• Imaging Science in Dentistry
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• v.44 no.2
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• pp.149-154
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• 2014

Purpose: This study assessed the effectiveness of three antimicrobial mouthrinses in reducing microbial growth on photostimulable phosphor (PSP) plates. Materials and Methods: Prior to performing a full-mouth radiographic survey (FMX), subjects were asked to rinse with one of the three test rinses ($Listerine^{(R)}$, $Decapinol^{(R)}$, or chlorhexidine oral rinse 0.12%) or to refrain from rinsing. Four PSP plates were sampled from each FMX through collection into sterile containers upon exiting the scanner. Flame-sterilized forceps were used to transfer the PSP plates onto blood agar plates (5% sheep blood agar). The blood agar plates were incubated at $37^{\circ}C$ for up to 72 h. An environmental control blood agar plate was incubated with each batch. Additionally, for control, 25 gas-sterilized PSP plates were plated onto blood agar and analyzed. Results: The mean number of bacterial colonies per plate was the lowest in the chlorhexidine group, followed by the Decapinol, Listerine, and the no rinse negative control groups. Only the chlorhexidine and Listerine groups were significantly different (p=0.005). No growth was observed for the 25 gas-sterilized control plates or the environmental control blood agar plates. Conclusion: The mean number of bacterial colonies was the lowest in the chlorhexidine group, followed by the Decapinol, Listerine, and the no rinse groups. Nonetheless, a statistically significant difference was found only in the case of Listerine. Additional research is needed to test whether a higher concentration (0.2%) or longer exposure period (two consecutive 30 s rinse periods) would be helpful in reducing PSP plate contamination further with chlorhexidine.

• 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.

• Journal of Nutrition and Health
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• v.17 no.2
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• pp.137-144
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• 1984

Due to the fact that blood gathering is not readily accepted by people, it has been difficult to make a full-scale study on zinc through blood analysis. For that reason, in this paper, a correlation of zinc contents in serum and hair was studied to find out whether only hair, which is relatively easy to collect, can be used for a measurement of zinc content. The subjects were 47 healthy female collegians selected at random whose average age was 22, mean height 159.1cm and average weight 49.7kg. The mean zinc value in serum of subjects was ${107.1}\pm{29.0}{\mu}g{/100ml}$, while the mean value in hair was ${150.2}\pm{42.7}ppm$. Correlation analysis shows that there was a significant correlation in zinc contents of serum and hair ( p<0.01). The results shows that measuring zinc level by using only hair samples would be satisfactory. But the use of hair sample for a measurement of zinc level has one demerit. That is, the method is more likely to be subjected to contamination because it makes more complicated procedures in sample preparation than the method of using blood sample.

• IMMUNE NETWORK
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• v.21 no.3
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• pp.24.1-24.13
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• 2021

Due to the inconsistent fluctuation of blood supply for transfusion, much attention has been paid to the development of artificial blood using other animals. Although mini-pigs are candidate animals, contamination of mini-pig T cells in artificial blood may cause a major safety concern. Therefore, it is important to analyze the cross-reactivity of IL-7, the major survival factor for T lymphocytes, between human, mouse, and mini-pig. Thus, we compared the protein sequences of IL-7 and found that porcine IL-7 was evolutionarily different from human IL-7. We also observed that when porcine T cells were cultured with either human or mouse IL-7, these cells did not increase the survival or proliferation compared to negative controls. These results suggest that porcine T cells do not recognize human or mouse IL-7 as their survival factor.

• Journal of Korean Academy of Nursing
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• v.29 no.4
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• pp.929-939
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• 1999

The purpose of this study was to identify knowledge of universal precautions and its performance in practice. The research was conducted from November 2 to 30, 1998. A total 515 student nurses ; 249 from a baccalaureate nursing college and 266 from second and third year of a 3-year community nursing college were surveyed. The results are as following : 1. The average score for universal precautions knowledge was 270.41$\pm$19.43/300(range 150-300). The results showed that 99.2% of students avoid injury from used needles, 98.6% answered that they always wash their hands if they had contact with the patient's blood and they always dispose of used needles in special collectors (97.7%) for needles. But, 39.2% responsed that they dispose of used needles after recapping them. 2. The average score for universal precautions knowledge of the senior students in the 4-year college was the highest (277.65$\pm$13.99). 3. The average score for the performance of universal precautions knowledge was 53.18 $\pm$5.91(range 14-70). The items : ‘I cautiously avoid injury from the used needles’(4.92$\pm$0.33), ‘I always wash my hands if there has been contact with the patient's blood’(4.91$\pm$0.34), and ‘I always disposed of used needles in the appropriate collector’(4.89$\pm$0.42) showed the highest performance. However ‘I always dispose of used needles after recapping them’(2.19$\pm$1.39) and ‘I always use protection goggles when in danger of contamination’(2.19$\pm$1.20) showed low performance level. 4. The highest average score for universal precautions performance was shown among the second year students in 3-year nursing college (54.19$\pm$6.92) between the groups. It showed that the level of the universal precautions performance was higher for those who had education on university precautions prior to performance of the universal precautions than for those without any prior education. 5. The percentage of students who reported the experience of direct contact with patients' blood and/or body fluids was 42.30%. The experience of direct contact with blood and/or body fluids of the educational group was significantly higher than those were not educated. 6. The most frequent cause of the direct contact was ‘needle pricking and/or skin cut’(63.04%). The most frequent substance with which the students contact was ‘blood’(59.85%). The majority of the sample had answered that the mode of contamination was ‘unknown’(63.54%). The majority of the sample answered that strategies used after contamination included ‘washing with soap’(33.61%). Reviewing the chart of patients or asking other health professionals(28.85%). 7. The number of students who had the experience of a needle stick and/or skin cut was 145(28.16%). The clinical practice places where the incidents occurred were mainly in the internal medicine unit (45.07%) and the surgical unit (31.92%) followed by the intensive care unit and the emergency unit in order. The experience of a needle stick and/or skin cut happened during on intra-muscular injection 47.34% and intravenous injection 21.81%. The causes of the needle stick and/or skin cut were ‘putting the needle cap back on 77(35.81%)’. The number of students who took an appropriate post management blood test and/or vaccination was 27(18.62%). 8. The Pearson Correlation Coefficient between the knowledge of universal precautions and performance of universal precautions in practice showed a positive correlation.

• Polymer(Korea)
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• v.37 no.4
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• pp.411-419
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• 2013

Various biomaterials have been widely used for biomedical applications, including bio-organs, medical devices, and clinical devices like vessel, blood pumps, artificial kidneys and hearts, even in contact with blood. The issue of blood compatibility has been studied intensively to prevent negative effects such as thrombosis due to the implanted devices. The use of lotus-leaf-like structured surfaces has been extended to an increasing number of applications such as contamination prevention and anticorrosion applications. Various methods such as template, sol-gel transition, layer-by-layer, and other methods, developed for the fabrication of lotus-leaf-like surfaces have been reported for major industrial applications. Recently, the non-wettable character of these surfaces has been shown to be useful for biomedical applications ranging from blood-vessel replacement to antibacterial surface treatment. In this review, we provide a summary of current and future research efforts and opportunities in the development and medical applications of lotus-leaf-like structure surfaces.

• Pediatric Infection and Vaccine
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• v.25 no.1
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• pp.17-25
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• 2018

Purpose: Blood culture is an essential diagnostic tool and requires clear indications, proper techniques, and quality control. We aimed to investigate whether blood cultures in children are appropriate for indications, are performed correctly, and receive proper quality control. Methods: We conducted an online survey targeting pediatric infectious diseases (ID) specialists working in general hospitals and neonatologists (Neo) working at hospitals operating a neonatal intensive care unit in Korea. Results: Approximately 81.1% (30/37) of pediatric ID specialists and 72.2% (52/72) of Neo responded to the survey. Some of the respondents (33.3% of ID and 59.6% of Neo) performed blood culture as a regular test irrespective of the indication. Approximately 40% of ID and 65.4% of Neo ordered only one set of blood culture in patients suspected with bacteremia. The most commonly used disinfectant for skin preparation was povidone-iodine, while the skin preparation method varied by institution. Approximately two-thirds of the institutions were monitoring the blood culture contamination rate, whereas relatively few provided staff with feedback on that rate. In addition, less than half of the institutions were providing regular staff training on blood culture (40% of ID and 28.8% of Neo). Conclusions: The indication and methods of blood culture for children varied according to institution, and few hospitals exert effort in improving the quality of blood culture. Institutions have to strive constantly toward improvement of blood culture quality and evidence-based recommendations for pediatric blood cultures should be standardized.

• International Journal of Oral Biology
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• v.39 no.3
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• pp.137-143
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• 2014

Dental professionals are repeatedly exposed to many microorganisms present in both blood and saliva. Thus, dental professionals are at a greater risk of acquiring and spreading infections, and the implementation of infections control guidelines is necessary. Cellular phones have become a necessary device for communicating in hospitals. Cellular phones contaminated with bacteria may serve as a fomite in the transmission of pathogens by the hands of medical personnel. Nevertheless, studies about rate and levels of bacterial contamination of cellular phones have been extremely limited with regards to dental personnel. The purpose of this study was to identify bacterial flora on the cellular phones of dentists by a molecular biological method using the 16S rRNA cloning and sequencing method. We acquired total 200 clones from dentists' cell phones and identified the bacterial species. Pseudomonas (34.6%), Lactobacillus (18.5%), Azomonas (11.5%), and Janthinobacterium (6%) were the dominant genera on dentists' cell phones. The oral bacteria identified were Anaerococcus lactolyticus, Gibbsiella dentisursi, Lactobacills leiae, Streptococcus mitis, Streptococcus oligofermentans, and Streptococcus sanguinis. Pathogenic bacteria and opportunistic pathogens such as Carnobacterium funditum, Raoultella planticola, Shigella flexneri, Lactobacillus iners, Staphylococcus aureus, and Staphylococcus epidermidis were also identified.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.3
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• pp.178-184
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• 2005

Carry over contamination has been reduced in some systems by flushing the internal and external surfaces of the sample probe with copious amount of diluent. It between specimens should be kept as small as possible. A built-in, continuous-flow wash reservoir, which allows the simultaneous washing of the interior and exterior of the syringe needles, addresses this issue. In addition, residual contamination can further be prevented through the use of efficient needle rinsing procedures. In discrete systems with disposable reaction vessels and measuring cuvets, any carry over is entirely caused by the pipetting system. In analyzers with reuseable cuvets or flow cells, carry over may arise at every point through which high samples pass sequentially. Therefore, disposable sample probe tips can eliminate both the contamination of one sample by another inside the probe and the carry over of in specimen into the specimen in the cup. The results of the applicative carry over experiment studied on 21 items for total protein (TP), albumin (ALB), total bilirubin (TB), alkaline phosphatase (ALP), aspratate aminotranferase (AST), alanine aminotranferase (ALT), gamma glutamyl transferase (GGT), creatinine kinase (CK), lactic dehydrogenase (LD), creatnine (CRE), blood urea nitrogen (BUN), uric acid (UA), total cholesterol (TC), triglyceride (TG), glucose (GLU), amylase (AMY), calcium (CA), inorganic phosphorus (IP), sodium (Na), potassium (K), chloride (CL) tests in chematology were as follows. Evaluation of process performance less than 1% in all tests was very good, but a percentage of ALB, TP, TB, ALP, CRE, UA, TC, GLU, AMY, IP, K, Na, and CL was 0%, implying no carry over. Other tests were ALT(-0.08%), GGT(-0.09%), CK(0.08%), LD(0.06%), BUN(0.12%), TG (-0.06%), and CA(0.89%).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.31 no.4
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• pp.427-439
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• 2021

Objectives: This study aims to investigate differences in microbial contamination according to the duration and environment of mask wearing. Methods: Forty-five participants were recruited from workers in an offices, multi-purpose facilities, and a schools. After wearing of KF94 mask for two. four, and six hours, the microorganisms adsorbed on the outer and inner layers of the mask were inoculated on BAP(Blood Agar Plate), Chocolate agar, and SDA plates. The bacterial count (CFUs: colony-forming units) cultured in each plate was measured and analyzed for changes in filtration efficiency. Results: The microbial contamination of masks worn in classrooms, offices, and multi-purpose facilities showed a significant difference depending on the environment (p<0.000). The measured CFUs increased significantly according to the time wearing the mask. The difference between the inner and outer layers of the mask was also significant (p<0.05). However, there was no statistical difference in the filtration efficiency of the masks by duration time (p=0.515). Conclusions: Masks worn by workers in the offices, multi-purpose facilities, and schools showed an increase of microbial contamination with the amount of time wearing the mask. The results indicate that the masks used in daily life may have adverse health effects if they are worn for a long time or reused over several days without the realizing that the masks can be contaminated with biological hazards. Guidelines on the safe threshold time for mask use should be established through further research.