Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 31
Filter
1.
Antioxidants (Basel) ; 13(3)2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38539854

ABSTRACT

(1) Background: Oxidative stress adversely affects fertility by impairing oocyte fertilization potential, primarily due to meiotic segregation errors and cohesion loss. Superoxide dismutase (SOD) and Coenzyme Q10 (CoQ10) are prominent antioxidants known to mitigate oxidative damage. (2) Methods: This study recruited 86 patients undergoing in vitro fertilization (IVF) at a single center for a 12-week, randomized, double-blind, active-comparator-controlled trial. Participants were allocated into two groups: one receiving CoQ10 as an antioxidant (the CoQ10 group) and the other receiving GF Bacillus antioxidative enzyme SOD (the GF101 group). The primary endpoints were changes in serum oxidative markers (SOD and catalase) and IVF outcomes, including clinical pregnancy, miscarriage, and live birth rates. Follicular fluid (FF) SOD and catalase concentrations on the day of retrieval, the metaphase II (MII) oocyte rate, the fertilization rate, and lipid profiles were measured. (3) Results: Initially, 86 patients were enrolled, with 65 completing the protocol (30 in the GF101 group and 34 in the CoQ10 group). There were no significant differences between the GF101 and CoQ10 groups in serum SOD (p = 0.626) and catalase levels (p = 0.061) over 12 weeks. However, within the GF101 group, a significant increase in serum catalase from baseline to 12 weeks was observed (p = 0.004). The non-inferiority analysis for IVF outcomes indicated risk differences in the clinical pregnancy rate, live birth rate, and miscarriage rate of -6.27% (95% CI: -30.77% to 18.22%), -1.18% (95% CI: -25.28% to 22.93%), and -13.49% (95% CI: -41.14% to 14.15%), respectively, demonstrating non-inferiority for the GF101 group. Furthermore, the GF101 group experienced significant reductions in total cholesterol (p = 0.006) and low-density lipoprotein (LDL) levels (p = 0.009) in intra-group comparisons, with both groups exhibiting comparable safe profiles. (4) Conclusions: GF101 may be non-inferior to CoQ10 in treating infertility in women and potentially offers additional benefits for women with dyslipidemia.

2.
Eur J Immunol ; 48(5): 777-790, 2018 05.
Article in English | MEDLINE | ID: mdl-29313959

ABSTRACT

Mitochondrial defects and antimitochondrial cardiolipin (CL) antibodies are frequently detected in autoimmune disease patients. CL from dysregulated mitochondria activates various pattern recognition receptors, such as NLRP3. However, the mechanism by which mitochondrial CL activates APCs as a damage-associated molecular pattern to prime antigen-specific naïve T cells, which is crucial for T-cell-dependent anticardiolipin IgG antibody production in autoimmune diseases is unelucidated. Here, we show that CL increases the expression of costimulatory molecules in CD11c+ APCs both in vitro and in vivo. CL activates CD11c+ APCs via TLR2-PI3K-PKN1-AKT/p38MAPK-NF-κB signaling. CD11c+ APCs that have been activated by CL are sufficient to prime H-Y peptide-specific naïve CD4+ T cells and OVA-specific naïve CD8+ T cells. TLR2 is necessary for anti-CL IgG antibody responses in vivo. Intraperitoneal injection of CL does not activate CD11c+ APCs in CD14 KO mice to the same extent as in wild-type mice. CL binds to CD14 (Kd = 7 × 10-7 M). CD14, but not MD2, plays a role in NF-kB activation by CL, suggesting that CD14+ macrophages contribute to recognizing CL. In summary, CL activates signaling pathways in CD11c+ APCs through a mechanism similar to gram (+) bacteria and plays a crucial role in priming antigen-specific naïve T cells.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cardiolipins/immunology , Dendritic Cells/immunology , NF-kappa B/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Protein Kinase C/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Toll-Like Receptor 2/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism , Animals , Antiphospholipid Syndrome/immunology , Autoimmunity/immunology , CD11c Antigen/metabolism , Lipopolysaccharide Receptors/genetics , Lipopolysaccharide Receptors/metabolism , Lymphocyte Activation/immunology , Mice , Mice, Inbred C57BL , Mice, Knockout , Mitochondria/metabolism , Signal Transduction/immunology
3.
Acta Radiol ; 59(2): 236-246, 2018 Feb.
Article in English | MEDLINE | ID: mdl-28530139

ABSTRACT

Sacrococcygeal teratomas are the most common solid tumor in newborn infants. The diagnosis is not difficult in many cases; however, there should be additional information on imaging studies in order to manage those infants properly. Details include histology, morphologic classification, complications such as rupture, bleeding, and mass effects on the adjacent structures. Although imaging features cannot accurately predict the histologic subtypes of the tumors, thorough evaluation of the imaging features can help distinguish malignant tumors from benign tumors. In this article, pathogenesis, histological characteristics, clinical considerations, and morphologic characteristics will be discussed.


Subject(s)
Sacrococcygeal Region , Teratoma , Diagnostic Imaging , Humans , Infant, Newborn , Male , Teratoma/classification , Teratoma/diagnosis , Teratoma/embryology , Teratoma/pathology
4.
Med Ultrason ; 18(3): 386-93, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27622417

ABSTRACT

Brain ultrasound is widely used for the screening of prematurely born babies. Although the best imaging modality for the central nervous system anomaly is brain MRI, the first imaging study in the post-natal period is brain ultrasonography in most cases. Anomalies could be found incidentally on screening ultrasound, or in those cases already suspected on prenatal ultrasound. In order not to miss congenital structural abnormalities of the brain on screening ultrasound, systematic approaches would be very helpful. The ventricles and sylvian fissures are very important structures to suspect central nervous system anomalies: they are symmetric structures so we should look for any asymmetry or maldevelopment. And then, on sagittal images, the midline structures including the corpus callosum and cerebellar vermis should be observed carefully. Finally, we should look for any abnormality in gyration or cortical development. Skull defect with herniation of intracranial contents, a spectrum of encephalo-meningocele, could be also identified on ultrasound. Congenital infections such as cytomegalovirus infection may show ventriculomegaly and malformation of the cortical development on imaging studies.


Subject(s)
Brain/abnormalities , Brain/diagnostic imaging , Nervous System Malformations/diagnostic imaging , Ultrasonography , Humans , Infant, Newborn
5.
Radiographics ; 36(4): 1178-94, 2016.
Article in English | MEDLINE | ID: mdl-27399242

ABSTRACT

Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.


Subject(s)
Cranial Nerve Diseases/diagnostic imaging , Magnetic Resonance Imaging/methods , Child , Contrast Media , Diagnosis, Differential , Humans , Imaging, Three-Dimensional , Tomography, X-Ray Computed
6.
Ultrasonography ; 35(4): 353-8, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27101982

ABSTRACT

We report the case of a giant hypothalamic hamartoma with a large intracranial cyst in a neonate. On ultrasonography, the lesion presented as a lobulated, mass-like lesion with similar echogenicity to the adjacent brain parenchyma, located anterior to the underdeveloped and compressed left temporal lobe, and presenting as an intracranial cyst in the left cerebral convexity without definite internal echogenicity or septa. The presence of a hypothalamic hamartoma and intracranial neurenteric cyst were confirmed by surgical biopsy. The association of a giant hypothalamic hamartoma and a neurenteric cyst is rare. Due to the rarity of this association, the large size of the intracranial cyst, and the resulting distortion in the regional anatomy, the diagnosis of the solid mass was not made correctly on prenatal high-resolution ultrasonography.

7.
Medicine (Baltimore) ; 94(50): e2146, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26683922

ABSTRACT

Children are at greater risk of radiation exposure than adults because the rapidly dividing cells of children tend to be more radiosensitive and they have a longer expected life time in which to develop potential radiation injury. Some studies have surveyed computed tomography (CT) radiation doses and several studies have established diagnostic reference levels according to patient age or body size; however, no survey of CT radiation doses with a large number of patients has yet been carried out in South Korea. The aim of the present study was to investigate the radiation dose in pediatric CT examinations performed throughout South Korea. From 512 CT (222 brain CT, 105 chest CT, and 185 abdominopelvic CT) scans that were referred to our tertiary hospital, a dose report sheet was available for retrospective analysis of CT scan protocols and dose, including the volumetric CT dose index (CTDIvol), dose-length product (DLP), effective dose, and size-specific dose estimates (SSDE). At 55.2%, multiphase CT was the most frequently performed protocol for abdominopelvic CT. Tube current modulation was applied most often in abdominopelvic CT and chest CT, accounting for 70.1% and 62.7%, respectively. Regarding the CT dose, the interquartile ranges of the CTDIvol were 11.1 to 22.5 (newborns), 16.6 to 39.1 (≤1 year), 14.6 to 41.7 (2-5 years), 23.5 to 44.1 (6-10 years), and 31.4 to 55.3 (≤15 years) for brain CT; 1.3 to 5.7 (≤1 year), 3.9 to 6.8 (2-5 years), 3.9 to 9.3 (6-10 years), and 7.7 to 13.8 (≤15 years) for chest CT; and 4.0 to 7.5 (≤1 year), 4.2 to 8.9 (2-5 years), 5.7 to 12.4 (6-10 years), and 7.6 to 16.6 (≤15 years) for abdominopelvic CT. The SSDE and CTDIvol were well correlated for patients <5 years old, whereas the CTDIvol was lower in patients ≥6 years old. Our study describes the various parameters and dosimetry metrics of pediatric CT in South Korea. The CTDIvol, DLP, and effective dose were generally lower than in German and UK surveys, except in certain age groups.


Subject(s)
Clinical Protocols , Radiation Dosage , Tomography, X-Ray Computed/methods , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Radiometry , Republic of Korea , Retrospective Studies , Tertiary Care Centers
8.
Pediatr Gastroenterol Hepatol Nutr ; 18(3): 216, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26473144

ABSTRACT

[This corrects the article on p. 73 in vol. 18, PMID: 26157692.].

9.
Pediatr Gastroenterol Hepatol Nutr ; 18(2): 73-84, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26157692

ABSTRACT

Pediatric pancreatitis is not uncommon and results in considerable morbidity and mortality in the affected children. Unlike adults, pediatric pancreatitis is more frequently associated with underlying structural abnormalities, trauma, and drugs rather than an idiopathic etiology. Magnetic resonance cholangiopancreatography (MRCP) is a good imaging modality for evaluating pancreatitis and determining etiology without exposure to radiation. This article focuses on MRCP findings associated with various causes of pancreatitis in children, particularly structural abnormalities of the pancreaticobiliary system, as well as describing the feasibility, limitations, and solutions associated with pediatric MRCP.

10.
Seizure ; 27: 40-6, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25891925

ABSTRACT

PURPOSE: The aim of this study was to investigate cortical thickness and gray matter volume abnormalities in benign childhood epilepsy with centrotemporal spikes (BCECTS). We additionally assessed the effects of comorbid attention-deficit/hyperactivity (ADHD) on these abnormalities. METHODS: Surface and volumetric MR imaging data of children with newly diagnosed BCECTS (n = 20, 14 males) and age-matched healthy controls (n = 20) were analyzed using FreeSurfer (version 5.3.0, https://surfer.nmr.mgh.harvard.edu). An additional comparison was performed between BCECTS children with and without ADHD (each, n = 8). A group comparison was carried out using an analysis of covariance with a value of significance set as p < 0.01 or p < 0.05. RESULTS: Children with BCECTS had significantly thicker right superior frontal, superior temporal, middle temporal, and left pars triangularis cortices. Voxel-based morphometric analysis revealed significantly larger cortical gray matter volumes of the right precuneus, left orbitofrontal, pars orbitalis, precentral gyri, and bilateral putamen and the amygdala of children with BCECTS compared to healthy controls. BCECTS patients with ADHD had significantly thicker left caudal anterior and posterior cingulate gyri and a significantly larger left pars opercularis gyral volume compared to BCECTS patients without ADHD. CONCLUSION: Children with BCECTS have thicker or larger gray matters in the corticostriatal circuitry at the onset of epilepsy. Comorbid ADHD is also associated with structural aberrations. These findings suggest structural disruptions of the brain network are associated with specific developmental electro-clinical syndromes.


Subject(s)
Brain/pathology , Epilepsy, Rolandic/pathology , Attention Deficit Disorder with Hyperactivity/complications , Case-Control Studies , Child , Child, Preschool , Epilepsy, Rolandic/complications , Female , Gray Matter/pathology , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Retrospective Studies , Statistics, Nonparametric
11.
Joint Bone Spine ; 81(6): 533-6, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25241334

ABSTRACT

Multiple synostosis syndrome (SYNS) is an autosomal dominant skeletal disorder characterized by facial dysmorphism, progressive fusion of multiple joints, and conductive hearing loss. Currently, three genes, NOG, GDF5, and FGF9, have been identified as causative of SYNS. However, due to the phenotypic and genotypic heterogeneity of SYNS, as well as its extreme rarity, it is difficult to diagnose, either by clinical or genetic means. Here, we describe three unrelated Korean families with three different, novel NOG mutations. These mutations are located on the region of the protein critical for appropriate NOG function. The patients shared the general features of SYNS, but the phenotype was expressed differently both within and between the families. In addition, this phenotypic diversity was irrespective of the age of patients, indicating the importance of surveillance for the full spectrum of SYNS in each affected patient. Our report expands understanding of this rare condition from both clinical and genetic perspectives.


Subject(s)
Carpal Bones/abnormalities , Carrier Proteins/genetics , Foot Deformities, Congenital/genetics , Hand Deformities, Congenital/genetics , Phenotype , Stapes/abnormalities , Synostosis/genetics , Tarsal Bones/abnormalities , Adolescent , Carpal Bones/diagnostic imaging , Child, Preschool , Female , Foot Deformities, Congenital/diagnostic imaging , Hand Deformities, Congenital/diagnostic imaging , Humans , Mutation , Radiography , Stapes/diagnostic imaging , Synostosis/diagnostic imaging , Tarsal Bones/diagnostic imaging
12.
Ultrasonography ; 33(3): 184-90, 2014 Jul.
Article in English | MEDLINE | ID: mdl-25038808

ABSTRACT

PURPOSE: To assess the feasibility and effectiveness of transperineal ultrasonography (TPUS) for the evaluation of perianal Crohn disease (PCD) in pediatric patients. METHODS: Between September 2010 and August 2013, 64 TPUS examinations were performed in 43 patients (34 males and 9 females; mean age±standard deviation, 13.3±2.4 years; age range, 6 to 17 years) to evaluate PCD. The pain severity, location, and activity of perianal fistula, the presence of an abscess, and anal canal hyperemia were retrospectively evaluated. Spearman rank correlation analysis was performed to assess the relationship between the severity of the pain and the fistula activity, the presence of an abscess, and anal canal hyperemia. RESULTS: All examinations were successfully performed. Thirty-nine examinations (60.9%) were performed without any pain experienced by the patient, 19 examinations (29.7%) with mild pain, five examinations (7.8%) with moderate pain, and one examination (1.6%) with severe pain. The pain severity was correlated with the fistula activity (P<0.01). An anterior fistula location was more common than a posterior location. Active fistulas and abscesses were identified during 30 examinations (46.9%) and 12 examinations (18.8%), respectively. Anal canal hyperemia was identified in 31 examinations (48.4%). CONCLUSION: TPUS with a color Doppler study is useful for visualizing a perianal fistula or abscess and for assessing its inflammatory activity in pediatric Crohn patients.

13.
Diagn Microbiol Infect Dis ; 74(3): 307-10, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22921815
14.
Clin Imaging ; 36(4): 301-7, 2012.
Article in English | MEDLINE | ID: mdl-22726968

ABSTRACT

AIM: The aim was to review the clinical and imaging features of hypervascular hepatic nodule (HHN) in childhood cancer survivors. MATERIALS AND METHODS: We retrospectively reviewed 11 pediatric patients (female:male, 7:4; age range, 4.0-12.3 years) who had HHNs detected by surveillance computed tomography (CT) after treatment of a malignant solid tumor and subsequently followed by serial imaging without evidence of recurrent malignancy. The lesions were analyzed in terms of number, size, location, CT and ultrasonographic (US) features, and changes in background liver. In addition, clinical features were investigated along with follow-up changes of HHNs by imaging monitoring. RESULTS: Time between initial diagnosis of malignancy and HHN occurrence ranged from 3.2 to 8.5 years (median, 5.8 years). Ten patients had received high-dose chemotherapy and autologous stem cell transplantation for advanced neuroblastoma. A total of 22 nodules were detected, being multiple in six patients and measuring 0.5-3.0 cm in size. At sequential postcontrast CT, nodules demonstrated moderate to strong enhancement during the earlier phase and were isoattenuated during the later phase. On US, they appeared as hypo- or isoechoic lesions. During follow-up, 11 nodules (50%) regressed, 6 (27%) progressed, and 5 (23%) remained stable. Additional HHNs were noted in four patients during follow-up. CONCLUSION: Childhood cancer survivors are at risk of developing HHNs, which are often multiple and small, years after completing chemotherapy. They are nonaggressive and tend to have a benign course, making conservative management reasonable.


Subject(s)
Liver Neoplasms/diagnostic imaging , Lymph Nodes/pathology , Monitoring, Physiologic/methods , Neuroblastoma/pathology , Tomography, X-Ray Computed/methods , Ultrasonography, Interventional/methods , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Child , Child, Preschool , Cohort Studies , Disease Progression , Female , Follow-Up Studies , Humans , Liver Neoplasms/blood supply , Liver Neoplasms/secondary , Lymph Nodes/diagnostic imaging , Male , Neoplasm Invasiveness/pathology , Neuroblastoma/diagnostic imaging , Neuroblastoma/therapy , Retrospective Studies , Risk Assessment , Stem Cell Transplantation/methods , Survivors , Time Factors , Transplantation, Autologous
15.
Mol Genet Metab ; 105(3): 522-4, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22227073

ABSTRACT

Mesenteric lymphadenopathy has been rarely reported in pediatric patients with Gaucher disease, developing despite the enzyme replacement therapy. The clinical implication of this condition is undetermined, with no consensus on treatment strategies. However, this condition can reflect the progression of Gaucher disease. Moreover, it can be accompanied by the serious complication, protein-losing enteropathy. Our experience underlines the importance of careful monitoring and early intervention for mesenteric lymphadenopathy, especially in pediatric patients with neuronopathic Gaucher disease.


Subject(s)
Gaucher Disease/complications , Lymphatic Diseases/etiology , Mesenteric Lymphadenitis/etiology , Protein-Losing Enteropathies/etiology , Child , Disease Progression , Enzyme Replacement Therapy , Gaucher Disease/pathology , Humans , Lymphatic Diseases/pathology , Male , Mesenteric Lymphadenitis/pathology , Protein-Losing Enteropathies/pathology , Republic of Korea
16.
Plant Cell ; 23(6): 2155-68, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21673078

ABSTRACT

Leaf aging is a highly regulated developmental process, which is also influenced profoundly by diverse environmental conditions. Accumulating evidence in recent years supports that plant responsiveness to abiotic stress is intimately related with leaf longevity. However, molecular mechanisms underlying the signaling crosstalks and regulatory schemes are yet unknown. In this work, we demonstrate that an abscisic acid (ABA)-responsive NAC transcription factor VND-INTERACTING2 (VNI2) integrates ABA-mediated abiotic stress signals into leaf aging by regulating a subset of COLD-REGULATED (COR) and RESPONSIVE TO DEHYDRATION (RD) genes. The VNI2 gene was induced by high salinity in an ABA-dependent manner. In addition, spatial and temporal expression patterns of the VNI2 gene are correlated with leaf aging and senescence. Accordingly, leaf aging was delayed in transgenic plants overexpressing the VNI2 gene but significantly accelerated in a VNI2-deficient mutant. The VNI2 transcription factor regulates the COR and RD genes by binding directly to their promoters. Notably, transgenic plants overexpressing the COR or RD genes exhibited prolonged leaf longevity. These observations indicate that the VNI2 transcription factor serves as a molecular link that integrates plant responses to environmental stresses into modulation of leaf longevity.


Subject(s)
Abscisic Acid/metabolism , Arabidopsis Proteins/metabolism , Arabidopsis/physiology , Cellular Senescence/physiology , Plant Leaves/physiology , Signal Transduction/physiology , Transcription Factors/metabolism , Amino Acid Sequence , Arabidopsis/anatomy & histology , Arabidopsis/genetics , Arabidopsis Proteins/genetics , Gene Expression Regulation, Plant , Genes, Plant , Molecular Sequence Data , Plant Leaves/genetics , Plants, Genetically Modified/genetics , Plants, Genetically Modified/physiology , Stress, Physiological , Transcription Factors/genetics
17.
Am J Med Genet A ; 155A(3): 642-7, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21344639

ABSTRACT

Here, we describe the clinical features of a boy with a 5.6-Mb deletion at chromosome 7p15.1-p15.3. He has mild facial anomalies, hand-foot abnormalities, hypospadias, congenital heart defects, and supernumerary nipples. This deletion was detected by array comparative genomic hybridization and verified by fluorescence in situ hybridization using BACs selected from the USCS genome browser. This deletion was not found in subsequent FISH analysis of the parental chromosomes. The deleted region contains several genes, including contiguous developmental genes on the HOXA cluster, which play a role in regulating aspects of morphogenesis during normal embryonic development. The patient's limb and urogenital features were similar to those observed in hand-foot-genital syndrome, which is caused by haploinsufficiency of HOXA13, whereas the congenital heart defect may reflect the deletion of HOXA3. We hypothesized that many clinical features of the patient were due to combined haploinsufficiency of the HOXA cluster. Our study also demonstrates the clinical usefulness of a molecular cytogenetic tool that is capable of detecting imbalances in the genome.


Subject(s)
Base Pairing/genetics , Chromosome Deletion , Chromosomes, Human, Pair 7/genetics , Cytogenetic Analysis , Homeodomain Proteins/genetics , Multigene Family/genetics , Child, Preschool , Comparative Genomic Hybridization , Foot/diagnostic imaging , Genome, Human/genetics , Humans , In Situ Hybridization, Fluorescence , Infant , Male , Metaphase/genetics , Phenotype , Radiography
18.
Mol Cells ; 25(3): 438-45, 2008 May 31.
Article in English | MEDLINE | ID: mdl-18443413

ABSTRACT

Leaf senescence is a highly regulated genetic process that constitutes the last stage of plant development and provides adaptive fitness by relocating metabolites from senescing leaves to reproducing seeds. Characterization of various senescence mutants, mostly in Arabidopsis, and genome-wide analyses of gene expression, have identified a wide array of regulatory components, including transcription factors and enzymes as well as signaling molecules mediating growth hormones and environmental stress responses. In this work we demonstrate that a membrane-associated NAC transcription factor, NTL9, mediates osmotic stress signaling in leaf senescence. The NTL9 gene is induced by osmotic stress. Furthermore, activation of the dormant, membrane-associated NTL9 is elevated under the same conditions. A series of senescence-associated genes (SAGs) were upregulated in transgenic plants overexpressing an activated form of NTL9, and some of them were slightly but reproducibly downregulated in a T-DNA insertional NTL9 knockout mutant. These observations indicate that NTL9 mediates osmotic stress responses that affect leaf senescence, providing a genetic link between intrinsic genetic programs and external signals in the control of leaf senescence.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/genetics , Plant Leaves/growth & development , Transcription Factors/metabolism , Amino Acid Sequence , Arabidopsis/growth & development , Arabidopsis/metabolism , Arabidopsis Proteins/chemistry , Arabidopsis Proteins/genetics , Gene Expression Regulation, Plant , Molecular Sequence Data , Osmotic Pressure , Plant Leaves/genetics , Plant Leaves/metabolism , Plants, Genetically Modified/metabolism , Sequence Deletion , Sequence Homology, Amino Acid , Signal Transduction , Transcription Factors/chemistry , Transcription Factors/genetics , Transcription, Genetic
19.
Plant J ; 55(1): 77-88, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18363782

ABSTRACT

Gibberellic acid (GA) plays a key role in seed germination through coordinate interactions with other growth hormones and external signals. However, the way in which external signals are incorporated into the GA-signaling pathway is largely unknown. Here, we demonstrate that a membrane-bound NAC transcription factor NTL8 mediates the salt regulation of seed germination via the GA pathway, primarily independently of ABA. NTL8 is induced by high salinity. Its expression is also elevated by a GA biosynthetic inhibitor paclabutrazol (PAC), but is repressed by GA. Notably, high salinity greatly represses the GA3 oxidase 1 (GA3ox1) gene, supporting the hypothesis that salt signals inhibit seed germination by repressing GA biosynthesis. Induction of NTL8 and repression of GA3ox1 by high salinity still occur in the ABA-deficient aba3-1 mutant. Accordingly, the germination of a T-DNA insertional ntl8-1 mutant seed is resistant to high salinity and PAC. Interestingly, NTL8 is significantly induced during cold imbibition, but the induction declines quickly in germinating seeds, like RGL2. NTL8 activity is also regulated by controlled proteolytic release of the membrane-bound NTL8 form. Its release from the membranes is activated by PAC and high salinity. Our data support that NTL8 modulates GA-mediated salt signaling in regulating seed germination. This regulatory scheme may provide an adaptative fitness, which delays seed germination under high salinity conditions.


Subject(s)
Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Germination , Gibberellins/biosynthesis , Salinity , Signal Transduction , Abscisic Acid/metabolism , Arabidopsis/growth & development , Cold Temperature , Gibberellins/antagonists & inhibitors , Seeds/growth & development , Seeds/metabolism , Transcription Factors/metabolism , Triazoles/pharmacology
20.
Korean J Radiol ; 8(6): 498-505, 2007.
Article in English | MEDLINE | ID: mdl-18071280

ABSTRACT

OBJECTIVE: A hepatic mesenchymal hamartoma is an uncommon benign tumor in children and little is known about the spectrum of its radiological features. The purpose of this study is to describe the spectrum of radiological features of a hepatic mesenchymal hamartoma in children. MATERIALS AND METHODS: Thirteen children with a pathologically confirmed hepatic mesenchymal hamartoma (M:F = 7:6; mean age, 3 years 2 months) were included in our study. Ultrasonography (US) was performed in nine patients including color and power Doppler US (n = 7). CT scans were performed in all patients. We evaluated the imaging findings of the hepatic mesenchymal hamartomas and the corresponding pathological features. RESULTS: Each patient had a single tumor (mean diameter: 13 cm [1.8-20 cm]). On CT and/or US, four patients (31%) had a "multiseptated cystic tumor", five patients (38%) had a "mixed solid and cystic tumor", and four patients (31%) had a "solid tumor." The septa of the cystic portion were thin in the multiseptated cystic tumors and irregularly thick in the mixed solid and cystic tumors as seen on US. On a post-contrast CT scan, solid portions or thick septa of the tumors showed heterogeneous enhancement. The amount of hepatocytes was significantly different among the three tumor groups according to the imaging spectrum (p = 0.042). CONCLUSION: A hepatic mesenchymal hamartoma in children can show a wide spectrum of radiological features, from a multiseptated cystic tumor to a mixed solid and cystic tumor, and even a solid tumor.


Subject(s)
Hamartoma/diagnosis , Liver Neoplasms/diagnosis , Liver/diagnostic imaging , Mesoderm/diagnostic imaging , Child , Child, Preschool , Contrast Media/administration & dosage , Female , Humans , Infant , Male , Observer Variation , Radiographic Image Enhancement/methods , Retrospective Studies , Tomography, X-Ray Computed/methods , Ultrasonography, Doppler, Color/methods
SELECTION OF CITATIONS
SEARCH DETAIL
...