• Biomedical Science Letters
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• v.25 no.1
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• pp.75-82
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• 2019

We developed the multiplex LAMP assay using 16S rRNA, femA and mecA genes for direct detection of the methicillin resistance in Staphylococci from positive blood culture. To simultaneously recognize Staphylococci genus, S. aureus and methicillin resistance, three sets of six primers for 16S rRNA, femA and mecA were designed, respectively. The performance of LAMP assay was affirmed using VITEK system for the phenotypic methods of identification and for oxacillin and cefoxitin antimicrobial susceptibility. The optimal condition for LAMP assay was obtained under $64^{\circ}C$ for 50 min. The detection limit was determined to be of 20 copies and CFU/reaction ($10^4CFU/mL$). For clinical application of comparison with phenotypic methods, the sensitivity and specificity of the LAMP with femA gene for detecting S. aureus was 95.31% and 100%, respectively. The sensitivity and specificity of the LAMP with mecA gene for detecting methicillin resistance was 98.46% and 100%, respectively. The multiplex LAMP assay with femA and mecA gene successfully detected all of MRSA (38 isolates) isolates from 103 Staphylococci in blood cultures. The LAMP assay developed in this study is sensitive, specific, and of excellent agreement with the phenotypic methods.

• BioChip Journal
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• v.12 no.4
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• pp.287-293
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• 2018

Bacillus cereus can cause blood infections (i.e., sepsis). Its early detection is very important for treating patients. However, an antibody with high binding affinity to B. cereus is not currently available. Bacteriophage cell wall-binding domain (CBD) has strong and specific binding affinity to B. cereus. Here, we report the improvement in the sensitivity of an ATP bioluminescence assay for B. cereus detection using CBD-conjugated magnetic nanoparticles (CBD-MNPs). The assay was able to detect as few as 10 colony forming units (CFU) per mL and $10^3CFU\;per\;mL$ in buffer and blood. CBD-MNPs did not show any cross-reactivity with other microorganisms. These results demonstrate the feasibility of the ATP assay for the detection of B. cereus.

• Archives of Pharmacal Research
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• v.25 no.4
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• pp.505-510
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• 2002

An improved kinetic assay for prekallikrein activator (PKA), a potential vasodilator, has been developed to be used as an indicator for quality control during production of human albumin preparations. It consists of two reaction stages. In the first stage, PKA and prekallikrein are incubated at $37^{\circ}C$ for 45 min to allow the transformation into kallikrein. Kallikrein, a serine protease, catalyzes the splitting of p-nitroaniline (pNA) from its substrate H-D-Pro-Phe-Arg-pNA(S-2302). The rate at which pNA is released was measured spectrophotometrically at 405 nm. Prekallikrein, a substrate of PKA was purified by DEAE ion-exchange chromatography and the major potential variations in the assay were optimized; pH 8.0 and 150 mM sodium chloride were chosen to give a proper ionic strength. Reaction times in the range of 10 to 360 min provided linear dose-response curves. The concentration of prekallikrein was adjusted to fall between 1:1 and 1:3 dilutions to generate a linear standard calibration curve. Under the optimized conditions, reproducibility was checked. In a precision test, the coefficient of variation (CV) stayed within ${\pm}4%$ and the dose-response curve showed a good correlation (${r^2}=0.999$). An accuracy test with an international standard of PKA afforded a mean recovery of 97.5%.

• Perinatology
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• v.29 no.4
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• pp.165-169
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• 2018

Objective: Highly sensitive haptoglobin measurement should be used in neonates because the haptoglobin concentration in neonates is lower than that of adults. The aim of this study was to establish the reference values of haptoglobin levels in the cord blood of uninfected neonates. Methods: The cord blood of 29 preterm and 51 term babies was collected, and data from the mother and the newborn were recorded. The haptoglobin concentrations of 80 cord blood samples were simultaneously measured by enzyme-linked immunosorbent assay (ELISA; Assaypro, St Charles, MO, USA) and immunoturbidimetry assay (Roche Diagnostics, Basel, Switzerland). C-reactive protein (CRP) was also measured by immunoturbidimetry assay (Roche Diagnostics, Switzerland). Results: Mean values of CRP and ELISA haptoglobin were not significantly different between preterm and term babies. The 2.5 percentile and 97.5 percentile values of ELISA haptoglobin concentration were as follows: 80 neonates, 0.01 mg/dL and 0.59 mg/dL; 29 preterm babies, 0.08 mg/dL and 0.18 mg/dL; and 51 term babies, 0.07 mg/dL and 0.23 mg/dL. There were no differences in ELISA haptoglobin concentration according to maternal underlying diseases, delivery method, usage of antibiotics or steroids before delivery, gestational age, gender of baby, or twin gestation. Conclusion: A highly sensitive haptoglobin method should be used to determine the haptoglobin concentration in Korean newborns because the reference values of cord blood haptoglobin concentration in Korean newborns are less than the lower detection limit for commonly used immunoturbidimetric haptoglobin measurement methods.

• The Journal of the Korean Society for Microbiology
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• v.18 no.1
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• pp.67-71
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• 1983

Antisera to ox red blood cells were prepared by injection of ox red blood cell stroma without adjuvant in outbred white rabbits. Purified IgM fraction for T-cell subset assay was obtained from these rabbit anti-ox red blood cell stroma antisera by precipitation with 50% saturated ammonium sulphate followed by DEAE-Cellulose chromatography and Sephadex G-200 gel filtration. The serological identification of purified IgM fraction was achieved by immunoelectrophoresis with guinea pig antiserum against rabbit anti-ox red blood cell IgM antibody.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6429-6436
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• 2014

Poly-ADP-ribosylation (PAR) is a post-translational modification of mainly chromosomal proteins. It is known to be strongly involved in several molecular events, including nucleosome-remodelling and carcinogenesis. In this investigation, it was attempted to evaluate PAR level as a reliable biomarker for early detection of cancer in blood lymphocyte histones. PAR of isolated histone proteins was monitored in normal and dimethylnitrosamine (DMN)-exposed mice tissues using a novel ELISA-based immuno-probe assay developed in our laboratory. An inverse relationship was found between the level of PAR and period of DMN exposure in various histone proteins of blood lymphocytes and spleen cells. With the increase in the DMN exposure period, there was reduction in the PAR level of individual histones in both cases. It was also observed that the decrease in the level of PAR of histones resulted in progressive relaxation of genomic DNA, perhaps triggering activation of genes that are involved in initiation of transformation. The observed effect of carcinogen on the PAR of blood lymphocyte histones provided us with a handy tool for monitoring biochemical or physiological status of individuals exposed to carcinogens without obtaining biopsies of cancerous tissues, which involves several medical and ethical issues. Obtaining blood from any patient and separating blood lymphocytes are routine medical practices involving virtually no medical intervention, post-procedure medical care or trauma to a patient. Moreover, the immuno-probe assay is very simple, sensitive, reliable and cost-effective. Therefore, combined with the ease of preparation of blood lymphocytes and the simplicity of the technique, immuno-probe assay of PAR has the potential to be applied for mass screening of cancer. It appears to be a promising step in the ultimate goal of making cancer detection simple, sensitive and reliable in the near future.

• Journal of Microbiology and Biotechnology
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• v.30 no.3
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• pp.459-468
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• 2020

This study established a new polymerase spiral reaction (PSR) that combines with reverse transcription reactions for HCV detection targeting 5'UTR gene. To avoid cross-contamination of aerosols, an isothermal amplification tube (IAT), as a separate containment control, was used to judge the result. After optimizing the RT-PSR reaction system, its effectiveness and specificity were tested against 15 different virus strains which included 8 that were HCV positive and 7 as non-HCV controls. The results showed that the RT-PSR assay effectively detected all 8 HCV strains, and no false positives were found among the 7 non-HCV strains. The detection limit of our RT-PSR assay is comparable to the real-time RT-PCR, but is more sensitive than the RT-LAMP. The established RT-PSR assay was further evaluated for detection of HCV in clinical blood samples, and the resulting 80.25% detection rate demonstrated better or similar effectiveness compared to the RT-LAMP (79.63%) and real-time RT-PCR (80.25%). Overall, the results showed that the RT-PSR assay offers high specificity and sensitivity for HCV detection with great potential for screening HCV in clinical blood samples.

• The Journal of the Korean Society for Microbiology
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• v.15 no.1
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• pp.71-75
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• 1980

Antisera to ox red blood cell were prepared by intraperitoneal hypermultiple injections without adjuvant in outbred white rabits. Purified IgG fraction from these rabbits anti-ox red blood cell antiserum for T subset assay was obtained by precipitation with 50% saturated ammonium sulphate followed by DEAE-cellulose chromatography and Sephadex G-150 gel filtration. These purified IgG fraction was compared with Cappel company standard IgG fraction for $T_G$ subpopulation assay. We used home-made IgG fraction and obtained favorable results in $T_G$ subopulation assay as Cappel company standard IgG fraction.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.425-432
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• 1993

Alkaline phosphatase from Culex pipiens pallens was examined to determine the optimal assay condition and to assay the activity during ovarian development. The activity of alkaline phosphatase in a male and a nongravid female continuously were declined after eclosion. But by the stimulus of a blood meal, the enzyme activity was increased dramatically. At 30 hr. after a blood meal, the maximal activity was reached and then declined. And after 48 hr. after a blood meal, the second activity increase was revealed. This second increase was maintained up to oviposition. The first activity increase was revealed in the midgut and the second increase was done in the ovary to assay the organ distribution of alkaline phosphatase. In electrophresis data, it was shown 5 isozyme bands, ALP-1 and ALP-2 in the ovary, ALP-3 in the thorax and the midgut, and ALP-4 and ALP-5 in the thorax, the fatbody and the midgut in crude extract at 30 hr. after a blood meal. One the same ovary pattern were shown at 72 hr. after a blood meal.

• The Korean Journal of Food And Nutrition
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• v.14 no.5
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• pp.397-404
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• 2001

The purpose of this study was to investigate effects of inner skin of chestnut on the activation of a living body's function (regional cerebral blood flow and mean arterial blood pressure in Sprague-Dawley rats, proliferation of thymocytes in normal mice and L1210 cells transplanted mice) . We used inner skin of chestnut extract(Sample A : inner skin of chestnut-panbroiled after driedextract (100$\^{C}$ ), Sample B , inner skin of chestnut-panbroiled-extract(100$\^{C}$ ) , Sample C : inner skin of chestnut -panbroiled after dried-extract(80$\^{C}$ ), Sample D : inner skin of chestnut-panbroiled-extract(80$\^{C}$)} Regional cerebral blood flow(rCBF) and Mean arterial blood pressure(MABP) were tested using Leser -Doppler Flowmetry(LDF), and the proliferation of thymcytes was tested using a colorimetric tetrazoliun assay ( MTT assay) The experimental results as follows 1. rCBF was significantly increased by Sample C in a dose-dependent manner. 2. MABP was not changed by Sample C in a 0.1mg/kg∼10.0mg/kg treated group. 3. Proliferation of thymocytes was not changed by Sample C in normal mice. 4. Proliferation of thymocytes was significantly accelerated by Sample C in L1210 cells transplanted mice.