Long-term (35 years) cryopreservation of Echinococcus multilocularis metacestodes

Parasitology ◽  
2020 ◽  
Vol 147 (9) ◽  
pp. 1048-1054
Author(s):  
Teivi Laurimäe ◽  
Philipp A. Kronenberg ◽  
Cristian A. Alvarez Rojas ◽  
Theodor W. Ramp ◽  
Johannes Eckert ◽  
...  

AbstractThe metacestode of Echinococcus multilocularis is the etiological agent of alveolar echinococcosis. The metacestode stage used for research is maintained in rodents by serial passages. In order to determine whether cryopreservation of E. multilocularis metacestodes would be suitable for long-term maintenance and replace serial passages, isolates of different geographic origin were cryopreserved in 1984–1986. The aim of the current study was to test the viability of cryopreserved isolates following long-term cryopreservation (up to 35 years) and to determine the phylogenetic clades these isolates belonged to. Cryopreserved isolates were tested for viability in vitro and in vivo in gerbils. In vitro results of 5 isolates indicated protoscolex survival in 13 of 17 experiments (76%) and metacestode survival in 5 of 12 (42%) in vivo experiments. In vivo results showed ‘abortive lesions’ in 13 of the 36 animals, 15 were negative and 8 harboured proliferating metacestode tissue containing protoscoleces. Genetic analysis confirmed the isolates belonged to European, Asian and North-American clades. In conclusion, the results of the current study indicate that metacestodes of E. multilocularis are able to survive long-term cryopreservation. Therefore, cryopreservation is a suitable method for long-term storage of E. multilocularis metacestode isolates and reduces the number of experimental animals.

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1657
Author(s):  
Samah Shanwar ◽  
Liuen Liang ◽  
Andrey V. Nechaev ◽  
Daria K. Bausheva ◽  
Irina V. Balalaeva ◽  
...  

In the natural fluidic environment of a biological system, nanoparticles swiftly adsorb plasma proteins on their surface forming a “protein corona”, which profoundly and often adversely affects their residence in the systemic circulation in vivo and their interaction with cells in vitro. It has been recognized that preformation of a protein corona under controlled conditions ameliorates the protein corona effects, including colloidal stability in serum solutions. We report on the investigation of the stabilizing effects of a denatured bovine serum albumin (dBSA) protein corona formed on the surface of upconversion nanoparticles (UCNPs). UCNPs were chosen as a nanoparticle model due to their unique photoluminescent properties suitable for background-free biological imaging and sensing. UCNP surface was modified with nitrosonium tetrafluoroborate (NOBF4) to render it hydrophilic. UCNP-NOBF4 nanoparticles were incubated in dBSA solution to form a dBSA corona followed up by lyophilization. As produced dBSA-UCNP-NOBF4 demonstrated high photoluminescence brightness, sustained colloidal stability after long-term storage and the reduced level of serum protein surface adsorption. These results show promise of dBSA-based nanoparticle pretreatment to improve the amiability to biological environments towards theranostic applications.


2021 ◽  
Vol 10 (2) ◽  
pp. 6-12
Author(s):  
I.V. Arutyunyan Arutyunyan ◽  
◽  
T.K. Dubovaya ◽  

The transplantation of artificial tissues and organs is gradually becoming a part of our reality. At the same time, researchers are facing a problem common to all transplantologists, i.e. the need for a long-term storage of a biomedical product (transplant) without losing its properties. The possibility to cryopreserve cells adhered to various scaffolds' surface was first presented about 20 years ago. However, the data on the technology as a whole remains unsystematized and controversial. This review aimed to analyze the literature on tissue-engineered constructs (TEC) cryopreservation of different scientific groups to create a unified approach in assessing the technique's efficacy necessary for further regenerative medicine development. The comparison of studies on TEC cryopreservation conducted by various research groups is hampered not only by the lack of standardized protocols but also by different approaches to assessing the result. As experimental data were accumulated, the cryopreservation efficacy was reassessed from meeting the basic requirements for the structure preservation (thawed TEC retains its integrity, cells are partially alive and attached to the matrix) to focusing on the final result (thawed TEC retains its functional properties and is ready to be transplanted). Many of the currently used in vitro research methods presented in the review allow one to look for new ways of increasing the TEC cryopreservation efficacy; however, in our opinion, the next step on the way to introducing the technology into clinical practice should be research on experimental animals. Keywords: tissue engineered construction, cryopreservation, efficacy estimation


2016 ◽  
Vol 9 (3) ◽  
pp. 379-388 ◽  
Author(s):  
N. De Clercq ◽  
G. Vlaemynck ◽  
E. Van Pamel ◽  
D. Colman ◽  
M. Heyndrickx ◽  
...  

Penicillium expansum is the principal cause of blue mould rot and associated production of patulin, a weak mycotoxin, in apples worldwide. P. expansum growth and patulin production is observed during improper or long-term storage of apples. We have investigated the extent to which each successive step during long-term storage contributes to patulin production in various P. expansum isolates. Fungal isolates collected on apples from several Belgian orchards/industries were identified to species level. Random amplification of polymorphic DNA (RAPD) analysis and β-tubulin gene sequencing identified P. expansum and Penicillium solitum as the most prevalent Penicillium species associated with Belgian apples. All 27 P. expansum isolates and eight reference strains were characterised for their patulin production capacity on apple puree agar medium for five days under classical constant temperature and atmosphere conditions. Under these conditions, a large range of patulin production levels was observed. Based on this phenotypic diversity, five P. expansum isolates and one reference strain were selected for in vitro investigation of patulin production under representative conditions in each step of long-term apple storage. Patulin accumulation seemed highly strain dependent and no significant differences between the storage steps were observed. The results also indicated that a high spore inoculum may lead to a strong patulin accumulation even at cold temperatures (1 °C) combined with controlled atmosphere (CA) (3% O2, 1% CO2), suggesting that future control strategies may benefit from considering the duration of storage under CA conditions as well as duration of deck storage.


2003 ◽  
Vol 318 (2) ◽  
pp. 230-235 ◽  
Author(s):  
Wolfgang Walther ◽  
Ulrike Stein ◽  
Carsten Voss ◽  
Torsten Schmidt ◽  
Martin Schleef ◽  
...  

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1655
Author(s):  
Soňa Felšöciová ◽  
Przemysław Łukasz Kowalczewski ◽  
Tomáš Krajčovič ◽  
Štefan Dráb ◽  
Miroslava Kačániová

Contamination of malting barley grain and malt with micromycetes sampled at various periods post-harvest (3rd, 6th, and 9th month of storage) and types of storage (storage silo and floor warehouse) was investigated. Each of these barley grain samples was malted. This article reports on the changes in the fungal microbiome composition and their overall count in barley grain and malt. From the surface-disinfected barley grain samples collected immediately after harvest, there were eight genera isolated, with a predominance of Alternaria. A small increase of isolated microfungi was detected in barley stored in silo for 3 and 6 months (from 142 isolates to 149) and decreased below the number of isolates in barley before storage (133 isolates). Fungal count during storage gradually decreased up to 9 month in barley stored in floor warehouse (from 142 isolates to 84). The initial total count of microscopic fungi in malt before storage was the highest (112 isolates) with 7 genera detected, compared to malts prepared from barley stored for longer time (54 isolates, 7 genera, 9th month of storage). Alternaria was the most abundant and frequent genus. Quantitative representation of the filamentous microscopic fungi was lower compared to yeasts especially in barley and malt prepared from barley stored at third month of storage in both type of storage. Yeasts were identified from all grain samples and malt samples with mass spectrometry. Most attention was given to the widely distributed fungus Penicillium, 79% of strains produced at least one mycotoxin detected under in vitro assays using the TLC method (97% of them produced griseofulvin, 94% CPA, 79% patulin, 14% roquefortin C, and penitrem A was produced by two screening strains under laboratory conditions). It is therefore important to monitor the microflora throughout the production cycle of “barley to beer”.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 530A-530
Author(s):  
S.M. Scheiber ◽  
C.D. Robacker ◽  
M.A. Dirr

The genus Abelia contains ≈30 species, but A. × grandiflora, its cultivars, and A. `Edward Goucher' are the primary taxa grown. The nursery industry has stated that Abelia R. Br. taxa are important economically, and new selections or cultivars with increased cold hardiness, richer pink-rose flower colors, unique foliage colors, and compact habits are desired. Breeding and selection work in the genus is very limited due in part to limited access to germplasm. Pollen storage enables breeders to cross taxa with incongruent flowering cycles, save time and resources by eliminating the need to grow vast amounts of plant material, and incorporate otherwise unavailable germplasm into a breeding program. An experiment was conducted to determine the optimum levels of temperature and humidity for the long-term storage of A. chinensis and A. × grandiflora `Golden Glow' pollen. Temperature and humidity levels were analyzed by incubating undesiccated pollen of a given taxon at four humidity levels (0%, 50%, 80%, and 100%) for 72 h at 5 °C. Following incubation, the pollen was stored in glass vials at each of the following temperatures: 5, -20, and -70 °C. All combinations of temperature and humidity were tested. Pollen viability was assessed after 60 days by in vivo germination tests on styles. Abelia chinensis pollen germinated following storage at all temperature and humidity levels. Pollen of A. × grandiflora `Golden Glow' pollen germinated following all treatments except storage at -20 °C.


1970 ◽  
Vol 10 ◽  
pp. 15-20
Author(s):  
Shambhu P. Dhital ◽  
Hira K. Manandhar ◽  
Hak T. Lim

Cryopreservation has been recognized as a practical and efficient tool for long-term storage of vegetatively propagated plants. This study was conducted to investigate the effects of sucrose concentration, hardening temperature and different cryopreservation methods on the survival rate of potato shoot tips after cryopreservation. Excised shoot tips of in vitro plantlets of potato cultivars, Atlantic and Superior were cryopreserved by vitrification, encapsulationvitrification and encapsulation-dehydration. Cryopreservation by vitrification method was used to determine the optimum concentration of sucrose and cold hardening temperature during sub-culturing period to the donor plantlets. Nine-percent sucrose gave 46.7% survival in Atlantic and 40% in Superior. The most optimum hardening temperature for 50% survival in Atlantic and 43.3% in Superior was 10°C. In the case of comparative study of three different cryopreservation methods, the highest survival (52%) as well as regeneration (46%) were observed when the shoot tips were cryopreserved by encapsulation-vitrification method, and the lowest survival (36%) and regeneration (28%) from the vitrification. Plant and tuber morphology of potato regenerated after cryopreservation were similar to those of the non-cryopreserved in vitro plantlets (control). Thus, this study demonstrated that encapsulation-vitrification method was the most effective one among other methods for higher survival as well as regeneration in in vitro shoot tips of potato.Key words: Cryopreservation; Dehydration; Encapsulation; Potato; Regeneration; VitrificationDOI: 10.3126/njst.v10i0.2804Nepal Journal of Science and Technology Volume 10, 2009 December Page: 15-20


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