Changing chemosusceptibility in the second-stage larvae of Toxocara canis by long-term incubation

1993 ◽  
Vol 67 (2) ◽  
pp. 145-150 ◽  
Author(s):  
Nobuaki Akao ◽  
Yoshihisa Goto ◽  
Kaoru Kondo ◽  
Yoshisuke Tsuda
Keyword(s):  
Decanoic Acid ◽  
Toxocara Canis ◽  
Second Stage ◽  
One Year

AbstractSecond-stage larvae of Toxocara canis were maintained in vitro for one year. Susceptibility of the larvae to drugs was evaluated by means of minimal larvicidal concentration (MLC) and larval bursting percentage. MLCs of citral and decanoic acid were almost constant throughout all stages of incubation. However, bursting percentage markedly varied within the first 20 weeks of incubation. Therefore, while larvae are available for use in the MLC assay at any stage of incubation, those beyond the first 20 weeks after incubation should be used for the bursting assay to obtain reproducible results.

scholarly journals Development and test for long-term stability of a synthetic standard for a quantitative Cryptosporidium parvum LightCycler™ PCR assay

2005 ◽  
Vol 3 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Renata Filkorn-Kaiser ◽  
Konrad Botzenhart ◽  
Albrecht Wiedenmann
Keyword(s):  
Cryptosporidium Parvum ◽  
Surrogate Marker ◽  
Target Sequence ◽  
Positive Trend ◽  
Long Term Stability ◽  
Synthetic Standard ◽  
One Year

A recently described quantitative rapid cycle real time PCR (LightCycler™) assay detects Cryptosporidium parvum after in vitro excystation, which is a surrogate marker for the viability of the organisms. In the original assay the quantification standard is a dilution series of C. parvum oocysts with a microscopically determined excystation rate. The need to keep suspensions of viable oocysts in stock and to continuously monitor their excystation rate, however, renders the assay impracticable for routine application. A synthetic standard was developed to replace the in vivo standard and was calibrated using oocysts with known excystation rates. The standard consists of a 486 bp DNA segment ranging from 229 bp upstream to 79 bp downstream of the actual PCR target site. Aliquots of the standard were frozen and stored at −20 °C and at −70 °C or lyophilised and stored at room temperature in the dark. For a period of one year samples preserved with each of the three methods were restored every four or five weeks. They were amplified in the LightCycler™ and the crossing points (CP) were monitored. No significant trend in the raw CP values could be observed for any of the three storage methods. However, when the methods were compared to each other by calculating the CP ratios (−20 °C/−70 °C; −20 °C/lyophilised; −70 °C/lyophilised) at the 10 monitoring dates, the CP ratios −20 °C/−70 °C and −20 °C/lyophilised showed a highly significant positive trend (p<0.0001) while the CP ratio −70 °C/lyophilised did not differ from the null hypothesis (p=0.53). It can be concluded that the latter two preservation methods are both appropriate, while storage at −20 °C is less advisable. Calculations based on the molecular weight of the standard and on the assumption of an average yield of three sporozoites per oocyst led to the conclusion that the target sequence is probably located on a double copy gene

Toxocara canis: Potential activity of natural products against second-stage larvae in vitro and in vivo

2010 ◽  
Vol 126 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Mariana Reis ◽  
Alcione Trinca ◽  
Maria José U. Ferreira ◽  
Ana R. Monsalve-Puello ◽  
Maria Amélia A. Grácio
Keyword(s):  
Natural Products ◽  
Toxocara Canis ◽  
Second Stage ◽  
Potential Activity

scholarly journals Conservation and Production of Ipecac (Cephaelis ipecacuanha Rich.) Plants from Long Term Shoot Cultures

1970 ◽  
Vol 18 (2) ◽  
pp. 157-164 ◽  
Author(s):  
Rituparna Kundu Chaudhuri ◽  
Timir Baran Jha
Keyword(s):  
Growth Conditions ◽  
Shoot Cultures ◽  
Shoot Bud ◽  
Regenerated Plants ◽  
One Year ◽  
Bud Initiation ◽  
Cephaelis Ipecacuanha ◽  
Important Medicinal Plant

In vitro germplasms of ipecac (Cephaelis ipecacuanha Rich.), an important medicinal plant, maintained through reduced growth conditions for more than 12-years, were used as source material for micropropagation. MS with different combinations of Kn (2 mg/l), BAP (2 mg/l), 2iP (2-3 mg/l), NAA (0.2 mg/l) and adenine (40-100 mg/l) as additive was used to induce fresh multiplication of shoots from the nodal meristems and direct shoot bud initiation on the internodal segments. Complete plant regeneration has been achieved from such long term cultures. Regenerated plants maintained their phenotypic and chromosomal stability. Eighty per cent hardened plants, survived in the field condition, are growing well and 25% of them produced flowers within one year. Long term preservation through reduced growth conditions and successful regeneration of morphologically stable plants with stable chromosome numbers (2n = 22) from such long term cultures of ipecae plants.  Key words: Long term culture, Ipecac, micropropagation, flowering D.O.I. 10.3329/ptcb.v18i2.3646 Plant Tissue Cult. & Biotech. 18(2): 157-164, 2008 (December)

Biosynthesis and glycosylation of serine/threonine-rich secreted proteins from Toxocara canis larvae

Parasitology ◽  
1992 ◽  
Vol 105 (2) ◽  
pp. 297-308 ◽  
Author(s):  
A. P. Page ◽  
R. M. Maizels
Keyword(s):  
Molecular Weight ◽  
Apparent Molecular Weight ◽  
Toxocara Canis ◽  
Somatic Tissues ◽  
Minimum Delay ◽  
Glycosylation Inhibition ◽  
Major Surface ◽  
Kinetics Of

SUMMARYToxocara canis infective stage larvae continually produce excretory–secretory (TES) glycoproteins in long-term in vitro culture. The kinetics of synthesis and secretion were studied by metabolic labelling with radioactive [35S]methionine, [14C]serine and [14C]threonine. Maximal incorporation rates required overnight pre-incubation of parasites in medium depleted of the appropriate amino acid. Larvae rapidly incorporated isotope into their somatic tissues, but there was a minimum delay of 10 h before secretion of labelled antigens. Labelling with [14C]serine and [14C]threonine demonstrated a relative abundance of these amino acids in the major surface/secreted glycoproteins of this nematode (TES-32 and 120). Pulse-chase experiments suggested that TES-120 may be derived from a 58 kDa precursor, reflecting extensive post-translational glycosylation. Inhibition of N-glycosylation with tunicamycin and digestion with N-glycanase provided evidence of N-glycosylation in the lower molecular weight ES components (TES-32, 55 and 70). These agents had no effect on the higher molecular weight components (TES-120 and 400) implying that for these molecules glycosylation is predominantly O-linked. The largest ES component (TES-400) was unusual, in incorporating serine and threonine but not methionine, and by exhibiting increased apparent molecular weight following pronase digestion; it is suggested that this molecule is a proteoglycan.

scholarly journals In vitro cultivation of Toxocara cati adult worms for production of eggs and evaluation of oviposition

2009 ◽  
Vol 46 (1) ◽  
pp. 28-30 ◽  
Author(s):  
M. Zibaei ◽  
S. Sadjjadi ◽  
B. Sarkari ◽  
A. Oryan ◽  
S. Uga
Keyword(s):  
Culture Method ◽  
Toxocara Canis ◽  
Clinical Syndrome ◽  
Egg Laying ◽  
In Vitro Cultivation ◽  
Toxocara Cati ◽  
Second Stage ◽  
Immunological Diagnosis ◽  
The Mean

AbstractToxocariasis is the clinical syndrome caused by infection of zoonotic roundworms of dogs (Toxocara canis) or cats (Toxocara cati). Current research on the immunology and pathology aspects of toxocariasis requires Toxocara second stage larvae and a ready source of excretory-secretory (ES) antigens. We cultured eleven pairs of both sexes of Toxocara cati adult worms maintained in RPMI 1640 medium in order to evaluate the amounts and duration of egg laying. At the first day and last day (day 19), the mean egg counts were 9300 and 250 eggs/ml, respectively. These results showed that this culture method is very appropriate for collection of pure oviposited eggs and/or production of adult ES antigens of Toxocara cati that could be used for immunological diagnosis of toxocariasis.

scholarly journals Clonal fidelity of chrysanthemum regenerated from long term cultures

Genetika ◽  
2006 ◽  
Vol 38 (3) ◽  
pp. 243-249 ◽  
Author(s):  
Sladjana Jevremovic ◽  
Milana Trifunovic ◽  
Marija Nikolic ◽  
Angelina Subotic ◽  
Ljiljana Radojevic
Keyword(s):  
Morphological Characteristics ◽  
Flower Color ◽  
Stem Segment ◽  
Shoot Cultures ◽  
Ms Medium ◽  
Color Changes ◽  
In Vitro Plants ◽  
One Year

Morphological characteristics of flowers of long term regenerated chrysanthemum, cv. "White Spider", after ten years of micropropagation are investigated. Shoot cultures are established and maintained more than ten years by stem segment culture on MS medium supplemented with BAP and NAA (1.0, 0.1 mgL-1, respectively). Rooting of shoots (100 %) has done on MS medium without hormones and it was very successful after ten years, as well as, after two or eight years of micropropagation. Acclimation of rooted chrysanthemum plantlets at greenhouse conditions was excellent and after appropriate photoperiod "in vitro" plants flowered 90.3 % and have the same flower color, shape and size as mother plants. Flower color changes of "in vitro" plants are observed during another flowering cycle one year after acclimatization. Observed variations of chrysanthemum flowers could be attributed to epigenetic factors.

scholarly journals Experimental study of the liposomal form of fenoterol after improving the method of obtaining it

2020 ◽  
Vol 2 (2) ◽  
pp. 30-37
Author(s):  
Tatiana M. Ustinova ◽  
Nikolai Vengerovich ◽  
Mikhail A. Judin
Keyword(s):  
Average Diameter ◽  
Free Form ◽  
Quantitative Composition ◽  
Active Principle ◽  
Liposomal Form ◽  
Duration Of Action ◽  
Second Stage ◽  
The Stability

The effect of different concentrations of cryoprotector (sucrose) on the efficiency of fenoterol inclusion in the lipid matrix during lyophilization has been studied. It has been shown that the liposomal form with the content of cryoprotector in the internal environment of liposomes 2.5 % and in the external environment equal to 2 % provides long-term preservation of the drug in the liposome cavity. Under these conditions, it is possible to achieve a monodisperse distribution of particles with an average diameter of 4.281.62 m. The assumed quantitative composition of the cryoprotector ensures the manufacturability of the liposome production process, increases the stability of the lyophilizate structure and prevents the particles from sticking together, ensuring their uniformity. The profile of two-stage release of fenoterol from the liposomal form has been shown in vitro. The first stage of rapid release was characterized by a transition to free form within 15 minutes to 42 % of the encapsulated fenoterol. At the second stage, the active principle was released more slowly for 480 minutes. The model of bronchospasm induced by 1% histamine has shown the advantage of the liposomal form of fenoterol in comparison with its free form in the form of an aqueous solution. Intra-tracheal administration of the liposomal form of fenoterol at a dose of 17 ukg/kg provided for 360 minutes the preservation of external respiratory function at the level of initial values, despite histamine inhalation, while the duration of action of fenoterol did not exceed 120 minutes.

Use and Efficacy of Stem Cells Cryopreserved for More Than One Year.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 5214-5214
Author(s):  
Rachel Pawson ◽  
Jon Smythe ◽  
Dorothy Mcdonald ◽  
Martin Guttridge ◽  
Anatole Lubenko ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Retrospective Survey ◽  
Neutrophil Recovery ◽  
Long Term Storage ◽  
Use Of Resources ◽  
One Year ◽  
Term Storage ◽  
Neutrophil Engraftment

Abstract Adequate viability after cryostorage is essential to allow engraftment of autologous haematopoietic progenitor cells (HPC). Information on the effect of prolonged cryopreservation on HPC viability in humans is limited although donations are routinely stored for over a year. Long-term storage is expensive and demonstration of clinical efficacy of HPC after long-term cryopreservation is important in order to justify the use of resources. Available reports describe only isolated cases in which old cells have been infused. We have conducted a retrospective survey of transplants using HPC stored >1 year within the National Blood Service in England. In total 75 patients received HPC that had been frozen for >1yr in NBS Laboratories. Patients had AML (21), NHL (21), myeloma (18), CML (5), Hodgkins disease (6) and other diseases (4). Fifty seven patients received PBSCs cryopreserved for >1 yr with median time in storage of 23 (12.1–65) months and median infused CD34 dose of 4.6 (1.2–85) ×106/kg. Neutrophil recovery to >0.5 × 109/l was 12 (4–49) days and platelets to > 20 × 109/l was 13 (3–43) days. Thirteen patients received bone marrow that had been cryopreserved for >1 year (median 32 (13–67) months) with infused TNC dose of 1.7 (0.91 – 3.64) × 108/kg. Time to neutrophils >0.5 × 109/l was 17 (12–95) days and platelets > 20 × 109/l 16 (12–66) days. A further 5 patients received a mixture of PBSCs and BM products all of which had been stored for > 1 year. Delayed neutrophil engraftment (neutrophils <0.5 × 109/l at 21 days) occurred in 2/55 PBSC transplants and 2/8 BM transplants. Delayed platelet engraftment (platelets <20 × 109/l at 28 days) occurred in 4/48 PBSC transplants and 4/8 BM transplants. In this survey, although the use of HPC cryopreserved for more than one year was infrequent, satisfactory engraftment was achieved in most patients. The rate of delayed engraftment was higher in BM as compared to PBSC transplants but numbers are too small for statistical analysis. In vitro viability assays were not available in this study but may help inform decisions on the use of cells stored for long periods.

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