The purpose of this study was to provide an actual guideline in determining the shape, diameter, and position of the implant in immediate implantation by the measurement of the thickness of facial and palatal plate, the thickness of cortical bone on the facial and palatal plate, the diameter of the root, and the distance between the roots in the cadavers.
MATERIALS AND METHODS
The horizontal sections of 20 maxillae were measured and analyzed to obtain the average values. Resin blocks were produced and cut serially at 1 mm intervals from the cervical line to the root apex. Images of each section were obtained and the following measurements were performed: The thickness of the facial and palatal residual bone at each root surface, the thickness of the facial and palatal cortical bone at the interdental region, the diameter of all roots of each section on the faciopalatal and mesiodistal diameter, and the interroot distance. Three specimens with measurements close to the average values were chosen and 3-dimensional images were reconstructed.
The thickness of the facial and palatal cortical bone at the interdental region in the maxilla, the buccal cortical bone was thicker in the posterior region compared to the anterior region. The interroot distance of the alveolar bone thickness between the roots increased from anterior to posterior region and from coronal to apical in the maxilla.
In this study, the limited results of the morphometric analysis of the alveolar ridge using the sections of maxilla in the cadavers may offer the useful information when planning and selecting optimal implant for immediate implantation in the maxilla.
Immediate implantation; Maxillary alveolar region; Alveolar bone thickness; Root diameter; Cadavers
Cerebral hyperperfusion syndrome (CHS) is increasingly recognized as an uncommon, but serious, complication subsequent to carotid artery stenting (CAS) and carotid endarterectomy (CEA). The onset of CHS generally occurs within two weeks of CEA and CAS, and a delay in the onset of CHS of over one week after CAS is quite rare. We describe a patient who developed CHS three weeks after CAS with status epilepticus.
Cerebral hyperperfusion syndrome; Carotid artery stenting; Carotid artery stenosis; Status epilepticus
Thymic carcinomas are very rare tumors that are often associated with extrathoracic metastasis to other organs. However, it is well known that thymic carcinomas rarely metastasize to the spine, and the prognosis, treatment, and natural course of this disease are not yet standardized.
We describe seven thymic carcinoma patients with spinal metastasis who were diagnosed and treated in our institute from January 2006 to December 2011. We performed surgical treatment and adjuvant chemotherapy and/or radiation therapy, in consideration of each individual disease's course, and we regularly followed up the patients.
Of the seven patients, five were male and two were female. Six had metastases in the thoracic spine, and one had metastases in the lumbar spine. An extradural lesion was found in five patients, and two patients had both extradural and intradural lesions. The period from the primary diagnosis to spinal metastases varied widely (range, 1.23-14 years). After surgery, all patients showed an improvement of back pain and radicular pain. Two patients were lost to follow-up, but the other five maintained ambulatory function until their final follow-up. Four patients died because of pulmonary complications accompanied with the disease's progression. One patient died from uncontrolled brain metastases. After surgery, the median survival was 204±111.43 days.
Because metastasis to the spine from thymic carcinoma is very rare, there are no treatment guidelines. Nevertheless, we suggest that appropriate surgical management of the metastatic lesion is necessary for the preservation of the patient's quality of life during survival.
Thymic carcinoma; Spinal metastasis; Surgical management
The tuberculin skin test (TST) frequently yields false positive results among BCG-vaccinated persons thereby limiting its diagnostic value particularly in settings with high BCG vaccination rate. We determined the agreement between IGRA and TST using 2 cutoff values and identified possible relationships between the results of these tests and the development of active tuberculosis.
Adolescents aged 11–19 years in close contact with smear-positive tuberculosis cases and with normal chest radiographs were recruited from middle and high schools in South Korea. The TST was conducted by trained nurses, and blood was drawn for the QuantiFERON-TB Gold In-Tube (QFT-GIT). Participants were followed up for 2 years to check for incidence tuberculosis.
A total of 2,982 subjects were included in the study, the average age was 15.1 years (SD 1.3), 61% had BCG vaccination scars. The agreement of QFT-GIT and the TST was low (κ = 0.38, 95% CI 0.32 to 0.42) using 10 mm cutoff; however, when the 15 mm cutoff was used, the agreement was intermediate (κ = 0.56, 95% CI 0.50 to 0.61). The odds ratio (OR) for the development of active tuberculosis was 7.9 (95% CI 3.46 to 18.06) for QFT-GIT positive patients, 7.96 (95% CI 3.14-20.22) for TST/QFT-GIT+ and the OR 4.62 (95% CI 2.02 to 10.58) and 16.35 (95% CI 7.09 to 37.71) for TST 10 mm and 15 mm cutoff respectively.
The results of this study suggest that the TST cutoff point for patients aged 11–17 years would be 15 mm in other study. The OR of QFT-GIT for the development of active tuberculosis and its intermediate agreement with TST using 15 mm cutoff demonstrates its role as an adjunct diagnostic tool to current clinical practice. Positive responders to both TST and QFT-GIT at the outset may benefit from chemoprophylaxis.
Dehydroevodiamine·HCl (DHED) has been reported to prevent memory impairment and neuronal cell loss in a rat model with cognitive disturbance. We investigated the effect of DHED on memory impairment and behavioral abnormality caused by stress. We demonstrated that DHED can improve stress-induced memory impairments and depression-like behaviors by using open-field test, Y-maze test and forced swimming test. DHED treatment significantly recovered the decreases in the levels of neural cell adhesion molecule (NCAM) proteins caused by stress and the decreases in cell viability. Our results suggested that DHED is a potential drug candidate for neuronal death, memory impairment and depression induced by stress.
Depression; DHED; Fluoxetine; Memory; Stress
The F8 and F9 genes encode for coagulation factor VIII (FVIII) and FIX, respectively, and mutations in these genes are the genetic basis of hemophilia A/B. To determine whether a sequence variation in F8/F9 is a disease-causing mutation, frequency data from a control population is needed. This study aimed to obtain data on sequence variation in F8/F9 in a set of functionally validated control chromosomes of Korean descent.
We re-sequenced F8 and F9 from DNA samples of 100 Korean male control individuals with normal PT, aPTT, and FVIII activity. PCR and direct sequencing analyses were performed using primer pairs to cover all coding regions and the flanking intronic sequences.
Thirteen individuals (13%) were hemizygous for sequence variations in the coding region of F8. Six (6%) had c.3780C>G (p.Asp1260Glu), five (5%) had c.3864A>C (p.Ser1288=). One each individual (1%) had c.4794G>T (p.Glu1598Asp) and c.5069 A>G (p.Glu1690Gly). Asp1260Glu and Ser1288= were known SNPs (rs1800291 and rs1800292, respectively). Glu1598Asp was assigned as a missense mutation in public databases (HGMD and HAMSTeRS), and Glu1690Gly was a novel variation. Based on the normal FVIII activities in control individuals carrying these variations (109% and 148%, respectively), they were considered to be rare SNPs. No variation was observed in F9 of control individuals.
A significant proportion of control individuals carried sequence variations in F8, but not in F9. These results can be used as a reference dataset for molecular diagnosis of hemophilia A and B, particularly in Korea.
Hemophilia; F8; F9; Sequence variation; Control population; Korea
The cell-mediated immunity (CMI)-based in vitro gamma interferon release assay (IGRA) of Mycobacterium leprae-specific antigens has potential as a promising diagnostic means to detect those individuals in the early stages of M. leprae infection. Diagnosis of leprosy is a major obstacle toward ultimate disease control and has been compromised in the past by the lack of specific markers. Comparative bioinformatic analysis among mycobacterial genomes identified potential M. leprae-specific proteins called “hypothetical unknowns.” Due to massive gene decay and the prevalence of pseudogenes, it is unclear whether any of these proteins are expressed or are immunologically relevant. In this study, we performed cDNA-based quantitative real-time PCR to investigate the expression status of 131 putative open reading frames (ORFs) encoding hypothetical unknowns. Twenty-six of the M. leprae-specific antigen candidates showed significant levels of gene expression compared to that of ESAT-6 (ML0049), which is an important T cell antigen of low abundance in M. leprae. Fifteen of 26 selected antigen candidates were expressed and purified in Escherichia coli. The seroreactivity to these proteins of pooled sera from lepromatous leprosy patients and cavitary tuberculosis patients revealed that 9 of 15 recombinant hypothetical unknowns elicited M. leprae-specific immune responses. These nine proteins may be good diagnostic reagents to improve both the sensitivity and specificity of detection of individuals with asymptomatic leprosy.
Hearing loss (HL) is one of the most frequent clinical manifestations of patients who suffer with multi-systemic genetic disorders. HL in association with other physical stigmata is referred to as a syndromic form of HL. LEOPARD syndrome (LS) is one of the disorders with syndromic HL and it is caused by a mutation in the PTPN11 or RAF1 gene. In general, 5 year old children who undergo cochlear implantation usually show a marked change in behavior regarding sound detection within the first 6 months of implant use, but word identification may not be exhibited for at least another 6-12 months of implant use. We herein report on a 5-year-old girl with LS. Her clinical manifestations including bilateral sensorineural HL, which indicated the diagnosis of LS. We confirmed the diagnosis by identifying a disease-causing mutation in the PTPN11 gene, which was a heterozygous missense mutation Ala461Thr (c.1381G>A). She underwent cochlear implantation (CI) without complications and she is currently on regular follow-up at postoperative 1 year. This is the first reported case of CI in a patient with LS in the medical literature.
LEOPARD syndrome; Mutation; Cochlear implantation
Cotton, one of the world’s leading crops, is important to the world’s textile and energy industries, and is a model species for studies of plant polyploidization, cellulose biosynthesis and cell wall biogenesis. Here, we report the construction of a plant-transformation-competent binary bacterial artificial chromosome (BIBAC) library and comparative genome sequence analysis of polyploid Upland cotton (Gossypium hirsutum L.) with one of its diploid putative progenitor species, G. raimondii Ulbr.
We constructed the cotton BIBAC library in a vector competent for high-molecular-weight DNA transformation in different plant species through either Agrobacterium or particle bombardment. The library contains 76,800 clones with an average insert size of 135 kb, providing an approximate 99% probability of obtaining at least one positive clone from the library using a single-copy probe. The quality and utility of the library were verified by identifying BIBACs containing genes important for fiber development, fiber cellulose biosynthesis, seed fatty acid metabolism, cotton-nematode interaction, and bacterial blight resistance. In order to gain an insight into the Upland cotton genome and its relationship with G. raimondii, we sequenced nearly 10,000 BIBAC ends (BESs) randomly selected from the library, generating approximately one BES for every 250 kb along the Upland cotton genome. The retroelement Gypsy/DIRS1 family predominates in the Upland cotton genome, accounting for over 77% of all transposable elements. From the BESs, we identified 1,269 simple sequence repeats (SSRs), of which 1,006 were new, thus providing additional markers for cotton genome research. Surprisingly, comparative sequence analysis showed that Upland cotton is much more diverged from G. raimondii at the genomic sequence level than expected. There seems to be no significant difference between the relationships of the Upland cotton D- and A-subgenomes with the G. raimondii genome, even though G. raimondii contains a D genome (D5).
The library represents the first BIBAC library in cotton and related species, thus providing tools useful for integrative physical mapping, large-scale genome sequencing and large-scale functional analysis of the Upland cotton genome. Comparative sequence analysis provides insights into the Upland cotton genome, and a possible mechanism underlying the divergence and evolution of polyploid Upland cotton from its diploid putative progenitor species, G. raimondii.
BIBAC library; Gossypium hirsutum; Gossypium raimondii; BIBAC end sequence (BES); Genome evolution; SSR; Polyploidization and evolution
Therapy-related myeloid neoplasms (t-MN) occur as late complications of cytotoxic therapy. This study reviewed clinical and cytogenetic characteristics of patients with t-MN at a single institution in Korea.
The study subjects included 39 consecutive patients diagnosed with t-MN. Each subject's clinical history of previous diseases, treatments, and laboratory data was reviewed, including cytogenetics. The primary diagnosis was hematologic malignancy in 14 patients and solid tumor in 25 patients.
Therapy-related acute myeloid leukemia (t-AML, 66.7%) was found to be more common than therapy-related myelodysplastic syndrome (t-MDS). Primary hematologic malignancies that were commonly implicated included mature B-cell neoplasm and acute leukemia. Breast cancer was the most common primary solid tumor. The mean time interval from cytotoxic therapy initiation to t-MN detection was 49 months. Chromosomal aberrations were observed in 35 patients, and loss of chromosome 5, 7, or both accounted for 41% of all cases. Balanced rearrangements occurred in 13 patients; these patients showed shorter latency intervals (mean, 38 months) than patients with loss of chromosome 5 or 7 (mean, 61 months).
In this study, we determined the clinical and cytogenetic characteristics of Korean patients with t-MN. Although our results were generally consistent with those of previous reports, we found that t-MN resulting from de novo leukemia was common and that t-AML was more common than t-MDS at presentation. Multi-institutional studies involving a larger number of patients and additional parameters are required to investigate the epidemiology, genetic predisposition, and survival rate of t-MN in Korea.
Therapy-related neoplasms; Myelodysplastic syndrome; Acute myeloid leukemia; Cytogenetics; Korea
Usher syndrome type II (USH2) is the most common form of Usher syndrome, characterized by moderate to severe hearing impairment and progressive visual loss due to retinitis pigmentosa. It has been shown that mutations in the USH2A gene are responsible for USH2. The authors herein describe a 34-year-old Korean woman with the typical clinical manifestation of USH2; she had bilateral hearing disturbance and progressive visual deterioration, without vestibular dysfunction. Molecular genetic study of the USH2A gene revealed a novel frameshift mutation (c.2310delA; Glu771LysfsX17). She was heterozygous for this mutation, and no other mutation was found in USH2A, suggesting the possibility of an intronic or large genomic rearrangement mutation. To the best of our knowledge, this is the first report of a genetically confirmed case of USH2 in Korea. More investigations are needed to delineate genotype-phenotype correlations and ethnicity-specific genetic background of Usher syndrome.
Usher syndrome type II; USH2A; Mutation; Frameshift; Korea
MYC rearrangement, a characteristic cytogenetic abnormality of Burkitt lymphoma and several subsets of other mature B-cell neoplasms, typically involves an immunoglobulin gene partner. Herein, we describe a case of precursor B-cell lymphoblastic leukemia harboring a MYC rearrangement with a novel non-immunoglobulin partner locus. The patient was a 4-yr-old Korean boy with ALL of the precursor B-cell immunophenotype. At the time of the second relapse, cytogenetic analyses revealed t(4;8)(q31.1;q24.1) as a clonal evolution. The MYC rearrangement was confirmed by FISH analysis. He died 3 months after the second relapse without achieving complete remission. To our knowledge, this is the first report of a case of MYC rearrangement with a non-immunoglobulin partner in precursor B-cell lymphoblastic leukemia.
Precursor B-cell acute lymphoblastic leukemia; MYC gene rearrangement; Non-immunoglobulin partner
In this report, we describe a Korean patient with May-Hegglin anomaly from a mutation of the MYH9 gene. The proband was a 21-year-old man with thrombocytopenia. He did not have a bleeding tendency. His neutrophil count was normal at 7490/mm3; however, the neutrophils contained abnormal basophilic inclusions in their cytoplasm. The platelet count was decreased at 15000/mm3 with giant platelets. Coagulation test results were not remarkable. Direct sequencing of MYH9 revealed that he was heterozygous for a mutation in exon 1, which was a 97T>A substitution mutation affecting codon 33, substituting tryptophan with arginine (Trp33Arg). Family study showed that both of his parents had normal phenotype and genotypes, indicating a de novo occurrence of the mutation in the proband.
May-Hegglin anomaly; MYH9; thrombocytopenia; Korean
Hereditary thrombophilia (HT) is a major risk factor for idiopathic pulmonary embolism (iPE) and shows different prevalence among ethnic groups. The prevalence and clinical characteristics of HT in Korean patients with iPE were investigated.
Materials and Methods
Patients with PE on computed tomography (CT) scan were recruited, and those with malignancy were excluded. Patients were divided into iPE and provoked PE (pPE) groups. The presence of HT in the iPE group was assessed by DNA sequencing of the corresponding gene in patients who had low levels of natural anticoagulants. The clinical characteristics of iPE with HT (iPE/HT+) were compared with those of iPE without HT (iPE/HT-) and pPE.
Out of 161 patients, 84 patients had iPE and 77 patients had pPE. Among 54 patients in the iPE group whose coagulation profiles were tested, 28 patients were diagnosed with HT (51.9%; 28/54). Compared with the iPE/HT- and pPE groups, the iPE/HT+ group showed the highest proportion of male patients (71.4%; p<0.001); the youngest mean age (44±14 years; p<0.001); and the highest frequencies for history of venous thromboembolism (64.3%; p<0.001), concurrent deep vein thrombosis (75.0%; p=0.021), and adverse clinical outcomes (42.9%, p<0.001). Protein C deficiency was the most common HT. On molecular genetic tests, causative mutation was identified in 13 patients.
In this study of Korean patients, about half of the patients with iPE had HT. Patients with iPE and HT were mostly young males with deep venous thrombosis (DVT), previous venous thromboembolism (VTE), and frequent adverse clinical outcomes. Therefore, Korean patients with iPE should be tested for HT.
Pulmonary embolism; hereditary thrombophilia; protein C deficiency; Korea
This study evaluated the surface characteristics and bond strength produced using a novel technique for coating hydroxyapatite (HA) onto titanium implants.
HA was coated on the titanium implant surface using a super-high-speed (SHS) blasting method with highly purified HA. The coating was performed at a low temperature, unlike conventional HA coating methods. Coating thickness was measured. The novel HA-coated disc was fabricated. X-ray diffraction analysis was performed directly on the disc to evaluate crystallinity. Four novel HA-coated discs and four resorbable blast medium (RBM) discs were prepared. Their surface roughnesses and areas were measured. Five puretitanium, RBM-treated, and novel HA-coated discs were prepared. Contact angle was measured. Two-way analysis of variance and the post-hoc Scheffe's test were used to analyze differences between the groups, with those with a probability of P<0.05 considered to be statistically significant. To evaluate exfoliation of the coating layer, 7 sites on the mandibles from 7 mongrel dogs were used. Other sites were used for another research project. In total, seven novel HA-coated implants were placed 2 months after extraction of premolars according to the manufacturer's instructions. The dogs were sacrificed 8 weeks after implant surgery. Implants were removed using a ratchet driver. The surface of the retrieved implants was evaluated microscopically.
A uniform HA coating layer was formed on the titanium implants with no deformation of the RBM titanium surface microtexture when an SHS blasting method was used.
These HA-coated implants exhibited increased roughness, crystallinity, and wettability when compared with RBM implants.
Biocompatible coated materials; Dental implants; Hydroxyapatites; Titanium
Mutations in the transcription factor CCAAT/enhancer binding protein α gene (CEBPA) are found in 5-14% of the patients with AML and have been associated with a favorable clinical outcome. In this study, we aimed to assess the frequencies and characteristics of mutations in CEBPA. Between 2006 and 2009, CEBPA mutations were assessed using archival DNA samples obtained from 30 consecutive adult patients diagnosed with AML with a normal karyotype at our institution. CEBPA mutations were detected using direct sequencing analyses. These mutations were detected and described with reference to GenBank Accession No. NM_004364.3. In our series, CEBPA mutations were detected in 4 patients (13.3%). These mutations occurred as double mutations in all 4 patients. Among the 8 mutant alleles, 5 were novel (c.179_180dupCG, c.50_53delGCCA, c.178_182delACGTinsTTT, c.243_244insGTCG, and c.923_924insCTC). The frequency of occurrence of CEBPA mutations in Korean patients with AML is comparable to that in previous reports. Long-term follow-up data from a larger series of patients with comprehensive molecular profiling are needed to delineate the prognostic implications.
CEBPA; Mutation; Acute myeloid leukemia; Normal Karyotype; Korea
Acquired hemophilia A (AHA) is a rare coagulopathy caused by autoantibodies to coagulation factor VIII (FVIII). Most patients with AHA have been previously healthy; however, a variety of morbidities have been associated with the condition including pregnancy. A 40-yr-old woman visited our institution with extensive hematoma on the right hip area. Her medical history revealed no personal or familial history of bleeding diathesis. Her coagulation tests showed markedly prolonged aPTT (117 sec), markedly decreased level of FVIII activity (0.4%) and high-titer FVIII inhibitor (77 BU). Collectively, she was diagnosed as having postpartum AHA and was treated with bypassing agents and corticosteroids. Her aPTT was normalized on the 174th postpartum day and FVIII inhibitor showed negative conversion on the 224th postpartum day. This is the first case of postpartum AHA with high-titer FVIII inhibitor in Korea. Timely diagnosis and management can reduce morbidity and mortality of this potentially life-threatening condition.
Acquired hemophilia A; Postpartum; Factor VIII inhibitor; Korea
Fibrin-related markers (FRM) such as fibrin monomer (FM) and D-dimer (DD) are considered useful biological markers for the diagnosis of disseminated intravascular coagulation (DIC). However, no studies on the diagnostic performance of different FRMs have been published in Korea. The aim of this study was to evaluate the diagnostic performance of FM for DIC in comparison with DD.
The reference limit of FM was determined based on plasma sample data obtained from 210 control individuals. To evaluate diagnostic performance, FM data from the plasma samples of 139 patients with DIC-associated diseases were obtained for DIC scoring. FM was measured by immunoturbidimetry using STA-LIATEST FM (Diagnostica Stago, France). Patients were classified according to the DIC score as non-DIC, non-overt DIC, or overt DIC. ROC curve analyses were performed.
The reference limit in the control individuals was determined to be 7.80 µg/mL. Patients with DIC-associated diseases were categorized as non-DIC (N=43), non-overt DIC (N=80), and overt DIC (N=16). ROC curve analyses showed that the diagnostic performance of FM was comparable to DD in both non-overt DIC and overt DIC (P=0.596 and 0.553, respectively). In addition, FM had higher sensitivity, specificity, positive predictive value, and negative predictive value than DD for differentiating overt DIC from non-DIC.
This study demonstrated that the diagnostic performance of FM for DIC was comparable to DD. FM might be more sensitive and more specific than DD in the diagnosis of overt DIC, but not non-overt DIC.
Area under the curve (AUC); Disseminated intravascular coagulation (DIC); D-dimer (DD); Fibrin monomer (FM); Fibrin-related marker (FRM); ROC
Amyloidosis is a heterogeneous group of diseases in which misfolding of extracellular proteins is the pathogenic factor. Light chain amyloidosis (AL) is the most common form of amyloidosis, and the causative proteins in AL are the immunoglobulin light chains produced by clonal plasma cells. Hemorrhagic events, ranging from mild subcutaneous hemorrhage to life-threatening bleeding, account for a significant proportion of morbidities and mortality in AL patients. Deficiency of factor X from deposition into amyloid fibrils has been reported to be the most common acquired factor deficiency in AL. We herein report 2 patients with acquired factor X deficiency in AL. A 55-yr-old woman with AL had a prolonged prothrombin time (PT) and an activated partial thromboplastin time (aPTT) of 2.51 International Normalized Ratio (INR) and 75.1 sec, respectively, which were corrected on mixing with normal plasma. Factor X activity was markedly decreased at 5%. The other patient was a 67-yr-old man with AL with a PT of 1.63 INR and an aPTT of 50.3 sec, which were corrected on mixing with normal plasma. Factor X activity was decreased at 17%. Neither of the patients had apparent hemorrhagic manifestations. Identification of acquired factor deficiency and timely coagulation tests are needed in the diagnostic workup and management in AL.
Amyloidosis; Factor X deficiency; Korea
Sihler's staining allows visualization of the nerve distribution within soft tissues without extensive dissection and does not require slide preparation, unlike traditional approaches. This technique can be applied to the mucosa, muscle, and organs that contain myelinated nerve fibers. In particular, Sihler's technique may be considered the best tool for observing nerve distribution within skeletal muscles. The intramuscular distribution pattern of nerves is difficult to observe through manual manipulation due to the gradual tapering of nerves toward the terminal end of muscles, so it should be accompanied by histological studies to establish the finer branches therein. This method provides useful information not only for anatomists but also for physiologists and clinicians. Advanced knowledge of the nerve distribution patterns will be useful for developing guidelines for clinicians who perform operations such as muscle resection, tendon transplantation, and botulinum toxin injection. Furthermore, it is a useful technique to develop neurosurgical techniques and perform electrophysiological experiments. In this review, Sihler's staining technique is described in detail, covering its history, staining protocol, advantages, disadvantages, and possible applications. The application of this technique for determining the arterial distribution pattern is also described additionally in this study.
Review; Sihler's staining; Whole mount nerve staining; Nerve; Artery
Hearing impairment (HI) is the most common sensory deficit in human. The Gap Junction Protein, Beta-2 (GJB2) gene encodes the protein connexin 26, and this gene accounts for up to half of the cases of autosomal recessive nonsyndromic HI. This study was conducted to obtain a set of sequence variations (SVs) of the GJB2 gene among Koreans from the general population for making molecular genetic diagnoses and performing genetic counseling.
We resequenced the GJB2 gene in 192 chromosomes from 96 adult individuals of Korean descent and who were without a history of hearing difficulty. The data of the SVs was obtained and the haplotypes were reconstructed from the data.
Five SVs were observed, including a novel one (c.558G>A; p.T186T), with the allele frequencies ranging from 0.5% (1/192) to 41% (79/192). The linkage disequilibrium study and haplotype construction showed that some of the SVs are in tight linkage, resulting in a limited number of haplotypes.
We observed SVs of the GJB2 gene with different allele frequencies, and a limited number of haplotypes were constructed. The data from this study can be used as reference data for GJB2-related hearing genetic studies, including studies on the founder effect and population genetics, and this data is particularly relevant to people of East Asian decent.
GJB2; Resequencing; Sequence variations; Haplotype; Korea
The collapse of North Korea's public health system has increased the development of tuberculosis (TB) in its populace. This study investigated the prevalence of active and latent TB infection (LTBI) in such people who have settled in the Republic of Korea since 1999. From 1999 to August 2006, 7,722 dislocated North Koreans entered the Republic of Korea and all were screened immediately for active TB. Demographic and clinical characteristics were reviewed from the official records of the Settlement Support Office for Dislocated North Koreans, based in the Ministry of Unification. Of 7,722 participants, 87 (1.13%) were diagnosed with active TB from 1999 to August 2006. Of these, 78 (90%) had pulmonary TB. Checking for the presence of a Bacille Calmette-Guérin (BCG) scar and tuberculin skin test has been performed in all dislocated North Koreans since November 2005. Of 1,112 participants, BCG vaccination scars were found in 67.4%. The tuberculin-positive rate using two tuberculin unit doses of the purified protein derivative RT23 (≥10 mm in diameter) was 81.5%. The prevalence of active TB and LTBI in dislocated North Koreans was high. Because this group bears a disproportionate burden of TB, we need to initiate a specific control programme and to plan for the impact of this disease in the Republic of Korea.
Tuberculosis; Dislocated North Korean; Refugees; Latent TB infection