scholarly journals Development and Characterization of a Multiplex Assay to Quantify Complement-Fixing Antibodies against Dengue Virus

2021 ◽  
Vol 22 (21) ◽  
pp. 12004
Author(s):  
Eduardo J. M. Nascimento ◽  
Brooke Norwood ◽  
Allan Parker ◽  
Ralph Braun ◽  
Eloi Kpamegan ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Natural Infection ◽  
Antibody Test ◽  
Cross Reactivity ◽  
Serum Antibodies ◽  
Alternative Approach ◽  
Functional Antibodies ◽  
The Complement System

Antibodies capable of activating the complement system (CS) when bound with antigen are referred to as “complement-fixing antibodies” and are involved in protection against Flaviviruses. A complement-fixing antibody test has been used in the past to measure the ability of dengue virus (DENV)-specific serum antibodies to activate the CS. As originally developed, the test is time-consuming, cumbersome, and has limited sensitivity for DENV diagnosis. Here, we developed and characterized a novel multiplex anti-DENV complement-fixing assay based on the Luminex platform to quantitate serum antibodies against all four serotypes (DENV1-4) that activate the CS based on their ability to fix the complement component 1q (C1q). The assay demonstrated good reproducibility and showed equivalent performance to a DENV microneutralization assay that has been used to determine DENV serostatus. In non-human primates, antibodies produced in response to primary DENV1-4 infection induced C1q fixation on homologous and heterologous serotypes. Inter-serotype cross-reactivity was associated with homology of the envelope protein. Interestingly, the antibodies produced following vaccination against Zika virus fixed C1q on DENV. The anti-DENV complement fixing antibody assay represents an alternative approach to determine the quality of functional antibodies produced following DENV natural infection or vaccination and a biomarker for dengue serostatus, while providing insights about immunological cross-reactivity among different Flaviviruses.

Molecular characterization of the kinetoplastid membrane protein-11 genes from the parasiteTrypanosoma rangeli

Parasitology ◽  
2005 ◽  
Vol 130 (6) ◽  
pp. 643-651 ◽  
Author(s):  
H. DIEZ ◽  
M. C. THOMAS ◽  
C. P. URUEÑA ◽  
S. P. SANTANDER ◽  
C. L. CUERVO ◽  
...  
Keyword(s):  
Amino Acid ◽  
Membrane Protein ◽  
Amino Acid Sequence ◽  
Natural Infection ◽  
Cross Reactivity ◽  
Trypanosoma Rangeli ◽  
B Cell Epitopes ◽  
Cytotoxic Responses ◽  
Medical Interest

Trypanosomatids are early divergent parasites which include several species of medical interest.Trypanosoma rangeliis not pathogenic for humans but shows a high immunological cross-reactivity withTrypanosoma cruzi, the causative agent of Chagas' disease that affects more than 17 million people throughout the world. Recent studies have suggested thatT. cruziKMP-11 antigen could be a good candidate for the induction of immunoprotective cytotoxic responses againstT. cruzinatural infection. In the present paper the genes coding for theT. rangelikinetoplastid membrane protein-11 have been characterized. The results show that the locus encoding this protein is formed by 4 gene units measuring 550 nucleotides in length, organized in tandem, and located in different chromosomes in KP1(+) and KP1(−) strains. The gene units are transcribed as a single mRNA of 530 nucleotides in length. Alignment of theT. rangeliKMP-11 deduced amino acid sequence with the homologous KMP-11 protein fromT. cruzirevealed an identity of 97%. Interestingly, the T and B cell epitopes of theT. cruziKMP-11 protein are conserved in theT. rangeliKMP-11 amino acid sequence.

Detection of dengue virus in Aedes mosquitoes in Delhi, India

ENTOMON ◽  
2019 ◽  
Vol 44 (3) ◽  
pp. 213-218
Author(s):  
Suresh Chand Kaushik ◽  
Sukhvir Singh ◽  
Purnima Srivastava ◽  
R. Rajendran
Keyword(s):  
Early Intervention ◽  
Early Detection ◽  
Aedes Aegypti ◽  
Dengue Virus ◽  
Infection Rate ◽  
Transmission Season ◽  
Aedes Mosquitoes ◽  
Alternative Approach ◽  
Human Sera ◽  
Minimum Infection Rate

Detection of viruses in human sera particularly in endemic areas is cumbersome and laborious. Therefore, an alternative approach, Immuno-fluorescence assay (IFA) was performed to determine dengue virus (DENV) positivity in mosquitoes. A total of 1055 adult Aedes aegypti female mosquitoes were tested for IFA test against DENV. Minimum infection rate (MIR) for DENV was found higher during August to November 2016 ranging from 10.75 to 20.83. The average yearly MIR was about 6.64. Higher MIR for Ae. aegypti was found in Sarfabad, Noida (12.71) and Khoda Colony, Ghaziabad (11.90). Minimum MIR (4.67) was observed in Sanjay colony (Faridabad). The main contribution of this study resides in the development of a more suitable monitoring system for early detection of viral circulation and to prioritize early intervention in the non-transmission season.

Physicochemical and bacteriological characterization of hospital effluents and their impact on the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Human Health ◽  
Fecal Coliforms ◽  
Chemical Pollution ◽  
Hospital Effluents ◽  
Biological Contaminants ◽  
Almost All ◽  
Direct Discharge ◽  
Significant Chemical

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.

scholarly journals Proteomic Advances in Milk and Dairy Products

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3832
Author(s):  
Rubén Agregán ◽  
Noemí Echegaray ◽  
María López-Pedrouso ◽  
Radwan Kharabsheh ◽  
Daniel Franco ◽  
...  
Keyword(s):  
Dairy Products ◽  
Two Dimensional Gel Electrophoresis ◽  
Vast Number ◽  
Post Translational Modifications ◽  
Fundamental Parameters ◽  
Complex Fluid ◽  
Proteins And Peptides ◽  
Milk And Dairy Products

Proteomics is a new area of study that in recent decades has provided great advances in the field of medicine. However, its enormous potential for the study of proteomes makes it also applicable to other areas of science. Milk is a highly heterogeneous and complex fluid, where there are numerous genetic variants and isoforms with post-translational modifications (PTMs). Due to the vast number of proteins and peptides existing in its matrix, proteomics is presented as a powerful tool for the characterization of milk samples and their products. The technology developed to date for the separation and characterization of the milk proteome, such as two-dimensional gel electrophoresis (2DE) technology and especially mass spectrometry (MS) have allowed an exhaustive characterization of the proteins and peptides present in milk and dairy products with enormous applications in the industry for the control of fundamental parameters, such as microbiological safety, the guarantee of authenticity, or the control of the transformations carried out, aimed to increase the quality of the final product.

scholarly journals Physicochemical Characterization Cascade of Nanoadjuvant–Antigen Systems for Improving Vaccines

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 544
Author(s):  
Giuditta Guerrini ◽  
Antonio Vivi ◽  
Sabrina Gioria ◽  
Jessica Ponti ◽  
Davide Magrì ◽  
...  
Keyword(s):  
Immune Response ◽  
Protein Structure ◽  
Physicochemical Properties ◽  
Physicochemical Characterization ◽  
Protein Antigen ◽  
Efficacy And Safety

Adjuvants have been used for decades to enhance the immune response to vaccines, in particular for the subunit-based adjuvants. Physicochemical properties of the adjuvant-protein antigen complexes, such as size, morphology, protein structure and binding, influence the overall efficacy and safety of the vaccine. Here we show how to perform an accurate physicochemical characterization of the nanoaluminum–ovalbumin complex. Using a combination of existing techniques, we developed a multi-staged characterization strategy based on measurements of increased complexity. This characterization cascade has the advantage of being very flexible and easily adaptable to any adjuvant-protein antigen combinations. It will contribute to control the quality of antigen–adjuvant complexes and immunological outcomes, ultimately leading to improved vaccines.

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.

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