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The Inducible Defense System: Antibody Molecules and Antigen-Antibody Reactions
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
The classical example of an agglutination assay is the direct hemagglutination assay (Figure 7.16). In order to determine if a person has antibodies to antigens expressed on the surface of another person′s erythrocytes, various dilutions of serum from the person are added to wells of a microtiter plate. Then, a suspension of the erythrocytes to be tested is added. If antibodies are present in sufficient concentration to cross-link the erythrocytes, the immune complex, which forms, precipitates as a fluffy layer on the bottom of the well. If antibodies are not present, the erythrocytes roll down the sides of the well, and a compact pellet of cells forms at the center of the well, in the example shown, a positive reaction is seen with serum diluted 1:20,1:40 and 1:80, but not 1:160. The term titer is used to refer to the reciprocal of the highest dilution that gives a positive reaction. Thus, we would say that the serum used in the test had a titer of 1:80.
Vinca rosea (Madagascar Periwinkle) and Adhatoda vesica (Malabar Nut)
Published in Azamal Husen, Herbs, Shrubs, and Trees of Potential Medicinal Benefits, 2022
Rajib Hossain, Md Shahazul Islam, Dipta Dey, Muhammad Torequl Islam
Influenza viruses are important etiologic agents of human respiratory diseases, and they cause significant health and economic harm. The current research investigated the antiviral activity of A. vasica crude extracts against influenza virus in vitro by reducing hemagglutination (HA) in two distinct layouts of simultaneous and post-treatment assays. Antiviral activity in the noncytotoxic range was tested using aqueous and methanolic extracts. At a dosage of 10 mg/ml, the methanolic extract reduced HA by 100% in both simultaneous and posttreatment tests. In a simultaneous test, aqueous extracts at doses of 10 mg/ml and 5 mg/ml decreased HA to 33% and 16.67%, respectively. These findings indicate that extracts have potent anti-influenza virus action, inhibiting viral attachment and/or replication, and therefore may be utilized as a viral prophylactic. (Chavan and Chowdhary, 2014).
Order Articulavirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The configurations of influenza VLPs have included a heterologous M1 derived from an unrelated influenza virus strain (Prel et al. 2008) or even a retrovirus Gag protein in place of M1. Thus, the coexpression of murine leukemia virus (MLV) Gag and influenza HA, NA, and M2 in mammalian 293T cells led to VLPs that mimicked the properties of the viral surface of the two highly pathogenic avian influenza viruses of either H7N1 or H5N1 antigenic subtype (Szécsi et al. 2006). Then, the involvement of the MLV Gag by baculovirus-driven expression resulted in retrovirus-like particles containing HA of the H5N1 subtype, in that these pseudotyped particles appeared as consistent 100-nm spheres (Haynes et al. 2009). A Gag-to-HA ratio was noted to be approximately 3–4:1 and to exhibit hemagglutination specific activity, which were like those found in the influenza virus. Therefore, while there may exist specific interactions between cytoplasmic domains of viral envelope proteins and matrix or core components, such virus specific interactions were not required for efficient release of a self-sufficient budding protein Gag (Haynes et al. 2009).
Association between ABO blood groups and preeclampsia
Published in Hypertension in Pregnancy, 2023
Hid Felizardo Cordero-Franco, Ana María Salinas-Martínez, Luis Ángel Garza-de Hoyos, Sofía Denisse González-Rueda, Joaquín Darío Treviño Báez, Francisco Javier Guzmán-de la Garza
The following clinical data were collected: systolic and diastolic blood pressure at the first antenatal visit (first trimester), history of gestational diabetes, and gestational weight gain (weight difference between the last and first antenatal visit). Obstetrical data included the number of pregnancies, inter-pregnancy interval in multiparous women, current multiple pregnancy, number of antenatal visits, fetal sex, and gestational age at the last antenatal visit. Medical history data included a history of preeclampsia/eclampsia, hypertension, type 2 diabetes, pre-pregnancy overweight/obesity (body mass index≥25 kg/m2), and aspirin use during pregnancy. Sociodemographic data included information on maternal age, education, and occupation. Neonatal data included the gestational age, birth weight, and one- and five-minute Apgar scores. Laboratory data included the blood group type and Rh factor. Blood groups were determined using the hemagglutination technique. All data were collected from electronic medical records. The mean arterial pressure was calculated from the systolic and diastolic blood pressures using the following formula: ([systolic blood pressure - diastolic blood pressure/3] + diastolic blood pressure).
Preservation of red blood cell antigenicity in a new storage solution in vitro
Published in Annals of Medicine, 2023
Sheng-Hui Tang, Hsin-Chung Lin, Jin-Biou Chang, Yung-Shu Chan, Hui-Fei Tang, Feng-Yee Chang, Tzong-Shi Chiueh, Bing-Heng Yang
Positive hemagglutination in pretransfusion testing indicates the presence of RBC antibodies in the serum. However, hemagglutination activity in commercial RBC reagents usually expresses a time-dependent decline and probably causes a false negative reaction for allo-antibody detection, especially when expiring or outdate RBC reagents are used. In addition, early haemolysis of RBC reagents can result in false-positive reactions and decrease the sensitivity of pretransfusion antibody screening and identification assays. Therefore, the development of a new RBC storage solution to maintain RBC integrity is crucial for accurate pretransfusion testing. Compared with the conventional storage solution, the decline of RBC hemagglutination scores in the new solution was often later than that in the control solution for most antigen phenotyping, especially for labile antigens such as D, P1, and M. Moreover, our data indicated that RBCs stored in the new solution exhibited delayed haemolysis up to 70 days storage.
Differences in Urinary Bacterial Anti-Adhesion Activity after Intake of Cranberry Dietary Supplements with Soluble versus Insoluble Proanthocyanidins
Published in Journal of Dietary Supplements, 2022
Amy B. Howell, Jean-François Dreyfus, Bilal Chughtai
Investigational cranberry supplement products were tested for in vitro bacterial AAA on a per weight basis using the MRHA assay specific for uropathogenic P-fimbriated E. coli according to Foo et al. (2000a). WCFD caplet, pulverized with a mortar and pestle and CJD capsule contents were separately suspended (60 mg/mL) in phosphate buffered saline solution (PBS), neutralized to pH 7 with 1 N NaOH and diluted in a twofold dilution series in PBS. P-type E. coli bacteria were harvested from agar slants and suspended directly in PBS at pH 7.0 at a concentration of 5 × 108 bacteria/mL of PBS for AAA testing. A 30-μL drop of each dilution in the series was incubated with 10 μL of bacterial suspension on a 24-well polystyrene plate for 10 min at room temperature on a rotary shaker. Freshly drawn A type Rh + human red blood cells (HRBC) were suspended (3%) in PBS and 10 μL added to each test suspension. Suspensions were incubated for 20 min on a rotary shaker at room temperature, and then, evaluated microscopically for hemagglutination. The dilution concentration at which hemagglutination activity was suppressed by 50% was recorded as the endpoint for the assay and was considered the minimum inhibitory concentration (MIC). The lower the MIC, the higher the AAA of the sample. Anti-adhesion assays were repeated four times on duplicate product samples and the results averaged. Negative controls included wells containing bacteria + PBS, HRBC + PBS, bacteria + test material, HRBC + test material. Positive control well was bacteria + HRBC.