[Diagnosis and Treatment of GastroEsophageal Reflux Disease at the Primary Health Care Clinics in Korea].

Background/Aims: The prevalence of GERD and treatment costs are continuously rising in Korea, and the importance of primary health care clinics where the most treatment of actual patients is conducted is increasing. In this study, the diagnosis of GERD, selection of therapeutic drugs, and treatment methods in primary health care clininics were investigated through a large-scale multi-dimensional surveys. Methods: From January 2015 to December 2018, the study data of 18,010 patients with GERD were retrospectively investigated based on eletronic medical record at 542 primary health care clinics in Korea. Results: Among all GERD patients, endoscopy was used for diagnosis in 16.11% of cases, and the most frequently performed in gastroenterology department (28.85%). The average BMI and the proportion of patients in stages 1 to 3 of obesity were highest in the ERD group, and the majority of the severity of ERD group was mild. Symptoms of the patients with GERD were mainly heartburn, gastric acid reflux, and chest pain. Drug treatment was performed in most of the patients with GERD, and PPI was the main drug, and Esomeprazol was prescribed the most among the main ingredients, and the ratio of PPI alone was high. The rate of symptom improvement after GERD treatment was slightly higher in the ERD group (75.91%) and the NERD group (74.36%) than in the GERD diagnosed without endoscopy group (63.89%). Conclusions: In domestic primary health care clinics, the majority were diagnosed with GERD without endoscopy on the basis of symptoms. The most preferred treatment for GERD was PPI, which was prescribed alone in the majority.

Colon Polyp Detection in Primary Health Care Institutions of Korea: Detection Rate and Issues with Following the Guidelines.

Background/Aims: There have been few multicenter studies on colonic polyps conducted by primary medical institutions. This study examined the detection rate of colonic polyps in primary health care institutions and the related factors while following the guidelines. Methods: The medical records of 14,029 patients who underwent colonoscopy between January-June 2020 at 40 primary medical institutions in Korea were analyzed. High-risk adenoma was defined as advanced adenoma, carcinoma, or ≥3 adenomas. Results: Most patients (71.2%) aged ≥50 years underwent re-colonoscopy within 5 years (51.3%) for diagnostic purposes (61.3%) in Korean primary medical institutions. The detection rates of colon polyps, adenoma, advanced adenoma, high-risk adenoma, and carcinoma was 59.9%, 38.9%, 5.9%, 11.4%, and 0.3% in all subjects and 59.8%, 37.5%, 8.5%, 12.9%, and 0.3% in average-risk patients, respectively. The incidences of adenoma in average-risk patients increased significantly with age (30s/40s/50s: 20.1%/29.4%/43% for adenoma, 4.4%/6.7%/10.3% for advanced adenoma, and 5.6%/9.5%/14.6% for high-risk adenoma; p<0.05). Before 50 years of age, high-risk adenoma was detected in 9.1% of patients in the first-time screening group, and the significant risk factors were being male and ≥40 years of age. The detection rate of high-risk adenoma in the normal index colonoscopy group within 5 years was 9.0%. The significant risk factors included older age, male sex, positive fecal occult blood test, stool form changes, and nonspecific symptoms (gas and indigestion). Conclusions: More colonic adenoma studies targeting real-world clinical practice will be needed to revise the Korean guidelines for colorectal cancer screening and surveillance.

Comparative analysis of allele variation using allele frequencies according to sample size in Korean population.

BACKGROUND: Allele frequency using short tandem repeats (STRs) is used to calculate likelihood ratio for database match, to interpret DNA mixture and to estimate ethnic groups in forensic genetics. In Korea, three population studies for 23 STR loci have been conducted with different sample size for forensic purposes. OBJECTIVE: We performed comparative analysis to determine how the difference of sample size affects the allele frequency and allele variation within same ethnic population (i.e. Korean). Furthermore, this study was conducted to check how the sampling group and multiplex kit also affect allele variation such as rare alleles and population specific alleles. METHODS: To compare allele variation, we used allele frequencies of three population data published from three Korean forensic research groups. Allele frequencies were calculated using different sample sizes and multiplex kits: 526, 1000, and 2000 individuals, respectively. RESULTS: The results showed the different distribution of allele frequencies in some loci. There was also a difference in the number of rare alleles observed by the sample size and sampling bias. In particular, an allele of 9.1 in the D2S441 locus was not observed in population study with 526 individuals due to multiplex kits. CONCLUSION: Because the allele frequencies play an important role in forensic genetics, even if the samples are derived from the same population, it is important to consider the effects of sample size, sampling bias, and selection of multiplex kits in population studies.

A forensic case study for body fluid identification using DNA methylation analysis.

Recently, a method of identifying body fluids using DNA methylation has been developed (Frumkin et al., 2011). An existing multiplex assay using 9 CpG markers could differentiate 5 body fluids: semen, blood, saliva, menstrual blood, and vaginal fluid. To validate this technique, we evaluated the previously described body fluid identification method by means of single base extension (SBE). DNA methylation was applied to 22 samples in 18 forensic cases; seven of these were semen, three were blood, eight were saliva, three were vaginal fluid, and one was menstrual blood. Total of 18 samples were tested, the DNA methylation profiles were coincident from preliminary tests (acid phosphatase (AP), leucomalachite green (LMG, Sigma Aldrich, St Louis, MO, USA) and SALIgAE®) except one sample which displayed an all-negative result. After applying the DNA methylation method to forensic samples, we determined that it could be very useful for differentiating vaginal secretions from menstrual blood, for which there is no conventional preliminary testing method.

Genetic variation for three Y-STR loci: DYS390, DYS518, and DYS643.

Y chromosome short tandem repeats (Y-STRs) are commonly used to analyze male-specific DNA. Although biallelic patterns due to duplication events have been detected at some loci, Y-STRs generally appear as a single peak except for DYS385 because the Y chromosome is haploid. STR loci in regions of segmental duplication by homologous recombination on the Y chromosome exhibit double allelic peaks, rather than single peaks. In this study, we report a bi- and triallelic pattern observed simultaneously in DYS390, DYS518, and DYS643. A bi- and triallelic pattern has not previously been observed simultaneously for these three loci. We also identified the copy number variation in the region including these loci by the microarray-based analysis. Given the peak balance pattern, the copy number variation, and the close position of these three loci on the Y chromosome, we consider that this phenomenon is caused by a segmental duplication in the euchromatin region. By ruling out mixed samples, a common interpretation of multiple peaks, these results have practical implications for the interpretation of Y-STR results in forensics analyses.

Rapid oral bacteria detection based on real-time PCR for the forensic identification of saliva.

This study developed a new method for forensic saliva identification using three oral bacteria, Streptococcus salivarius, Streptococcus sanguinis, and Neisseria subflava, combined with a real-time polymerase chain reaction (RT-PCR) system we called OB mRT-PCR. Analytical sensitivity results showed that the target bacteria were amplified at 102-107 copies/reaction, and analytical specificity was assessed using 24 other viruses, bacteria, and protozoa. To evaluate the OB mRT-PCR kit for forensic applications, saliva from 140 Korean individuals was tested, and at least two target bacteria were detected in all the samples. Additional studies on non-saliva samples demonstrated the specificity of the kit. Comparison of the kit with two conventional saliva test methods, the SALIgAE and RSID-Saliva assays, indicated that it was more sensitive and applicable to saliva samples in long-term storage (up to 14 weeks). Additionally, through amplification of mock forensic items and old DNA samples (isolated without lysis of the bacterial cells, regardless of their Gram-positivity), we found that the kit was applicable to not only saliva swabs, but also DNA samples. We suggest that this simple RT-PCR-based experimental method is feasible for rapid on-site analysis, and we expect this kit to be useful for saliva detection in old forensic DNA samples.

Enhanced sensitivity of CpG island search and primer design based on predicted CpG island position.

DNA methylation has important biological roles, such as gene expression regulation, as well as practical applications in forensics, such as in body fluid identification and age estimation. DNA methylation often occurs in the CpG site, and methylation within the CpG islands affects various cellular functions and is related to tissue-specific identification. Several programs have been developed to identify CpG islands; however, the size, location, and number of predicted CpG islands are not identical due to different search algorithms. In addition, they only provide structural information for predicted CpG islands without experimental information, such as primer design. We developed an analysis pipeline package, CpGPNP, to integrate CpG island prediction and primer design. CpGPNP predicts CpG islands more accurately and sensitively than other programs, and designs primers easily based on the predicted CpG island locations. The primer design function included standard, bisulfite, and methylation-specific PCR to identify the methylation of particular CpG sites. In this study, we performed CpG island prediction on all chromosomes and compared CpG island search performance of CpGPNP with other CpG island prediction programs. In addition, we compared the position of primers designed for a specific region within the predicted CpG island using other bisulfite PCR primer programs. The primers designed by CpGPNP were used to experimentally verify the amplification of the target region of markers for body fluid identification and age estimation. CpGPNP is freely available at http://forensicdna.kr/cpgpnp/.

How Effective is Plasmonic Enhancement of Colloidal Quantum Dots for Color-Conversion Light-Emitting Devices?

Enhancing the fluorescence intensity of colloidal quantum dots (QDs) in case of color-conversion type QD light-emitting devices (LEDs) is very significant due to the large loss of QDs and their quantum yields during fabrication processes, such as patterning and spin-coating, and can therefore improve cost-effectiveness. Understanding the enhancement process is crucial for the design of metallic nanostructure substrates for enhancing the fluorescence of colloidal QDs. In this work, improved color conversion of colloidal green and red QDs coupled with aluminum (Al) and silver (Ag) nanodisk (ND) arrays designed by in-depth systematic finite-difference time domain simulations of excitation, spontaneous emission, and quantum efficiency enhancement is reported. Calculated results of the overall photoluminescence enhancement factor in the substrate of 500 × 500 µm2 size are 2.37-fold and 2.82-fold for Al ND-green QD and Ag ND-red QD structures, respectively. Experimental results are in good agreement, showing 2.26-fold and 2.66-fold enhancements for Al ND and Ag ND structures. Possible uses of plasmonics in cases such as white LED and total color conversion for possible display applications are discussed. The theoretical treatments and experiments shown in this work are a proof of principle for future studies of plasmonic enhancement of various light-emitting materials.

Selective engineering of oxygen-containing functional groups using the alkyl ligand oleylamine for revealing the luminescence mechanism of graphene oxide quantum dots.

Oxygen-containing functional groups such as epoxy, hydroxyl, carboxylic, and carboxyl groups have a great influence on the luminescence properties of graphene oxide quantum dots (GOQDs). Understanding their roles is essential for the design and optimization of GOQD performance. Herein, we investigate the effect of epoxide functional groups in GOQDs on the luminescence mechanism through passivation of the epoxide functional groups using the alkyl ligand oleylamine. Luminescence in the as-synthesized GOQDs has two separate origins: intrinsic states derived from localized sp2 carbon subdomains and extrinsic states formed by oxygen-functional groups. When the oleylamine ligand is conjugated on the GOQDs, intrinsic PL emission from the localized sp2 carbon subdomains decreases. This is discussed in detail, based on optical characterization and first-principles density functional theory calculations, which reveal that the role of the epoxide functional groups is to form localized sp2 carbon subdomains emitting intrinsic PL. To the best of our knowledge, this is the first investigation of the role of epoxide functional groups on the luminescence mechanism in GOQDs.

Evaluation of forensic genetic parameters of 12 STR loci in the Korean population using the InvestigatorⓇ HDplex kit.

We genotyped and calculated the forensic parameters of 10 non-CODIS loci and 2 CODIS loci of 990 Korean individuals using the InvestigatorⓇ HDplex kit. No significant deviations from Hardy-Weinberg equilibrium (after Bonferroni correction for multiple testing) or genetic linkage disequilibrium were observed. The calculated matching probability and power of discrimination ranged from 0.0080 to 0.2014, and 0.7986 to 0.9920, respectively. We conclude that the markers of the kit are highly informative corroborative tools for forensic DNA analysis.

Forensic genetic study of 29 Y-STRs in Korean population.

In this study, we compared two recently released commercial Y-chromosomal short tandem repeat (Y-STR) kits: the PowerPlex Y23 System (PPY23) and Yfiler® Plus PCR amplification kit (YPlus). We performed validation studies, including sensitivity, tolerance to PCR inhibitors, and mixture analysis, and a population genetics study using 306 unrelated South Korean males. PPY23 and YPlus showed similar sensitivity, but PPY23 showed higher tolerance to humic acid than YPlus. Furthermore, the detection rate of unique minor alleles called from male/male mixtures was higher for PPY23 than for YPlus. Comparing the newly added loci, the mean values of gene diversity for PPY23 and YPlus were 0.6715 and 0.8158, respectively. The discrimination capacity in the 306 unrelated South Korean males for PPY23 was 0.9837, and that for YPlus was 0.9935. These results will inform the selection of suitable Y-STR kits based on the purpose of forensic DNA analysis.

Protective effect of Cornus walteri Wangerin leaf against UVB irradiation induced photoaging in human reconstituted skin.

ETHNOPHARMACOLOGICAL RELEVANCE: Cornus walteri Wangerin has been used in oriental traditional medicine for the treatment of antidiarrheal and inflammation. AIM OF THE STUDY: The efficacy of Cornus walteri Wangerin on skin anti-photoaging was investigated. MATERIALS AND METHODS: Hydrolyzed Cornus walteri Wangerin leaf was tested for the anti-photoaging effects against ultraviolet B (UVB)-induced matrix metalloproteinase (MMP)-1, pro-inflammatory cytokines using human reconstituted skin (KeraSkin™-FT) and also tested for elastase activity in vitro. The MMP-1 and pro-inflammatory cytokine levels of the extract were evaluated by enzyme-linked immunosorbent assay (ELISA). RESULTS: The extract of hydrolyzed Cornus walteri Wangerin leaf (CWE) had the elastase inhibitory activity (IC50: 0.457mg/mL). CWE inhibited MMP-1 expression up to 61% in comparison with the control group which was not treated using CWE, but exposed to UVB. CWE also showed an inhibitory effect on releasing pro-inflammatory cytokines (IL-6 and IL-8) in KeraSkin™-FT (30% and 57% inhibition at dose of 50µg/mL, respectively). CONCLUSION: CWE is a promising anti-photoaging agent for the treatment of UVB-induced skin.

Thumb Replantation Using the Superficial Palmar Branch of the Radial Artery.

The thumb is the most important part of the hand. If thumb is amputated, all efforts should be made to replant it to preserve hand functions. Good functional outcome can be obtained with successful thumb replantation than with other reconstructive surgery. We present a case of thumb amputation of a 44 -year-old male with severe damage to the soft tissues and bony structures of the radial part of the hand. We performed the replantation anastomosing the superficial palmar branch of the radial artery as donor artery as the proximal part of thumb digital arteries were severely damaged due to crush injury and got favorable result.

Population genetic study for 24 STR loci and Y indel (GlobalFiler™ PCR Amplification kit and PowerPlex® Fusion system) in 1000 Korean individuals.

Allele frequencies for 23 autosomal short tandem repeat loci (D3S1358, vWA, D16S539, CSF1PO, TPOX, D8S1179, D21S11, D18S51, TH01, FGA, D5S818, D13S317, D7S820, D2S441, D19S433, D22S1045, D10S1248, D1S1656, D12S391, D2S1338, SE33, Penta D, Penta E), 1 Y-chromosome short tandem repeat locus (DYS391) and Y indel were obtained from 1000 unrelated individuals of the Korean population.

A Digital Squamous Cell Carcinoma Mimicking a Diabetic Foot Ulcer, With Early Inguinal Metastasis and Cancer-Related Lymphedema.

Although squamous cell carcinoma (SCC) is the second most common nonmelanoma skin cancer, clinicians have difficulty diagnosing SCC of the toe because its clinical features can mimic other less serious diseases. Clinicians are especially prone to misdiagnose SCC of the toe as diabetic foot ulcer in patients with diabetes mellitus because of the clinical similarity of the 2 ailments. SCC of the toe is generally considered to have a low risk of metastasis. Locoregional or distant metastases without bone or tendon involvement are particularly rare. The authors report here an interesting case of rapidly spreading SCC of the toe with metastasis to multiple lymph nodes and cancer-related lymphedema. Physicians should be aware of the possibility of malignancy when they encounter chronic and recalcitrant ulcerative lesions of the digits.

Association between polymorphisms of estrogen receptor 2 and benign prostatic hyperplasia.

Estrogens and estrogen receptors (ESRs) have been implicated in the stimulation of aberrant prostate growth and the development of prostate diseases. The aim of the present study was to investigate four single nucleotide polymorphisms (SNPs) of the ESR2 gene in order to examine whether ESR2 is a susceptibility gene for benign prostatic hyperplasia (BPH). In order to evaluate whether an association exists between ESR2 and BPH risk, four polymorphisms [rs4986938 (intron), rs17766755 (intron), rs12435857 (intron) and rs1256049 (Val328Val)] of the ESR2 gene were genotyped by direct sequencing. A total of 94 patients with BPH and 79 control subjects were examined. SNPStats and Haploview version 4.2 we used for the genetic analysis. Multiple logistic regression models (codominant1, codominant2, dominant, recessive and log-additive) were produced in order to obtain the odds ratio, 95% confidence interval and P-value. Three SNPs (rs4986938, rs17766755 and rs12435857) showed significant associations with BPH (rs4986938, P=0.015 in log-additive model; rs17766755, P=0.033 in codominant1 model, P=0.019 in dominant model and P=0.020 in log-additive model; rs12435857, P=0.023 in dominant model and P=0.011 in log-additive model). The minor alleles of these SNPs increased the risk of BPH, and the AAC haplotype showed significant association with BPH (χ2=6.34, P=0.0118). These data suggest that the ESR2 gene may be associated with susceptibility to BPH.

Cosine apodization of dual-resonance all-fiber acousto-optic tunable filters.

We experimentally demonstrate a novel cosine apodization technique for dual-resonance all-fiber acoustic-optic tunable filter. The technique is based on a hybrid control of input acoustic polarization state and circumferential fiber twist. We will show that intrinsic sidelobe spectra occurring between dual filtering bands are successfully suppressed through our approach, which will be also theoretically confirmed via our analytical and numerical studies. The results illustrate that the spectral positions of each resonance are tuned linearly and continuously by the fiber twist, and that overall sidelobe spectra between two resonances are suppressed regardless of fiber twist angle. The proposed scheme is useful to minimize cross talk between adjacent wavelength channels in optical sensor systems. We highlight that our approach is directly applicable to low-noise matched filtering.

A new method for ABO genotyping using fluorescence melting curve analysis based on peptide nucleic acid probes.

ABO genotyping has been routinely used to identify suspects or unknown remains in crime investigations. Probe-based fluorescence melting curve analysis (FMCA) is a powerful tool for mutation detection and is based on melting temperature shifts due to thermal denaturation. In the present study, we developed a new method for ABO genotyping using peptide nucleic acid (PNA) probe-based FMCA. This method allowed for the simultaneous detection of three single nucleotide polymorphism (SNP) sites in the ABO gene (nucleotide positions 261, 526, and 803) and the determination of 14 ABO genotypes (A/A, A/O01 or A/O02, A/O03, B/B, B/O01 or B/O02, B/O03, O01/O01 or O01/O02 or O02/O02, O01/O03 or O02/O03, O03/O03, A/B, cis-AB01/A, cis-AB01/B, cis-AB01/O01 or cis-AB01/O02, and cis-AB01/cis-AB01). Using this method, we analyzed 80 samples and successfully identified ABO genotypes (A/A [n=5], A/O01 or A/O02 [n=23], B/B [n=3], B/O01 or B/O02 [n=18], A/B [n=9], O01/O01 or O01/O02 or O02/O02 [n=20], cis-AB01/A [n=1], and cis-AB01/O01 or cis-AB01/O02 [n=1]). In addition, all steps in the method, including polymerase chain reaction, PNA probe hybridization, and FMCA, could be performed in one single closed tube in less than 3h. Since no processing or separation steps were required during analysis, this method was more convenient and rapid than traditional methods and reduced the risk of contamination. Thus, this method may be an effective and helpful tool in forensic investigations.

A microsurgical suture technique without the need for vascular clamps.

Vascular clamps are often used during microvascular repair and anastomosis. However, pressure exerted by the clamps may damage the vessels, which compromises patency of vessels. This article reports on a microsurgical suture technique performed without any clamp to avoid clamp-related problems.

Flexible, compact WDM receivers using cascaded optical and electrical down-conversion.

We propose a super-channel flexible wavelength division multiplexing (WDM) receiver architecture. The receiver, which requires no optical filtering, only a pair (I and Q phases) of coherent optical detectors, and an electrical receiver system, can simultaneously recover multiple wavelength-multiplexed channels using cascaded optical and electrical down-conversion. The receiver data capacity increases in proportion to the number of electrical sub-carrier channels. The proposed receiver concept has been described using a six-channel WDM receiver, and a two-channel ( ± 25 GHz) receiver IC, which is a key block of the WDM receiver, has been successfully demonstrated with two and three 2.5 Gb/s binary-phase-shift-key (BPSK) modulated channels.