Evaluation of Shear Horizontal Surface Acoustic Wave Biosensors Using “Layer Parameter” Obtained from Sensor Responses during Immunoreaction

Shear horizontal surface acoustic wave (SH-SAW) biosensors measure the reaction of capture antibodies immobilized on the sensing surface to capture test molecules (antigens) by using the change in SH-SAW propagation characteristics. SH-SAW displacement exists not only on the SH-SAW propagating surface, but also partially penetrates the specimen liquid to a certain depth, which is determined by the liquid properties of the specimen and the operating frequency of the SH-SAW. This phenomenon is called viscosity penetration. In previous studies, the effect of viscosity penetration was not considered in the measurement of SH-SAW biosensors, and the mass or viscosity change caused by the specific binding of capture antibodies to the target antigen was mainly used for the measurement. However, by considering the effect of viscosity penetration, it was found that the antigen–antibody reaction could be measured and the detection characteristics of the biosensor could be improved. Therefore, this study aims to evaluate the detection properties of SH-SAW biosensors in the surface height direction by investigating the relationship between molecular dimensions and SH-SAW propagation characteristics, which are pseudo-changed by varying the diameter of gold nanoparticles. For the evaluation, we introduced a layer parameter defined by the ratio of the SH-SAW amplitude change to the SH-SAW velocity change caused by the antigen–antibody reaction. We found a correlation between the layer parameter and pseudo-varied molecular dimensions. The results suggest that SH-SAW does not only measure the mass and viscosity but can also measure the size of the molecule to be detected. This shows that SH-SAW biosensors can be used for advanced functionality.

The evaluation of factors affecting antibody response after administration of the BNT162b2 vaccine: A prospective study in Japan

The aim of this study was to evaluate the antibody reaction after administration of the BNT162b2 vaccine, and to reveal the factors that affect antibody production. This prospective study was carried out in the Association of EISEIKAI Medical and Healthcare Corporation Minamitama Hospital, in Tokyo, Japan, from April 15, 2021 to June 09, 2021. All our hospital's workers who were administered the BNT162b2 vaccine as part of a routine program were included in this study. We calculated the anti-SARS-CoV-2 spike-specific antibody titter 1) before vaccination, 2) seven to twenty days after the first vaccination, and 3) seven to twenty days after the second vaccination. The low-antibody titer group (LABG) was defined as the group having less than 25 percentiles of antibody titer. Univariate and Multivariate logistic regression analysis were performed to ascertain the effects of factors on the likelihood of LABG. 374 participants were eventually included in our study, and they were divided into 94 LABG and 280 non-LABG. All samples showed significant antibody elevation in the second antibody test, with a mean value of 3476 U/mL. When comparing the LABG and non-LABG groups, the median age, blood sugar, and HbA1c were significantly higher in the LABG group. The rates of participants with low BMI (<18.5) and high BMI (>30) were significantly higher in the LABG group. The proportion of chronic lung disease, hypertension, diabetes, dyslipidemia, autoimmune disease, and cancer were significantly higher in the LABG group. Although there was no significant difference confirmed with respect to the exercise hours per day, the proportion of participants that did not perform outdoor activities was significantly higher in the LABG group. The time interval between the second vaccination and the second antibody test, and between the first and the second vaccination was significantly longer in the non-LABG group. Our logistic regression analysis revealed that the age, obesity, hypertension, diabetes, dyslipidemia, antihypertensive drug, antilipid drug, γ-GT, BS, HbA1c, and lack of outdoor activity were significant suppressors of antibody reaction, whereas maintaining the appropriate time interval between the first and the second vaccination could promote a significant antibody response. In the multivariate logistic regression analysis, age, obesity, and lack of outdoor activities were significant suppressors of antibody reaction, whereas the length of days from the first to the second vaccination promoted a significant antibody response. Our single-center study demonstrates that age, obesity, and lack of outdoor activities were significant suppressors of antibody response, whereas maintaining the appropriate time interval between the first and the second vaccination could promote a significant antibody response. Evidence from multi-center studies is needed to develop further vaccination strategies.

Evaluation of Anti-Anaphylactic Activity of methanolic extract of Momordica charantia in Experimental Animals

Anaphylaxis is a syndrome that can be fatal, which is seen due to systemic release of inflammatory mediators. Antigen and Antibody reaction is usually a trigger in the body to go into anaphylactic shock. In this study, anaphylaxis induced by egg albumin in the rats. The efficiency of MC (Momordica charantia) against anaphylaxis was evaluated. The standard drug used was Dexamethasone. The MC extract is given in doses 100 and 200 mg/kg p.o. Results: The MC extract was found to be effective (p<0.01) inhibitor of egg albumin induced anaphylactic reaction. Conclusion: From this study, we can conclude that Momordica charantia fruits have good anti-anaphylactic activity. Keywords: Anaphylaxis, Momordica charantia, Egg albumin, Passive paw anaphylaxis, Dexamethasone.

Preliminary Immunochemical Studies to Detect Lard

Detection of lard in food using immunochemical methods has been carried out. This method has been applied and developed in food analysis. The purpose of this study was to detect the presence of lard in food. The method used was immunochemical which in this case is tested to its application in food analysis. The principle method is based on the antigen-antibody reaction, between lipids as antigens that can be deposited by antibodies in the agar medium. Antibodies were obtained by inducing lard into the blood vessels of rabbits. This method is based on the antigen-antibody reaction between fat as an antigen and antibodies that contain anti-lard as reagents and the occurrence of precipitation in agar media. The antibody was obtained by inducing lard, pork broth, and pig plasma into the blood vessels of rabbits. The results of this study were significant.

Review Article: Systemic Lupus Erythematosus

Systemic lupus erythematosus or SLE is a persistent heterogeneous autoimmune disease that affects multisystem of the body. It is distinguished by acute and chronic inflammation of various tissues and even organs of the body principally the skin and joints. Systemic lupus erythematosus is a multisystem disorder and hence, it can affect any tissues, organs and even systems of the body. There are few categories of lupus for instance, lupus dermatitis or cutaneous lupus erythematosus (CLE) that affects the skin and causes malar rash, discoid lupus erythematosus (DLE) as well as systemic lupus erythematosus that causes damage to single or multiple internal organs. The damage is due to the inflammation that is caused by direct antibody reaction to the body tissues as well the deposition of immune complexes. Glucocorticoids, immunosuppressant, and anti- malarial are the combination therapy used to treat SLE besides providing counseling and awareness. Lupus erythematosus in any form particularly systemic lupus erythematosus (SLE) are prevalent in women compared to men with ratio of 6:1. It has the tendency to affect all ages but most frequently attacks women of aged 20 to 45 years old compared to men. On the other hand, if lupus erythematosus causes damage to internal organs either single or multiple, it is known as systemic lupus erythematosus. The damage is due to the inflammation that is caused by direct antibody reaction to the body tissues as well the deposition of immune complexes.

Antibody reaction of leptospirosis in asymptomatic feral boars, Thailand

Aim: This study aimed to determine the proportion of exposure to leptospirosis and evaluate the degree of serovar antibody reaction in feral boars. Materials and Methods: A total of 58 sera obtained from feral boars in Khao Prathab Chang Wildlife Breeding Center, Ratchaburi, Thailand, were screened for leptospirosis exposure by microscopic agglutination test, conducted with a reference panel of 23 pathogenic serovars and a non-pathogenic serovar. Results: Overall exposure rate of 62.07% was found in the studied population. An antibody reaction presented in 18 of 24 leptospiral serovars. Among the seropositive, Ballum serovar showed predominant exposure in the feral boar population. Conclusion: The results show a relatively high exposure to leptospirosis and the predominant serovar was Ballum followed by Canicola, the first finding in feral boars in Thailand. It has been revealed that feral boars act as a natural reservoir host of leptospirosis. There should be more concern about public health problems in leptospirosis arising where feral boars appear.