• Journal of Biomedical Engineering Research
• /
• v.36 no.4
• /
• pp.86-94
• /
• 2015

In order for medical devices to be used outside hospital, they have to be not only of small size but also power consumption has to be kept at low level. This study investigates the feasibility of application of ADS1298 ECG single-chip solution developed by Texas Instruments Inc. for use in development of a new platform for diagnostic resting ECG. To prove the feasibility of commercial products based on the ADS1298 chip, the performance of the ADS1298 chip was measured in terms of input impedance, common mode rejection, frequency response, and input dynamic range using the testing method under the suitability criteria of the IEC 60601-2-25 standard. Result of the this study shows that commercialization of the ECG products based on the ADS1298 ECG single-chip solution that satisfies the international standards would be possible, if the manufactures take the filter characteristics into account in building a new platform for diagnostic resting ECG.

• Tuberculosis and Respiratory Diseases
• /
• v.83 no.4
• /
• pp.289-294
• /
• 2020

Background: Line probe assay (LPA) is standard diagnostic tool to detect multidrug resistant tuberculosis. Non-interpretable (NI) results in LPA (complete missing or light wild-type 3 and 8 bands with no mutation band in rpoB gene region) poses a diagnostic challenge. Methods: Sputum samples obtained between October 2016 and July 2017 at the Intermediate Reference Laboratory, All India Institute of Medical Sciences Hospital, New Delhi, India were screened. Smear-positive and smear-negative culture-positive specimens were subjected to LPA Genotype MTBDRplus Ver 2.0. Smear-negative with culture-negative and culture contamination were excluded. LPA NI samples were subjected to phenotypic drug susceptibility testing (pDST) using MGIT-960 and sequencing. Results: A total of 1,614 sputum specimens were screened and 1,340 were included for the study (smear-positive [n=1,188] and smear-negative culture-positive [n=152]). LPA demonstrated 1,306 (97.5%) valid results with TUB (Mycobacterium tuberculosis) band, 24 (1.8%) NI, three (0.2%) valid results without TUB band, and seven (0.5%) invalid results. Among the NI results, 22 isolates (91.7%) were found to be rifampicin (RIF) resistant and two (8.3%) were RIF sensitive in the pDST. Sequencing revealed that rpoB mutations were noted in all 22 cases with RIF resistance, whereas the remaining two cases had wild-type strains. Of the 22 cases with rpoB mutations, the most frequent mutation was S531W (n=10, 45.5%), followed by S531F (n=6, 27.2%), L530P (n=2, 9.1%), A532V (n=2, 9.1%), and L533P (n=2, 9.1%). Conclusion: The present study showed that the results of the Genotype MTBDRplus assay were NI in a small proportion of isolates. pDST and rpoB sequencing were useful in elucidating the cause and clinical meaning of the NI results.

• Parasites, Hosts and Diseases
• /
• v.53 no.1
• /
• pp.95-99
• /
• 2015

Strongyloides stercoralis can cause systemic infection, termed strongyloidiasis, and gastrointestinal ulcer disease in immunocompromised patients. However, to our knowledge, there are no reported cases of comorbid gastric adenocarcinoma and S. stercoralis infection. Here, we report a case of an 81-year-old Korean man who presented with S. stercoralis infection coexisting with early gastric adenocarcinoma (T1aN0M0). S. stercoralis eggs, rhabditiform larvae, and adult females were observed in normal gastric and duodenal crypts. They were also observed in atypical glands representative of adenocarcinoma and adenoma. Preliminary laboratory tests revealed mild neutrophilic and eosinophilic leukocytosis. A routine stool test failed to detect rhabditiform larvae in the patient's fecal sample; however, S. stercoralis was identified by PCR amplification and 18S rRNA sequencing using genomic DNA extracted from formalin-fixed paraffin-embedded tissues. Postoperatively, the patient had a persistent fever and was treated with albendazole for 7 days, which alleviated the fever. The patient was followed-up by monitoring and laboratory testing for 4 months postoperatively, and no abnormalities were observed thus far. The fact that S. stercoralis infection may be fatal in immunocompromised patients should be kept in mind when assessing high-risk patients.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.30 no.2
• /
• pp.124-133
• /
• 2020

Objectives: Mask fit is a crucial factor in preventing respiratory infections among healthcare workers. The current coronavirus(COVID-19) pandemic calls for the replacement of imported N95 medical masks with domestic N95 versions. In this study, we aimed to determine whether these masks provide proper protection. Methods: Thirty-five participants from three healthcare institutions donned four types of masks and Quantitative Fit Tests(Portacount, USA) were performed. The order of fit test for the four types of masks was randomized, and a three-minute washout period was applied between test times(2 min 29 sec) to reduce potential error stemming from physical exhaustion. Results: There were no significant differences in the Fit Factor for the four types of masks, and there were no gender differences. However, the Fit Factor significantly differed across the three healthcare institutions (p=0.007). With eight of the 35 participants passing, the pass rate with the criteria of 100 or higher was 21%. Conclusions: The mask used in this study was a new domestic N95 medical mask, and the participants were unfamiliar with how to wear it. They reported difficulties with mask fitting. In light of a previous finding that mask fit improved with frequently used masks, wearer preferred masks, or when masks that are regularly worn are used during fit training, the fact that participants were unfamiliar with the mask used in this study is a limitation that should not be overlooked.

• Microbiology and Biotechnology Letters
• /
• v.49 no.4
• /
• pp.587-593
• /
• 2021

Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.8
• /
• pp.1101-1110
• /
• 2023

Streptococcus mutans is the primary causative agent of caries, which is one of the most common human diseases. Thus, rapid and early detection of cariogenic bacteria is critical for its prevention. This study investigated the combination of loop-mediated isothermal amplification (LAMP) and microfluid technology to quantitatively detect S. mutans. A low-cost, rapid microfluidic chip using LAMP technology was developed to amplify and detect bacteria at 2.2-2.2 × 10⁶ colony-forming units (CFU)/ml and its detection limits were compared to those of standard polymerase chain reaction. A visualization system was established to quantitatively determine the experimental results, and a functional relationship between the bacterial concentration and quantitative results was established. The detection limit of S. mutans using this microfluidic chip was 2.2 CFU/ml, which was lower than that of the standard approach. After quantification, the experimental results showed a good linear relationship with the concentration of S. mutans, thereby confirming the effectiveness and accuracy of the custom-made integrated LAMP microfluidic system for the detection of S. mutans. The microfluidic system described herein may represent a promising simple detection method for the specific and rapid testing of individuals at risk of caries.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.4
• /
• pp.1917-1923
• /
• 2016

Background: Lynch Syndrome (LS) is a familial cancer condition caused by germline mutations in DNA mismatch repair genes. Individuals with LS have a greatly increased risk of developing colorectal cancer (CRC) and it is therefore important to identify mutation carriers so they can undergo regular surveillance. Tumor DNA from LS patients characteristically shows microsatellite instability (MSI). Our aim here was to screen young CRC patients for MSI as a first step in the identification of unrecognized cases of LS in the Saudi population. Materials and Methods: Archival tumor tissue was obtained from 284 CRC patients treated at 4 institutes in Dammam and Riyadh between 2006 and 2015 and aged less than 60 years at diagnosis. MSI screening was performed using the BAT-26 microsatellite marker and positive cases confirmed using the pentaplex MSI analysis system. Positive cases were screened for BRAF mutations to exclude sporadic CRC and were evaluated for loss of expression of 4 DNA mismatch repair proteins using immunohistochemistry. Results: MSI was found in 33/284 (11.6%) cases, of which only one showed a BRAF mutation. Saudi MSI cases showed similar instability in the BAT-26 and BAT-25 markers to Australian MSI cases, but significantly lower frequencies of instability in 3 other microsatellite markers. Conclusions: MSI screening of young Saudi CRC patients reveals that approximately 1 in 9 are candidates for LS. Patients with MSI are strongly recommended to undergo genetic counselling and germline mutation testing for LS. Other affected family members can then be identified and offered regular surveillance for early detection of LS-associated cancers.

• Journal of Pharmacopuncture
• /
• v.15 no.3
• /
• pp.48-52
• /
• 2012

Objective: This study was performed to analyze the single-dose toxicity of Aconitum kusnezoffii Reichb. pharmacopuncture (AKRP). Methods: All experiments were conducted at the Korea Testing & Research Institute (KTRI), an institute authorized to perform non-clinical studies, under the regulations of Good Laboratory Practice (GLP). Twenty (20) Sprague-Dawley rats were chosen for the pilot study. The animals were divided into four groups of five animals per group: group 1 (G1) being the control group with each animal receiving an injection of 0.3 ml of saline and groups 2, 3, and 4 (G2, G3, and G4) being the experimental groups with each animal receiving an injection of 0.1, 0.2 or 0.3 ml of AKRP, respectively. This study was conducted with the approval of the Institutional Animal Ethics Committee. Results: No deaths occurred in any of the 4 groups, and the $LD_{50}$ of AKRP administered via IV was higher than 1.77 ml/kg. Some changes in the weights of the male rates were observed between the control group and the experimental groups, but no significant differences were noted in the weights of the female rats. To check for abnormalities in organs and tissues, we stained representative sections of each specified organ with Hematoxylin & Eosin for light microscopic examination. The results showed no significant differences in any of the organs or tissues. Conclusions: The above findings suggest that Aconitum kusnezoffii Reichb. pharmacopuncture is a relatively safe treatment. Further studies on the subject should be conducted to yield more concrete evidence.

• Clinical and Experimental Pediatrics
• /
• v.55 no.12
• /
• pp.481-486
• /
• 2012

Purpose: Precocious puberty is defined as breast development before the age of 8 years in girls. The present study aimed to reveal the diagnosis of Korean girls referred for precocious puberty and to compare the constitutional and endocrinological features among diagnosis groups. Methods: The present study used a retrospective chart review of 988 Korean girls who had visited a pediatric endocrinology clinic from 2006 to 2010 for the evaluation of precocious puberty. Study groups comprised fast puberty, true precocious puberty (PP), pseudo PP, premature thelarche, and control. We determined the height standard deviation score (HSDS), weight standard deviation score (WSDS), and body mass index standard deviation score (BMISDS) of each group using the published 2007 Korean growth charts. Hormone tests were performed at our outpatient clinic. Results: The PP groups comprised fast puberty (67%), premature thelarche (17%), true PP (15%), and pseudo PP (1%). Advanced bone age and levels of estradiol, basal luteinizing hormone (LH), and peak LH after gonadotropin-releasing hormone stimulation testing were significantly high in the fast puberty and true PP groups compared with the control group. HSDS, WSDS, and BMISDS were significantly higher in the true PP group than in the control group (P<0.05). Conclusion: The frequent causes of PP were found to be fast puberty, true PP, and premature thelarche. Furthermore, BMISDS were significantly elevated in the true PP group. Therefore, we emphasize the need for regular follow-up of girls who are heavier or taller than others in the same age group.

• Korean Journal of Clinical Laboratory Science
• /
• v.38 no.1
• /
• pp.16-21
• /
• 2006

Parallel testing means ordering a number of tests at the same time so abnormalities in any of the tests can be found quickly and used in making the diagnosis. This is a good medical strategy to eliminate diseases and it is relatively inexpensive if all the tests are potential sources of information and performed on the same analyzer. In regression, the equation for the straight line is recast as y = bx + a. This change in terminology leads to confusion. Here a is the y-intercept or constant and b is the coefficient or slope of the line. A few more words of caution about regression - as in all of statistics there are certain assumptions: the x value is a true measure, both X and Y distributions are normal, and homoscedasticity, i.e., the variance of y is the same for each value of x. In this study the linearity classification made by different scientists were always in agreement. Typical examples of curves that were considered linear are presented in Fig. 1-5. Because these automated procedures values were usually within five percent of each other the curvature could be easily detected. The plot of the WBC, RBC, hemoglobin, hematocrit and platelet concentrations from approximately 74.4 to $0{\times}10^3/{\mu}L$ and $80.4-0{\times}10^3/{\mu}L$, $5.6-0{\times}10^6/{\mu}L$ and $6.1-0{\times}1106/{\mu}L$, 18.3-0 g/dL and 19.0-0 g/dL, 54.1-0% and 56.8-0% and 642.0 to $0.03{\times}10^3{\mu}L$ and $754.0-0{\times}10^3/{\mu}L$ on the ADVIA 2120 C Versus and A and B typical of an acceptable linear study as shown in Fig. 1-5. The grand mean of R2, intercept and slope is 0.99898, 0.99459 and 1.54626.