• Clinical and Experimental Pediatrics
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• 제57권4호
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• pp.178-185
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• 2014

Purpose: Blood culture is the most important tool for detecting bacteremia in children with fever. However, blood culture contamination rates range from 0.6% to 6.0% in adults; rates for young children have been considered higher than these, although data are limited, especially in Korea. This study determined the contamination rate and risk factors in pediatric patients visiting the emergency room (ER) or being admitted to the ward. Methods: We conducted a retrospective chart review of blood cultures obtained from children who visited Yonsei Severance Hospital, Korea between 2006 and 2010. Positive blood cultures were labeled as true bacteremia or contamination according to Centers for Disease Control and Prevention/National Healthcare Safety Network definitions for laboratory-confirmed bloodstream infection, after exclusion of cultures drawn from preexisting central lines only. Results: Among 40,542 blood cultures, 610 were positive, of which 479 were contaminations and 131 were true bacteremia (overall contamination rate, 1.18%). The contamination rate in the ER was significantly higher than in the ward (1.32% vs. 0.66%, P<0.001). The rate was higher in younger children (2.07%, 0.94%, and 0.61% in children aged <1 year, 1-6 years, and >6 years, respectively). Conclusion: Overall, contamination rates were higher in younger children than in older children, given the difficulty of performing blood sampling in younger children. The contamination rates from the ER were higher than those from the ward, not accounted for only by overcrowding and lack of experience among personnel collecting samples. Further study to investigate other factors affecting contamination should be required.

• 대한수의학회지
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• 제38권2호
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• pp.359-365
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• 1998

This study was conducted to isolate the protozoan parasite Babesia gibsoni by intraerythrocytic culture method of micoraerophilous stationary phase(MASP) and evaluate the possibility of application for the detection of B gibsoni in canine babesiosis. Also, indirect fluorescent antibody test(IFAT) and thick blood smear(giemsa stain), direct light microscopy (DLM), as control diagnostic tests, were conducted to compare diagnostic effects between MASP, IFAT and DLM. The results obtained from this study were summarized as follows. The protozoan parasite B gibsoni multiplied in 24-well polystyrene plate containing 1.2ml of canine red blood cell suspension in RPMI 1640 medium(pH 7.0) which is contained 20~40% normal canine serum(NCS) under the MASP condition of 5% $CO_2$ and 95% air at $37^{\circ}C$ incubator. Under the above MASP culturing system the percentage of parasitized erythrocytes(PPE) after incubation for 9 days reached the peak. The levels of PPE in MASP culture were shown more higher by exchanging the medium at 24 hour intervals. The parasite were purely isolated from MASP culture of canine red blood cells collected from dogs(pit bullterrier) infected with B gibsoni naturally. Among the total of 83 heads of pit bullterrier blood samples the positive rate was 32 heads(38.5%) in DLM, 45 heads(54.2%) in IFAT and 42 heads(50.6) in MASP culture. In negative cases of IFAT and DLM the isolation rates of B gibsoni by MASP culture were 16 heads(42.1%) of 38 heads and 16 heads(28.6%)% of 56 heads, respectively. From this study it was suggested that MASP culture method by RPMI 1640 medium was a reliable and useful diagnostic test for the diagnosis of B gibsoni infections in canine babesiosis.

• Journal of Microbiology and Biotechnology
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• 제15권4호
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• pp.728-733
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• 2005

To elucidate the question of whether biofilm formed by the intercellular adhesion (ica) gene cluster has influences on antibiotic resistance in Staphylococcus epidermidis, we compared 124 skin strains with strains isolated from 50 blood cultures that cause septicemic diseases. The results revealed that the blood culture isolates were more resistant to the antibiotics tested than the saprophytic isolates. Moreover, antibiotic multiresistance was more prevalent in the clinical isolates. In the blood culture isolates, $46\%$ of the strains were resistant to three or more antibiotics, whereas only $12\%$ of the saprophytic isolates were resistant to three or more antibiotics. Interestingly, these characteristics were highly correlated with the biofilm formed by the ica gene cluster. In biofilm-producing strains, $84\%$ of the blood culture isolates and $44\%$ of the saprophytic isolates were antibiotic multiresistant, whereas only $22\%=;and\;9\%$, respectively, were antibiotic multiresistant in biofilm-nonproducing strains. Additionally, in the biofilm-producing ica-positive strains, $89\%$ of the blood culture isolates and $57\%$ of the saprophytic isolates were antibiotic multiresistant. However, the rate of the antibiotic multiresistance in the ica-negative strains was very low, thus indicating that the biofim formed by the lea gene cluster in S. epidermidis is an important pathogenic factor in association with the antibiotic multiresistance.

• 한국정밀공학회지
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• 제28권4호
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• pp.526-533
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• 2011

This research is about the pulsatile pump system utilized in the perfusion bioreactor for the in vitro human tissue culture. A pulsatile pump system which can be applied to the culture of the vascular tissues including blood vessel is developed by using the idea of human heart's blood pumping into organs as followings: culture chamber, a pressurizing device which generates laminar pulsatile flow by controlling the x-sectional area of the culture media delivering tubing, a compliance chamber which supplies the pressuring device with a constant pressure, and a peristaltic pump which circulates the culture media in a circuit ranging from the culture chamber to the compliance chamber. The developed pulsatile pump system shows that a physiology of the human heart's blood pumping including pulsatile pressure waveform of systolic-diastolic pressure is well represented. Not only time domain but also frequency domain characteristics of pulsatile pump system which are necessary for the vascular tissue culture such as pulsatile pressure waveform's shape, the frequency, and the magnitude can be easily generated and manipulated by using the proposed system.

• 한국임상수의학회지
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• 제37권2호
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• pp.61-66
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• 2020

Nickel is a nutritionally essential trace element that plays an important role in the immune system of several animal species. The aim of this study was to examine the effect of nickel chloride on chemotactic activity of peripheral blood polymorphonuclear cells (PMNs) and whether this effect is associated with interleukin (IL)-8 and a nuclear factor-kappa B (NF-κB)-dependent pathway. Peripheral blood mononuclear cells (PBMCs) and PMNs were isolated by Percoll solution (Specific gravity; 1.080) and 1.5% dextran treatment, respectively. A modified Boyden chamber assay was used to measure the chemotactic activity of PMNs. The level of IL-8 in culture supernatant from PBMCs was measured by enzyme-linked immunosorbent assay (ELISA). Both of PBMCs and PMNs exhibited a low viability when cultured with concentration of greater than 1,000 μM of nickel chloride for 24 h. Thus, nickel chloride was used at concentration of 500 μM, which preserved cell viability. Treatment with nickel did not directly affect the chemotactic activity of PMNs. However, the chemotactic activity of PMNs was remarkably increased by culture supernatant from PBMCs treated with nickel chloride (500 μM) for 24 h. Recombinant porcine IL-8 polyclonal antibody (pAb) neutralized the enhancing effect on the chemotactic activity of PMNs by culture supernatant from PBMCs treated with nickel and this culture supernatant had higher IL-8 levels than the culture supernatant from untreated PBMCs. In addition, n-tosyll-phenylalanine chloromethyl ketone (TPCK), a NF-κB inhibitor, antagonized the enhancing effect on the chemotactic activity of PMNs by the culture supernatant from PBMCs treated with nickel. These results suggested that nickel stimulates porcine PBMCs to produce IL-8, which increases the chemotaxis of PMNs via NF-κB-dependent pathway.

• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.422-428
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• 2003

Umbilical cord blood (UCB), a rich source of hematopoietic stem/progenitor cells, has been proposed as an alternative to bone marrow and peripheral blood for transplantation treatment. Ex vivo expansion of cord blood stem cells could make the use of cord blood transplant feasible even for adult patients. However, the optimal cytokine cocktail for expansion of stem cells is yet to be established. This study compares proliferation, apoptosis, and telomerase activities in human cord blood stem cells cultured ex vivo with FLT3 ligand (FL)/thrombopoietin (TPO) or FL/TPO/stem cell factor (SCF), with a view to determine optimal combination of cytokines. CD34+ cells were cultured in DMEM containing either FL (50 ng/ml) and TPO (10 ng/ml) (FT group) or FL (50 ng/ml), TPO (10 ng/ml) and SCF (50 ng/ml) (FTS group). The cell proliferation rate was ten times higher in the FTS group. Although cells cultured with the two different combinations of cytokines were maintained for a long term (up to 8 weeks), a large number of cells underwent differentiation during this period. Cells cultured in FTS displayed lower levels of apoptosis compared to those of the FT group during the Initial 7 days of culture. The CD34+ fraction in both groups was markedly decreased to $21-30\%$ , and only $5-6\%$ was detected at 14 days of culture. Telomerase activity detected in human CD34+ cord blood at low levels was upregulated during the early phase of culture and decreased to baseline levels in the later phase. The telomerase activity of cord blood cultured in FT was lower than that of the FTS group. Our results suggest that, on adding stem cell factors to the FT cytokines, cultured CD34+ cord blood cells display a greater degree of cell proliferation and decreased apoptosis. However, during CD34+ cord blood cell culture, a Barge number of cells undergo differentiation, indicating that more potent novel cytokines or new culture conditioning methods should be developed to maintain their ability to engraft and sustain long-term hematopoiesis.

• Asian-Australasian Journal of Animal Sciences
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• 제24권10호
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• pp.1377-1385
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• 2011

This study was conducted to determine the nutritive value of live yeast culture (RumiSacc, Saccharomyces cerevisiae) and to investigate its effects on milk yield, milk composition and some blood parameters in lactating cows. Six multiparous Holstein cows were allocated to two groups of three cows and assigned randomly to one of two diets in a cross-over experiment. Daily 50 g RumiSacc was top dressed at the p.m. feeding for the treatment group. RumiSacc supplied a high protein and energy with high organic matter digestibility values (83.35%) determined by in vitro enzymatic analysis. Yeast culture supplementation significantly increased milk yield, tended to increase fat yield, protein yield and lactose yield of milk. Methylated fatty acid level of 18:3 (n-3) in milk fat was increased by yeast culture supplementation. The concentrations of methionine, phenyalanine, tyrosine, tryptophan and taurine were significantly increased with dietary inclusion of yeast culture. Live yeast culture supplementation did not affect other performance characteristics, milk quality characteristics and blood parameters. As a conclusion live yeast culture (RumiSacc, Saccharomyces cerevisiae) had high nutritive value and positive effects on milk production and some milk quality characteristics in lactating cows under field conditions.

• Journal of Microbiology
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• 제43권3호
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• pp.257-259
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• 2005

Although automated continuous-monitoring blood culture systems are both rapid and sensitive, false-positive and false-negative results still occur. The objective of this study, then, was to evaluate negative results occurring with BacT/Alert 3D blood culture systems. A total of 1032 samples were cultured with the BacT/Alert 3D automated blood culture system, using both aerobic (BPA) and anaerobic (BPN) media, and 128 of these samples yielded positive results. A total of 904 negative blood samples were then subcultured in $5\%$ sheep blood agar, eosin methylene blue, chocolate agar, and sabouraud-dextrose agar. Organisms growing on these subcultures were subsequently identified using both Vitek32 (bioMerieux, Durham, NC) and conventional methods. Twenty four $(2.6\%)$ of the 904 subcultures grew on the subculture media. The majority $(83.3\%)$ of these were determined to be gram-positive microorganisms. Fourteen $(58.3\%)$ were coagulase-negative staphylococci, two $(8.3\%)$ were Bacillus spp., one $(4.2\%)$ was Staphylococcus aureus, and one $(4.2\%)$ was identified as Enterococcus faecium. Streptococcus pneumoniae and Neisseria spp. were isolated together in two $(8.3\%)$ vials. Gram-negative microorganisms comprised $12.5\%$ of the subcultures, of which two $(8.3\%)$ were found to be Pseudomonas aeruginosa, and one $(4.2\%)$ was Pseudomonas fluorescens. The other isolate $(4.2\%)$ was identified as Candida albicans. We conclude that the subculture of negative results is valuable in the BacT/Alert 3D system, especially in situations in which only one set of blood cultures is taken.

• International Journal of Advanced Culture Technology
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• 제8권4호
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• pp.95-100
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• 2020

Recently, the problem of hypoxia caused by jogging is attracting attention. To solve this problem, this paper proposed a new solution. This paper proved that as a vocalization method of reading aloud, it is possible to increase air intake and activate lung function to exchange more air and obtain more oxygen. Then, blood oxygen saturation was used as an evaluation index for the body's oxygen content level to prove its effectiveness. A photoelectric pulse oximeter developed on the basis of different light absorption principles in blood was used to test blood oxygen saturation. Experimental results show that a certain degree of hypoxia is induced when a lot of oxygen is required due to jogging. Therefore, it was proved that the new vocal breathing method by reading books can increase the blood oxygen saturation of the body and improve the hypoxia of the body. Reading vocal breathing is a simple and efficient oxygen saturation recovery breathing method.

• Tuberculosis and Respiratory Diseases
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• 제53권5호
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• pp.497-509
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• 2002

연구배경 : 대표적 세포내 감염질환인 결핵에 대한 숙주의 방어기전 및 면역반응은 아직도 정확히 이해되지 못하고 있으며 이러한 병리기전을 연구하기 위하여서는 적절한 감염모델이 필요하다. 전혈 (whole blood)은 체액성 면역과 세포성 면역을 모두 포함한 생체의 상태를 반영하므로 다양한 대상에서 면역상태의 차이에 따른 개체간 결핵균 살균력의 차이를 비교 할 수 있는 적절한 모델로 추정된다. 따라서 본 연구의 목적은 인체의 결핵균 전혈 배양모델을 개발하여 궁극적으로 시험관내에서 숙주면역의 정도를 측정하는 대리 표지자를 개발하고자하는 것이다. 방 법 : PPD 양성 정상인을 대상으로 제대혈, 결핵환자, 당뇨 및 폐암환자와 비교하였다. 전혈을 희석하여 결핵균 Mycobacterium avium과 M. tuberculosis $H_{37}Ra$에 낮은 감염률로 감염시키고 $37^{\circ}C$, 5% $CO_2$ 배양기 속의 회전교반기에서 회전시키면서 배양(rotating culture) 하였다. 배양 1 일, 3일 및 4일 뒤 증류수로 긴장저하용해 시킨 후 Middlebrook 7H10/OADC 평판배지에서 결핵균 집락이 형성될 때까지 3-4주간 $37^{\circ}C$, 5% $CO_2$ 배양기에 배양하여 집락수를 계산하였다. 일부실험에서 TNF-${\alpha}$의 분비능을 90%이상 감소시키 기 위하여 methylpredmsolone과 pentoxifylline을 첨가하여 면역조정을 하였으며, CD4+ T-림프구와 CD8+ T-림프구를 magnetic bead에 코팅된 단클론 항체를 사용하여 제거하였다. 결핵균의 수는 용해질 $m{\ell}$ 당 CFU로 계산하였다. 살균력은 ${\Delta}$ log killing ratio로 표시하였다. ${\Delta}$ logKR=$log_{10}$(Final CFU/Initial CFU). 결 과 : 1. 제대혈의 결핵균 살균력이 PPD 양성 대조군에 비하여 다소 감소된 경향을 보였으며, 결핵환자의 결핵균 살균력은 PPD 양성 대조군과 특별한 차이를 보이지 않았다. 또한 당뇨군과 폐암군의 결핵균 살균력도 정상 대조군에 비하여 특별한 차이를 보이지 않았다. 2. Methylprednisolone과 pentoxyfylline을 사용한 면역조정 시에 제대혈, PPD 양성 정상 대조군과 결핵군 모두에서 전혈에서의 결핵균의 살균력이 감소되는 경향을 보였다. 3. CD4+ 및 CD8+ T-림프구 삭제시 log KR가 증가되어 유의하게 결핵균 살균력이 감소되었으며 CD4+ 및 CD8+ T-림프구 동시 삭제시 현저한 상승효과를 보였고 이러한 결과는 Mycobacterium avium보다는 독력이 없는 균인 Mycobacterium tuberculosis $H_{37}Ra$에서 보다 뚜렷하였다. 4. 폐결핵 치료후의 결핵균 살균력은 치료 전과 비교하여 유의하게 ${\Delta}$ logKR가 감소하였으며, 배양 3-4일에도 현저한 결핵균 증식의 억제를 보였다. 결 론 : 인체의 결핵균에 대한 감수성인 개체간의 면역상태를 전혈에서 결핵균 살균력을 통하여 비교할 수는 없었다. 그러나 인체 전혈 모델은 간단하고 임상경과 관찰이 쉬우며 결핵환자에서 치료 전과 후에 현저한 결핵균 살균력의 차이를 보이므로, 최근 결핵연구의 가장 중요한 과제의 하나인 백신 개발에서 그 성과를 판단하는 vaccine trial에 이용할 수 있을 가능성을 시사한다.