Sandwich ELISA for quantitative detection of human collagen prolyl 4-hydroxylase

A continuous mashing system controlled by mean residence time

Continuous processes offer more environmentally friendlier beer production compared to the batch production. However, the continuous production of mashing has not become state-of-the-art in the brewing industry. The controllability and flexibility of this process still has hurdles for practical implementation, but which are necessary to react to changing raw materials. Once overcome, a continuous mashing can be efficiently adapted to the raw materials. Both mean residence time and temperature were investigated as key parameters to influence the extract and fermentable sugar content of the wort. The continuous mashing process was implemented as continuous stirred tank reactor (CSTR) cascade consisting of mashing in (20°C), protein rest (50°C), β-amylase rest (62-64°C), saccharification rest (72°C) and mashing out (78°C). Two different temperature settings for the β-amylase rest were investigated with particular emphasis on fermentable sugars. Analysis of Variance (ANOVA) and a post-hoc analysis showed that the mean residence time and temperature settings were suitable control parameters for the fermentable sugars. In the experimental conditions, the most pronounced effect was with the β-amylase rest. These results broaden the understanding of heterogenous CSTR mashing systems about assembly and selection of process parameters

Effect of abrupt and gradual calorie restriction regimens on biochemical and behavioral markers in obese mice model

Background: Although Calorie Restriction (CR) is primarily considered in obesity management, behavioral studies of CR and its methodology of implementation are not well-defined. Objective: The study aimed to determine the efficacy of the extensively researched method of CR-abrupt calorie restriction (ACR) and a newly proposed gradual calorie restriction (GCR) in terms of body weight, behavioral and biochemical parameters in the obese animal model-C57BL/6J mice. Design: Male obese mice were subjected to GCR regimen for 14 weeks which was compared and evaluated for anxiety-like behavior and stress levels with ACR. Plasma corticosterone was measured before initiation of CR and every three weeks following GCR and ACR, whereas plasma insulin was measured twice-after obesity induction and post 14 weeks of CR. The behavioral assessments were conducted before inducing CR and every three weeks following ACR and GCR. Results: A significant anxiety-like behavior and an increase in plasma corticosterone were observed in mice on GCR during the critical initial six weeks of CR (p < 0.05). Both groups showed a decrease in plasma glucose levels; however, the GCR group showed a significant reduction (p < 0.01). There was a significant decrease in social interaction in both groups with an increase in the latency period and a decrease in time spent with the stranger animal during the social interaction test (p < 0.05). Conclusion: The mice on GCR regimen demonstrated lesser anxiety-like behavior and low plasma corticosterone levels compared to those on ACR. This gives us a new avenue in CR research to evaluate the methodologies of implementing CR.

In Vitro Liver Toxicity Testing of Chemicals: A Pragmatic Approach

The liver is among the most frequently targeted organs by noxious chemicals of diverse nature. Liver toxicity testing using laboratory animals not only raises serious ethical questions, but is also rather poorly predictive of human safety towards chemicals. Increasing attention is, therefore, being paid to the development of non-animal and human-based testing schemes, which rely to a great extent on in vitro methodology. The present paper proposes a rationalized tiered in vitro testing strategy to detect liver toxicity triggered by chemicals, in which the first tier is focused on assessing general cytotoxicity, while the second tier is aimed at identifying liver-specific toxicity as such. A state-of-the-art overview is provided of the most commonly used in vitro assays that can be used in both tiers. Advantages and disadvantages of each assay as well as overall practical considerations are discussed.

Microfluidic-Based Detection of AML-Specific Biomarkers Using the Example of Promyelocyte Leukemia

A microfluidic assay for the detection of promyelocytic leukemia (PML)-retinoic acid receptor α (RARα) fusion protein was developed. This microfluidic-based system can be used for rapid personalized differential diagnosis of acute promyelocyte leukemia (APL) with the aim of early initiation of individualized therapy. The fusion protein PML-RARα occurs in 95% of acute promyelocytic leukemia cases and is considered as diagnostically relevant. The fusion protein is formed as a result of translocation t(15,17) and is detected in the laboratory by fluorescence in situ hybridization (FISH) or reverse transcriptase polymerase chain reaction (RT-PCR). Diagnostic methods require many laboratory steps with specialized staff. The developed microfluidic assay includes a sandwich enzyme-linked immunosorbent assay (ELISA) system for PML-RARα on surface of magnetic microparticles in a microfluidic chip. A rapid detection of PML-RARα in cell lysates is achieved in less than one hour. A biotinylated PML-antibody on the surface of magnetic streptavidin coated microparticles is used as capture antibody. The bound translocation product is detected by a RARα antibody conjugated with horseradish peroxidase and the substrate QuantaRed. The analysis is performed in microfluidic channels which involves automated liquid processing with stringent washing and short incubation times. The results of the developed assay show that cell lysates of PML-RARα-positive cells (NB-4) can be clearly distinguished from PML-RARα-negative cells (HL-60, MV4-11).

Detecting Collagen Molecules at Picogram Level through Electric Field-Induced Accumulation

The demand for sensors capable of measuring low-abundant collagen in human fluids has highly increased in recent years. Indeed, collagen is expected to be a biomarker for chronic diseases and could monitor their progression. Here we show detection of highly diluted samples of collagen at picogram level thanks to an innovative pyro-electrohydrodynamic jet (p-jet) system. Through the intense electric fields generated by the pyroelectric effect in a ferroelectric crystal, the collagen solution was concentrated on a small area of a slide that was appropriately functionalized to bind proteins. The collagen molecules were labeled by an appropriate fluorophore to show how the number of tiny droplets influences the limit of detection of the technique. The results show that the p-jet is extremely promising for overcoming the current detection limits of collagen-based products in human fluids, performing 10 times better than the enzyme-linked immunosorbent assay (ELISA) and thus paving the way for the early diagnosis of related chronic diseases.

Enhancement of the therapeutic efficacy of praziquantel in murine Schistosomiasis mansoni using silica nanocarrier

The main objective of this work is preparation of mesoporous silica nanoparticles loaded with praziquantel (PZQ-Si) in order to enhance the therapeutic efficacy of praziquantel (PZQ). Mice were experimentally infected with Schistosoma mansoni and treated 6 weeks post-infection with PZQ in different doses via either oral or intraperitoneal (IP) routes. PZQ in the same doses orally administered to S. mansoni-infected mice was used as a drug control, and infected and non-infected non-treated mice served as positive and negative controls, respectively. PZQ-Si exhibited good physicochemical attributes in terms of small uniform size (105 nm), spherical shape, and PZQ entrapment efficiency (83%). A maximum antischistosomal effect was achieved using orally administered PZQ-Si as reflected by total worm burden, tissue egg count, oogram pattern, and hepatic granuloma count and diameter. The biomarkers related to liver oxidative stress status and immunomodulatory effect (serum TNF-α and IL-10) were significantly improved. Data obtained implied that IP route was less efficacious for the delivery of PZQ-Si. Encapsulation of PZQ permits the reduction of the used therapeutic dose of PZQ. Hepatic DNA fragmentation, measured by comet assay, was significantly improved in infected mice treated with maximum dose of PZQ-Si as compared to positive or PZQ control groups. The results indicate that mesoporous silica NP is a promising safe nanocarrier for PZQ potentiating its antischistosomal, antioxidant, immunomodulatory, and anti-inflammatory action in animal model infected with S. mansoni. From a practical standpoint, PZQ-Si using a lower dose of PZQ could be suggested for effective PZQ antischistosomal mass chemotherapy.

Enhanced production of anti-PD1 antibody in CHO cells through transient co-transfection with anti-apoptotic genes Bcl-x L and Mcl-1

Apoptosis has a negative impact on the cell survival state during cell cultivation. To optimize mammalian cell culture for production of biopharmaceuticals, one of the important approaches is to extend cell life through over-expression of anti-apoptotic genes. Here, we reported a cost-effective process to enhance cell survival and production of an antibody through transient co-transfection with anti-apoptotic genes Bcl-x _L or Mcl-1 in Chinese hamster ovary (CHO) cells with polyethylenimine (PEI). Under the optimal conditions, it showed reduced levels of apoptosis and improved cell viability after co-transfected with Bcl-x _L or Mcl-1. The overall production yield of the antibody anti-PD1 increased approximately 82% in CHO cells co-transfected with Bcl-x _L , and 34% in CHO cells co-transfected with Mcl-1. This work provides an effective way to increase viability of host cells through delaying apoptosis onset, thus, raise production yield of biopharmaceuticals without the process of generating stable cell lines and subsequent screening.

Enhanced Sensitivity for Detection of Plasmodium falciparum gametocytes by magnetic nanoparticles combined with enzyme substrate system

The highly sensitive and specific detection of Pfg377 gene of Plasmodium falciparum gametocyte using Magnetic Nanoparticles PCR Enzyme-Linked Gene Assay (MELGA) was successfully developed. The MELGA included amplification of the Pfg377 gene by polymerase chain reaction (PCR) using magnetic nanoparticles (MNPs)-conjugated forward primer and biotinylated reverse primer, followed by post-analytical process using horseradish peroxidase (HRP)-conjugated streptavidin (SA). The complexes of MELGA product were incubated with the peroxidase substrate and hydrogen peroxide to produce the signal for colorimetric measurement. Altogether, the MELGA technique provided a highly sensitive and specific detection at 1 P. falciparum gametocyte/µL, which was more efficient than that of microscopic examination and rapid diagnostic tests (RDTs). Additionally, the MELGA could detect target gene at femtogram level, which was greater sensitive than the conventional PCR, nested PCR and loop-mediated isothermal amplification (LAMP). The MELGA technique could become a novel and practical method that overcome limitation of traditional gametocyte detection.

Magnetic Nanoparticles PCR Enzyme-Linked Gene Assay for Quantitative Detection of BCR/ABL Fusion Gene in Chronic Myelogenous Leukemia

BACKGROUND

Magnetic nanoparticles (MNPs) have been widely used in medical diagnostic research. In this work, two technologies, MNPs and polymerase chain reaction (PCR), were combined to increase detection sensitivity and specificity. A novel technique based on the MNPs-PCR enzyme-linked gene assay (MELGA) was developed for detection of the BCR/ABL abnormal gene in chronic myelogenous leukemia (CML) patients.

METHODS

An MNPs-labeled BCR forward primer and a biotin-labeled ABL reverse primer were used to specifically amplify the target gene. After magnetic separation, the PCR product bound to MNPs labeled with streptavidin-conjugated horseradish peroxidase was incubated with the peroxidase substrate and hydrogen peroxide to generate the colorimetric signal.

RESULTS

When compared with real-time quantitative-PCR (RQ-PCR), the MELGA technique exhibited an increased sensitivity of <1 fg with high specificity for the BCR/ABL fusion gene in CML patients. In addition, MELGA colorimetric results correlated well with the number of copies obtained from RQ-PCR.

CONCLUSION

This simple and cost-effective technique is suitable for monitoring CML patients during targeted therapy (tyrosine kinase inhibitors) especially in rural hospitals.