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Bae JP, Kim KG, Kang HC, Jeong CB, Park KH, Hwang JM. A study on hemorrhage detection using hybrid method in fundus images. J Digit Imaging 2011; 24:394-404. [PMID: 20177733 DOI: 10.1007/s10278-010-9274-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Image processing of a fundus image is performed for the early detection of diabetic retinopathy. Recently, several studies have proposed that the use of a morphological filter may help extract hemorrhages from the fundus image; however, extraction of hemorrhages using template matching with templates of various shapes has not been reported. In our study, we applied hue saturation value brightness correction and contrast-limited adaptive histogram equalization to fundus images. Then, using template matching with normalized cross-correlation, the candidate hemorrhages were extracted. Region growing thereafter reconstructed the shape of the hemorrhages which enabled us to calculate the size of the hemorrhages. To reduce the number of false positives, compactness and the ratio of bounding boxes were used. We also used the 5 × 5 kernel value of the hemorrhage and a foveal filter as other methods of false positive reduction in our study. In addition, we analyzed the cause of false positive (FP) and false negative in the detection of retinal hemorrhage. Combining template matching in various ways, our program achieved a sensitivity of 85% at 4.0 FPs per image. The result of our research may help the clinician in the diagnosis of diabetic retinopathy and might be a useful tool for early detection of diabetic retinopathy progression especially in the telemedicine.
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Mao JH, Wu D, Kim IJ, Kang HC, Wei G, Climent J, Kumar A, Pelorosso FG, DelRosario R, Huang EJ, Balmain A. Hipk2 cooperates with p53 to suppress γ-ray radiation-induced mouse thymic lymphoma. Oncogene 2011; 31:1176-80. [PMID: 21785465 PMCID: PMC3307058 DOI: 10.1038/onc.2011.306] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A genome-wide screen for genetic alterations in radiation-induced thymic lymphomas generated from p53+/- and p53-/- mice showed frequent loss of heterozygosity (LOH) on chromosome 6. Fine mapping of these LOH regions revealed three non-overlapping regions, one of which was refined to a 0.2 Mb interval that contained only the gene encoding homeobox-interacting protein kinase 2 (Hipk2). More than 30% of radiation-induced tumors from both p53+/- and p53-/- mice showed heterozygous loss of one Hipk2 allele. Mice carrying a single inactive allele of Hipk2 in the germline were susceptible to induction of tumors by γ-radiation, but most tumors retained and expressed the wild-type allele, suggesting that Hipk2 is a haploinsufficient tumor suppressor gene for mouse lymphoma development. Heterozygous loss of both Hipk2 and p53 confers strong sensitization to radiation-induced lymphoma. We conclude that Hipk2 is a haploinsufficient lymphoma suppressor gene.
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Andrabi SA, Kang HC, Haince JF, Lee YI, Zhang J, Chi Z, West AB, Koehler RC, Poirier GG, Dawson TM, Dawson VL. Iduna protects the brain from glutamate excitotoxicity and stroke by interfering with poly(ADP-ribose) polymer-induced cell death. Nat Med 2011; 17:692-9. [PMID: 21602803 PMCID: PMC3709257 DOI: 10.1038/nm.2387] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 04/27/2011] [Indexed: 11/08/2022]
Abstract
Glutamate acting on N-methyl-D-aspartate (NMDA) receptors induces neuronal injury following stroke, through activation of poly(ADP-ribose) polymerase-1 (PARP-1) and generation of the death molecule poly(ADP-ribose) (PAR) polymer. Here we identify Iduna, a previously undescribed NMDA receptor-induced survival protein that is neuroprotective against glutamate NMDA receptor-mediated excitotoxicity both in vitro and in vivo and against stroke through interfering with PAR polymer-induced cell death (parthanatos). Iduna's protective effects are independent and downstream of PARP-1 activity. Iduna is a PAR polymer-binding protein, and mutation at the PAR polymer binding site abolishes the PAR binding activity of Iduna and attenuates its protective actions. Iduna is protective in vivo against NMDA-induced excitotoxicity and middle cerebral artery occlusion-induced stroke in mice. To our knowledge, these results define Iduna as the first known endogenous inhibitor of parthanatos. Interfering with PAR polymer signaling could be a new therapeutic strategy for the treatment of neurologic disorders.
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Park HY, Cho DH, Joe DH, Kang HC, Yun SJ. A case of xanthoma disseminatum with spontaneous resolution over 10 years: review of the literature on long-term follow-up. Dermatology 2011; 222:236-43. [PMID: 21613781 DOI: 10.1159/000328137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Accepted: 04/02/2011] [Indexed: 11/19/2022] Open
Abstract
Xanthoma disseminatum (XD) is a rare and potentially progressive non-Langerhans-cell histiocytosis. To date, a few cases of XD with spontaneous complete resolution have been described. The present report describes a 16-year-old girl who presented with yellow to red-brown papules and nodules on her eyelids, cheeks, axillae, back and buttocks. Indirect laryngoscopy showed multiple xanthomatous plaques on the larynx, posterior pharynx, epiglottis, and vocal cords. Additional findings were polyuria, polydipsia, and amenorrhea. Skin biopsy and electron microscopy results confirmed the diagnosis of XD. The patient was treated with fenofibrate, simvastatin, desmopressin, and sex-hormone replacement therapy. Her skin lesions began to slowly fade 6 years after disease onset, eventually resolving spontaneously and completely, but leaving an atrophic scar, frank anetoderma, and persisting diabetes insipidus. This case report together with a review of the English-language literature on the long-term follow-up of XD patients provides additional information on the natural history of this disease.
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Wang Y, Kim NS, Haince JF, Kang HC, David KK, Andrabi SA, Poirier GG, Dawson VL, Dawson TM. Poly(ADP-ribose) (PAR) binding to apoptosis-inducing factor is critical for PAR polymerase-1-dependent cell death (parthanatos). Sci Signal 2011; 4:ra20. [PMID: 21467298 DOI: 10.1126/scisignal.2000902] [Citation(s) in RCA: 316] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The mitochondrial protein apoptosis-inducing factor (AIF) plays a pivotal role in poly(ADP-ribose) polymerase-1 (PARP-1)-mediated cell death (parthanatos), during which it is released from the mitochondria and translocates to the nucleus. We show that AIF is a high-affinity poly(ADP-ribose) (PAR)-binding protein and that PAR binding to AIF is required for parthanatos both in vitro and in vivo. AIF bound PAR at a site distinct from AIF's DNA binding site, and this interaction triggered AIF release from the cytosolic side of the mitochondrial outer membrane. Mutation of the PAR binding site in AIF did not affect its NADH (reduced form of nicotinamide adenine dinucleotide) oxidase activity, its ability to bind FAD (flavin adenine dinucleotide) or DNA, or its ability to induce nuclear condensation. However, this AIF mutant was not released from mitochondria and did not translocate to the nucleus or mediate cell death after PARP-1 activation. These results suggest a mechanism for PARP-1 to initiate AIF-mediated cell death and indicate that AIF's bioenergetic cell survival-promoting functions are separate from its effects as a mitochondrially derived death effector. Interference with the PAR-AIF interaction or PAR signaling may provide notable opportunities for preventing cell death after activation of PARP-1.
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Lee SY, Cho IH, Kim JM, Kang HC, Noh DY. Hard X-ray microbeam lithography using a Fresnel zone plate with a long focal length. JOURNAL OF SYNCHROTRON RADIATION 2011; 18:143-147. [PMID: 21335899 DOI: 10.1107/s0909049510044535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 10/31/2010] [Indexed: 05/30/2023]
Abstract
Focused hard X-ray microbeams for use in X-ray nanolithography have been investigated. A 7.5 keV X-ray beam generated at an undulator was focused to about 3 µm using a Fresnel zone plate fabricated on silicon. The focused X-ray beam retains a high degree of collimation owing to the long focal length of the zone plate, which greatly facilitates hard X-ray nanoscale lithography. The focused X-ray microbeam was successfully utilized to fabricate patterns with features as small as 100 nm on a photoresist.
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Shin JH, Kang HC, Park YY, Ha DH, Choi YH, Eum HY, Kang BG, Chae JH, Shin I, Lee JH, Kim CG. Corepressor MMTR/DMAP1 is an intrinsic negative regulator of CAK kinase to regulate cell cycle progression. Biochem Biophys Res Commun 2010; 402:110-5. [PMID: 20920467 DOI: 10.1016/j.bbrc.2010.09.126] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Accepted: 09/29/2010] [Indexed: 11/28/2022]
Abstract
We have previously reported that MMTR (MAT1-mediated transcriptional repressor) is a co-repressor that inhibits TFIIH-mediated transcriptional activity via interaction with MAT1 (Kang et al., 2007). Since MAT1 is a member of the CAK kinase complex that is crucial for cell cycle progression and that regulates CDK phosphorylation as well as the general transcription factor TFIIH, we investigated MMTR function in cell cycle progression. We found that MMTR over-expression delayed G1/S and G2/M transitions, whereas co-expression of MAT1 and MMTR rescued the cell growth and proliferation rate. Moreover, MMTR was required for inhibition of CAK kinase-mediated CDK1 phosphorylation. We also showed that the expression level of MMTR was modulated during cell cycle progression. Our data support the notion that MMTR is an intrinsic negative cell cycle regulator that modulates the CAK kinase activity via interaction with MAT1.
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Kang HC, Chae JH, Jeon J, Kim W, Ha DH, Shin JH, Kim CG, Kim CG. PIAS1 regulates CP2c localization and active promoter complex formation in erythroid cell-specific alpha-globin expression. Nucleic Acids Res 2010; 38:5456-71. [PMID: 20421208 PMCID: PMC2938217 DOI: 10.1093/nar/gkq286] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Data presented here extends our previous observations on α-globin transcriptional regulation by the CP2 and PIAS1 proteins. Using RNAi knockdown, we have now shown that CP2b, CP2c and PIAS1 are each necessary for synergistic activation of endogenous α-globin gene expression in differentiating MEL cells. In this system, truncated PIAS1 mutants lacking the ring finger domain recruited CP2c to the nucleus, as did wild-type PIAS1, demonstrating that this is a sumoylation-independent process. In vitro, recombinant CP2c, CP2b and PIAS1 bound DNA as a stable CBP (CP2c/CP2b/PIAS1) complex. Following PIAS1 knockdown in MEL cells, however, the association of endogenous CP2c and CP2b with the α-globin promoter simultaneously decreased. By mapping the CP2b- and CP2c-binding domains on PIAS1, and the PIAS1-binding domains on CP2b and CP2c, we found that two regions of PIAS1 that interact with CP2c/CP2b are required for its co-activator function. We propose that CP2c, CP2b, and PIAS1 form a hexametric complex with two units each of CP2c, CP2b, and PIAS1, in which PIAS1 serves as a clamp between two CP2 proteins, while CP2c binds directly to the target DNA and CP2b mediates strong transactivation.
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Marathe S, Kim SS, Kim SN, Kim C, Kang HC, Nickles PV, Noh DY. Coherent diffraction surface imaging in reflection geometry. OPTICS EXPRESS 2010; 18:7253-7262. [PMID: 20389746 DOI: 10.1364/oe.18.007253] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We present a reflection based coherent diffraction imaging method which can be used to reconstruct a non periodic surface image from a diffraction amplitude measured in reflection geometry. Using a He-Ne laser, we demonstrated that a surface image can be reconstructed solely from the reflected intensity from a surface without relying on any prior knowledge of the sample object or the object support. The reconstructed phase image of the exit wave is particularly interesting since it can be used to obtain quantitative information of the surface depth profile or the phase change during the reflection process. We believe that this work will broaden the application areas of coherent diffraction imaging techniques using light sources with limited penetration depth.
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Chae JH, Kang HC, Kim CG. The relative cellular levels of CP2a and CP2b potentiates erythroid cell-specific expression of the alpha-globin gene by regulating the nuclear localization of CP2c. Biochem Biophys Res Commun 2009; 380:813-7. [PMID: 19338758 DOI: 10.1016/j.bbrc.2009.01.172] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 01/26/2009] [Indexed: 11/29/2022]
Abstract
CP2b activates alpha-globin expression in an erythroid cell-specific manner, through interaction with CP2c and PIAS1. Although CP2a is identical to CP2b except for lacking an exon encoding additional 36 amino acids and has the intrinsic DNA binding and transactivation properties, it does not exert any role in alpha-globin expression. Investigation of subcellular localization of exogenous CP2 proteins revealed that CP2a and CP2b were exclusively localized in the cytosol and nucleus, respectively. The CP2b-specific exon was in charge of the nuclear localization of CP2b. Interestingly, subcellular localization of CP2c was either in the nucleus or cytosol depending on the relative level of CP2a and CP2b although CP2c intrinsically localized in the cytosol in the absence of CP2a/CP2b. Finally, dramatic increment of hemoglobin expression was correlated with nuclear translocation of CP2c during MEL cell differentiation. Our data suggest that CP2b potentiate erythroid cell-specific alpha-globin expression by recruiting CP2c into the nucleus.
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Kang BG, Shin JH, Yi JK, Kang HC, Lee JJ, Heo HS, Chae JH, Shin I, Kim CG. Corepressor MMTR/DMAP1 is involved in both histone deacetylase 1- and TFIIH-mediated transcriptional repression. Mol Cell Biol 2007; 27:3578-88. [PMID: 17371848 PMCID: PMC1899998 DOI: 10.1128/mcb.01808-06] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A transcription corepressor, MAT1-mediated transcriptional repressor (MMTR), was found in mouse embryonic stem cell lines. MMTR orthologs (DMAP1) are found in a wide variety of life forms from yeasts to humans. MMTR down-regulation in differentiating mouse embryonic stem cells in vitro resulted in activation of many unrelated genes, suggesting its role as a general transcriptional repressor. In luciferase reporter assays, the transcriptional repression activity resided at amino acids 221 to 468. Histone deacetylase 1 (HDAC1) interacts with MMTR both in vitro and in vivo and also interacts with MMTR in the nucleus. Interestingly, MMTR activity was only partially rescued by competition with dominant-negative HDAC1(H141A) or by treatment with an HDAC inhibitor, trichostatin A (TSA). To identify the protein responsible for HDAC1-independent MMTR activity, we performed a yeast two-hybrid screen with the full-length MMTR coding sequence as bait and found MAT1. MAT1 is an assembly/targeting factor for cyclin-dependent kinase-activating kinase which constitutes a subcomplex of TFIIH. The coiled-coil domain in the middle of MAT1 was confirmed to interact with the C-terminal half of MMTR, and the MMTR-mediated transcriptional repression activity was completely restored by MAT1 in the presence of TSA. Moreover, intact MMTR was required to inhibit phosphorylation of the C-terminal domain in the RNA polymerase II largest subunit by TFIIH kinase in vitro. Taken together, these data strongly suggest that MMTR is part of the basic cellular machinery for a wide range of transcriptional regulation via interaction with TFIIH and HDAC.
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Kang HC, Hwang YS, Kim DS, Kim HD. Vagus nerve stimulation in pediatric intractable epilepsy: a Korean bicentric study. ACTA NEUROCHIRURGICA. SUPPLEMENT 2007; 99:93-6. [PMID: 17370772 DOI: 10.1007/978-3-211-35205-2_18] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
OBJECTIVE To present our experience with vagus nerve stimulation (VNS) and to evaluate the long-term efficacy and safety of the procedure in pediatric intractable epilepsy. METHODS This study included sixteen patients, who were implanted with a vagus nerve stimulator and could be followed up for at least more than 12 months in two epilepsy centers. Data including seizure frequency, EEG, quality of life measures and adverse events were prospectively filed over a 5-year period. RESULTS VNS resulted in a > 50% reduction in seizure frequency in 50.0% (8/16) of children with 31.3% (5/16) of patients achieving a > 90% reduction. Additionally, enhancements in quality of life were as follows: memory in 50.0% (8/16), mood in 62.5% (10/16), behavior in 68.8% (11/16), alertness in 68.8% (11/16), achievement in 37.5% (6/16), and verbal skills in 43.8% (7/16) of the patients. Adverse events included hoarseness in two patients, dyspnea during sleep in two patients, and sialorrhea in one patient. However, these events were tolerable or could be controlled by the adjustment of output currents. In one patient, wound revision was required. CONCLUSION Our data supports the role of VNS as an alternative therapy for pediatric intractable epilepsy.
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Hong JS, Kang HC, Yi SW, Han YJ, Nam CM, Gombojav B, Ohrr H. A comparison of perinatal mortality in Korea on holidays and working days. BJOG 2006; 113:1235-8. [PMID: 16978232 DOI: 10.1111/j.1471-0528.2006.01054.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To examine whether the perinatal mortality of infants born during holidays differs from that of infants born on workdays, and to elucidate its cause. DESIGN Cross-sectional study. Setting Vital statistics linked to the National Infant Mortality Survey data for 1999 births in Korea. POPULATION In all, 628 485 births in 1999 in Korea. METHODS Number of births and perinatal mortality were classified according to the day of the week using the occurrence index. After adjusting for confounding factors, the odds ratios (ORs) for increased holiday mortality were estimated using logistic regression. MAIN OUTCOME MEASURE Birthweight-adjusted perinatal mortality. RESULTS Births on holidays were 33% fewer and perinatal deaths 24% higher than expected (PMR, Perinatal Mortality Rate, 16.4 versus 12.8; OR, 1.3; 95% CI, 1.2-1.4). After the adjustment of birthweight, gender, plurality and congenital anomalies, the odds ratio for death of infants born during holidays was 1.2 (95% CI, 1.1-1.3). CONCLUSIONS The higher perinatal mortality during holidays in Korea appears to be due to different qualities of perinatal care, rather than difference in case-mix.
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Chung BM, Kang HC, Han SY, Heo HS, Lee JJ, Jeon J, Lim JY, Shin I, Hong SH, Cho YS, Kim CG. Jak2 and Tyk2 are necessary for lineage-specific differentiation, but not for the maintenance of self-renewal of mouse embryonic stem cells. Biochem Biophys Res Commun 2006; 351:682-8. [PMID: 17078929 DOI: 10.1016/j.bbrc.2006.10.081] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2006] [Accepted: 10/18/2006] [Indexed: 11/30/2022]
Abstract
As the LIF-induced Jak1/STAT3 pathway has been reported to play a crucial role in self-renewal of mESCs, we sought to determine if Jak2, which is also expressed in mESCs, might also be involved in the pathway. By employing an RNAi strategy, we established both Jak2 and Jak2/Tyk2 knockdown mESC clones. Both Jak2 and Jak2/Tyk2 knockdown clones maintained the undifferentiated state as wild-type controls, even in a very low concentration of LIF. However, we observed not only faster onset of differentiation but also differential expression of tissue-specific lineage genes for ectodermal and mesodermal, but not endodermal origins from embryoid bodies generated from both types of knockdown clones compared to the wild-type. Furthermore, the reduced level of Jak2 caused differentiation of mESCs in the presence of LIF when the Wnt pathway was activated by LiCl treatment. Taken together, we demonstrated that Jak2 and Tyk2 are not involved in LIF-induced STAT3 pathway for self-renewal of mESCs, but play a role in early lineage decision of mESCs to various differentiated cell types.
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Kim CG, Lee JJ, Jung DY, Jeon J, Heo HS, Kang HC, Shin JH, Cho YS, Cha KJ, Kim CG, Do BR, Kim KS, Kim HS. Profiling of differentially expressed genes in human stem cells by cDNA microarray. Mol Cells 2006; 21:343-55. [PMID: 16819296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
Stem cells are unique cell populations with the ability to undergo both self-renewal and differentiation, although a wide variety of adult stem cells as well as embryonic stem cells have been identified and stem cell plasticity has recently been reported. To identify genes implicated in the control of the stem cell state as well as the characteristics of each stem cell line, we analyzed the expression profiles of genes in human embryonic, hematopoietic (CD34+ and CD133+), and mesenchymal stem cells using cDNA microarrays, and identified genes that were differentially expressed in specific stem cell populations. In particular we were able to identify potential hESC signature-like genes that encode transcription factors (TFAP2C and MYCN), an RNA binding protein (IMP-3), and a functionally uncharacterized protein (MAGEA4). The overlapping sets of 22 up-regulated and 141 down-regulated genes identified in this study of three human stem cell types may also provide insight into the developmental mechanisms common to all human stem cells. Furthermore, our comprehensive analyses of gene expression profiles in various adult stem cells may help to identify the genetic pathways involved in self-renewal as well as in multi-lineage specific differentiation.
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Kang HC, Maser J, Stephenson GB, Liu C, Conley R, Macrander AT, Vogt S. Nanometer linear focusing of hard x rays by a multilayer Laue lens. PHYSICAL REVIEW LETTERS 2006; 96:127401. [PMID: 16605955 DOI: 10.1103/physrevlett.96.127401] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Indexed: 05/08/2023]
Abstract
We report on a type of linear zone plate for nanometer-scale focusing of hard x rays, a multilayer Laue lens (MLL), produced by sectioning a multilayer and illuminating it in Laue diffraction geometry. Because of its large optical depth, a MLL spans the diffraction regimes applicable to a thin Fresnel zone plate and a crystal. Coupled wave theory calculations indicate that focusing to 5 nm or smaller with high efficiency should be possible. Partial MLL structures with outermost zone widths as small as 10 nm have been fabricated and tested with 19.5 keV synchrotron radiation. Focal sizes as small as 30 nm with efficiencies up to 44% are measured.
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Abstract
BACKGROUND It is well known that selective serotonin reuptake inhibitors (SSRIs) can cause sexual dysfunction, so it is possible that sibutramine, a serotonin and norepinephrine reuptake inhibitor, could induce sexual dysfunction. DESIGN AND SUBJECTS The effect of sibutramine on sexual function was evaluated in 46 overweight and obese (body mass index (BMI) > or = 23 kg/m2) but otherwise healthy married women (28-44 years). Participants were randomly assigned at baseline to either the sibutramine or control group. The Female Sexual Function Index (FSFI) questionnaire was used to assess sexual function at baseline and after treatment with behavioral therapy plus sibutramine 10 mg once daily or behavioral therapy alone (control) for 8 weeks. RESULTS Mean weight loss from baseline to week 8 was -6.03% in sibutramine group and -0.38% in the control group. There was significant improvement of FSFI total score, arousal domain score and lubrication domain score in the sibutramine group (P<0.05), and significant differences in arousal, orgasm, satisfaction domain score and total score (P<0.05) in favor of sibutramine. Decreases in body weight and BMI were correlated with the improvement of arousal (r = -0.44 and r = -0.48, respectively) and orgasm (r = -0.45 and r = -0.46, respectively) domains. CONCLUSION Treatment with sibutramine plus behavioral therapy did not induce sexual dysfunction and sibutramine-induced weight reduction appeared to have a positive impact on sexual function in this small group of overweight and moderately obese women. The degree of improvement in sexual function was correlated with the degree of weight reduction.
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Kang HC, Chae JH, Lee YH, Park MA, Shin JH, Kim SH, Ye SK, Cho YS, Fiering S, Kim CG. Erythroid cell-specific alpha-globin gene regulation by the CP2 transcription factor family. Mol Cell Biol 2005; 25:6005-20. [PMID: 15988015 PMCID: PMC1168829 DOI: 10.1128/mcb.25.14.6005-6020.2005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We previously demonstrated that ubiquitously expressed CP2c exerts potent erythroid-specific transactivation of alpha-globin through an unknown mechanism. This mechanism is reported here to involve specific CP2 splice variants and protein inhibitor of activated STAT1 (PIAS1). We identify a novel murine splice isoform of CP2, CP2b, which is identical to CP2a except that it has an additional 36 amino acids encoded by an extra exon. CP2b has an erythroid cell-specific transcriptional activation domain, which requires the extra exon and can form heteromeric complexes with other CP2 isoforms, but lacks the DNA binding activity found in CP2a and CP2c. Transcriptional activation of alpha-globin occurred following dimerization between CP2b and CP2c in erythroid K562 and MEL cells, but this dimerization did not activate the alpha-globin promoter in nonerythroid 293T cells, indicating that an additional erythroid factor is missing in 293T cells. PIAS1 was confirmed as a CP2 binding protein by the yeast two-hybrid screen, and expression of CP2b, CP2c, and PIAS1 in 293T cell induced alpha-globin promoter activation. These results show that ubiquitously expressed CP2b exerts potent erythroid cell-specific alpha-globin gene expression by complexing with CP2c and PIAS1.
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Kang HC, Chung BM, Chae JH, Yang SI, Kim CG, Kim CG. Identification and characterization of four novel peptide motifs that recognize distinct regions of the transcription factor CP2. FEBS J 2005; 272:1265-77. [PMID: 15720400 DOI: 10.1111/j.1742-4658.2005.04564.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Although ubiquitously expressed, the transcriptional factor CP2 also exhibits some tissue- or stage-specific activation toward certain genes such as globin in red blood cells and interleukin-4 in T helper cells. Because this specificity may be achieved by interaction with other proteins, we screened a peptide display library and identified four consensus motifs in numerous CP2-binding peptides: HXPR, PHL, ASR and PXHXH. Protein-database searching revealed that RE-1 silencing factor (REST), Yin-Yang1 (YY1) and five other proteins have one or two of these CP2-binding motifs. Glutathione S-transferase pull-down and coimmunoprecipitation assays showed that two HXPR motif-containing proteins REST and YY1 indeed were able to bind CP2. Importantly, this binding to CP2 was almost abolished when a double amino acid substitution was made on the HXPR sequence of REST and YY1 proteins. The suppressing effect of YY1 on CP2's transcriptional activity was lost by this point mutation on the HXPR sequence of YY1 and reduced by an HXPR-containing peptide, further supporting the interaction between CP2 and YY1 via the HXPR sequence. Mapping the sites on CP2 for interaction with the four distinct CP2-binding motifs revealed at least three different regions on CP2. This suggests that CP2 recognizes several distinct binding motifs by virtue of employing different regions, thus being able to interact with and regulate many cellular partners.
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Kim IJ, Ku JL, Kang HC, Park JH, Yoon KA, Shin Y, Park HW, Jang SG, Lim SK, Han SY, Shin YK, Lee MR, Jeong SY, Shin HR, Lee JS, Kim WH, Park JG. Mutational analysis of OGG1, MYH, MTH1 in FAP, HNPCC and sporadic colorectal cancer patients: R154H OGG1 polymorphism is associated with sporadic colorectal cancer patients. Hum Genet 2004; 115:498-503. [PMID: 15449173 DOI: 10.1007/s00439-004-1186-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Accepted: 08/16/2004] [Indexed: 10/26/2022]
Abstract
MYH, OGG1 and MTH1 are members of base excision repair (BER) families, and MYH germline mutations were recently identified in patients with multiple adenomas or familial adenomatous polyposis (FAP). A total of 20 APC-negative Korean FAP patients were analyzed for OGG1, MYH and MTH1 germline mutations. A total of 19 hereditary nonpolyposis colorectal cancer (HNPCC), 86 suspected HNPCC, and 246 sporadic colorectal cancer cases were investigated for OGG1 and MYH mutations. A total of 14 R154H OGG1 polymorphisms were identified in hereditary, sporadic colorectal cancers, and normal controls. For the case-control analysis of OGG1 R154H, a total of 625 hereditary or sporadic colorectal cancer patients and 527 normal controls were screened. R154H was a rare polymorphism associated with sporadic colorectal cancer patents (OR: 3.586, P= 0.053). R154H does not segregate with cancer phenotypes. Upon examining the possibility of recessive inheritance of R154H, we could not identify any complementary mutations in OGG1, MYH or MTH1. Samples with R154H were further screened for mutations of K-ras, beta-catenin, APC, p53, BRAF and the microsatellite instability (MSI) status. Eight somatic mutations were identified in these genes and G:C to T:A transversion mutations were not dominant in samples harboring R154H. This result raises the possibility that OGG1 R154H may function as a low/moderate-penetrance modifier for colorectal cancer development.
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71
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Tok ES, Ong SW, Kang HC. Dynamical scaling of sputter-roughened surfaces in 2+1 dimensions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 70:011604. [PMID: 15324062 DOI: 10.1103/physreve.70.011604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2003] [Revised: 04/26/2004] [Indexed: 05/24/2023]
Abstract
The asymptotic scaling behavior of sputter-roughened surfaces is of great current interest. In particular, the disparately wide-ranging values of the growth exponent found experimentally, and whether sputter-roughening belongs to the Kardar-Parisi-Zhang universality class in 2+1 dimensions, are two interesting issues. We address these issues using simulations of an atomistic model. The asymptotic scaling appears to be Edwards-Wilkinson. Crossover behavior in the model leads to effective growth exponents that vary widely depending upon the regime of observation.
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72
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Kang HC, Chae JH, Kim BS, Han SY, Kim SH, Auh CK, Yang SI, Kim CG. Transcription factor CP2 is involved in activating mBMP4 in mouse mesenchymal stem cells. Mol Cells 2004; 17:454-61. [PMID: 15232220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023] Open
Abstract
CP2 is a member of a family of transcription factors that regulate genes involved in events from early development to terminal differentiation. In an effort to understand how it selects its target genes we carried out a database search, and located several CP2 binding motifs in the promoter region of bone morphogenetic protein-4 (BMP4). BMP4 is a key regulator of cell fate and body patterning throughout development. For the CP2 binding motifs in BMP4 promoter region to be relevant in vivo, CP2 and BMP4 should be expressed together. We found that CP2b and CP2c, two potent transcriptional activators, are expressed in a manner similar to BMP4 during osteoblast differentiation of C3H10T1/2 cells. In in vitro assays, the CP2 proteins bound to two CP2 binding motifs (-715 to -676 and -147 to -118) in the BMP4 promoter, and luciferase reporter assays indicated that this binding was essential for transcription of BMP4 during osteoblast differentiation. Taken together, our data indicate that CP2b and CP2c play important roles during bone development by activating BMP4 transcription.
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73
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Kim HJ, Kwak HH, Hu KS, Park HD, Kang HC, Jung HS, Koh KS. Topographic anatomy of the mandibular nerve branches distributed on the two heads of the lateral pterygoid. Int J Oral Maxillofac Surg 2003; 32:408-13. [PMID: 14505626 DOI: 10.1054/ijom.2002.0382] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The purpose of this study was to evaluate the topography of the nerve distribution on the two heads of the lateral pterygoid and to clarify their morphological-functional correlations. The nerve distribution on the lateral pterygoid was studied in 24 hemi-sectioned heads. Both heads of the lateral pterygoid were innervated from the mandibular nerve branches, but with various nerve distribution patterns. The nerves innervating the superior head of the lateral pterygoid originated from the buccal nerve only in 45.8% of cases. In contrast, the nerves innervating the inferior head of the lateral pterygoid originated from both the buccal and mandibular nerve trunk in 58.3% of cases. In the seven distribution categories of the mandibular nerve branches, both the superior and inferior heads of the lateral pterygoid had a common source of nerve innervation in only 20.8% of cases, the buccal nerve. In contrast, in 45.9% of cases, additional nerve twigs from the mandibular nerve trunk were distributed on the inferior head of the lateral pterygoid. In summary, besides the buccal nerve described in anatomy textbooks, the nerve branches that originated directly from the mandibular nerve trunk innervated the lateral pterygoid.
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Kim IJ, Park JH, Kang HC, Shin Y, Lim SB, Ku JL, Yang HK, Lee KU, Park JG. A novel germline mutation in the MET extracellular domain in a Korean patient with the diffuse type of familial gastric cancer. J Med Genet 2003; 40:e97. [PMID: 12920089 PMCID: PMC1735541 DOI: 10.1136/jmg.40.8.e97] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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75
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Park JH, Kim IJ, Kang HC, Lee SH, Shin Y, Kim KH, Lim SB, Kang SB, Lee K, Kim SY, Lee MS, Lee MK, Park JH, Moon SD, Park JG. Germline mutations of the MEN1 gene in Korean families with multiple endocrine neoplasia type 1 (MEN1) or MEN1-related disorders. Clin Genet 2003; 64:48-53. [PMID: 12791038 DOI: 10.1034/j.1399-0004.2003.00091.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Multiple endocrine neoplasia type 1 (MEN1) is a familial cancer syndrome characterized by the combined occurrence of tumours of the parathyroid glands, pancreatic islet cells and anterior pituitary gland. Mutation analysis of the MEN1 gene has enabled the genetic diagnosis of patients with MEN1. Two MEN1-related disorders - familial isolated hyperparathyroidism (FIHP) and familial pituitary adenoma - are considered to be variants of MEN1, or at least to be incompletely expressed variants. Germline mutations of the MEN1 gene have been reported in some with FIHP, but familial pituitary adenoma usually lacks the MEN1 mutation and has been described as a genetically distinct disorder. In this work, we investigated five Korean families with MEN1, one family with FIHP and one family with familial pituitary adenoma. Polymerase chain reaction (PCR)-based single-strand conformation polymorphism (PCR-SSCP) analysis, denaturing high-performance liquid chromatography (DHPLC) and sequencing were used to detect the MEN1 mutations. Screening of the genetic variations of the MEN1 gene revealed four germline mutations in five typical MEN1 families. All four germline mutations led to truncated proteins or a change in the amino acids of the functional domains. In this study, we identified three novel MEN1 germline mutations (969C >A, 973G >C and 1213C >T) and one previously reported mutation (200-201insAGCCC). The frequency of the MEN1 germline mutation in Korean MEN1 families (four of five; 80%) was similar to those reported previously. In accordance with previous studies, no MEN1 germline mutation was detected in two families with FIHP or familial pituitary adenoma.
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