The effects of various maintenance conditions on the survival of hymenolepidid cysticercoids

1989 ◽  
Vol 67 (2) ◽  
pp. 259-262 ◽  
Author(s):  
William S. Evans ◽  
Ceayon McKenzie ◽  
Marie Novak ◽  
Hatem Howlader
Keyword(s):  
Salt Solution ◽  
Storage Period ◽  
Tribolium Confusum ◽  
Hymenolepis Diminuta ◽  
Distilled Water ◽  
Storage Medium ◽  
Hymenolepis Nana ◽  
Hymenolepis Microstoma

Cysticercoids of Hymenolepis microstoma, Hymenolepis nana, and Hymenolepis diminuta were examined for their ability to excyst in vitro after being stored in balanced salt solution, distilled water, or the bodies of dead hosts (Tribolium confusum). The number capable of excysting decreased as the duration of the storage period was increased but the rate of decrease varied with the storage medium and was invariably slower when the parasites were stored at 4 °C than when they were kept at 22 °C. The combination of storage medium and temperature that produced the slowest rate of decrease in the ability of the parasites to excyst varied according to species.

The effect of mebendazole on different developmental stages of Hymenolepis diminuta cysticercoids

1978 ◽  
Vol 56 (4) ◽  
pp. 604-607 ◽  
Author(s):  
Marie Novak ◽  
W. S. Evans
Keyword(s):  
Population Size ◽  
Post Infection ◽  
Developmental Stages ◽  
Tribolium Confusum ◽  
Hymenolepis Diminuta

Tribolium confusum beetles infected with Hymenolepis diminuta were fed continuously from day 1, 3, 5, 6, or 7 to day 10 post infection (p.i.) on a mixture composed of two parts Telmin (containing 16.67% of mebendazole) and one part flour. The drug inhibited the worm development and this effect decreased as the age of larvae at the time of the first exposure increased. Lowered incidence of infection, decreased population size, and retarded development were apparent when the beetles were given drug from day 3 p.i. or earlier. Retarded development was also observed in cysticercoids from beetles given drug from day 5 p.i. When given from day 6 or later, it had no effect on worm development. However, when compared with larvae from beetles fed only flour, cysticercoids exposed to the drug from day 6 or later showed reduced infectivity and a decrease in their ability to excyst in vitro. Fully developed infective cysticercoids exposed to the drug from day 10 p.i. or later were not affected by it.

Hymenolepis diminuta and H. microstoma: uptake of cyclosporin A and drug binding to parasite cyclophilins

Parasitology ◽  
1995 ◽  
Vol 111 (5) ◽  
pp. 591-597 ◽  
Author(s):  
H. C. Roberts ◽  
J. M. Sternberg ◽  
L. H. Chappell
Keyword(s):  
Cyclosporin A ◽  
Mode Of Action ◽  
Drug Binding ◽  
Hymenolepis Diminuta ◽  
Isomerase Activity ◽  
Intracellular Compartments ◽  
And Function ◽  
Hymenolepis Microstoma

SUMMARYCyclosporin A (CsA) acts as a powerful immunosuppressant through its binding to the cytosolic isomerase, cyclophilin (CyP), forming a complex which inhibits the phosphatase activity of calcineurin. The drug is also selectively anti-parasitic but its mode of action remains unknown. The mouse tapeworm, Hymenolepis microstoma is sensitive to CsA, but the rat tapeworm, H. diminuta is not susceptible either in rats, mice or in vitro. Using these two tapeworm models, the uptake and binding of CsA were examined in relation to parasite cyclophilins. Uptake and compartmentalization of the drug were markedly different in the two species: H. microstoma takes up more drug than does H. diminuta and sequesters more drug into intracellular compartments. Characterization of cyclophilins using both CsA binding and isomerase activity assays reveals that H. microstoma possesses two cyclophilin isoforms (Mr 17700 and 21400) with isomerase activity that is inhibited by CsA. Using identical assays, we have been unable to demonstrate CsA-binding proteins or CsA-sensitive isomerase activity in H. diminuta. These data suggest that the anthelmintic action of CsA relates in some way to the presence and function of parasite cyclophilins.

scholarly journals The relationship between the storage methods and the formation of dentinal defects (cracks)

2019 ◽  
Vol 67 ◽  
Author(s):  
Fábio Nakao ARASHIRO ◽  
Michelle Tavares Galotto NANTES ◽  
Pedro Gregol da SILVA ◽  
Key Fabiano Souza PEREIRA ◽  
Muryllo Eduardo Sales dos SANTOS
Keyword(s):  
Storage Period ◽  
Root Apex ◽  
Surgical Instruments ◽  
Distilled Water ◽  
Chi Square ◽  
Significance Level ◽  
Significant Difference ◽  
And Storage ◽  
Group 1

ABSTRACT Objective: This research study aims at conducting an in vitro evaluation of crack formation in freshly extracted teeth after undergoing different storage and decontamination methods. Methods: 60 erupted upper third molars conventionally extracted using forceps # 210h (quinelato surgical instruments, rio claro - sp) and randomly distributed in three groups (n = 30): group 1 - storage in dry environment for 30 days, group 2 - sterilization in autoclave and storage for 30 days in distilled water, and group 3 - 10% formaldehyde decontamination for 14 days and storage in distilled water for additional 30 days. after the storage period, teeth had their roots transversely sectioned at 2, 4 and 6 mm below the root apex using a low rotation diamond disk under constant cooling. the evaluation of fragments was performed using a 30-time magnification microscope. Results: Cracks were seen only in group 1 and the chi-square statistical test with 5% significance level showed a statistically significant difference comparing the dry storage group to the others. Conclusion: The storage of extracted teeth in a dry environment influences the formation of dentinal defects.

scholarly journals Influence of Toothbrush Abrasion and Surface Treatments on Roughness and Gloss of Polymer-Infiltrated Ceramics

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3694
Author(s):  
Nawaf Labban ◽  
Mohammad D. Al Al Amri ◽  
Sarah M Alnafaiy ◽  
Saleh M. Alhijji ◽  
Mohammad A. Alenizy ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Mean Value ◽  
Control Group ◽  
P Value ◽  
Distilled Water ◽  
Storage Medium ◽  
Significant Difference ◽  
Toothbrush Abrasion ◽  
Surface Gloss

The aim of this study was to compare the surface roughness and gloss of polymer-infiltrated ceramics after simulated in vitro toothbrushing in different storage mediums. Four polymer- infiltrated ceramics were evaluated, Lava ultimate (LU), Vita enamic (EN), Shofu (SH), and Crystal ultra (CU). The control group was a feldspathic ceramic, Vita Mark II (VM). One hundred and twenty specimens (12 × 14 × 2.5 mm) were prepared using a precision saw. For each material (n = 24), the specimens were allocated into two groups, polished and stained. The specimens of each group were stored (for 7 days) in either citric acid (0.2N) or distilled water. Data for surface gloss (ΔE*SCE-SCI) and roughness (Ra) were evaluated before (baseline) and after simulated toothbrushing. For toothbrushing simulation, a toothpaste slurry containing a toothpaste of 100 relative dentin abrasion (RDA) and 0.3 mL distilled water was used for 3650 cycles (7300 strokes) for each specimen. Data were analyzed using t-test and ANOVA. A p-value of ≤ to 0.05 was considered significant. The highest mean value of surface gloss was identified in CU (stained—water) (4.3 (0.47)) (ΔE*) and EN (stained—acid) (4.3 (1.00)) (ΔE*) specimens, whereas the lowest mean value was shown by SH (stained—acid) (2.04 (0.42)) (ΔE*) samples. The highest mean value of surface roughness was observed in SH (0.40 (0.99)) Ra (stained—acid) whereas the lowest in VM (0.13 (0.039)) Ra (polished—water). A significant difference (p < 0.05) was observed in surface roughness and gloss between the materials with simulated toothbrushing, except in VM and LU, respectively. Therefore, it can be concluded that simulated toothbrushing impacts on surface roughness and gloss, irrespective of the storage medium.

Membrane (contact) digestion in the three species of tapeworm Hymenolepis diminuta, Hymenolepis microstoma and Moniezia expansa

Parasitology ◽  
1968 ◽  
Vol 58 (3) ◽  
pp. 535-546 ◽  
Author(s):  
E. W. Taylor ◽  
J. N. Thomas
Keyword(s):  
Electron Microscope ◽  
Hymenolepis Diminuta ◽  
Contact Digestion ◽  
Rate Of Hydrolysis ◽  
Membrane Contact ◽  
Rats And Mice ◽  
Meat Market ◽  
Hydrolysis Of ◽  
Hymenolepis Microstoma

The presence of living tapeworm increases the rate of hydrolysis of starch by α-amylase in vitro. This effect indicates that ‘membrane digestion’ may be one function of the tegument of tapeworms. The effect varies with the surface area and region of the tapeworm. Fixed tapeworm pieces do not enhance starch hydrolysis. The results may provide evidence both for and against the current explanations of membrane digestion. Some possible mechanisms involved in membrane digestion in tapeworms are considered. The importance of membrane digestion in the physiology of gut parasites and the possibility of its wide occurrence are discussed.We wish to thank Dr J. Llewellyn for his criticism and advice during the preparation of this manuscript and for providing rats and mice infected with Hymenolepis. We also thank Dr R. A. Thornhill for examining some tapeworm tissue under the electron microscope; also Mr A. Wilson of the Meat Inspection Department of the Birmingham Meat Market for his unfailing co-operation.

In vitro oncospheral agglutination given by immune sera from mice infected, and rabbits injected, with eggs of Hymenolepis nana

Parasitology ◽  
1975 ◽  
Vol 71 (3) ◽  
pp. 465-473 ◽  
Author(s):  
Akira Ito
Keyword(s):  
Salt Solution ◽  
Primary Infection ◽  
Protective Immunity ◽  
Secondary Infection ◽  
Hymenolepis Nana ◽  
Intravenous Injections

Oncospheral agglutination given by sera immunized with Hymenolepisnana eggs is described as a new way of assessing H. nana infection. All sera of mice which possessed acquired protective immunity against reinfection by H. nana eggs had the potency to induce oncospheral agglutination in vitro. Only oncospheres, which had been hatched, agglutinated, no agglutination occurred in sera from uninfected mice. Oncospheral agglutination was carried out by mixing 0·1 ml of serial two-fold dilutions of serum and 0·1 ml of Hanks' balanced salt solution containing about 600 hatched oncospheres. Titre of agglutinins was indicated as a reciprocal of the final dilution capable of giving agglutination clusters made of three or more oncospheres. Agglutinins developed within 14 days after a primary infection with 500 shell-free eggs. There was no rapid increase of agglutinins within 4 days following a secondary infection. The titre increase coincided with the increase in dosages of eggs. Agglutinins were thought to be immunoglobulins, because the potency of the serum to agglutinate oncospheres was extinguished after absorption of globulins with rabbit anti-mouse globulin serum.Agglutinins were produced in rabbits by intravenous injections of shell-free eggs. The titres of the rabbit sera were much higher than those of mouse sera.

Factors influencing zoospore production by Phytophthora cinnamomi in axenic cultui

1980 ◽  
Vol 58 (19) ◽  
pp. 2117-2122 ◽  
Author(s):  
Calvin L. Schoulties ◽  
Kenneth F. Baker ◽  
Carol Sabersky-Lehmann
Keyword(s):  
Salt Solution ◽  
Phytophthora Cinnamomi ◽  
Mineral Salt ◽  
Distilled Water ◽  
Sporulation Medium ◽  
Uniform Size ◽  
Factors Influencing ◽  
Zoospore Release ◽  
Zoospore Production

Factors and procedures found to increase the quantity and consistency of axenic zoospore production in a selected isolate of Phytophthora cinnamomi were (i) the use of single-zoospore cultures of uniform size that were between 48 and 72 h old; (ii) thorough washing of mycelial mats at the time of sporangium induction to remove nutrients; (iii) agitation of the sporulation medium (mineral salt solution) 24 h after the initial induction; (iv) standardization of the volume of the sporulation medium; (v) adequate removal of the sporulation medium and replacement with distilled water before triggering zoospore release; and (vi) placement of colonies that had been induced to sporulate under light. The addition of a purified sporangium stimulatory substance to mycelial mats which had been induced to sporulate enabled the fungus to sporulate under conditions which normally suppressed sporulation in vitro. In the presence of this stimulatory substance, the fungus sporulated prolifically in darkness and with limited quantities of added nutrients. Other isolates of P. cinnamomi responded in a similar manner to many of these factors and procedures.

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