scholarly journals Chitosan and phenolic compounds in the control of anthracnose in mango

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Luana Sabrine Silva ◽  
Edson Hiydu Mizobutsi ◽  
Regina Cássia Ferreira Ribeiro ◽  
Fernando da Silva Rocha ◽  
Gisele Polete Mizobutsi ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Mangifera Indica ◽  
In Vitro Test ◽  
Dunnett Test ◽  
Significant Difference ◽  
Mango Peel ◽  
Total Growth ◽  
Vitro Test

Abstract Mango (Mangifera indica L.) has great socioeconomic importance to Brazil, but its production is affected by anthracnose. Chitosan films have shown potential in controlling this disease. In this study, the effect of the association of chitosan with phenolic compounds and extracts on the Colletotrichum tropicaledevelopment was evaluated. Phenolic compounds and extracts from mango peel were incorporated into 2.0% chitosan solutions and tested in vitro. In the in vivo experiment, after pathogen inoculation and application of treatments, fruits were evaluated for anthracnose incidence and severity. Controls consisted of the application of water or pure culture medium and fungicide imazalil. The experimental design was completely randomized and data were submitted to analysis of variance. In the in vitro test and in the assessment of disease intensity, means were compared using the Scott-Knott and Tukey tests (p <0.05), respectively. Controls were compared to the other treatments using the Dunnett test (p <0.05). Total growth inhibition, conidia production and C. tropicale germination were verified with the incorporation of citric, pyrocatecoic and transcinamic acids to chitosan, with no significant difference between them and the fungicide. Low anthracnose incidence and severity was observed in mangoes treated with chitosan combined with phenolic compounds.

Alterations in Erythrocyte Morphology Induced by Blood Pumps

1993 ◽  
Vol 16 (9) ◽  
pp. 653-658 ◽  
Author(s):  
P. Calzavara ◽  
S. De Angeli ◽  
A. Nieri ◽  
C. Furlan ◽  
R. Bolzonella ◽  
...  
Keyword(s):  
Toxic Substances ◽  
In Vitro Test ◽  
Significant Drop ◽  
Erythrocyte Morphology ◽  
In Vivo Test ◽  
Significant Difference ◽  
Image Analyser ◽  
Vitro Test

A scanning electron microscopy was used after in vitro and in vivo tests to investigate any alterations caused by the peristaltic roller pump in erythrocyte morphology. The electron micrographs of samples were examined as follows: 1) by image analyser; 2) by applying Bessis's classification for the qualitative study of crenated red blood cells (RBCs). The in vitro test was repeated four times using blood from healthy donors. Each basal blood sample was divided into 250 ml portions, each of which was recirculated for 12 minutes at different flow rates. In order to verify any persistent erythrocyte damage caused by the peristaltic pump, 15 minutes after recirculation at 450 ml/min, another sample was prepared using the blood remaining from the last test. A statistically significant direct correlation was found between blood flow (Qb) increase and the percentage of morphologically altered RBCs, when either using an image analyser (r = 0.97; p < 0.05) or Bessis's classification (r = 0.95; p < 0.05). However, neither method showed any statistically significant difference between the percentage of deformed RBCs, determined in the basal sample, or in the percentage found at the end of the 450 ml/min test after standing 15 minutes at room temperature. The in vivo test was carried out on 6 patients over 2 dialysis sessions, which differed only for the Qb: 250 versus 400 ml/min. The two dialysis sessions gave comparable results when using both study methods regarding the presence of deformed RBCs. While Bessis's classification showed a significant drop in the post-dialysis percentage of dysmorphic RBCs compared to the pre-dialysis value, both with a Qb of 250 ml/min and 400 ml/min, no significant change was found with the image analyser. The contradictory results of the two tests can be attributed to the presence of spherocytes and stomatocytes in the in vivo test which on the other hand were absent in the in vitro test and not easily distinguished by the image analyser with the parameter used. Reduction in the number of deformed RBCs after dialysis in the in vivo test can be attributed to improvement in the acidosis, correction of the hydroelectric imbalances and removal of toxic substances as a result of dialysis, thus allowing the echinocytes, spherocytes and stomatocytes to be transformed into discocytes.

In Vitro Toxicology Methods in Risk Assessment

1996 ◽  
Vol 24 (3) ◽  
pp. 325-331
Author(s):  
Iain F. H. Purchase
Keyword(s):  
Risk Assessment ◽  
Hazard Assessment ◽  
Human Health Risk ◽  
In Vitro Test ◽  
In Vitro Methods ◽  
New Concepts ◽  
Vitro Test

The title of this paper is challenging, because the question of how in vitro methods and results contribute to human health risk assessment is rarely considered. The process of risk assessment usually begins with hazard assessment, which provides a description of the inherent toxicological properties of the chemical. The next step is to assess the relevance of this to humans, i.e. the human hazard assessment. Finally, information on exposure is examined, and risk can then be assessed. In vitro methods have a limited, but important, role to play in risk assessment. The results can be used for classification and labelling; these are methods of controlling exposure, analogous to risk assessment, but without considering exposure. The Ames Salmonella test is the only in vitro method which is incorporated into regulations and used widely. Data from this test can, at best, lead to classification of a chemical with regard to genotoxicity, but cannot be used for classification and labelling on their own. Several in vitro test systems which assess the topical irritancy and corrosivity of chemicals have been reasonably well validated, and the results from these tests can be used for classification. The future development of in vitro methods is likely to be slow, as it depends on the development of new concepts and ideas. The in vivo methods which currently have reasonably developed in vitro alternatives will be the easiest to replace. The remaining in vivo methods, which provide toxicological information from repeated chronic dosing, with varied endpoints and by mechanisms which are not understood, will be more difficult to replace.

Animal Models and Alternatives in the Quality Control of Vaccines: Are In Vitro Methods or In Vivo Methods the Scientific Equivalent of the Emperor's New Clothes?

1995 ◽  
Vol 23 (1) ◽  
pp. 61-73
Author(s):  
Coenraad Hendriksen ◽  
Johan van der Gun
Keyword(s):  
Quality Control ◽  
Test Methods ◽  
In Vitro Test ◽  
Large Numbers ◽  
Alternative Approach ◽  
Inactivated Vaccines ◽  
Vitro Test

In the quality control of vaccine batches, the potency testing of inactivated vaccines is one of the areas requiring very large numbers of animals, which usually suffer significant distress as a result of the experimental procedures employed. This article deals with the potency testing of diphtheria and tetanus toxoids, two vaccines which are used extensively throughout the world. The relevance of the potency test prescribed by the European Pharmacopoeia monographs is questioned. The validity of the potency test as a model for the human response, the ability of the test to be standardised, and the relevance of the test in relation to the quality of the product are discussed. It is concluded that the potency test has only limited predictive value for the antitoxin responses to be expected in recipients of these toxoids. An alternative approach for estimating the potency of toxoid batches is discussed, in which a distinction is made between estimation of the immunogenic potency of the first few batches obtained from a seed lot and monitoring the consistency of the quality of subsequent batches. The use of animals is limited to the first few batches. Monitoring the consistency of the quality of subsequent batches is based on in vitro test methods. Factors which hamper the introduction and acceptance of the alternative approach are considered. Finally, proposals are made for replacement, reduction and/or refinement (the Three Rs) in the use of animals in the routine potency testing of toxoids.

scholarly journals Tablet Scoring: Current Practice, Fundamentals, and Knowledge Gaps

2019 ◽  
Vol 9 (15) ◽  
pp. 3066 ◽  
Author(s):  
Emmanuel Reginald Jacques ◽  
Paschalis Alexandridis
Keyword(s):  
Prescription Drugs ◽  
In Vitro Test ◽  
Dose Administration ◽  
Solid Dosage ◽  
Non Invasive ◽  
Health Care Practitioners ◽  
Tablet Splitting ◽  
Vitro Test

Oral solid dosage formulations and/or tablets have remained the preferred route of administration by both patients and health care practitioners. Oral tablets are easy to administer, they are non-invasive and cause less risk adversity. Because of the lack of commercially available tablet dose options, tablets are being split or partitioned by users. Tablet scoring refers to the breakage of a tablet to attain a desired efficacy dose and is an emerging concept in the pharmaceutical industry. The primary reason for the tablet scoring practice is to adjust the dose: dose tapering or dose titrating. Other reasons for tablet partitioning are to facilitate dose administration, particularly among the pediatric and the geriatric patient population, and to mitigating the high cost of prescription drugs. The scope of this review is to: (1) evaluate the advantages and inconveniences associated with tablet scoring/portioning, and (2) identify factors in the formulation and the manufacturing of tablets that influence tablet splitting. Whereas tablet partitioning has been a common practice, there is a lack of understanding regarding the fundamentals underpinning the performance of tablets with respect to splitting. Several factors can influence tablet partitioning: tablet size, shape, and thickness. A requirement has recently been set by the European Pharmacopoeia and the U.S. Food and Drug Administration for the uniformity of mass of subdivided tablets. For breaking ease, an in-vivo reference test and a routinely applicable in-vitro test need to be established.

Characteristics and Biocompatibility of the Hydroxyapatite Based Two Ternary Biocomposites

2016 ◽  
Vol 720 ◽  
pp. 130-140
Author(s):  
Berrak Bulut ◽  
Ziya Engin Erkmen ◽  
Eyup Sabri Kayali
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Secondary Phase ◽  
In Vitro Test ◽  
Compression Tests ◽  
Vitro Test ◽  
Dental Applications ◽  
The Ideal

Hydroxyapatite (HA) is a very popular bioceramic for orthopedic and dental applications. Although HA has excellent biocompatibility, its inferior mechanical properties make it unsuitable for load-bearing implant applications. Therefore, HA should be strengthened by a secondary phase for robust mechanical properties. The aim of this study was to compare the properties of HA-Al2O3 (HAC) and HA-ZrO2 (HZC) composites with the addition of 5 and 10 wt% commercial inert glass (CIG); independently. The mixture powders were pressed and then, the pellets were sintered between 1000-1300 °C for 4 hours. Microstructural characterizations were carried out using SEM + EDS and XRD, while hardness and compression tests were done to measure mechanical properties. In order to investigate the biocompatibility behavior of the samples in vitro and in vivo tests were performed. The mechanical properties of HAC composites increased with rising CIG content and increasing sintering temperature. For HZC composites, increasing CIG content caused an elevation in hardness and a decrease in compressive strength values at 1300 °C. The composites having the best physical and mechanical properties also showed improved bioactive properties at in vitro test. In this study, the ideal composite was selected as HZC5 sintered at 1200 °C depending on the microstructure, mechanical and biocompatibility properties.

scholarly journals Prediction of in Vivo Cytotoxicity of Chemotherapeutic Agents by Their Effect on Malignant Leukocytes in Vitro

Blood ◽  
1967 ◽  
Vol 30 (2) ◽  
pp. 176-188 ◽  
Author(s):  
MARTIN J. CLINE
Keyword(s):  
Test System ◽  
Chemotherapeutic Agents ◽  
Response To Treatment ◽  
In Vitro Test ◽  
Malignant Cells ◽  
Vitro Test ◽  
In Vitro Effects ◽  
In Vivo Cytotoxicity

Abstract In order to develop a test system for predicting the response to chemotherapeutic agents, leukocytes from patients with leukemia and leukolymphosarcoma were cultured in vitro and the effect of several drugs on the incorporation of H3-uridine into ribonucleic acid was measured. Cortisol, vincristine and cytosine arabinoside at concentrations near the therapeutic range produced inhibition of H3-uridine incorporation in sensitive leukocytes. The in vitro effects of 6-mercaptopurine and methotrexate were variable. In 39 trials on 25 patients with leukemia or lymphosarcoma, the in vitro test was used successfully to predict the response to treatment with prednisone and vincristine. It was concluded that the in vitro test system can predict the in vivo cytotoxicity of certain drugs for malignant cells, although it cannot be used to predict the likelihood of the induction of remissions with these drugs.

IN VITRO DEMONSTRATION OF "HEPARIN REBOUND"

1987 ◽  
Author(s):  
C Taylor ◽  
R F Baugh
Keyword(s):  
Whole Blood ◽  
Cardiovascular Surgery ◽  
Anticoagulant Activity ◽  
Blood Levels ◽  
In Vitro Test ◽  
Neutralizing Activity ◽  
Vitro Test ◽  
The Stability

"Heparin rebound", the in vivo appearance of measurable heparin anticoagulant activity following theapparent neutralization of heparin by protamine, hasbeen a problem sporadically associated with the use of heparin in cardiovascular surgery. A number of mechanisms have been proposed to explain rebound, and to some extent each may contribute to the phenomena. As yet no reliable, predictable method has been demonstrated for measuring, reproducing or quantifying "heparin rebound".We have demonstrated and measured the appearance of heparin anticoagulant activity following neutralization with protamine in citrated whole blood. The reappearance of heparin anticoagulant activity was associated with a rapid loss of protamine. The loss of protamine followed 1st order enzyme kinetics, and was indicative of the action of an enzyme. The anticoagulant activity which eappeared could be titrated againwith protamine. The loss of protamine neutralizing activity, in whole blood, could be followed by titration with heparin using a recalcified activated clotting time. The rate of loss varied with both individual blood donors and with the type and source of protamine. The rate of loss of protamine was great enough to influence in. vivo heparin/protamine neutralization ratios, i.e. at 4 units of heparin/ml, 1 unit/ml anticoagulant activity was routinely recovered within 30 minutes following initial neutralization. The indications for cardiovascular surgery are:1)the in vivo neutralization ratio should be adjusted to account for loss of protamine activity, 2) the higherthe blood levels of heparin used during surgery, themore significant the potential for heparin rebound, and 3) protamines may be evaluated in an in vitro test which measures the stability of protamine neutralizing activity in whole blood.

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