141 research outputs found
Phase Contrast Microradiography of Mouse Lung Using Synchrotron X-ray: Correlation with Optical Microscopy
Purpose: The purpose of this study is to evaluate the feasibility of phase contrast X-ray microtomography and microradiography, using a polychromatic synchrotron X-ray, for analysis of the mouse lung microstructure. Materials and Methods: Normal mice were used for experiments. Some of the mouse lungs were prepared by the lung fixation-inflation method. The resulting sponge-like inflated lung samples were used for microtomography. The remaining mouse lungs were cut into 10 um sections and were used for microradiography and optical microscopic correlation. The experiments on mouse lung samples were per-formed at the 7B2 beamline of the Pohang Light Source in Korea. Results: Phase contrast X-ray microtomography of inflated lung samples showed individual alveolar structure on 3-D reconstruction. Phase contrast microradiographs of thin lung samples showed microstructure of lung, such as alveoli and bronchioles, and were well correlated with optical microscopic images. Conclusions: The results indicate that the phase contrast X-ray microtomography and microradiography using polychromatic synchrotron X-ray is feasible for evaluation of microstructure of the lung.X115sciescopuskc
The Risk of Cytomegalovirus Infection in Non-myeloablative Peripheral Stem Cell Transplantation Compared with Conventional Bone Marrow Transplantation
Non-myeloablative allogeneic peripheral stem cell transplantation (NST) is a novel therapeutic strategy for patients with hematologic malignancies. Whether non-myeloablative transplants are associated with increased risk of cytomegalovirus (CMV) infections is unknown. To clarify this issue, we compared the outcome of CMV infection following 24 allogeneic non-myeloablative peripheral blood stem cell transplants and 40 conventional bone marrow transplants (CBT). The NST regimen consisted of busulfan (4mg/kg/day), fludarabine (30mg/m2) and anti-thymocyte globulin (10 mg/kg). Twelve patients (50%) in the NST group and 17 (43%) in the CBT group developed positive antigenemia before day 100 (p=0.60). The time to the first appearance of positive antigenemia was not different between these two groups (p=0.40), and two groups showed similar initial and maximal antigenemia values (p=0.56 and p=0.68, respectively). Only one case of CMV colitis developed in the CBT group whereas CMV disease did not develop in the NST group. Although statistically insignificant, the treatment response against CMV antigenemia using ganciclovir was in favor of NST group. In conclusion, there was no difference in the risk of CMV infection between NST group and CBT group. Further prospective and controlled study is needed to clarify the impact of non-myeloablative procedure on the outcome of CMV infection
The First Very Long Baseline Interferometry Image of 44 GHz Methanol Maser with the KVN and VERA Array (KaVA)
We have carried out the first very long baseline interferometry (VLBI)
imaging of 44 GHz class I methanol maser (7_{0}-6_{1}A^{+}) associated with a
millimeter core MM2 in a massive star-forming region IRAS 18151-1208 with KaVA
(KVN and VERA Array), which is a newly combined array of KVN (Korean VLBI
Network) and VERA (VLBI Exploration of Radio Astrometry). We have succeeded in
imaging compact maser features with a synthesized beam size of 2.7
milliarcseconds x 1.5 milliarcseconds (mas). These features are detected at a
limited number of baselines within the length of shorter than approximately 650
km corresponding to 100 Mlambda in the uv-coverage. The central velocity and
the velocity width of the 44 GHz methanol maser are consistent with those of
the quiescent gas rather than the outflow traced by the SiO thermal line. The
minimum component size among the maser features is ~ 5 mas x 2 mas, which
corresponds to the linear size of ~ 15 AU x 6 AU assuming a distance of 3 kpc.
The brightness temperatures of these features range from ~ 3.5 x 10^{8} to 1.0
x 10^{10} K, which are higher than estimated lower limit from a previous Very
Large Array observation with the highest spatial resolution of ~ 50 mas. The 44
GHz class I methanol maser in IRAS 18151-1208 is found to be associated with
the MM2 core, which is thought to be less evolved than another millimeter core
MM1 associated with the 6.7 GHz class II methanol maser.Comment: 19 pages, 3 figure
Genotype and Phenotype Spectrum of FRMD7-Associated Infantile Nystagmus Syndrome
PURPOSE. We investigate the genotype and phenotype spectrum of FRMD7-associated infantile nystagmus syndrome in Korean probands. METHODS. A total of 37 patients with infantile nystagmus syndrome were recruited prospectively for genetic analysis. We performed polymerase chain reaction (PCR)-based direct sequencing and haplotype analysis for FRMD7. Detailed ophthalmic examinations and eye movement recordings were compared between FRMD7 and non-FRMD7 groups. RESULTS. In 13 (35%) of 37 patients, five different mutations of FRMD7 were detected: start codon mutation c.1A>G, splice site mutation c.162thorn6T>C, and three missense mutations (c.575A>C, c.722A>G, and c.875T>C). The latter mutation was identified in seven unrelated patients, and always was accompanied with two single nucleotide polymorphisms of exon 12 (rs6637934, rs5977623). Compared to non-FRMD7 groups, a cup-to-disc ratio was significantly decreased in FRMD7 groups (P < 0.001), and a disc-macula distance to disc diameter ratio markedly increased in the FRMD7 group (P = 0.015). Most patients in the FRMD7 group had at least two types of the nystagmus waveforms, and the most common type was unidirectional jerk nystagmus (75%), such as pure jerk and jerk with extended foveation, followed by pendular (25%), bidirectional jerk (19%), and dual jerk (6%) nystagmus. No significant differences were observed between FRMD7 and non-FRMD7 groups in terms of the nystagmus waveform, presence of periodic alternating nystagmus, and mean foveation time. CONCLUSIONS. We identified five FRMD7 mutations in 35% of our infantile nystagmus syndrome cohort, expanding its mutational spectrum. The missense mutation c.875T>C may be a common mutation arisen from the founder effect in Korea. Optic nerve dysplasia associated with FRMD7 mutations suggests that the abnormal development of afferent visual systems may affect neural circuitry within the oculomotor syste
The Outcomes of Hypertransfusion in Major ABO Incompatible Allogeneic Stem Cell Transplantation
Major ABO incompatibility may be potentially associated with immediate or delayed hemolysis and delayed onset of erythropoiesis in patients receiving allogeneic hematopoietic stem cell transplantation (HSCT). To determine if hemolysis can be prevented by the inhibition of graft erythropoiesis, we performed hypertransfusion and assessed red cell transfusion requirement and independence. Between October 1995 and December 2001, 28 consecutive patients receiving major ABO incompatible HSCT at Samsung Medical Center were hypertransfused to maintain their hemoglobin levels at 15 g/dL or more. We retrospectively compared the outcomes of these patients with those of 47 patients at Asan Medical Center whose target hemoglobin levels were 10 g/dL. Reticulocyte engraftment was significantly delayed in hypertransfused group (51 days vs. 23 days; p=.001). There was no significant difference in the total amount of red cells transfused within 90 days post-HSCT (25 units vs. 26 units; p=.631). No significant difference in the time to red cell transfusion independence was observed between the two groups (63 days vs. 56 days; p=.165). In conclusion, we failed to improve red cell transfusion requirement and independence in major ABO incompatible HSCT with hypertransfusion
Increasing uptake of colorectal cancer screening in Korea: a population-based study
<p>Abstract</p> <p>Background</p> <p>Colorectal cancer (CRC) screening rates are low in most Asian countries and remain largely unknown. This study examined trends in CRC screening rates after the introduction of the Korean National Cancer Screening Programme (NCSP) and determined the factors associated with uptake of CRC screening by test modality over time.</p> <p>Methods</p> <p>An annual population-based survey conducted through nationally representative random sampling from 2005-2008. In total, 3,699 participants from the 2005-2008 surveys were selected as study subjects. Face-to-face interviews were performed to assess the utilization rate of CRC screening by each screening modality.</p> <p>Results</p> <p>Overall, CRC screening within the recommended time interval increased significantly from 22.9% in 2005 to 36.6% in 2008 (<it>p </it>< 0.001). The proportion of subjects receiving a fecal occult blood test (FOBT) test within the previous year increased significantly from 7.2% in 2005 to 21.3% in 2008 (<it>p </it>< 0.001). Increases in FOBT testing were highest among those who had a lower income status (relative difference = 511.9%) and women (relative difference = 266.1%). Endoscopy use also increased from 18.0% in 2005 to 20.5% in 2008, albeit not significant. Overall, those who were male, non-smokers, 60-69 years old, and had a higher income status were more likely to have undergone up-to-date endoscopy and CRC screening.</p> <p>Conclusions</p> <p>This study revealed a substantial increase in up-to-date CRC screening in the general population from 2005 to 2008. However, more than half of adults in Korea are still not up-to-date with their CRC tests. It will be important to continue to investigate factors associated with up-to-date CRC screening by each modality.</p
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