD have a higher prevalence in MS patients.•Narcolepsy, RBD and propriospinal myoclonus have been reported in some case reports.•Sleep disorders in MS can arise from damage to specific CNS areas.•MRI could provide helpful indications on MS patients with sleep disorders.
Spore-forming bacteria are of particular concern in the context of planetary protection because their tough endospores may withstand certain sterilization procedures as well as the harsh environments ...of outer space or planetary surfaces. To test their hardiness on a hypothetical mission to Mars, spores of Bacillus subtilis 168 and Bacillus pumilus SAFR-032 were exposed for 1.5 years to selected parameters of space in the experiment PROTECT during the EXPOSE-E mission on board the International Space Station. Mounted as dry layers on spacecraft-qualified aluminum coupons, the "trip to Mars" spores experienced space vacuum, cosmic and extraterrestrial solar radiation, and temperature fluctuations, whereas the "stay on Mars" spores were subjected to a simulated martian environment that included atmospheric pressure and composition, and UV and cosmic radiation. The survival of spores from both assays was determined after retrieval. It was clearly shown that solar extraterrestrial UV radiation (λ≥110 nm) as well as the martian UV spectrum (λ≥200 nm) was the most deleterious factor applied; in some samples only a few survivors were recovered from spores exposed in monolayers. Spores in multilayers survived better by several orders of magnitude. All other environmental parameters encountered by the "trip to Mars" or "stay on Mars" spores did little harm to the spores, which showed about 50% survival or more. The data demonstrate the high chance of survival of spores on a Mars mission, if protected against solar irradiation. These results will have implications for planetary protection considerations.
Matrix-assisted laser desorption ionization-time of flight mass spectrometry has emerged as a rapid, cost-effective alternative for bacterial species identification. Identifying 60 blind-coded ...nonfermenting bacteria samples, this international study (using eight laboratories) achieved 98.75% interlaboratory reproducibility. Only 6 of the 480 samples were misidentified due to interchanges (4 samples) or contamination (1 sample) or not identified because of insufficient signal intensity (1 sample).
We evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) Biotyper as a tool for the identification of anaerobic bacteria compared with 500 base-pair ...(bp) 16S ribosomal ribonucleic acid (rRNA) gene sequencing analysis, which is considered to be the “gold standard” method. A total of 484 anaerobic bacteria were retrieved from the clinical specimens of 318 pediatric patients. Molecular identification resulted in 18 genera and 51 species. The most prevalent genus was
Clostridium
(76.85 %), with 70 %
C. difficile
isolates. The concordance and sensitivity determined by MALDI-TOF MS for
C. difficile
, the most prevalent species isolated, was 94.08 %, whereas the specificity was 100 %. For the other anaerobes, the sensitivity and specificity were 94.07 % and 81.82 %, respectively, with a concordance of 93.15 %. Low performance was observed for
Propionibacterium acnes
and
Fusobacterium nucleatum
, for which a dedicated pretreatment procedure should likely be set up. MALDI-TOF MS was shown to be a valid alternative for the fast and reliable identification of the most clinically relevant anaerobic bacteria; moreover, it is less time-consuming, the cost for reagents is minimized, and it does not require dedicated personnel.
Objective
Our objective was to compare the intravenous and oral pharmacokinetics of tacrolimus among subjects of three different ethnic backgrounds, African American, white, and Latin American.
...Methods
Ten African American, 12 white, and 12 Latin American subjects received intravenous and oral tacrolimus in an open‐label, two‐period, parallel group study. All of the subjects received intravenous tacrolimus (0.015 mg/kg) as a constant infusion over 4 hours and oral tacrolimus capsules (5 mg) as single doses in randomized order. Concentrations of tacrolimus and its metabolites were measured in whole blood with the use of a validated HPLC‐mass spectrometry assay.
Results
There were no significant differences in pharmacokinetic parameters among the three study groups after intravenous administration of the drugs. After oral administration, the tacrolimus maximum concentration was significantly lower (P < .01) in the African American subjects (20.8 μg/L) than in the white subjects (37.8 μg/L) and Latin American subjects (33.0 μg/L). Absolute bioavailability was significantly lower (P = .01) in the African American subjects (11.9%) and in the Latin American subjects (14.4%) than in the white subjects (18.8%). After the oral dose, the area under the plasma concentration‐time curve was lower in the African American subjects (179 μg/L · h, geometric mean) than in the white (293 μg/L · h) and Latin American subjects (239 μg/L · h, differences not statistically significant). Maximum concentration (P < .02) and area under the plasma concentration‐time curve (not statistically significant) of the main tacrolimus metabolite 13‐O‐desmethyl tacrolimus was lower in the African American subjects than in the white and Latin American subjects.
Conclusions
Significant differences in tacrolimus pharmacokinetics exist among the three different ethnic groups. Our results indicate that this may result from differences in intestinal CYP3A or P‐glycoprotein activities.
Clinical Pharmacology & Therapeutics (2001) 69, 24–31; doi: 10.1067/mcp.2001.113183
Transient ischemic attack (TIA) is defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, with clinical symptoms typically lasting less ...than one hour, and without evidence of acute infarction. In this type of ischemic event, there are no data about a possible cardiac injury tested with troponin. After a stroke, it is well established the cardiac involvement due to a neuro-inflammatory response (recently defined as Stroke Heart Syndrome). The aim of this study is to compare the troponin elevation after a stroke with the troponin elevation after a TIA.
This is a retrospective, single center study on 565 patients (73 TIAs, 492 stroke). We collected demographic characteristics, cardiovascular risk factors, cardiac data such as troponin, NT-proBNP, left atrial dilatation, etiology of the ischemic event (TOAST classification).
We compare IS and TIA for each TOAST subtype. In all groups no substantial differences were found in demographic and past medical history (p > 0.05). However, the maximum troponin level reached were significantly lower in TIAs than IS (p < 0.05), except in lacunar etiology were troponin elevation was low also in IS group. We found a trend in favor to IS in the rise and fall troponin elevation over 30% in all the TOAST subgroups, but only in the cryptogenic etiology the difference was significant. About the others cardiac markers of injury, a significant higher rate of elevated NT-proBNP was found in the IS cohort.
Troponin level after TIAs is significantly lower than after IS. Troponin elevation after an ischemic event may be more relevant in patients with higher NT-proBNP levels and older age. More studies are needed to better understand the pathophysiology of this phenomenon after an ischemic event.
Experiments were conducted in a Mars simulation chamber (MSC) to characterize the survival of endospores of
Bacillus subtilis under high UV irradiation and simulated martian conditions. The MSC was ...used to create Mars surface environments in which pressure (8.5 mb), temperature (−80, −40, −10, or +23
°C), gas composition (Earth-normal N
2/O
2 mix, pure N
2, pure CO
2, or a Mars gas mix), and UV-VIS-NIR fluence rates (200–1200 nm) were maintained within tight limits. The Mars gas mix was composed of CO
2 (95.3%), N
2 (2.7%), Ar (1.7%), O
2 (0.2%), and water vapor (0.03%). Experiments were conducted to measure the effects of pressure, gas composition, and temperature alone or in combination with Mars-normal UV-VIS-NIR light environments. Endospores of
B. subtilis, were deposited on aluminum coupons as monolayers in which the average density applied to coupons was 2.47×10
6 bacteria per sample. Populations of
B. subtilis placed on aluminum coupons and subjected to an Earth-normal temperature (23
°C), pressure (1013 mb), and gas mix (normal N
2/O
2 ratio) but illuminated with a Mars-normal UV-VIS-NIR spectrum were reduced by over 99.9% after 30 sec exposure to Mars-normal UV fluence rates. However, it required at least 15 min of Mars-normal UV exposure to reduce bacterial populations on aluminum coupons to non-recoverable levels. These results were duplicated when bacteria were exposed to Mars-normal environments of temperature (−10
°C), pressure (8.5 mb), gas composition (pure CO
2), and UV fluence rates. In other experiments, results indicated that the gas composition of the atmosphere and the temperature of the bacterial monolayers at the time of Mars UV exposure had no effects on the survival of bacterial endospores. But Mars-normal pressures (8.5 mb) were found to reduce survival by approximately 20–35% compared to Earth-normal pressures (1013 mb). The primary implications of these results are (a) that greater than 99.9% of bacterial populations on sun-exposed surfaces of spacecraft are likely to be inactivated within a few tens of seconds to a few minutes on the surface of Mars, and (b) that within a single Mars day under clear-sky conditions bacterial populations on sun-exposed surfaces of spacecraft will be sterilized. Furthermore, these results suggest that the high UV fluence rates on the martian surface can be an important resource in minimizing the forward contamination of Mars.
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