21 results on '"Niklaus L"'
Search Results
2. Deciphering host lysosome-mediated elimination of Plasmodium berghei liver stage parasites
- Author
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Niklaus, L., Agop-Nersesian, C., Schmuckli-Maurer, J., Wacker, R., Grünig, V., and Heussler, V. T.
- Published
- 2019
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3. Same-day versus rapid ART initiation in HIV-positive individuals presenting with symptoms of tuberculosis: Protocol for an open-label randomized non-inferiority trial in Lesotho and Malawi.
- Author
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Felix Gerber, Robina Semphere, Blaise Lukau, Palesa Mahlatsi, Timeo Mtenga, Tristan Lee, Maurus Kohler, Tracy Renée Glass, Alain Amstutz, Mamello Molatelle, Peter MacPherson, Nthuseng Bridgett Marake, Marriot Nliwasa, Irene Ayakaka, Rachael Burke, and Niklaus Labhardt
- Subjects
Medicine ,Science - Abstract
BackgroundIn absence of contraindications, same-day initiation (SDI) of antiretroviral therapy (ART) is recommended for people testing HIV-positive who are ready to start treatment. Until 2021, World Health Organization (WHO) guidelines considered the presence of TB symptoms (presumptive TB) a contraindication to SDI due to the risk of TB-immune reconstitution inflammatory syndrome (TB-IRIS). To reduce TB-IRIS risk, ART initiation was recommended to be postponed until results of TB investigations were available, and TB treatment initiated if active TB was confirmed. In 2021, the WHO guidelines changed to recommending SDI even in the presence of TB symptoms without awaiting results of TB investigations based on the assumption that TB investigations often unnecessarily delay ART initiation, increasing the risk for pre-ART attrition from care, and noting that the clinical relevance of TB-IRIS outside the central nervous system remains unclear. However, this guideline change was not based on conclusive evidence, and it remains unclear whether SDI of ART or TB test results should be prioritized in people with HIV (PWH) and presumptive TB.Design and methodsSaDAPT is an open-label, pragmatic, parallel, 1:1 individually randomized, non-inferiority trial comparing two strategies for the timing of ART initiation in PWH with presumptive TB ("ART first" versus "TB results first"). PWH in Lesotho and Malawi, aged 12 years and older (re)initiating ART who have at least one TB symptom (cough, fever, night sweats or weight loss) and no signs of intracranial infection are eligible. After a baseline assessment, participants in the "ART first" arm will be offered SDI of ART, while those in the "TB results first" arm will be offered ART only after active TB has been confirmed or refuted. We hypothesize that the "ART first" approach is safe and non-inferior to the "TB results first" approach with regard to HIV viral suppression (Expected outcomesSaDAPT will provide evidence on the safety and effects of SDI of ART in PWH with presumptive TB in a pragmatic clinical trial setting.Trial registrationThe trial has been registered on clinicaltrials.gov (NCT05452616; July 11 2022).
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- 2024
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4. Severe acute respiratory syndrome coronavirus 2, primary varicella zoster virus coinfection, and a polymicrobial ventilator-associated tracheobronchitis in an adult immunocompetent male: a case report
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Jowita Bruno, Silvio Ragozzino, Jonas Quitt, Martin Siegemund, and Niklaus Labhardt
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SARS-CoV-2 ,COVID-19 ,COVID-19-related skin lesions ,Varicella zoster virus ,Chickenpox ,Coinfection ,Medicine - Abstract
Abstract Background The spectrum of clinical manifestations and differential diagnosis associated with coronavirus disease 2019 is broad, ranging from fever and cutaneous eruptions to respiratory distress or even neurological disorders. Coexisting multipathogen infections significantly increase the complexity of the proper diagnostic and therapeutic approach and correlate with the rate of intensive care unit admissions and in-hospital mortality. Case presentation We present a case of multipathogen respiratory infection with severe acute respiratory syndrome coronavirus 2, varicella zoster virus, and polymicrobial tracheobronchitis in a 48-year-old Caucasian male hospitalized after traumatic brain injury. The patient tested positive for severe acute respiratory syndrome coronavirus 2 infection upon admission. During his stay in the intensive care unit, the patient developed a vesicular exanthema along with respiratory failure and signs of septic shock. Conclusion This case of an adult presenting with severe acute respiratory syndrome coronavirus 2 infection and simultaneous primary varicella zoster virus infection illustrates the importance of considering coinfections in patients with coronavirus disease 2019 with unusual clinical manifestations.
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- 2022
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5. Electrochemical devices | Electrochromic windows
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Niklaus, L., Schott, M., and Posset, U.
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- 2013
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6. An Anti-Gravity Treadmill following fractures of the foot or ankle: Does its use enhance gait rehabilitation?
- Author
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Niklaus, L., primary, Lange, J.S., additional, and Milani, T.L., additional
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- 2015
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7. Moving towards evidence based emergency medicine: use of a structured critical appraisal journal club.
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Carley, S D, primary, Mackway-Jones, K, additional, Jones, A, additional, Morton, R J, additional, Dollery, W, additional, Maurice, S, additional, Niklaus, L, additional, and Donnan, S, additional
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- 1998
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8. Melamine Resin Admixture Effect on Strength of Mortars.
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AIGNESBERCER, ALOIS, FAH, NIKLAUS L., and REY, THEO
- Abstract
An analysis of variance was used to evaluate quantitatively the effect of a new type of mela-mine resin admixture, a 20 percent aqueous solu-tion of a sodium salt of a special polymerized product of melamine and formaldehyde, on the setting, water-reducing effect and the compressive and flexural strengths of mortars made from ground clinker and portland cement. This resin greatly increases the retarding action of gypsum, acts as a powerful water-reducing agent and, above all, increases the compressive and flexural strengths by up to 150 percent for mortars of ground clinker and by up to 65 percent for mor-tars of portland cement. The maximum effect is obtained when 6 to 9 percent resin is added, though little additional improvement is achieved above 5 percent. [ABSTRACT FROM AUTHOR]
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- 1971
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9. Sample Size Requirements for Assessing Statistical Moments of Simulated Crop Yield Distributions
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Pierluigi Calanca, Tommy Klein, Niklaus Lehmann, and Robert Finger
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crop yield distributions ,statistical moments ,sample sizes requirements ,crop models ,stochastic weather generator ,climate change ,Agriculture (General) ,S1-972 - Abstract
Mechanistic crop growth models are becoming increasingly important in agricultural research and are extensively used in climate change impact assessments. In such studies, statistics of crop yields are usually evaluated without the explicit consideration of sample size requirements. The purpose of this paper was to identify minimum sample sizes for the estimation of average, standard deviation and skewness of maize and winterwheat yields based on simulations carried out under a range of climate and soil conditions. Our results indicate that 15 years of simulated crop yields are sufficient to estimate average crop yields with a relative error of less than 10% at 95% confidence. Regarding standard deviation and skewness, sample size requirements depend on the degree of symmetry of the underlying population’s distribution. For symmetric distributions, samples of 200 and 1500 yield observations are needed to estimate the crop yields’ standard deviation and skewness coefficient, respectively. Higher degrees of asymmetry increase the sample size requirements relative to the estimation of the standard deviation, while at the same time the sample size requirements relative to the skewness coefficient are decreased.
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- 2013
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10. Melamine Resin Admixture Effect on Strength of Mortars
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Theo Rey, Niklaus L. Fah, and Alois Aignesberger
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Materials science ,Melamine resin ,Synthetic resin ,General Engineering ,engineering.material ,Clinker (cement) ,law.invention ,chemistry.chemical_compound ,Portland cement ,Compressive strength ,chemistry ,Flexural strength ,law ,engineering ,Composite material ,Mortar ,Melamine - Abstract
AN ANALYSIS OF VARIANCE WAS USED TO EVALUATE QUANTITATIVELY THE EFFECT OF A NEW TYPE OF MELAMINE RESIN ADMIXTURE, A 20 PERCENT AQUEOUS SOLUTION OF A SODIUM SALT OF A SPECIAL POLYMERIZED PRODUCT OF MELAMINE AND FORMALDEHYDE, ON THE SETTING, WATER-REDUCING EFFECT AND THE COMPRESSIVE AND FLEXURAL STRENGTHS OF MORTARS MADE FROM GROUND CLINKER AND PORTLAND CEMENT. THIS RESIN GREATLY INCREASES THE RETARDING ACTION OF GYPSUM, ACTS AS A POWERFUL WATER- REDUCING AGENT AND, ABOVE ALL, INCREASES THE COMPRESSIVE AND FLEXURAL STRENGTHS BY UP TO 150 PERCENT FOR MORTARS OF GROUND CLINKER AND BY UP TO 65 PERCENT FOR MORTARS OF PORTLAND CEMENT. THE MAXIMUM EFFECT IS OBTAINED WHEN 6 TO 9 PERCENT RESIN IS ADDED, THOUGH LITTLE ADDITIONAL IMPROVEMENT IS ACHIEVED ABOVE 5 PERCENT. /AUTHOR/
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- 1971
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11. Best evidence in emergency medicine. Moving towards evidence based emergency medicine: use of a structured critical appraisal journal club.
- Author
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Carley SD, Mackway-Jones K, Jones A, Morton RJ, Dollery W, Maurice S, Niklaus L, and Donnan S
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- 1998
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12. Moving towards evidence based emergency medicine: use of a structured critical appraisal journal club.
- Author
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Carley, S D, Mackway-Jones, K, Jones, A, Morton, R J, Dollery, W, Maurice, S, Niklaus, L, and Donnan, S
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- 1998
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13. Electropolymerization of an EDOT-Quinoxaline Monomer for Green Electrochromic Thin Films and Devices.
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Schott M, Niklaus L, Janietz S, Völkel C, Egorov-Brening T, and Bilkay-Troni T
- Abstract
In this study, we present a 5,8-bis(3,4-ethylenedioxythiophene)quinoxaline monomer with two 4-(octyloxy)phenyl side chains (EDOTPQ) that can be electropolymerized on ITO glass in standard electrolytes containing lithium salts and propylene carbonate as solvent. The electrochemically deposited PEDOTPQ layers show very good adhesion and homogeneity on ITO. The green-colored polymer thin films exhibit promising electrochromic (EC) properties and are interesting for applications such as adaptive camouflage, as well as smart displays, labels, and sensors. Novel organic-inorganic (hybrid) EC cell configurations were realized with Prussian blue (PB) or titanium-vanadium oxide (TiVO
x ) as ion storage electrodes, showing a highly reversible and fast color change from green to light yellow.- Published
- 2024
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14. Flexible Electrochromic Device on Polycarbonate Substrate with PEDOT:PSS and Color-Neutral TiO 2 as Ion Storage Layer.
- Author
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Johannes C, Macher S, Niklaus L, Schott M, Hillmer H, Hartung M, and Heim HP
- Abstract
Electrochromic (EC) windows on glass for thermal and glare protection in buildings, often referred to as smart (dimmable) windows, are commercially available, along with rearview mirrors or windows in aircraft cabins. Plastic-based applications, such as ski goggles, visors and car windows, that require lightweight, three-dimensional (3D) geometry and high-throughput manufacturing are still under development. To produce such EC devices (ECDs), a flexible EC film could be integrated into a back injection molding process, where the films are processed into compact 3D geometries in a single automized step at a low processing time. Polycarbonate (PC) as a substrate is a lightweight and robust alternative to glass due to its outstanding optical and mechanical properties. In this study, an EC film on a PC substrate was fabricated and characterized for the first time. To achieve a highly transmissive and colorless bright state, poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) was used as the working electrode, while titanium dioxide (TiO
2 ) was used as the counter electrode material. They were deposited onto ITO-coated PC films using dip- and slot-die coating, respectively. The electrodes were optically and electrochemically characterized. An ECD with a polyurethane containing gel electrolyte was investigated with regard to optical properties, switching speed and cycling behavior. The ECD exhibits a color-neutral and highly transmissive bright state with a visible light transmittance of 74% and a bluish-colored state of 64%, a fast switching speed (7 s/4 s for bleaching/coloring) and a moderately stable cycling behavior over 500 cycles with a decrease in transmittance change from 10%to 7%.- Published
- 2023
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15. Subliminal electrical and mechanical stimulation does not improve foot sensitivity in healthy elderly subjects.
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Zippenfennig C, Niklaus L, Karger K, and Milani TL
- Abstract
Objective: Deterioration of cutaneous perception may be one reason for the increased rate of falling in the elderly. The stochastic resonance phenomenon may compensate this loss of information by improving the capability to detect and transfer weak signals. In the present study, we hypothesize that subliminal electrical and mechanical noise applied to the sole of the foot of healthy elderly subjects improves vibration perception thresholds (VPT)., Methods: VPTs of 99 healthy elderly subjects were measured at 30 Hz at the heel and first metatarsal head (MET I). Participants were randomly assigned to one of five groups: vibration (Vi-G), current (Cu-G), control (Co-G), placebo-vibration (Pl-Vi), and placebo-current (Pl-Cu). Vi-G and Cu-G were stimulated using 90% (subliminal) of their individual perception thresholds for five minutes in a standing position. Co-G received no stimulation. The placebo groups were treated with mock stimulation. VPTs were measured twice before the intervention (baseline (BASE) and pre-measurement (PRE)), and once after the intervention (post-measurement (POST))., Results: Significant differences were found between measurement conditions comparing BASE and POST, and PRE and POST. VPTs between groups within each measurement condition showed no significant differences. Vi-G was the only group that showed significantly higher VPTs in POST compared to BASE and PRE, which contradicts previous studies., Conclusion: We analyzed increased VPTs after subliminal mechanical stimulation. The pressure load of standing for five minutes combined with subliminal stimulation may have shifted the initial level of mechanoreceptor sensitivity, which may lead to a deterioration of the VPT. The subliminal electrical stimulation had no effect on VPT., Significance: Based on our results, we cannot confirm positive effects of subliminal electrical or mechanical stimulation on the sole of the foot.
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- 2018
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16. Host cell cytosolic immune response during Plasmodium liver stage development.
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Agop-Nersesian C, Niklaus L, Wacker R, and Theo Heussler V
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- Animals, Hepatocytes immunology, Hepatocytes parasitology, Humans, Life Cycle Stages, Cytosol immunology, Cytosol parasitology, Host-Parasite Interactions immunology, Liver immunology, Liver parasitology, Plasmodium growth & development, Plasmodium immunology
- Abstract
Recent years have witnessed a great gain in knowledge regarding parasite-host cell interactions during Plasmodium liver stage development. It is now an accepted fact that a large percentage of sporozoites invading hepatocytes fail to form infectious merozoites. There appears to be a delicate balance between parasite survival and elimination and we now start to understand why this is so. Plasmodium liver stage parasites replicate within the parasitophorous vacuole (PV), formed during invasion by invagination of the host cell plasma membrane. The main interface between the parasite and hepatocyte is the parasitophorous vacuole membrane (PVM) that surrounds the PV. Recently, it was shown that autophagy marker proteins decorate the PVM of Plasmodium liver stage parasites and eliminate a proportion of them by an autophagy-like mechanism. Successfully developing Plasmodium berghei parasites are initially also labeled but in the course of development, they are able to control this host defense mechanism by shedding PVM material into the tubovesicular network (TVN), an extension of the PVM that releases vesicles into the host cell cytoplasm. Better understanding of the molecular events at the PVM/TVN during parasite elimination could be the basis of new antimalarial measures.
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- 2018
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17. LC3-association with the parasitophorous vacuole membrane of Plasmodium berghei liver stages follows a noncanonical autophagy pathway.
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Wacker R, Eickel N, Schmuckli-Maurer J, Annoura T, Niklaus L, Khan SM, Guan JL, and Heussler VT
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- Autophagosomes metabolism, Autophagy physiology, CRISPR-Cas Systems physiology, Lysosomes metabolism, Signal Transduction physiology, Sporozoites metabolism, Liver physiopathology, Plasmodium berghei metabolism, Plasmodium berghei pathogenicity, Vacuoles metabolism
- Abstract
Eukaryotic cells can employ autophagy to defend themselves against invading pathogens. Upon infection by Plasmodium berghei sporozoites, the host hepatocyte targets the invader by labelling the parasitophorous vacuole membrane (PVM) with the autophagy marker protein LC3. Until now, it has not been clear whether LC3 recruitment to the PVM is mediated by fusion of autophagosomes or by direct incorporation. To distinguish between these possibilities, we knocked out genes that are essential for autophagosome formation and for direct LC3 incorporation into membranes. The CRISPR/Cas9 system was employed to generate host cell lines deficient for either FIP200, a member of the initiation complex for autophagosome formation, or ATG5, responsible for LC3 lipidation and incorporation of LC3 into membranes. Infection of these knockout cell lines with P. berghei sporozoites revealed that LC3 recruitment to the PVM indeed depends on functional ATG5 and the elongation machinery, but not on FIP200 and the initiation complex, suggesting a direct incorporation of LC3 into the PVM. Importantly, in P. berghei-infected ATG5
-/- host cells, lysosomes still accumulated at the PVM, indicating that the recruitment of lysosomes follows an LC3-independent pathway., (© 2017 The Authors Cellular Microbiology Published by John Wiley & Sons Ltd.)- Published
- 2017
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18. Generation of transgenic rodent malaria parasites by transfection of cell culture-derived merozoites.
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Kaiser G, De Niz M, Burda PC, Niklaus L, Stanway RL, and Heussler V
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- Animals, Cell Culture Techniques, Liver, Merozoites genetics, Merozoites growth & development, Mice, Mice, Inbred BALB C, Microorganisms, Genetically-Modified genetics, Microorganisms, Genetically-Modified growth & development, Plasmodium berghei genetics, Schizonts genetics, Schizonts growth & development, Schizonts physiology, Transfection, Merozoites physiology, Microorganisms, Genetically-Modified physiology, Plasmodium berghei physiology
- Abstract
Background: Malaria research is greatly dependent on and has drastically advanced with the possibility of genetically modifying Plasmodium parasites. The commonly used transfection protocol by Janse and colleagues utilizes blood stage-derived Plasmodium berghei schizonts that have been purified from a blood culture by density gradient centrifugation. Naturally, this transfection protocol depends on the availability of suitably infected mice, constituting a time-based variable. In this study, the potential of transfecting liver stage-derived merozoites was explored. In cell culture, upon merozoite development, infected cells detach from the neighbouring cells and can be easily harvested from the cell culture supernatant. This protocol offers robust experimental timing and temporal flexibility., Methods: HeLa cells are infected with P. berghei sporozoites to obtain liver stage-derived merozoites, which are harvested from the cell culture supernatant and are transfected using the Amaxa Nucleofector
® electroporation technology., Results: Using this protocol, wild type P. berghei ANKA strain and marker-free PbmCherryHsp70 -expressing P. berghei parasites were successfully transfected with DNA constructs designed for integration via single- or double-crossover homologous recombination., Conclusion: An alternative protocol for Plasmodium transfection is hereby provided, which uses liver stage-derived P. berghei merozoites for transfection. This protocol has the potential to substantially reduce the number of mice used per transfection, as well as to increase the temporal flexibility and robustness of performing transfections, if mosquitoes are routinely present in the laboratory. Transfection of liver stage-derived P. berghei parasites should enable generation of transgenic parasites within 8-18 days.- Published
- 2017
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19. Shedding of host autophagic proteins from the parasitophorous vacuolar membrane of Plasmodium berghei.
- Author
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Agop-Nersesian C, De Niz M, Niklaus L, Prado M, Eickel N, and Heussler VT
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- Animals, Cell Line, Cytoplasm metabolism, Genes, Reporter, Humans, Liver metabolism, Liver parasitology, Mice, Mice, Transgenic, Microtubule-Associated Proteins genetics, Microtubule-Associated Proteins metabolism, Models, Biological, Protein Transport, Time-Lapse Imaging, Autophagy, Host-Parasite Interactions, Malaria metabolism, Malaria parasitology, Plasmodium berghei physiology, Vacuoles metabolism
- Abstract
The hepatic stage of the malaria parasite Plasmodium is accompanied by an autophagy-mediated host response directly targeting the parasitophorous vacuolar membrane (PVM) harbouring the parasite. Removal of the PVM-associated autophagic proteins such as ubiquitin, p62, and LC3 correlates with parasite survival. Yet, it is unclear how Plasmodium avoids the deleterious effects of selective autophagy. Here we show that parasites trap host autophagic factors in the tubovesicular network (TVN), an expansion of the PVM into the host cytoplasm. In proliferating parasites, PVM-associated LC3 becomes immediately redirected into the TVN, where it accumulates distally from the parasite's replicative centre. Finally, the host factors are shed as vesicles into the host cytoplasm. This strategy may enable the parasite to balance the benefits of the enhanced host catabolic activity with the risk of being eliminated by the cell's cytosolic immune defence.
- Published
- 2017
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20. Bioinspired Hybrid White Light-Emitting Diodes.
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Weber MD, Niklaus L, Pröschel M, Coto PB, Sonnewald U, and Costa RD
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- Escherichia coli, Gels chemistry, Light, Lighting methods, Polyethylene Glycols chemistry, Recombinant Proteins chemistry, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Spectrophotometry, Vacuum, Biomimetic Materials chemistry, Lighting instrumentation, Luminescent Proteins chemistry, Luminescent Proteins isolation & purification, Luminescent Proteins metabolism
- Abstract
The first bioinspired hybrid white-light-emitting diodes (bio-HLEDs) featuring protein cascade coatings are presented. For easy fabrication a new strategy to stabilize proteins in rubber-like material was developed. The synergy between the excellent features of fluorescent proteins and the easily processed rubber produces bio-HLEDs with less than 10% loss in luminous efficiency over 100 hours., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
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21. A cysteine protease inhibitor of plasmodium berghei is essential for exo-erythrocytic development.
- Author
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Lehmann C, Heitmann A, Mishra S, Burda PC, Singer M, Prado M, Niklaus L, Lacroix C, Ménard R, Frischknecht F, Stanway R, Sinnis P, and Heussler V
- Subjects
- Animals, Erythrocytes parasitology, Fluorescent Antibody Technique, Gene Knockout Techniques, Hep G2 Cells, Hepatocytes parasitology, Humans, Life Cycle Stages, Malaria metabolism, Mice, Plasmodium berghei metabolism, Protozoan Proteins metabolism, Transfection, Cysteine Proteinase Inhibitors metabolism, Malaria parasitology, Plasmodium berghei growth & development
- Abstract
Plasmodium parasites express a potent inhibitor of cysteine proteases (ICP) throughout their life cycle. To analyze the role of ICP in different life cycle stages, we generated a stage-specific knockout of the Plasmodium berghei ICP (PbICP). Excision of the pbicb gene occurred in infective sporozoites and resulted in impaired sporozoite invasion of hepatocytes, despite residual PbICP protein being detectable in sporozoites. The vast majority of these parasites invading a cultured hepatocyte cell line did not develop to mature liver stages, but the few that successfully developed hepatic merozoites were able to initiate a blood stage infection in mice. These blood stage parasites, now completely lacking PbICP, exhibited an attenuated phenotype but were able to infect mosquitoes and develop to the oocyst stage. However, PbICP-negative sporozoites liberated from oocysts exhibited defective motility and invaded mosquito salivary glands in low numbers. They were also unable to invade hepatocytes, confirming that control of cysteine protease activity is of critical importance for sporozoites. Importantly, transfection of PbICP-knockout parasites with a pbicp-gfp construct fully reversed these defects. Taken together, in P. berghei this inhibitor of the ICP family is essential for sporozoite motility but also appears to play a role during parasite development in hepatocytes and erythrocytes.
- Published
- 2014
- Full Text
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