In vitro hardness, water sorption, and resin solubility of laboratory-processed and autopolymerized long-term resilient denture liners over one year of water storage

2002 ◽  
Vol 88 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Gregory R. Parr ◽  
Frederick A. Rueggeberg
Keyword(s):  
Water Sorption ◽  
Water Storage ◽  
Denture Liners ◽  
One Year

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

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 Influence of chlorhexidine on longitudinal bond strength to dentin: in vitro study

2017 ◽  
Vol 20 (1) ◽  
pp. 17 ◽  
Author(s):  
Beatriz Maria Fonseca ◽  
Daphne Camara Barcellos ◽  
César Rogério Pucci ◽  
Eduardo Bresciani ◽  
Maria Amélia Máximo de Araújo
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Water Storage ◽  
In Vitro Study ◽  
Chlorhexidine Gluconate ◽  
Acid Etching ◽  
Single Bond ◽  
Etch And Rinse

<p><strong>Objective</strong>: This study evaluated the effect of 0.2% chlorhexidine gluconate solution used as an therapeutic primer on the long-term bond strength of etch-and-rinse adhesive to dentin. <strong>Material</strong> <strong>and</strong> <strong>Methods</strong>: Bovine incisors were worn to expose an area of dentin and were divided into 2 groups: Group C (Control) - acid etching with 37% phosphoric acid + Single Bond; Group CHX (0.2% CHX) - acid etching with 37% phosphoric acid + 0.2% CHX for 30 s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukey tests. <strong>Results</strong>: Mean (±SD) values (in MPa) were as follow: Group CHX/24h - 41.8(±2.62)A; Group C/24h - 40.8(±3.35)AB; Group CHX/6 months – 36.4(±3.52)B; Group CHX/6 months - 26.1(±1.54)C. <strong>Conclusion</strong>: CHX improve the imediatte bond strength of resin-dentin and significantly lowered the loss of bond strength after 6 months water storage as seen in the control bonds.</p><p><strong>Keywords</strong></p><p>Tensile bond strength; Dentin; Total-etch adhesives; Chlorhexidine gluconate.</p>

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)

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.

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.

scholarly journals Characterization of Water Sorption, Solubility, and Roughness of Silorane- and Methacrylate-based Composite Resins

2014 ◽  
Vol 39 (3) ◽  
pp. 264-272 ◽  
Author(s):  
M Giannini ◽  
M Di Francescantonio ◽  
RR Pacheco ◽  
LC Cidreira Boaro ◽  
RR Braga
Keyword(s):  
Surface Roughness ◽  
Water Sorption ◽  
Composite Resin ◽  
Water Storage ◽  
Composite Resins ◽  
Constant Mass ◽  
One Year ◽  
Post Hoc ◽  
Better Than

SUMMARY Objective The objective of this study was to evaluate the surface roughness (SR), water sorption (WS), and solubility (SO) of four composite resins after finishing/polishing and after one year of water storage. Materials and Methods Two low-shrinkage composites (Filtek Silorane [3M ESPE] and Aelite LS [Bisco Inc]) and two composites of conventional formulations (Heliomolar and Tetric N-Ceram [Ivoclar Vivadent]) were tested. Their respective finishing and polishing systems (Sof-Lex Discs, 3M ESPE; Finishing Discs Kit, Bisco Inc; and Astropol F, P, HP, Ivoclar Vivadent) were used according to the manufacturers' instructions. Ten disc-shaped specimens of each composite resin were made for each evaluation. Polished surfaces were analyzed using a profilometer after 24 hours and one year. For the WS and SO, the discs were stored in desiccators until constant mass was achieved. Specimens were then stored in water for seven days or one year, at which time the mass of each specimen was measured. The specimens were dried again and dried specimen mass determined. The WS and SO were calculated from these measurements. Data were analyzed by two-way analysis of variance and Tukey post hoc test (α=0.05). Results Filtek Silorane showed the lowest SR, WS, and SO means. Water storage for one year increased the WS means for all composite resins tested. Conclusions The silorane-based composite resin results were better than those obtained for methacrylate-based resins. One-year water storage did not change the SR and SO properties in any of the composite resins.

scholarly journals In Vitro Modulatory Effect of Stevioside, as a Partial Sugar Replacer in Sweeteners, on Human Child Microbiota

2021 ◽  
Vol 9 (3) ◽  
pp. 590
Author(s):  
Florentina Gatea ◽  
Ionela Sârbu ◽  
Emanuel Vamanu
Keyword(s):  
Antioxidant Status ◽  
Short Chain Fatty Acids ◽  
Partial Replacement ◽  
Bacterial Strains ◽  
One Year ◽  
Vitro Effect

The effect of stevioside on human health is still insufficiently highlighted by recent research. The total or partial replacement of sugar with sweeteners influences the general state of health, especially the human microbiota’s response as a determining factor in the onset of type 2 diabetes. The present study aimed to present the long-term (one-year) in vitro effect that regular stevioside consumption had on children’s pattern microbiota. A metabolomic response was established by determining the synthesis of organic acids and a correlation with antioxidant status. An increase in the number of bacterial strains and the variation of amount of butyrate and propionate to the detriment of lactic acid was observed. The effect was evidenced by the progressive pH increasing, the reduction of acetic acid, and the proliferation of Escherichia coli strains during the simulations. Synthesis of the main short-chain fatty acids (SCFAs) was interpreted as a response (adaptation) of the microbiota to the stevioside, without a corresponding increase in antioxidant status. This study demonstrated the modulatory role of stevioside on the human microbiota and on the fermentation processes that determine the essential SCFA synthesis in maintaining homeostasis. The protection of the microbiota against oxidative stress was also an essential aspect of reducing microbial diversity.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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