Preparation of immunomagnetic beads coupled with a rhodamine hydrazine immunosensor for the detection of Mycobacterium avium subspecies paratuberculosis in bovine feces, milk, and colostrum

Association of Mycobacterium avium paratuberculosis serostatus with age at first calving, calving interval, and milk production in dairy cows

Mycobacterium avium ssp. paratuberculosis (MAP) is the causative agent of bovine paratuberculosis, also known as Johne's disease. This infection is responsible for negative effects, ranging from reduction of milk production to reproductive compromise and increased susceptibility to other diseases such as mastitis. Contradictory information on the association between this infection and reproductive performance has been reported in dairy cows. The aim of this work was to investigate associations between individual cow MAP seropositivity and lifetime reproduction and production performance. The MAP serum ELISA (IDEXX MAP Ac) results from all the 13,071 adult cows present on 191 farms and corresponding birth- and calving-date records obtained from the National Association for Genetic Improvement of Dairy Cattle were used. Cows and farms were classified as positive or negative, based on ELISA results. Outcomes assessed were age at first calving (AFC), intercalving intervals (ICI) from first to fourth interval, and average milk production per day of productive cycle (Milk-305/ICI, a ratio between 305-d corrected milk production and the number of days of the respective calving interval). Multilevel mixed models were used to investigate the association of cow MAP status with AFC, ICI, and Milk-305/ICI. Three levels were considered in the models: "measurement occasion," the first level, was nested within cows and cows were nested within farms. The "measurement occasion" is the time point to which all the observed measures (between 2 successive parturitions, such as milk production and somatic cell count) were referred. Our results indicate that MAP-positive cows have a significantly lower 14-d mean AFC than MAP-negative cows. The overall average ICI in our study was 432.5 d (standard deviation: 94.6). The average ICI, from first to fourth, was not significantly affected by MAP seropositivity. No significant effect of MAP positivity was found on the overall ICI. In relation to Milk-305/ICI, MAP-positive cows did not produce significantly less milk than negative cows across their productive lifetime. We observed higher but nonsignificant Milk-305/ICI (kg/d) in MAP-positive cows. In our study, the proportion of MAP-positive cows within lactations remained similar across all lactations, suggesting that seropositivity did not increased drop-off rate.

A portable microfluidic photometric detection method based on enzyme linked immunoscatter enhancement

Currently, the combination of smart phones and microfluidic chips is a commonly used device for point-of-care testing (POCT) detection. Enzyme linked immunosorbent assay (ELISA) is an effective way to detect specific proteins in disease. Because the detection accuracy of smartphone cameras is difficult to directly replace high-precision spectral devices, the combination of smartphones and ELISA has not been widely used. Therefore, this paper proposes a microfluidic photometric detection method based on ELISA scattering enhancement. Firstly, the scattering characteristics of IMB are mined, and the optimal value of absorbance error compensation parameter is obtained. Secondly, the absorbance error compensation model based on scattering enhancement characteristics is established to improve the image acquisition accuracy of smart phones. Finally, the microfluidic photometric detection chip is developed, and the optical path system, optical path adjustment system and POCT detection App of smart phone are designed. The optimal compensation parameters of IMB were obtained based on simulated samples, and the linearity of absorbance and concentration increased by 22.6% after compensation. In the IL-6 sample experiment, the detection results of the platform in this paper had a good linear correlation with IL-6 sample concentration, and the linear correlation coefficient was above 0.95459. At the same time, the detection limit and accuracy meet the detection requirements. Therefore, with the participation of smart phones and microfluidic chips, problems such as difficult carrying and complex operation in traditional ELISA daily detection have been solved, laying a foundation for the future promotion and application of ELISA based POCT platform.

Separation of spring viraemia of carp virus from large-volume samples using immunomagnetic beads

A method for separation of spring viraemia of carp virus (SVCV) from large-volume samples using immunomagnetic beads (IMBs) coated with a polyclonal antibody against SVCV was developed. The optimum amount of IMBs was 2 mg in 100 mL. After IMB treatment, the detection limit of SVCV in reverse transcription quantitative PCR (RT-qPCR) was 103 times the 50% tissue culture infectious dose per mL in 100-mL samples. The concentration of viral RNA extracted from SVCV that had been separated using IMBs was 5.18 × 103-fold higher than that of the unseparated SVCV. When fish samples were tested, the concordance rates of the IMBs/RT-qPCR and RT-qPCR were 100% and 67.5%, respectively.

The effects of the differentiated macrophages by dexamethasone on the immune responses

The characteristics of M2 macrophages suggest immunotherapeutic approaches for inducing immunological tolerance. The current study aimed to evaluate the effect of Dexamethasone (Dex) treatment on monocytes polarization and its impact on immune responses. The monocytes were extracted from the rat's blood samples. The effects of Dex concentration and treatment duration on monocyte viability, phagocytosis of rabbit red blood cell (RRBC) antigens, and cytokine gene expression were evaluated using MTT, ELISA, and Real-Time PCR analysis, respectively. The monocytes treated with Dex were injected into the rats as an autograft. The effects of the grafted cells were assessed on immune responses, monocyte differentiation, and pathological lesions, in comparison to the control groups. Treatment of monocytes with 10-5 M of Dex for 48 h increased the expression of IL-10 and TGF-β genes, while reducing the expression of TNF-α and IL-1 genes. The monocytes treated with antigen and Dex showed higher CD206 gene expression compared to CD80. The cells that were treated with Dex had the highest concentration of antigens after five days. Administration of the grafted cells to the animals has some significant effects on innate immune responses and no impact on pathological lesions. The group that received cells treated with Dex and antigen experienced a significant decrease in anti-RBC antibody titers. Additionally, there was a significant difference in the expression of cytokine genes and M2 differentiation markers among the groups that were evaluated. The effects of Dex on the viability and differentiation of monocytes depend on the dosage, timing, and duration of the treatment.

Separation mixed semen of two individuals using magnetic beads coupled ABH blood group antibody

In sexual assault cases, one of the most common samples collected is a mixed semen stain, which is often found on the vagina, female underwear, or bed sheets. However, it is usually difficult to identify the perpetrator based on this sample alone. One technique that has been developed to address this issue is magnetic bead-based separation. This method involves using modified magnetic microspheres to capture and enrich specific target cells, in this case, sperm cells. In this study, we utilized magnetic beads coupled with ABH blood group antibody to isolate sperm cells from an individual of a single ABO blood type. Subsequently, polymerase chain reaction amplification and capillary electrophoresis were employed to perform the genotyping the short tandem repeat (STR) loci. This approach allows for the identification of different individuals in a mixed seminal stain sample from two individuals, by first separating sperm cells based on ABH antigen differences and subsequently utilizing autosomal STR typing on the enriched single blood group cells.

Recent Progress in Photoresponsive Biomaterials

Photoresponsive biomaterials have garnered increasing attention recently due to their ability to dynamically regulate biological interactions and cellular behaviors in response to light. This review provides an overview of recent advances in the design, synthesis, and applications of photoresponsive biomaterials, including photochromic molecules, photocleavable linkers, and photoreactive polymers. We highlight the various approaches used to control the photoresponsive behavior of these materials, including modulation of light intensity, wavelength, and duration. Additionally, we discuss the applications of photoresponsive biomaterials in various fields, including drug delivery, tissue engineering, biosensing, and optical storage. A selection of significant cutting-edge articles collected in recent years has been discussed based on the structural pattern and light-responsive performance, focusing mainly on the photoactivity of azobenzene, hydrazone, diarylethenes, and spiropyrans, and the design of smart materials as the most targeted and desirable application. Overall, this review highlights the potential of photoresponsive biomaterials to enable spatiotemporal control of biological processes and opens up exciting opportunities for developing advanced biomaterials with enhanced functionality.

Biogenic Synthesis of Iron Oxide Nanoparticles Using Enterococcus faecalis: Adsorption of Hexavalent Chromium from Aqueous Solution and In Vitro Cytotoxicity Analysis

The biological synthesis of nanoparticles is emerging as a potential method for nanoparticle synthesis due to its non-toxicity and simplicity. In the present study, a bacterium resistant to heavy metals was isolated from a metal-contaminated site and we aimed to report the synthesis of Fe3O4 nanoparticles via co-precipitation using bacterial exopolysaccharides (EPS) derived from Enterococcus faecalis_RMSN6 strains. A three-variable Box-Behnken design was used for determining the optimal conditions of the Fe3O4 NPs synthesis process. The synthesized Fe3O4 NPs were thoroughly characterized through multiple analytical techniques such as XRD, UV-Visible spectroscopy, FTIR spectroscopy and finally SEM analysis to understand the surface morphology. Fe3O4 NPs were then probed for the Cr(VI) ion adsorption studies. The important parameters such as optimization of initial concentration of Cr(VI) ions, effects of contact time, pH of the solution and contact time on quantity of Cr(VI) adsorbed were studied in detail. The maximum adsorption capacity of the nanoparticles was found to be 98.03 mg/g. The nanoparticles could retain up to 73% of their efficiency of chromium removal for up to 5 cycles. Additionally, prepared Fe3O4 NPs in the concentration were subjected to cytotoxicity studies using an MTT assay. The investigations using Fe3O4 NPs displayed a substantial dose-dependent effect on the A594 cells. The research elucidates that the Fe3O4 NPs synthesized from EPS of E. faecalis_RMSN6 can be used for the removal of heavy metal contaminants from wastewater.