A direct in vitro assay for evaluation of diphtheria vaccine efficacy. Measurement of the competition of toxin and toxoids for neutralizing antibodies

1997 ◽  
Vol 56 (1-3) ◽  
pp. 293-294
Author(s):  
A Wahby
Keyword(s):  
Vaccine Efficacy ◽  
Neutralizing Antibodies ◽  
In Vitro Assay ◽  
Vitro Assay

In vitro assay system for the detection of neutralizing antibodies against salmon calcitonin

1987 ◽  
Vol 116 (3_Suppl) ◽  
pp. S91-S92
Author(s):  
A. GRAUER ◽  
H. G. SCHNEIDER ◽  
A. ZINK ◽  
K. FRANK ◽  
H. SCHMIDT-GAYK ◽  
...  
Keyword(s):  
Salmon Calcitonin ◽  
Neutralizing Antibodies ◽  
In Vitro Assay ◽  
Assay System ◽  
Vitro Assay

In Vitro Assay of Platelet Adhesiveness with Washed and Tanned Human Red Cells

1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin
Keyword(s):  
Platelet Adhesion ◽  
Sodium Citrate ◽  
Blood Platelets ◽  
In Vitro Assay ◽  
Red Cells ◽  
Platelet Adhesiveness ◽  
Vitro Assay ◽  
In Vitro System ◽  
Human Red Cells

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.

A comparative study on adhesion and recovery of potential probiotic strains ofLactobacillusspp. by in vitro assay and analysis of human colon biopsies

2009 ◽  
Vol 21 (2) ◽  
Author(s):  
Nadja Larsen ◽  
Kim F. Michaelsen ◽  
Anders Pærregaard ◽  
Finn K. Vogensen ◽  
Mogens Jakobsen
Keyword(s):  
Comparative Study ◽  
Human Colon ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Probiotic Strains

scholarly journals A Bacterially-Expressed Recombinant Envelope Protein from Usutu Virus Induces Neutralizing Antibodies in Rabbits

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 157
Author(s):  
Kinga Böszörményi ◽  
Janet Hirsch ◽  
Gwendoline Kiemenyi Kayere ◽  
Zahra Fagrouch ◽  
Nicole Heijmans ◽  
...  
Keyword(s):  
Envelope Protein ◽  
Neutralizing Antibodies ◽  
Size Exclusion ◽  
Vitro Assay ◽  
Usutu Virus ◽  
Transmission Electron ◽  
Exclusion Chromatography ◽  
Efficacious Vaccine ◽  
Human Infections

Background: Recently, an emerging flavivirus, Usutu virus (USUV), has caused an epidemic among birds in Europe, resulting in a massive die-off in Eurasian blackbirds. Currently found only in Europe and Africa, it can be envisioned that Usutu virus will follow the path of other flaviviruses, like West Nile virus and Zika virus, and will spread via its mosquito vectors and bird hosts to other parts of the world. Several cases of human infections by Usutu virus have already been published. Anticipating this spread, development of an efficacious vaccine would be highly desirable. Method: This study describes the production in E. coli, purification, and refolding of a partial USUV envelope protein. Prior to immunization, the protein was characterized using size exclusion chromatography, transmission electron microscopy and dynamic light scattering, showing the limited presence of virus-like structures, indicating that the protein solution is probably a mixture of mono and multimeric envelope proteins. Results: Immunizations of two rabbits with the refolded E-protein fraction, mixed with a strong adjuvant, resulted in the generation of neutralizing antibodies, as evidenced in an in vitro assay. Discussion: The way forward towards a subunit vaccine against Usutu virus infection is discussed.

Angiogenic Effect of Pravastatin Alone and with Sera from Healthy and Complicated Pregnancies Studied by in vitro Vasculogenesis/Angiogenesis Assay

2021 ◽  
pp. 1-9
Author(s):  
Anita Virtanen ◽  
Outi Huttala ◽  
Kati Tihtonen ◽  
Tarja Toimela ◽  
Tuula Heinonen ◽  
...  
Keyword(s):  
Direct Effect ◽  
Late Onset ◽  
Maternal Serum ◽  
In Vitro Assay ◽  
Serum Samples ◽  
Therapeutic Concentration ◽  
Tubule Formation ◽  
Vitro Assay ◽  
Angiogenesis Assay

<b><i>Objective:</i></b> To determine the direct effect of pravastatin on angiogenesis and to study the interaction between pravastatin and maternal sera from women with early- or late-onset pre-eclampsia (PE), intrauterine growth restriction, or healthy pregnancy. <b><i>Methods:</i></b> We collected 5 maternal serum samples from each group. The effect of pravastatin on angiogenesis was assessed with and without maternal sera by quantifying tubule formation in a human-based in vitro assay. Pravastatin was added at 20, 1,000, and 8,000 ng/mL concentrations. Concentrations of angiogenic and inflammatory biomarkers in serum and in test medium after supplementation of serum alone and with pravastatin (1,000 ng/mL) were measured. <b><i>Results:</i></b> Therapeutic concentration of pravastatin (20 ng/mL) did not have significant direct effect on angiogenesis, but the highest concentrations inhibited angiogenesis. Pravastatin did not change the levels of biomarkers in the test media. There were no changes in angiogenesis when therapeutic dose of pravastatin was added with maternal sera, but there was a trend to wide individual variation towards enhanced angiogenesis, particularly in the early-onset PE group. <b><i>Conclusions:</i></b> At therapeutic concentration, pravastatin alone or with maternal sera has no significant effect on angiogenesis, but at high concentrations the effect seems to be anti-angiogenic estimated by in vitro assay.

In Vitro Assay for Single-cell Characterization of Impaired Deformability in Red Blood Cells under Recurrent Episodes of Hypoxia

Lab on a Chip ◽  
2021 ◽  
Author(s):  
YUHAO QIANG ◽  
Jia Liu ◽  
Ming Dao ◽  
E Du
Keyword(s):  
Shear Stress ◽  
Red Blood Cells ◽  
Single Cell ◽  
Blood Cells ◽  
Blood Circulation ◽  
In Vitro Assay ◽  
Vitro Assay ◽  
Cyclic Shear

Red blood cells (RBCs) are subjected to recurrent changes in shear stress and oxygen tension during blood circulation. The cyclic shear stress has been identified as an important factor that...

Purification of Chalcone Synthase from Tulip Anthers and Comparison with the Synthase from Cosmos Petals

1981 ◽  
Vol 36 (1-2) ◽  
pp. 30-34 ◽  
Author(s):  
Rainer Sütfeld ◽  
Rolf Wiermann
Keyword(s):  
Chalcone Synthase ◽  
In Vitro Assay ◽  
Flavonoid Biosynthesis ◽  
Chalcone Isomerase ◽  
Gel Chromatography ◽  
Purification Procedure ◽  
Reaction Products ◽  
Complete Elimination ◽  
Vitro Assay

Abstract Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.

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