• Korean Journal of Clinical Laboratory Science
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• v.52 no.4
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• pp.381-388
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• 2020

The quality control of pathological specimens is important for accurate molecular pathology testing. This study evaluated that specimen factors affecting the DNA quality during tissue processing and sample types for BRAF, EGFR, and KRAS mutations tests. One thousand seven hundred and seventy-two molecular pathology tests were investigated for the factors influencing the DNA quality, such as sample type, formalin fixation time, and reexamination status. Cytology samples stored in a saline solution had better DNA quality than commercial cytology preservation. Tissue samples fixed in formalin within 24 hours had better DNA quality than the samples fixed over 24 hours. Between the types of samples, fresh tissue samples and tissue samples with a high tumor cell density had relatively better DNA quality than the formalin-fixed paraffin-embedded (FFPE) tissues and cytology specimens. Of real-time PCR, the non-PNA Ct value increased proportionally with samples held for longer than 24 hours in formalin, and that the formalin-fixed time affects the sample DNA quality. In conclusion, the appropriate tumor cellularity and 10% neutral formalin fixation time are the most important factors for maintaining the DNA quality. These factors should be managed properly for an accurate pathological molecular test to ensure optimal DNA quality.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.369-375
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• 2015

We investigated the prevalence of fungi isolated from a university-affiliated hospital during 6 years (2006-2011) to provide relevent information for the patient management. The general characteristics of the clinical isolates and gender, age, and type of specimens were analyzed. Among a total of 163,530 requested samples to culture for the Laboratory of Clinical Microbiology, Department of Laboratory Medicine, Gyeongsang National University Hospital in the Republic of Korea, 5,387 (3.3%) showd positive results for fungi. The most prevalent isolates were Candida albicans 41.9%, Candida glabrata 15.5%, and Candida tropicalis 14.6%. Total isolates of fungi increased from 526 in 2006 to 1,145 in 2011. They were most commonly isolated from sixties (27.0%) and seventies (26.5%). The most common clinical specimen was urine (44.8%). Males (52.4%) were slightly more than females (47.6%). In the future, a nationwide survey and additional antifungal convergence drugs susceptibility results will provide more useful information.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.311-316
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• 1999

Background: The drug-resistant tuberculosis has recently decreased in Korea, but it is still one of the major obstacles in the treatment of pulmonary tuberculosis. Unfortunately there are no reliable ways to figure out the drug sensitivity pattern of the M. tuberculosis in the starting point of treatment. At least several months which is critical for the success of treatment have to be passed away before getting the report of drug-sensitivity test. The aim of this study was to find out the clinical and radiological parameters that make it possible to predict the drug-resistant pulmonary tuberculosis and to make a correct decision on the antituberculosis drug regimens. Method: We studied 253 pulmonary TB patients with sputum and/or bronchial washing fluid culture-positive diagnosed at the Chung-Ang University Young-San Hospital in the period of 1989-1994. The differences in the clinical and raiological variables between the drug-sensitive and the drug-resistant tuberculosis patients were evaluated. Results: In 66 out of 253 patients(26.1%), drug resistant tuberculosis to at least one antituberculosis drug were found. Patients with retreatment showed higher resistance rate than those with initial treatment(30/69, 43.5% vs 36/184, 19.5%, p<0.01). Patients with cavitary TB showed higher resistance rate than those with non-cavitary TB(24/54, 44.4% vs 42/199, 21.1%, p<0.05). Among patients with initial treatment, those with far-advanced TB showed a higher drug resistance rate than those with minimal lesion(9/23, 36.9% vs 10/82, 12.5%, p<0.05). Patients with culture positive only in the bronchial washing fluid showed lower resistance rate than those with sputum culture positive(7/63, 11.1 % vs 59/190, 31.1%, p<0.05). Conclusion: Prior treatment history for pulmonary tuberculosis, the presence of cavity & far advanced tuberculosis in the radiologic exam, sputum rather than solely bronchial washing culture positivity would be the related factors to the drug resistance. So in the patients with such characteristics, it is needed to try to find out the drug sensitivity pattern of the infecting tuberculosis organism as soon as possible.

• Journal of Digital Convergence
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• v.12 no.9
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• pp.237-244
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• 2014

Pathogenic fungal infections are predominantly occurred in patients with severe immune or metabolic defects. In the present study, we aimed to investigate the last five years (2007~2011) 190,250 cases clinical specimens of yeast 3,487 results that had shown positive culture and to look at the significance of regional difference and identify relationship between provide the characteristics about association between clinical isolates and gender, age, and type of specimens. The yearly strain-specific isolation frequency of yeast separated was 1,925(55.2%) for C. albicans the largest of them. All kinds of clinical specimen was 1,495(42.9%) in urine, 998(28.6%) in sputum. Strain-specific gender differences in C. albicans for males was 1,177(57.8%) of the total of 2,037 and 748(51.6%) of 1,450 and as for age, those between 70 and 79 were the largest with 639(55.1%) of the 1,925 strain. In this study, well presented the general characteristics of pathogenic yeast seen in diverse specimens. This limitation has been implemented in a single area, Future research is expected to examine more on nationwide distribution chart, dynamic characteristics and future antibiotic sensitivity.

• Biomedical Science Letters
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• v.3 no.1
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• pp.55-67
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• 1997

Considering many problems caused by the abuse of antibiotics recently, the appearance of antibiotic resistance bacteria is believed to help the cure of patients greatly. From Jan. 1st, 1996 to Dec. 31, 1996, 6135 strains were examined after being asked of and seperated from the clinical pathology departments of general hospitals, and the isolation frequency of identified bacteria and the susceptibility of antibiotics showed the following result. 1. The isolation frequency of strains was Escherichia coli, 1134 strains (18.4%), Pseudomonas aeruginosa, 856 strains (13.9%), coagulase negative Staphylococcus, 793 strains (12.89%), Staphylococcus aureus, 555 strains (9.02%), B. cepacia, 421 strains (6.84%), Enterobacter cloacae, 366 strains (5.95%), Enterobacter faecalis (4.86%), and Klebsiella pneumonia, 220 strains (3.85%). 2. The isolation rate of specimen was urine, 1, 969 strains, wound 1, 104 strains, sputum 701 strains, blood 643 strains, vaginal swab, 342 strains, and eye discharge, 192 strains, 40% of urine strains were E. coli 18％ of wound strains were B. cepacia, 43.7％ of sputum were P. aeruginosa, and in blood strains there were Enterobacter cloacae (25.8%), coagulase negative Staphylococcus (19.6%), and P. aeruginosa (8.7%). 3. The result of antibiotics susceptibility showed that, among gram negative bacilli, P. aeruginoas had resistance in almost all antibiotics except ceftazidme imipenem. But B. cepacia, the same glucose non-fermentation gram negative bacilli had more than 90％ of sensitivity in aztreonam, ceftazidime, ciproflxacin, piperacillin, trimethoprim/sulfa and had resistance in the others. Enterococcus faecalis showed more than 85% of sensitivity in penicillin-G, ampicillin, ciprofloxacin. 4. In the case of specimen antibiotics susceptibility, Enterobacter cloacae was lower in specimen isolated from blood than in those isolated from others and p. aeruginosa was low in specimen isolated from urine, which showed that there was difference in specimen antibiotics susceptibility. The result of this study shows that there happen many resisitances in antibiotics used frequently and some countermeasure is necessary because many bacteria began to show new resistance. Also it is desirable that the choice of antibiotics for infection diagnosis and its cure should be made after the inspection of antibiotics.

• Pediatric Infection and Vaccine
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• v.12 no.2
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• pp.157-165
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• 2005

Purpose : Children occupy a large proportion of burn victims. So we want to aid to pediatric burn care through the understanding of the bacterial distribution in burn wounds and antibiotic susceptibility against isolated microorganisms from burn wounds. Methods : We analysed the medical records of 213 pediatric burn patients(0~15 years), 406 samples that grew bacteria in burn wound sites. Results : Of the total 213 patients, male were 59.6% and female were 40.4%. Scalding burn was the most common(78.4%), flame burn was the second(16.4%). Pathogens were isolated in 406 samples. The most common was Pseudomonas aeruginosa(58.1%). Next were Enterococcus species, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus species, Acinetobacter species. P. aeruginosa was resistant to trimethoprim-sulfamethoxazole in 100%, cephalothin in 98.1%, ampicillin-sulbactam in 96.2%, ampicillin in 95.3%, ceftriaxone in 95.2%, tobramycin in 93.7%, cefoperazone in 68.9%, ceftazidime in 67.7%. Enterococcus species were resistant to tetracycline in 63.9%, streptomycin in 45.5%, gentamicin in 36.1%, penicillin G in 13.7%. S. aureus was resistant to gentamicin in 89.7%, tetracycline in 86.2%, ciprofloxacin in 86.2%, penicillin G in 84.3%, oxacillin in 78.4%, erythromycin in 76.5%. Acinetobacter species were resistant to ampicillin-sulbactam in 100%, gentamicin in 85.7%, ampicillin in 83.3%, piperacillin in 61.5%. Conclusion : P. aeruginosa was highly resistant to drugs like cefoperazone in 68.9%, ceftazidime 67.7%. S. aureus was highly resistant to penicillin G in 84.3%, oxacillin in 25.9 %, but none to vancomycin in 0%, teicoplanin in 2.2%. According to the study, Acinetobacter species turned out to be multi-resistant strains, so careful attention must be paid to the choice of antibiotics.

• Annals of Clinical Microbiology
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• v.18 no.2
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• pp.37-43
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• 2015

Background: Tuberculosis is globally the most important cause of death from single pathogen. Rapid and accurate identification of mycobacteria is essential for the control of tuberculosis. We evaluated a fluorescence in situ hybridization (FISH) method using peptide nucleic acid (PNA) probes for the differentiation of Mycobacterium tuberculosis complex (MTB) and nontuberculous mycobacteria (NTM) in direct smears of sputum specimens. Methods: The cross-reactivity of MTB- and NTM-specific PNA probes was examined with reference strains of M. tuberculosis ATCC 13950, Mycobacterium kansasii ATCC 12479, Mycobacterium fortuitum ATCC 6841, several clinical isolates of mycobacteria (Mycobacterium abscessus, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium gordonae and Mycobacterium chelonae), and 11 frequently isolated respiratory bacterial species other than mycobacteria. A series of 128 sputa (89 MTB culture positive, 29 NTM culture positive, and 10 under treatment culture negative) with grades of trace to 4+ were used to evaluate the performance of the method. Results: The MTB- and NTM-specific PNA probes showed specific reactions with the reference strains of MTB and M. kansasii and clinical isolates of mycobacteria except M. fortuitum ATCC 6841, and no cross-reactivity with other tested bacteria. The PNA probe-based FISH assay for detection of MTB had a sensitivity and specificity of 100%, respectively. The sensitivity and specificity of the NTM-specific PNA probe was 100%. The smear grades of the PNA FISH test were same as with those of the fluorescence AFB stain in 2+ or higher grade. Conclusion: Detection and differentiation based on PNA FISH is sensitive and accurate for detecting mycobacteria and for differentiating MTB from NTM in clinical sputum smears.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.107-114
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• 2005

모발은 고통 없이 검체를 채취할 수 있고 저장이 간편하며 인체에 장기간 축적된 미네랄과 중금속함량을 측정하는데 매우 적당한 재료이다. 그러므로 45세 전후의 남자두발을 검체로 하여 상습흡연자(3년 이상 하루 1갑 이상흡연자)와 비흡연자 그리고 청소년을 대상으로 15종의 영양원소와 8종의 독성원소, 그리고 15종류의 기타원소를 조사하여 이들 미네랄 함량의 기초 자료를 제시하고자 하였다. 총 38종류의 원소분석은 정확도를 기하기 위하여 Trace elements, Inc (Dallas, Tx, USA)사에 의뢰하였으며, 이곳에서는 유도결합 플라즈마 질량분석기를 사용하여 분석하였다. 결과는 흡연자가 비 흡연자에 비하여 영양원소는 대체적으로 비슷하였으나 특히 Mg(P<0.05)와 Cu함량이 각각 3.9와 2.4 ppm의 차이로 흡연자가 낮았고, 독성원소는 Hg(P<0.001)가 0.16과 0.31 ppm으로써 0.15 ppm 차이로 흡연자가 높은 특징을 보였는데, 이것은 최대허용치인 0.18 ppm과 비교해 보았을 때 약 2배 이상 초과하는 것이 였엇다. 이러한 원인들은 흡연에 있다고 볼 수 있으며, Hg의 중독증상은 중추신경 장애와 의욕상실, 만성피로를 일으킬 수 있으며 미나마타병의 원인물질로 알려져 있다. 한편,청소년과 성인에 있어서 영양원소의 함량은 Cu, P, Mn, B가 각각 3.2, 2.1, 0.016, 0.03 ppm의 차이로 성인에서 높았다. 그러나 생리활성물질인 Ca, Na, K은 각각 55.3, 15.2, 9.0 ppm의 차이로 청소년에서 높았는데, 이것은 성장기 청소년들에게 있어서의 특징이라고 할 수 있다. 독성원소는 Hg가 0.16 ppm으로 성인에서, Cd는 0.01 ppm으로 청소년에서 높았지만 각각 최대 허용치인 0.18과 0.014 ppm 이하였다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.143-152
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• 2004

Purpose: The purpose of this study is to detect viral coproantigens in children who were hospitalized with acute diarrhea and to compare its association with clinical symptoms. Methods: Seventy-four stool samples were collected from children admitted to Ewha Mokdong Hospital from March 1996 to December 1999. The samples were frozen and analyzed for rotavirus, adenovirus, enterovirus, astrovirus, and calicivirus by enzyme immunoassay (EIA) with monoclonal antibody. 53 stool samples were collected from patients with diarrhea (diarrheal group) and 21 stool samples from patients hospitalized for reasons other than diarrhea (control group). Clinical features and laboratory findings were reviewed in both groups. Results: Among 74 stool samples, virus antigens were detected in 60 samples. Of the 60 virus-positive stool samples, 47 enterovirus, 26 rotavirus, 16 adenovirus, 11 astrovirus, and 11 calicivirus antigens were detected by EIA. Of the 60 virus-positive stool samples, 28 samples have one viral antigen, 30 samples have 2 or more viral antigens, and 2 samples showed a simultaneous infection of Salmonella group B and enterovirus. There was no relationship between the detected virus and clinical features. Conclusion: In this study, viral coproantigen and clinical symptoms were not associated. In the future, further larger scale studies are necessary.

• Clinical and Experimental Pediatrics
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• v.46 no.9
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• pp.846-853
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• 2003

Purpose : Pneumoccocus is one of the most important causes of invasive infection through the childhood period and the prevelance of antibiotics resistance of pneumococcus is increasing worldwide. A 7-valent conjugate vaccine has been developed. It is important to know the prevalence of each serotype of pneumococci in the countries where the vaccine is used to estimate the coverage rate by the vaccine. Methods : One hundred and twenty seven strains of clinical isolates and 72 strains from healthy carriers recovered from Korean children during the period from 1997 to 2002 were subjected to determination of serotype by Quellung reaction and penicillin susceptibility with oxacillin disc diffusion test. Results : Forty-three per cent of clinical isolates were obtained from children under two years of age. Thirty strains(24%) were isolated from normally sterile body fluids. The frequent serotypes were 19F, 19A, 23F, 6A, 6B and 9V. Fifty-six per cent of the clinical isolates were represented in the current 7-valent protein conjugate pneumococccal vaccine, and 84% when the cross-reactive serotypes were included. Frequent serotypes of strains isolated from one to five year-old healthy children were 19F, 14, 11A, 23F, 18C, and 19A. Seventy-one per cent of the carrier strains were included in the 7-valent vaccine. Ninety-three per cent of the clinical isolates and 86% of carrier strains were not susceptible to penicilline. Conclusion : Fifty-six to 84% of pneumococci recovered from Korean children are covered by the current 7-valent protein conjugate pneumococcal vaccine and the prevalence of penicillin resistance was very high.