scholarly journals NATURE OF THE TOXIC MOIETY OF STREPTOCOCCUS SCARLATINÆ

1927 ◽  
Vol 46 (2) ◽  
pp. 379-390 ◽  
Author(s):  
Charles W. Duval ◽  
R. J. Hibbard
Keyword(s):  
Toxic Effect ◽  
Culture Filtrate ◽  
Germ Plasm ◽  
Skin Tests ◽  
Large Numbers ◽  
Similar Dose ◽  
Natural Result ◽  
Derivatives Of

The cutaneous reaction demonstrates that the culture lysate of Streptococcus scarlatinæ is approximately ten time more potent in its toxic effect than is the culture filtrate since repeated and carefully controlled human skin tests show that 0.1 cc. of a 1:2000 dilution of lysate reacts equally as well as a similar dose of a 1:250 dilution of culture filtrate (Dick's standard skin unit). Animal tests and the human intradermal reaction clearly reveal that the toxic principle of culture filtrate (Dick's toxin) and culture lysate (Duval-Hibbard endotoxin) are of the same nature) namely intracellular derivatives of the streptococcal cell. The in vivo prepared lysate affords a more potent antigen for the production of an antiendotoxic serum than the living, killed or culture filtrate of Streptococcus scarlatinæ. The inoculations into dogs of culture filtrate and of the "washed coccal bodies" yield strikingly different results. In those that receive filtrate no toxic effect is produced while in the ones injected with the washed coccal bodies a severe and often fatal toxemia results. The dog is highly susceptible to infection with Streptococcus scarlatinæ and also readily affected by injections of the in vivo prepared lysate. Toxic effects are produced almost immediately following the intravenous injection of lysate and death usually occurs in 24 to 48 hours from an acute hemorrhagic nephritis. Daily urinary examination shows a high percentage of albumin, large numbers of fine granular casts and quantities of macroscopic blood. A study of the kidney sections reveals an extensive glomerulonephritis. The work reported constitutes further evidence in support of our original contention that the poisonous substance of the scarlatinal streptococcus is derived from the bacterial cell set free through the dissolution of the germ plasm. The liberation of the poison in vitro occurs as the natural result of autolysis while in vivo it is produced through specific action of bacteriolysin.

Derivatives of Deoxypodophyllotoxin Induce Apoptosis Through Bcl-2/Bax Proteins Expression

2020 ◽  
Vol 20 ◽  
Author(s):  
Ya-Nan Li ◽  
Ni Ning ◽  
Lei Song ◽  
Yun Geng ◽  
Jun-Ting Fan ◽  
...  
Keyword(s):  
Annexin V ◽  
Mtt Method ◽  
Anthriscus Sylvestris ◽  
Anti Tumor Activity ◽  
Derivatives Of ◽  
Toxicity In Vitro ◽  
Ht 29 ◽  
Mcf 7

Background: Deoxypodophyllotoxin, isolated from theTraditional Chinese Medicine Anthriscus sylvestris, is well-known because of its significant antitumor activity with strong toxicity in vitro and in vivo. Objective: In this article, we synthesized a series of deoxypodophyllotoxin derivatives, and evaluated their antitumor effectiveness.Methods:The anti tumor activity of deoxypodophyllotoxin derivatives was investigated by the MTT method. Apoptosis percentage was measured by flow cytometer analysis using Annexin-V-FITC. Results: The derivatives revealed obvious cytotoxicity in the MTT assay by decreasing the number of late cancer cells. The decrease of Bcl-2/Bax could be observed in MCF-7, HepG2, HT-29 andMG-63 using Annexin V-FITC. The ratio of Bcl-2/Bax in the administration group was decreased, which was determined by the ELISA kit. Conclusion: The derivatives of deoxypodophyllotoxin could induce apoptosis in tumor cell lines by influencing Bcl-2/Bax.

scholarly journals In Vitro and In Vivo Antifungal Activity of Sorbicillinoids Produced by Trichoderma longibrachiatum

2021 ◽  
Vol 7 (6) ◽  
pp. 428
Author(s):  
Men Thi Ngo ◽  
Minh Van Nguyen ◽  
Jae Woo Han ◽  
Myung Soo Park ◽  
Hun Kim ◽  
...  
Keyword(s):  
Late Blight ◽  
Culture Filtrate ◽  
Fungal Pathogens ◽  
Gray Mold ◽  
Trichoderma Longibrachiatum ◽  
Chemical Structures ◽  
Natural Agents ◽  
Blight Disease

In the search for antifungal agents from marine resources, we recently found that the culture filtrate of Trichoderma longibrachiatum SFC100166 effectively suppressed the development of tomato gray mold, rice blast, and tomato late blight. The culture filtrate was then successively extracted with ethyl acetate and n-butanol to identify the fungicidal metabolites. Consequently, a new compound, spirosorbicillinol D (1), and a new natural compound, 2′,3′-dihydro-epoxysorbicillinol (2), together with 11 known compounds (3–13), were obtained from the solvent extracts. The chemical structures were determined by spectroscopic analyses and comparison with literature values. The results of the in vitro antifungal assay showed that of the tested fungal pathogens, Phytophthora infestans was the fungus most sensitive to the isolated compounds, with MIC values ranging from 6.3 to 400 µg/mL, except for trichotetronine (9) and trichodimerol (10). When tomato plants were treated with the representative compounds (4, 6, 7, and 11), bisvertinolone (6) strongly reduced the development of tomato late blight disease compared to the untreated control. Taken together, our results revealed that the culture filtrate of T. longibrachiatum SFC100166 and its metabolites could be useful sources for the development of new natural agents to control late blight caused by P. infestans.

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.

Activation of the peptidergic neurosecretory system in Diphyllobothrium dendriticum (Cestoda: Pseudophyllidea)

Parasitology ◽  
1981 ◽  
Vol 83 (2) ◽  
pp. 243-247 ◽  
Author(s):  
Margaretha K. S. Gustafsson ◽  
Marianne C. Wikgren
Keyword(s):  
Neurosecretory Cells ◽  
Final Host ◽  
Fish Host ◽  
Neurosecretory System ◽  
Weak Reaction ◽  
Diphyllobothrium Dendriticum ◽  
Large Numbers ◽  
Short Times

SUMMARYThe activation of the peptidergic neurosecretory system in Diphyllobothrium dendriticum was studied following cultivation of plerocercoids for short times in vitro and in vivo. In the plerocercoid the neurosecretory cells gave a very weak reaction with paraldehyde fuchsin (PAF). After cultivation for 1 h large numbers of neurosecretory cells filled with PAF-positive granules were evident. The significance of the activation of the neurosecretory system during the transfer of the worm from the cold-blooded fish host to the warm-blooded final host is discussed.

Synthesis, in vitro and in vivo antitumor activity of symmetrical bis-Schiff base derivatives of isatin

2014 ◽  
Vol 74 ◽  
pp. 742-750 ◽  
Author(s):  
Chengyuan Liang ◽  
Juan Xia ◽  
Dong Lei ◽  
Xiang Li ◽  
Qizheng Yao ◽  
...  
Keyword(s):  
Schiff Base ◽  
Antitumor Activity ◽  
Schiff Base Derivatives ◽  
In Vivo Antitumor Activity ◽  
Derivatives Of

Synthesis, characterization and in vitro and in vivo anticancer activity of Pt(iv) derivatives of [Pt(1S,2S-DACH)(5,6-dimethyl-1,10-phenanthroline)]

2017 ◽  
Vol 46 (21) ◽  
pp. 7005-7019 ◽  
Author(s):  
Benjamin W. J. Harper ◽  
Emanuele Petruzzella ◽  
Roman Sirota ◽  
Fernanda Fabiola Faccioli ◽  
Janice R. Aldrich-Wright ◽  
...  
Keyword(s):  
Anticancer Activity ◽  
Biological Evaluation ◽  
Synthesis And Biological Evaluation ◽  
Derivatives Of

Synthesis and biological evaluation in vitro and in vivo of functionalized Pt(iv) derivatives of Pt56MeSS.

scholarly journals ELECTRON MICROSCOPY OF PLASMA-CELL TUMORS OF THE MOUSE

1961 ◽  
Vol 9 (2) ◽  
pp. 369-381 ◽  
Author(s):  
D. F. Parsons ◽  
M. A. Bender ◽  
E. B. Darden ◽  
Guthrie T. Pratt ◽  
D. L. Lindsley
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Complex Structure ◽  
Granular Body ◽  
Virus Particles ◽  
Culture Cells ◽  
Large Numbers ◽  
Tumor Agent

The X5563 tumor has been grown in tissue culture. Cells similar to those of the original tumor migrated from the explant and attached to the glass walls of the culture vessels. Electron microscopy showed that large numbers of particles, similar in morphology to virus particles, were associated with these cells after 7 days of culture. The two principal types of particles found in the tumor in vivo appear to be present in vitro. Many more of these particles, however, were larger and showed a more complex structure. Whereas the particles were mainly localized inside endoplasmic reticulum or the Golgi zone in the tumors in vivo, in the tissue culture the majority of the particles were associated with the plasma membrane and were found outside of the cells. The relation of the particles to the granular body is discussed as well as a possible relation to the mammary tumor agent.

scholarly journals Modulatory effect of Syzygium aromaticum and Pelargonium graveolens on oxidative stress and inflammation

2018 ◽  
Author(s):  
Ilias Marmouzi ◽  
El Mostafa Karym ◽  
Rachid Alami ◽  
Meryem El Jemli ◽  
Mourad Kharbach ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Essential Oils ◽  
Toxic Effect ◽  
Tetrahymena Pyriformis ◽  
Syzygium Aromaticum ◽  
Minimal Risk ◽  
Pelargonium Graveolens ◽  
Anti Inflammatory

AbstractBackgroundTherapy combination is defined as disease treatment with two or more medication to acheive efficacy with lower doses or lower toxicity. Regarding its reported toxicities and efficacy, the Essential Oils (EOs) from Syzygium aromaticum (SA) and Pelargonium graveolens (PG) were combined for in vitro and in vivo assays and toxicities.MethodsThe Essential Oils and mixture were tested for in vivo/in vitro antioxidant and anti-inflammatory activities. The assays included the animal model of acute inflammation (carrageenan model), the protective effect on H2O2/Sodium nitroprissude induced stress in Tetrahymena pyriformis, and the in vitro antioxidant assays.ResultsThe chemical analysis of the investigated Oils has lead to the identification of Eugenol (74.06%), Caryophyllene (11.52%) and Carvacrol acetate (7.82%) as the major element in SA; while PG was much higher in Citronellol (30.77%), 10-epi-γ-Eudesmol (22.59%), and Geraniol (13.95%). In our pharmacological screening of samples, both Oils demonstrated good antioxidant effects. In vivo investigation of the antioxidant activity in the protozoa model (T. pyriformis) demonstrated a lesser toxic effect of EOs mixture with no significant differences when oxidative stress markers and antioxidant enzymes (MDA, SOD and CAT) were evaluated. On the other hand the in vivo model of inflammatory response to carrageenan demonstrated a good inhibitory potential of both EOs. The EOs Mixture demonstrated equivalent bioactivity with lower toxic effect and minimal risk for each compound.ConclusionsThe results from this study indicate that EOs mixture from SA and PG demonstrated promising modulatory antioxidant/anti-inflammatory effect, which suggest an efficient association for therapy.

scholarly journals Stem-loops direct precise processing of 3′ UTR-derived small RNA MicL

2018 ◽  
Author(s):  
Taylor B Updegrove ◽  
Andrew B Kouse ◽  
Katarzyna J Bandyra ◽  
Gisela Storz
Keyword(s):  
Small Rna ◽  
Cleavage Site ◽  
Differential Sensitivity ◽  
Rnase E ◽  
Small Regulatory Rnas ◽  
Regulatory Rnas ◽  
Derivatives Of

AbstractIncreasing numbers of 3′UTR-derived small, regulatory RNAs (sRNAs) are being discovered in bacteria, most generated by cleavage from longer transcripts. The enzyme required for these cleavages has been reported to be RNase E, the major endoribonuclease in enterica bacteria. Previous studies investigating RNase E have come to a range of different conclusions regarding the determinants for RNase E processing. To understand the sequence and structure determinants for the precise processing of the 3′ UTR-derived sRNAs, we examined the cleavage of multiple mutant and chimeric derivatives of the 3′ UTR-derived MicL sRNA in vivo and in vitro. Our results revealed that tandem stem-loops 3′ to the cleavage site define optimal, correctly-positioned cleavage of MicL and likely other similar sRNAs. Moreover, our assays of MicL, ArcZ and CpxQ showed that sRNAs exhibit differential sensitivity to RNase E, likely a consequence of a hierarchy of sRNA features recognized by the endonuclease.

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