A Novel Frameshift Mutation of the USH2A Gene in a Korean Patient with Usher Syndrome Type II

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.

Role of Mesenchymal Stem Cells in Patients with Nontraumatic Osteonecrosis of the Femoral Head / 대한정형외과연구학회지

Mesenchymal stem cells are stem cells originated from the mesoderm have the capacity to differentiate into cells of connective tissue lineages, including bone, fat, cartilage and muscle. Nontraumatic osteonecrosis of the femoral head has been suggested the cause is likely relevant to the poor proliferation activity of mesenchymal stem cells in the femoral head region. The altered function of mesenchymal stem cells may be responsible for the pathogenesis and progression of osteonecrosis, in steroid or alcohol induced nontraumatic osteonecrosis of femoral head.

Two Cases of Extragenital Infection by Mycoplasma hominis / 대한임상미생물학회지

Mycoplasma hominis is a commensal organism in the genitourinary tract. Extragenital infections by M. hominis are rare, and its occurrence is usually limited to immunocompromised patients. Here we report two patients with extragenital infection by M. hominis. The first patient, a woman with angioimmunoblastic T cell lymphoma, underwent autologous peripheral blood stem cell transplantation. The second patient, a woman with endometrial cancer, received laparoscopically-assisted vaginal hysterectomy. They both presented with septic symptoms, including fever, and M. hominis was isolated from pleural effusion and ascitic fluid, respectively. We are reporting these two cases of extragenital infection by M. hominis with a literature review to emphasize that the rapid isolation of M. hominis with early treatment can lead to a better prognosis.

Determination of Urinary Iodine Concentration by Inductively Coupled Plasma-mass Spectrometry in Thyroid Cancer Patients on Low-iodine Diet / 대한진단검사의학회지

BACKGROUND: Thyroid cancer patients should be on low-iodine diet (LID) before radioactive iodine therapy (RAIT) to maximize the effect of RAIT. Urinary iodine excretion is the most accurate marker of very recent dietary iodine intake. We developed and evaluated the analytical performance of inductively coupled plasma-mass spectrometry (ICP-MS) to determine urinary iodine concentration. METHODS: We evaluated the linearity, precision, accuracy, and lower limit of quantification (LLOQ) of an ICP-MS method (Agilent 7500ce) to determine urinary iodine concentration in accordance with the Food and Drug Administration (FDA) guidelines for bioanalytical method validation. This method was used to determine and compare the iodine concentration in random urine samples of 120 thyroid cancer patients on LID for 1 week and 80 healthy adults on normal diet. RESULTS: Our ICP-MS method showed good linearity (1.0-1,913 microgram/L; R2>0.999). Both intra-day and inter-day precision CV were within 20% for the LLOQ (1 microgram/L) and within 15% for the other concentrations. Accuracy was 110-120% for the LLOQ and 95-115% for the other concentrations. The median concentration of iodine in random urine samples from thyroid cancer patients on LID (38.7 microgram/L) was significantly lower than that of healthy subjects (238.8 microgram/L) (P<0.0001). CONCLUSIONS: Urinary iodine analysis by ICP-MS showed good linearity, precision, accuracy, wide measuring range of detection, and lower LLOQ. This method will be very useful to evaluate the status of dietary iodine intake and the appropriateness of LID in thyroid cancer patients, thereby maximizing the effect of RAIT.

The Common NF-kappaB Essential Modulator (NEMO) Gene Rearrangement in Korean Patients with Incontinentia Pigmenti

Incontinentia pigmenti (IP) is a rare X-linked dominant disorder characterized by highly variable abnormalities of the skin, eyes and central nervous system. A mutation of the nuclear factor-kappa B essential modulator (NEMO) located at Xq28 is believed to play a role in pathogenesis and the mutation occurs mostly in female patients due to fatal consequence of the mutation in males in utero. This study was designed to identify the common NEMO rearrangement in four Korean patients with IP. Deletion of exons 4 to 10 in the NEMO, the most common mutation in IP patients, was detected in all of the patients by the use of long-range PCR analysis. This method enabled us to discriminate between NEMO and pseudogene rearrangements. Furthermore, all of the patients showed skewed XCI patterns, indicating pathogenicity of IP was due to cells carrying the mutant X chromosome. This is the first report of genetically confirmed cases of IP in Korea.

Discrepant Immunophenotypic Characteristics between the Lymph Node and Bone Marrow in Two Mixed-Phenotype Acute Leukemia Patients / 대한진단검사의학회지

The immunophenotypic profile of hematological malignancies is usually consistent among different sites of involvement; this consistency allows reliable diagnosis from peripheral blood, bone marrow, or lymph node, especially in cases of acute leukemia. Although in a minority of lymphoma patients, two or more different populations with discordant immunophenotypes have been described, either at the same or distinct sites. Here, we report two Korean patients with acute leukemia where the results of immunophenotypic analysis of the bone marrow specimen were different from those of immunohistochemical studies of a biopsy sample of a cervical lymph node, particularly with respect to myeloperoxidase and CD3. The clinical significance of the immunophenotypic disparity found in the patients still remains unknown; however, discrepancies between the different anatomic sites that are simultaneously involved can occur in a subset of leukemia patients. Therefore, integration of all the relevant results, including those of the bone marrow studies, may be helpful for accurate diagnosis and selecting appropriate treatment modalities.

Calcification Comparison of Polymers for Vascular Graft

Polytetrafluoroethylene (PTFE), polyurethane (PU) and silicone are widely known biocompatible polymers which are commonly used for vascular grafts. However, in vitro and in vivo calcifications of these polymers have been found to seriously compromise their quality as biomaterials. In consideration of this problem, the present study compared the calcification rate and extent of PTFE, PU and silicone. Using the in vitro flow-type method, PTFE, PU and silicone films were tested for 1, 4, 7, 10, 14 and 21 days. After 21 days of in vitro calcification test, the calcium levels on PTFE, PU and silicone were 35.89 5.01 microgram /cm2, 23.73 0.68 microgram/cm2 and 19.86 5.28 microgram/cm2, respectively. The higher observed calcium level for PTFE may be due to the effect of the rough surface of PTFE in accumulating calcium ions on the polymer surface. From the 7th day of test, the [Ca]/[P] molar ratio started to decrease over time, and PTFE showed a faster calcification process. This decreasing [Ca]/[P] molar ratio demonstrated the typical calcification mechanism consisting of phosphorus ion accumulation following calcium ion accumulation. This study concluded that PU and silicone are less calcified than PTFE film, a finding in good agreement with previously published studies.