scholarly journals The evaluation of Pythium oligandrum and chitosan in control of Phytophthora infestans (Mont.) de Bary on potato plants

2009 ◽  
Vol 21 (2) ◽  
pp. 13-23 ◽  
Author(s):  
Halina Kurzawińska ◽  
Stanisław Mazur
Keyword(s):  
Phytophthora Infestans ◽  
Linear Growth ◽  
Plant Protection ◽  
In Vitro Tests ◽  
Pythium Oligandrum ◽  
Chemical Preparation ◽  
Potato Plants ◽  
The University

Abstract The studies were carried out both in in vitro and in vivo conditions. The field experiment was conducted during the years 2005-2007 at the Experimental Station in Mydlniki, owned by the Department of Plant Protection at the University of Agriculture in Krakow. The aim of these studies was to determine the effect of tuber dressing and plant spraying with Polyversum (B.A.S. Pythium oligandrum) and Biochikol 020 PC (B.A.S. chitosan) bio-preparations on the top leaves and tubers of ‘Ibis’ potatoes infested by Phytophthora infestans. The chemical preparation Vitavax 2000 FS (B.A.S. karboxin and thiuram) was used. The in vitro evaluation of Polyversum and Biochikol 020 PC bio-preparations on the P. infestans mycelium linear growth was investigated. The above-mentioned preparations were applied at three different concentrations. The experiment was carried out using the Kowalik and Krechniak method (1961). Based on the results it was found that the preparations under examination significantly inhibited top leaf and tuber infestation by Phytophthora infestans. Moreover, according to the results obtained from in vitro tests, a significant effect from the Vitavax 2000 FS and Polyversum preparations and from the highest concentration (2%) of Biochikol 020 PC preparation on the percentage inhibition of P. infestans mycelium linear growth was observed (in comparison to the control).

scholarly journals The Dominance of Chitosan Hydrochloride over Modern Natural Agents or Basic Substances in Efficacy against Phytophthora infestans, and Its Safety for the Non-Target Model Species Eisenia fetida

Horticulturae ◽  
2021 ◽  
Vol 7 (10) ◽  
pp. 366
Author(s):  
Martin Žabka ◽  
Roman Pavela
Keyword(s):  
Phytophthora Infestans ◽  
Plant Protection ◽  
Crop Protection ◽  
Model Species ◽  
Natural Conditions ◽  
Natural Agents ◽  
Modern Natural ◽  
Chitosan Hydrochloride

Growing pressure to reduce the environmental pesticide burden has the greatest impact on agriculture and crop protection. There is an enormous increase in the demand for research on new, effective, naturally based agents that do not pose an environmental risk. Phytophthora infestans is one of the most destructive phytopathogens, especially in cases where synthetic fungicides are not allowed. This paper describes the high efficacy and safety of the natural polymer chitosan under in vitro and in vivo conditions and its dominance over other natural agents or products. Chitosan demonstrated the highest efficacy against P. infestans. A concentration of 0.2–0.4% was highly effective. The protective effect of chitosan was 99.3% in natural conditions. Direct activity, equivalent to synthetic fungicides (MIC50 0.293 mg/mL), was confirmed. Chitosan was rated non-toxic to useful non-target species. We promote further chitosan expansion within legislation and implementation of chitosan as a safe substance that could reduce the pesticide burden, particularly in eco-friendly plant protection and production of non-harmful foods.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

A Comparison of the in Vitro and in Vivo Thrombogenic Activity of Factor IX Concentrates Using Stasis (Wessler) and Non-Stasis Rabbit Models

1980 ◽  
Vol 44 (02) ◽  
pp. 081-086 ◽  
Author(s):  
C V Prowse ◽  
A E Williams
Keyword(s):  
Platelet Rich Plasma ◽  
Thrombus Formation ◽  
Factor Ix ◽  
Coagulation System ◽  
In Vitro Tests ◽  
Clinical Use ◽  
Low Activity

SummaryThe thrombogenic effects of selected factor IX concentrates were evaluated in two rabbit models; the Wessler stasis model and a novel non-stasis model. Concentrates active in either the NAPTT or TGt50 in vitro tests of potential thrombogenicity, or both, caused thrombus formation in the Wessler technique and activation of the coagulation system in the non-stasis model. A concentrate with low activity in both in vitro tests did not have thrombogenic effects in vivo, at the chosen dose. Results in the non-stasis model suggested that the thrombogenic effects of factor IX concentrates may occur by at least two mechanisms. A concentrate prepared from platelet-rich plasma and a pyrogenic concentrate were also tested and found to have no thrombogenic effect in vivo.These studies justify the use of the NAPTT and TGt50 in vitro tests for the screening of factor IX concentrates prior to clinical use.

Inhibition of Fibrinolysis and Fibrinogenolysis in Man: Comparison of ε-Aminocaproic Acid and Kallikrein Inhibitor

1963 ◽  
Vol 10 (01) ◽  
pp. 106-119 ◽  
Author(s):  
E Beck ◽  
R Schmutzler ◽  
F Duckert ◽  
Keyword(s):  
Aminocaproic Acid ◽  
Side Reactions ◽  
In Vitro Tests ◽  
Factor V ◽  
Clinical Use ◽  
Strong Inhibitor ◽  
Kallikrein Inhibitor ◽  
Therapeutic Possibilities

SummaryInhibitor of kallikrein and trypsin (KI) extracted from bovine parotis was compared with ε-aminocaproic acid (EACA): both substances inhibit fibrinolysis induced with streptokinase. EACA is a strong inhibitor of fibrinolysis in concentrations higher than 0, 1 mg per ml plasma. The same amount and higher concentrations are not able to inhibit completely the proteolytic-side reactions of fibrinolysis (fibrinogenolysis, diminution of factor V, rise of fibrin-polymerization-inhibitors). KI inhibits well proteolysis of plasma components in concentrations higher than 2,5 units per ml plasma. Much higher amounts of KI are needed to inhibit fibrinolysis as demonstrated by our in vivo and in vitro tests.Combination of the two substances for clinical use is suggested. Therapeutic possibilities are discussed.

Role of in vivo and in vitro Tests in the Diagnosis of Severe Cutaneous Adverse Reactions (SCAR) to Drug

2019 ◽  
Vol 25 (36) ◽  
pp. 3872-3880 ◽  
Author(s):  
Marcel M. Bergmann ◽  
Jean-Christoph Caubet
Keyword(s):  
Adverse Reactions ◽  
Lymphocyte Transformation ◽  
Stevens Johnson Syndrome ◽  
In Vitro Tests ◽  
High Morbidity ◽  
Patch Tests ◽  
Severe Cutaneous Adverse Reactions ◽  
Cutaneous Adverse Reactions

Severe cutaneous adverse reactions (SCAR) are life-threatening conditions including acute generalized exanthematous pustulosis (AGEP), Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) and drug reaction with eosinophilia and systemic symptoms (DRESS). Diagnosis of causative underlying drug hypersensitivity (DH) is mandatory due to the high morbidity and mortality upon re-exposure with the incriminated drug. If an underlying DH is suspected, in vivo test, including patch tests (PTs), delayed-reading intradermal tests (IDTs) and in vitro tests can be performed in selected patients for which the suspected culprit drug is mandatory, or in order to find a safe alternative treatment. Positivity of in vivo and in vitro tests in SCAR to drug varies depending on the type of reaction and the incriminated drugs. Due to the severe nature of these reactions, drug provocation test (DPT) is highly contraindicated in patients who experienced SCAR. Thus, sensitivity is based on positive test results in patients with a suggestive clinical history. Patch tests still remain the first-line diagnostic tests in the majority of patients with SCAR, followed, in case of negative results, by delayed-reading IDTs, with the exception of patients with bullous diseases where IDTs are still contra-indicated. In vitro tests have shown promising results in the diagnosis of SCAR to drug. Positivity is particularly high when the lymphocyte transformation test (LTT) is combined with cytokines and cytotoxic markers measurement (cyto-LTT), but this still has to be confirmed with larger studies. Due to the rarity of SCAR, large multi-center collaborative studies are needed to better study the sensitivity and specificity of in vivo and in vitro tests.

Hemostatic wound dressings: Predicting their effects by in vitro tests

2019 ◽  
Vol 33 (9) ◽  
pp. 1285-1297 ◽  
Author(s):  
Cornelia Wiegand ◽  
Martin Abel ◽  
Uta-Christina Hipler ◽  
Peter Elsner ◽  
Michael Zieger ◽  
...  
Keyword(s):  
Blood Clot ◽  
Wound Dressings ◽  
In Vitro Tests ◽  
Regenerated Cellulose ◽  
Oxidized Regenerated Cellulose ◽  
Inflammatory Reactions ◽  
In Vitro Techniques ◽  
Cotton Gauze

Background Application of controlled in vitro techniques can be used as a screening tool for the development of new hemostatic agents allowing quantitative assessment of overall hemostatic potential. Materials and methods Several tests were selected to evaluate the efficacy of cotton gauze, collagen, and oxidized regenerated cellulose for enhancing blood clotting, coagulation, and platelet activation. Results Visual inspection of dressings after blood contact proved the formation of blood clots. Scanning electron microscopy demonstrated the adsorption of blood cells and plasma proteins. Significantly enhanced blood clot formation was observed for collagen together with β-thromboglobulin increase and platelet count reduction. Oxidized regenerated cellulose demonstrated slower clotting rates not yielding any thrombin generation; yet, led to significantly increased thrombin-anti-thrombin-III complex levels compared to the other dressings. As hemostyptica ought to function without triggering any adverse events, induction of hemolysis, instigation of inflammatory reactions, and initiation of the innate complement system were also tested. Here, cotton gauze provoked high PMN elastase and elevated SC5b-9 concentrations. Conclusions A range of tests for desired and undesired effects of materials need to be combined to gain some degree of predictability of the in vivo situation. Collagen-based dressings demonstrated the highest hemostyptic properties with lowest adverse reactions whereas gauze did not induce high coagulation activation but rather activated leukocytes and complement.

scholarly journals Topical Application of Double-Stranded RNA Targeting 2b and CP Genes of Cucumber mosaic virus Protects Plants against Local and Systemic Viral Infection

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 963
Author(s):  
Maria C. Holeva ◽  
Athanasios Sklavounos ◽  
Rajendran Rajeswaran ◽  
Mikhail M. Pooggin ◽  
Andreas E. Voloudakis
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Topical Application ◽  
Plant Virus ◽  
Plant Protection ◽  
Post Inoculation ◽  
Tobacco Plants ◽  
Double Stranded Rna

Cucumber mosaic virus (CMV) is a destructive plant virus with worldwide distribution and the broadest host range of any known plant virus, as well as a model plant virus for understanding plant–virus interactions. Since the discovery of RNA interference (RNAi) as a major antiviral defense, RNAi-based technologies have been developed for plant protection against viral diseases. In plants and animals, a key trigger of RNAi is double-stranded RNA (dsRNA) processed by Dicer and Dicer-like (DCL) family proteins in small interfering RNAs (siRNAs). In the present study, dsRNAs for coat protein (CP) and 2b genes of CMV were produced in vitro and in vivo and applied onto tobacco plants representing a systemic solanaceous host as well as on a local host plant Chenopodium quinoa. Both dsRNA treatments protected plants from local and systemic infection with CMV, but not against infection with unrelated viruses, confirming sequence specificity of antiviral RNAi. Antiviral RNAi was effective when dsRNAs were applied simultaneously with or four days prior to CMV inoculation, but not four days post inoculation. In vivo-produced dsRNAs were more effective than the in vitro-produced; in treatments with in vivo dsRNAs, dsRNA-CP was more effective than dsRNA-2b, while the effects were opposite with in vitro dsRNAs. Illumina sequencing of small RNAs from in vivo dsRNA-CP treated and non-treated tobacco plants revealed that interference with CMV infection in systemic leaves coincides with strongly reduced accumulation of virus-derived 21- and 22-nucleotide (nt) siRNAs, likely generated by tobacco DCL4 and DCL2, respectively. While the 21-nt class of viral siRNAs was predominant in non-treated plants, 21-nt and 22-nt classes accumulated at almost equal (but low) levels in dsRNA treated plants, suggesting that dsRNA treatment may boost DCL2 activity. Taken together, our findings confirm the efficacy of topical application of dsRNA for plant protection against viruses and shed more light on the mechanism of antiviral RNAi.

In Vitro Methods as a Tool in Neurotoxicity Studies

1995 ◽  
Vol 23 (4) ◽  
pp. 491-496
Author(s):  
Hanna Tähti ◽  
Leila Vaalavirta ◽  
Tarja Toimela
Keyword(s):  
Risk Evaluation ◽  
Toxicity Testing ◽  
In Vitro Models ◽  
In Vitro Tests ◽  
Industrial Chemicals ◽  
Mercury Compounds ◽  
Toxicological Data ◽  
In Vivo Tests

— There are several hundred industrial chemicals with neurotoxic potential. The neurotoxic risks of most of these chemicals are unknown. Additional methods are needed to assess the risks more effectively and to elucidate the mechanisms of neurotoxicity more accurately than is possible with the conventional methods. This paper deals with general tasks concerning the use of in vitro models in the evaluation of neurotoxic risks. It is based on our previous studies with various in vitro models and on recent literature. The induction of glial fibrillary acidic protein in astrocyte cultures after treatment with known neurotoxicants (mercury compounds and aluminium) is discussed in more detail as an important response which can be detected in vitro. When used appropriately with in vivo tests and with previous toxicological data, in vitro neurotoxicity testing considerably improves risk assessment. The incorporation of in vitro tests into the early stages of risk evaluation can reduce the number of animals used in routine toxicity testing, by identifying chemicals with high neurotoxic potential.

A battery of in vivo and in vitro tests useful for genotoxic pollutant detection in surface waters

2006 ◽  
Vol 77 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Claudia Pellacani ◽  
Annamaria Buschini ◽  
Mariangela Furlini ◽  
Paola Poli ◽  
Carlo Rossi
Keyword(s):  
Surface Waters ◽  
In Vitro Tests ◽  
Pollutant Detection

scholarly journals Comparative Characteristics of Determination of Antioxidant Activity of Sea Buckthorn Fruits by Various Methods

2019 ◽  
Vol 8 (4) ◽  
pp. 48-52
Author(s):  
O. V. Trineeva
Keyword(s):  
Antioxidant Activity ◽  
Medicinal Plant ◽  
Plant Material ◽  
Natural Antioxidants ◽  
Sea Buckthorn ◽  
In Vitro Tests ◽  
Medicinal Plant Material

Introduction. Recently, much attention has been paid to the primary assessment of the pharmacological effect of various drugs using in vivo and in vitro tests. It is known that such a medicinal plant as sea buckthorn, in its phytochemical composition is rich in natural antioxidants: carotenoids, tocopherols, flavonoids, ascorbic acid, etc. In some publications there is information about the antioxidant activity of sea buckthorn and fatty oil based on them. However, information on the comparative characteristics of the use of various methods for determining the antioxidant activity of this type of medicinal plant material and the results obtained are not found in the scientific literature.Aim. The aim of this work was a comparative determination of the antioxidant activity of medicinal plant material of buckthorn fruits of various species of buckthorn.Materials and methods. The total antioxidant activity of water and water-alcohol extracts from the fruits of sea buckthorn fruits was determined using various techniques recommended in the literature. The antioxidant activity of the extracts was determined by permanganometric titration, in vitro inhibition of adrenaline autooxidation, and also in a biological model, Parametium caudatum cell culture.Results and discussion. The effect of the extractant polarity on the value of antioxidant activity was studied. It was found that the highest content of antioxidants in the extraction is observed when using 96 % ethanol as an extractant.Conclusion. Using three methods, the prospects of using sea buckthorn fruits and preparations based on them as a source of antioxidants are shown. 

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