scholarly journals A single step three-strain in vivo gateway reaction

Plasmid ◽  
2021 ◽  
pp. 102608
Author(s):  
Aaron Nicholas Gillman ◽  
Alexandra Helleux ◽  
Sören Abel
Keyword(s):  
2018 ◽  
Vol 69 (8) ◽  
pp. 2295-2299
Author(s):  
Elena Ionescu ◽  
Tanta Verona Iordache ◽  
Carmen Elena Tebrencu ◽  
Ruxandra Mihaela Cretu ◽  
Ana Mihaela Florea ◽  
...  

St. John s Wort (SJW) or Hypericum perforatum L. is a therapeutic plant highly used in pharmacology. Recent in vivo anti-cancer action of naphtodianthrones (NTs) has extended the research related to enrichment methodologies of SJW phyto-extracts. Therefore, the presented study pursuits the optimization of single-step extraction methodologies to obtain NTs-rich extracts from SJW.


1983 ◽  
Vol 3 (8) ◽  
pp. 1468-1477
Author(s):  
K D Mehta ◽  
R S Gupta

Stable mutants which are approximately three- and eightfold resistant to the pyrazolopyrimidine nucleosides formycin A and formycin B (FomR) have been selected in a single step from mutagenized Chinese hamster ovary cells. In cell extracts, the two FomR mutants which were examined were both found to contain no measurable activity of the enzyme adenosine kinase (AK). However, cross-resistance studies with other adenosine analogs such as toyocamycin and tubercidin show that these mutants are distinct from toyocamycin or tubercidin resistant (Toyr) mutants which also contain no measurable AK activity in cell extracts. Studies on the uptake and incorporation of [3H]adenosine and [3H]tubercidin by various mutants and parental cell lines show that unlike the Toyr mutants, which are severely deficient in the phosphorylation of these compounds, the FomR mutants possess nearly normal capacity to phosphorylate these compounds and incorporate them into cellular macromolecules. These results suggest that the FomR mutants contain normal levels of AK activity in vivo. In cell hybrids formed between FomR X FomS cells and FomR X Toyr cells, the formycin-resistant phenotype of both of the FomR mutants behaved codominantly. However, the extracts from these hybrid cells contained either congruent to 50% (FomR X FomS) or no measurable (FomR X Toyr) AK activity, indicating that the lesion in these mutants neither suppresses the wild-type AK activity nor complements the AK deficiency of the Toyr mutants. The presence of AK activity in the FomR mutants in vivo, but not in their cell extracts, along with the codominant behavior of the mutants in hybrids, indicates that the lesions in the FomR mutant are of a novel nature. It is suggested that the genetic lesion in these mutants affects AK activity indirectly and that it may involve an essential cellular function which exists in a complex form with AK. Some implications of these results regarding the mechanism of action of formycin B are discussed.


2016 ◽  
Vol 60 (11) ◽  
pp. 6859-6866 ◽  
Author(s):  
Zi Wei Chang ◽  
Benoit Malleret ◽  
Bruce Russell ◽  
Laurent Rénia ◽  
Carla Claser

ABSTRACTEx vivoassay systems provide a powerful approach to studying human malaria parasite biology and to testing antimalarials. For rodent malaria parasites, short-termin vitroculture andex vivoantimalarial susceptibility assays are relatively cumbersome, relying onin vivopassage for synchronization, since ring-stage parasites are an essential starting material. Here, we describe a new approach based on the enrichment of ring-stagePlasmodium berghei,P. yoelii, andP. vinckei vinckeiusing a single-step Percoll gradient. Importantly, we demonstrate that the enriched ring-stage parasites develop synchronously regardless of the parasite strain or species used. Using a flow cytometry assay with Hoechst and ethidium or MitoTracker dye, we show that parasite development is easily and rapidly monitored. Finally, we demonstrate that this approach can be used to screen antimalarial drugs.


2017 ◽  
Vol 7 (10) ◽  
pp. 3533-3542 ◽  
Author(s):  
Micol Falabella ◽  
Linqing Sun ◽  
Justin Barr ◽  
Andressa Z. Pena ◽  
Erin E. Kershaw ◽  
...  
Keyword(s):  

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Daniela De Venuto ◽  
Giovanni Mezzina

This paper details the design and the hardware implementation of a real-time diagnostic system based on FPGA for the muscle fibre conduction velocity estimation (MFCV). The MFCV is considered as a principal monitoring index for diabetic neuropathy (DPN), as well as in muscle fatigue assessment, to evaluate the muscle fibre status. The FPGA platform evaluates the MFCV during dynamic contractions (e.g., gait), by exploiting a multichannel sensing system composed of 4 wireless surface EMG electrodes, placed in pair on each leg. Raw data are digitized and made binary to create two bitstreams for each monitored limb. Then, a comparison between the two-bit streamed EMGs extracted from the same leg is carried out. The comparison, which allows extracting the MFCV, exploits a computationally light version of the cross-correlation method. The overall architecture implemented and validated on an Altera Cyclone V FPGA is HPS-free and exploits 22.5% ALMs, 10,874 ALUTs, 9.81% registers, 3.36% block memory, and <2.7% of the total wires available on the platform. The choice of FPGA as computing system lies in the possibility to determine resource utilization, related timing constraints for a future real-time ASIC implementation in wearable applications. From the actual muscle contraction during gait (cyclical starting point of the computing), the system spends about 316 ms to acquire useful data and 47.5 ms (on average) to process the signal and provide the output, dynamically dissipating 28.6 mW. The accuracy of the tool evaluation has been evaluated proving the repeatability of the measurements by in vivo test. In this context, 1250 contractions from each subject involved in a protocolled 10-meter walk have been acquired (n=10 subjects evaluated). On average, the same MFCV estimation has been extracted on 1184/1250 contractions (standard deviation of 11 contractions), reaching an accuracy of 94.7%. These estimations fully match the physiological value range reported in literature.


2020 ◽  
Vol 6 (28) ◽  
pp. eaba5855 ◽  
Author(s):  
Veronika Magdanz ◽  
Islam S. M. Khalil ◽  
Juliane Simmchen ◽  
Guilherme P. Furtado ◽  
Sumit Mohanty ◽  
...  

We develop biohybrid magnetic microrobots by electrostatic self-assembly of nonmotile sperm cells and magnetic nanoparticles. Incorporating a biological entity into microrobots entails many functional advantages beyond shape templating, such as the facile uptake of chemotherapeutic agents to achieve targeted drug delivery. We present a single-step electrostatic self-assembly technique to fabricate IRONSperms, soft magnetic microswimmers that emulate the motion of motile sperm cells. Our experiments and theoretical predictions show that the swimming speed of IRONSperms exceeds 0.2 body length/s (6.8 ± 4.1 µm/s) at an actuation frequency of 8 Hz and precision angle of 45°. We demonstrate that the nanoparticle coating increases the acoustic impedance of the sperm cells and enables localization of clusters of IRONSperm using ultrasound feedback. We also confirm the biocompatibility and drug loading ability of these microrobots, and their promise as biocompatible, controllable, and detectable biohybrid tools for in vivo targeted therapy.


2001 ◽  
Vol 45 (6) ◽  
pp. 1743-1745 ◽  
Author(s):  
Graham H. Coombs ◽  
Jeremy C. Mottram

ABSTRACT Methionine γ-lyase, the enzyme which catalyzes the single-step conversion of methionine to α-ketobutyrate, ammonia, and methanethiol, is highly active in many anaerobic pathogenic microorganisms but has no counterpart in mammals. This study tested the hypothesis that this pathogen-specific enzyme can be exploited as a drug target by prodrugs that are exclusively activated by it. Trifluoromethionine was confirmed as such a prodrug and shown to be highly toxic in vitro to the anaerobic protozoan parasiteTrichomonas vaginalis, to anaerobic bacteria containing methionine γ-lyase, and to Escherichia coli expressing the trichomonad gene. The compound also has exceptional activity against the parasite growing in vivo, with a single dose preventing lesion formation in five of the six mice challenged. These findings suggest that trifluoromethionine represents a lead compound for a novel class of anti-infective drugs with potential as chemotherapeutic agents against a range of prokaryotic and eukaryotic anaerobic pathogens.


Author(s):  
Baoqiang Li ◽  
Lei Wang ◽  
Yu Hao ◽  
Daqing Wei ◽  
Ying Li ◽  
...  

To promote bone regeneration in vivo using critical-size calvarial defect model, hybrid hydrogel was prepared by mixing chitosan with hydroxyapatite (HA) and ultraviolet (UV) irradiation in situ. The hydrosoluble, UV-crosslinkable and injectable N-methacryloyl chitosan (N-MAC) was synthesized via single-step N-acylation reaction. The chemical structure was confirmed by 1H-NMR and FTIR spectroscopy. N-MAC hydrogel presented a microporous structure with pore sizes ranging from 10 to 60 μm. Approximately 80% cell viability of N-MAC hydrogel against encapsulated 3T3 cell indicated that N-MAC is an emerging candidate for mimicking native extracellular matrix (ECM). N-MAC hydrogel hybridized with HA was used to accelerate regeneration of calvarial bone using rabbit model. The effects of hybrid hydrogels to promote bone regeneration were evaluated using critical size calvarial bone defect model. The healing effects of injectable hydrogels with/without HA for bone regeneration were investigated by analyzing X-ray image after 4 or 6 weeks. The results showed that the regenerated new bone for N-MAC 100 was significantly greater than N-MAC without HA and untreated controls. The higher HA content in N-MAC/HA hybrid hydrogel benefited the acceleration of bone regeneration. About 50% closure of defect site after 6 weeks postimplantation demonstrated potent osteoinductivity of N-MAC 100 UV-crosslinkable and injectable N-MAC/HA hybrid hydrogel would allow serving as a promising biomaterial for bone regeneration using the critical-size calvarial defect.


2019 ◽  
Vol 4 (1) ◽  
pp. 190-195 ◽  
Author(s):  
Huirong Lin ◽  
Shuang Li ◽  
Junqing Wang ◽  
Chengchao Chu ◽  
Yang Zhang ◽  
...  

A multi-level supramolecular system produced by single-step Fe3+-mediated ionic crosslinking self-assembly can overcome the critical issues of current sonodynamic therapy (SDT) and address the need to monitor therapeutic effects in vivo with a non-invasive approach.


Biomolecules ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 108 ◽  
Author(s):  
Muhammad Imran ◽  
Lina Tariq Al Kury ◽  
Humaira Nadeem ◽  
Fawad Ali Shah ◽  
Muzaffar Abbas ◽  
...  

Oxidative stress-induced neuroinflammation is the prominent feature of neurodegenerative disorders, and is characterized by a gradual decline of structure and function of neurons. Many biochemical events emerge thanks to the result of this neurodegeneration, and ultimately provoke neuroinflammation, activation of microglia, and oxidative stress, leading to neuronal death. This cascade not only explains the complexity of events taking place across different stages, but also depicts the need for more effective therapeutic agents. The present study was designed to investigate the neuroprotective effects of newly synthesized benzimidazole containing acetamide derivatives, 3a (2-(4-methoxyanilino)-N-[1-(4-methylbenzene-1-sulfonyl)-1H-benzimidazol-2-yl] acetamide) and 3b (2-(Dodecylamino)-N-[1-(4-methylbenzene-1-sulfonyl)-1H-benzimidazol-2-yl] acetamide) against ethanol-induced neurodegeneration in the rat model. Both derivatives were characterized spectroscopically by proton NMR (1H-NMR) and carbon-13 NMR (13C-NMR) and evaluated for neuroprotective potential using different pharmacological approaches. In vivo experiments demonstrated that ethanol triggered neurodegeneration characterized by impaired antioxidant enzymes and elevated oxidative stress. Furthermore, ethanol administration induced neuroinflammation, as demonstrated by elevated expression of tumor necrotic factor (TNF-α), nuclear factor κB (NF-κB), cyclooxygenase-2 (COX2), and ionized calcium-binding adapter molecule-1 (Iba-1), which was further validated by enzyme-linked immunosorbent assay (ELISA). Treatment with 3a and 3b ameliorated the ethanol-induced oxidative stress, neuroinflammation, and memory impairment. The affinity of synthesized derivatives towards various receptors involved in neurodegeneration was assessed through docking analysis. The versatile nature of benzimidazole nucleus and its affinity toward several receptors suggested that it could be a multistep targeting neuroprotectant. As repetitive clinical trials of neuroprotectants targeting a single step of the pathological process have failed previously, our results suggested that a neuroprotective strategy of acting at different stages may be more advantageous to intervene in the vicious cycles of neuroinflammation.


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