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Kang H, Schuman EM. Long-lasting neurotrophin-induced enhancement of synaptic transmission in the adult hippocampus. Science 1995; 267:1658-62. [PMID: 7886457 DOI: 10.1126/science.7886457] [Citation(s) in RCA: 1101] [Impact Index Per Article: 36.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The neurotrophins are signaling factors important for the differentiation and survival of distinct neuronal populations during development. To test whether the neurotrophins also function in the mature nervous system, the effects of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), and neurotrophic factor 3 (NT-3) on the strength of synaptic transmission in hippocampal slices were determined. Application of BDNF or NT-3 produced a dramatic and sustained (2 to 3 hours) enhancement of synaptic strength at the Schaffer collateral-CA1 synapses; NGF was without significant effect. The enhancement was blocked by K252a, an inhibitor of receptor tyrosine kinases. BDNF and NT-3 decreased paired-pulse facilitation, which is consistent with a possible presynaptic modification. Long-term potentiation could still be elicited in slices previously potentiated by exposure to the neurotrophic factors, which implies that these two forms of plasticity may use at least partially independent cellular mechanisms.
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30 |
1101 |
2
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Ruiz R, Kang H, Detcheverry FA, Dobisz E, Kercher DS, Albrecht TR, de Pablo JJ, Nealey PF. Density Multiplication and Improved Lithography by Directed Block Copolymer Assembly. Science 2008; 321:936-9. [DOI: 10.1126/science.1157626] [Citation(s) in RCA: 1002] [Impact Index Per Article: 58.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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17 |
1002 |
3
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Kang H, Schuman EM. A requirement for local protein synthesis in neurotrophin-induced hippocampal synaptic plasticity. Science 1996; 273:1402-6. [PMID: 8703078 DOI: 10.1126/science.273.5280.1402] [Citation(s) in RCA: 725] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Two neurotrophic factors, brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), are able to produce a long-lasting enhancement of synaptic transmission in the hippocampus. Unlike other forms of plasticity, neurotrophin-induced plasticity exhibited an immediate requirement for protein synthesis. Plasticity in rat hippocampal slices in which the synaptic neuropil was isolated from the principal cell bodies also required early protein synthesis. Thus, the neurotrophins may stimulate the synthesis of proteins in either axonal or dendritic compartments, allowing synapses to exert local control over the complement of proteins expressed at individual synaptic sites.
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Freeman C, Fenner N, Ostle NJ, Kang H, Dowrick DJ, Reynolds B, Lock MA, Sleep D, Hughes S, Hudson J. Export of dissolved organic carbon from peatlands under elevated carbon dioxide levels. Nature 2004; 430:195-8. [PMID: 15241411 DOI: 10.1038/nature02707] [Citation(s) in RCA: 475] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2003] [Accepted: 06/02/2004] [Indexed: 11/08/2022]
Abstract
Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increased river discharge--cannot offer satisfactory explanations. Here we show that the third proposed mechanism, namely shifting trends in the proportion of annual rainfall arriving in summer, is similarly unable to account for the trend. Instead we infer that a previously unrecognized mechanism--carbon dioxide mediated stimulation of primary productivity--is responsible. Under elevated carbon dioxide levels, the proportion of dissolved organic carbon derived from recently assimilated carbon dioxide was ten times higher than that of the control cases. Concentrations of dissolved organic carbon appear far more sensitive to environmental drivers that affect net primary productivity than those affecting decomposition alone.
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Research Support, Non-U.S. Gov't |
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475 |
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Kang H, Welcher AA, Shelton D, Schuman EM. Neurotrophins and time: different roles for TrkB signaling in hippocampal long-term potentiation. Neuron 1997; 19:653-64. [PMID: 9331355 DOI: 10.1016/s0896-6273(00)80378-5] [Citation(s) in RCA: 397] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We examined the role of TrkB ligands in hippocampal long-term potentiation (LTP) using function-blocking TrkB antiserum (Ab) and Trk-IgG fusion proteins. Incubation of hippocampal slices with TrkB Ab had no effect on basal synaptic transmission, short-term plasticity, or LTP induced by several trains of tetanic stimulation. The TrkB Ab-treated slices, however, showed significant deficits in LTP induced by either theta-burst stimulation (TBS) or "pairing." Slices exposed to the same number of inducing stimuli, delivered either as TBS or as a single 100 Hz epoch, only exhibited TrkB-sensitive LTP when TBS was used, indicating that the temporal pattern of stimulation determines the neurotrophin dependence. The late phase of LTP (2-3 hr) was also significantly impaired in slices pretreated with TrkB Ab or a TrkB-IgG. The application of a TrkB-IgG 30 min after LTP induction caused previously potentiated synaptic transmission to return to baseline levels, indicating that TrkB ligands are required to maintain LTP for up to 1 hr after induction. Taken together, these results indicate that both the temporal patterns of synaptic activity and the different temporal phases of synaptic enhancement are important in determining the neurotrophin dependence of plasticity in the hippocampus.
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397 |
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340 |
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Juliano R, Bauman J, Kang H, Ming X. Biological barriers to therapy with antisense and siRNA oligonucleotides. Mol Pharm 2009; 6:686-95. [PMID: 19397332 DOI: 10.1021/mp900093r] [Citation(s) in RCA: 225] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Attaining the full therapeutic utility of antisense and siRNA oligonucleotides will require understanding of the biological barriers that stand between initial administration of these drugs and their final actions within cells. This review examines some of the key barriers that affect the biodistribution of oligonucleotides both in molecular form and when they are associated with nanocarriers. An understanding of the biological processes underlying these barriers will aid in the design of more effective delivery systems.
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Review |
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225 |
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Kang H, Sun LD, Atkins CM, Soderling TR, Wilson MA, Tonegawa S. An important role of neural activity-dependent CaMKIV signaling in the consolidation of long-term memory. Cell 2001; 106:771-83. [PMID: 11572782 DOI: 10.1016/s0092-8674(01)00497-4] [Citation(s) in RCA: 212] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Calcium/calmodulin-dependent protein kinase IV (CaMKIV) has been implicated in the regulation of CRE-dependent transcription. To investigate the role of this kinase in neuronal plasticity and memory, we generated transgenic mice in which the expression of a dominant-negative form of CaMKIV (dnCaMKIV) is restricted to the postnatal forebrain. In these transgenic mice, activity-induced CREB phosphorylation and c-Fos expression were significantly attenuated. Hippocampal late LTP (L-LTP) was also impaired, whereas basic synaptic function and early LTP (E-LTP) were unaffected. These deficits correlated with impairments in long-term memory, specifically in its consolidation/retention phase but not in the acquisition phase. These results indicate that neural activity-dependent CaMKIV signaling in the neuronal nucleus plays an important role in the consolidation/retention of hippocampus-dependent long-term memory.
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Jais B, Rebours V, Malleo G, Salvia R, Fontana M, Maggino L, Bassi C, Manfredi R, Moran R, Lennon AM, Zaheer A, Wolfgang C, Hruban R, Marchegiani G, Fernández Del Castillo C, Brugge W, Ha Y, Kim MH, Oh D, Hirai I, Kimura W, Jang JY, Kim SW, Jung W, Kang H, Song SY, Kang CM, Lee WJ, Crippa S, Falconi M, Gomatos I, Neoptolemos J, Milanetto AC, Sperti C, Ricci C, Casadei R, Bissolati M, Balzano G, Frigerio I, Girelli R, Delhaye M, Bernier B, Wang H, Jang KT, Song DH, Huggett MT, Oppong KW, Pererva L, Kopchak KV, Del Chiaro M, Segersvard R, Lee LS, Conwell D, Osvaldt A, Campos V, Aguero Garcete G, Napoleon B, Matsumoto I, Shinzeki M, Bolado F, Fernandez JMU, Keane MG, Pereira SP, Acuna IA, Vaquero EC, Angiolini MR, Zerbi A, Tang J, Leong RW, Faccinetto A, Morana G, Petrone MC, Arcidiacono PG, Moon JH, Choi HJ, Gill RS, Pavey D, Ouaïssi M, Sastre B, Spandre M, De Angelis CG, Rios-Vives MA, Concepcion-Martin M, Ikeura T, Okazaki K, Frulloni L, Messina O, Lévy P. Serous cystic neoplasm of the pancreas: a multinational study of 2622 patients under the auspices of the International Association of Pancreatology and European Pancreatic Club (European Study Group on Cystic Tumors of the Pancreas). Gut 2016; 65:305-12. [PMID: 26045140 DOI: 10.1136/gutjnl-2015-309638] [Citation(s) in RCA: 206] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2015] [Accepted: 05/11/2015] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Serous cystic neoplasm (SCN) is a cystic neoplasm of the pancreas whose natural history is poorly known. The purpose of the study was to attempt to describe the natural history of SCN, including the specific mortality. DESIGN Retrospective multinational study including SCN diagnosed between 1990 and 2014. RESULTS 2622 patients were included. Seventy-four per cent were women, and median age at diagnosis was 58 years (16-99). Patients presented with non-specific abdominal pain (27%), pancreaticobiliary symptoms (9%), diabetes mellitus (5%), other symptoms (4%) and/or were asymptomatic (61%). Fifty-two per cent of patients were operated on during the first year after diagnosis (median size: 40 mm (2-200)), 9% had resection beyond 1 year of follow-up (3 years (1-20), size at diagnosis: 25 mm (4-140)) and 39% had no surgery (3.6 years (1-23), 25.5 mm (1-200)). Surgical indications were (not exclusive) uncertain diagnosis (60%), symptoms (23%), size increase (12%), large size (6%) and adjacent organ compression (5%). In patients followed beyond 1 year (n=1271), size increased in 37% (growth rate: 4 mm/year), was stable in 57% and decreased in 6%. Three serous cystadenocarcinomas were recorded. Postoperative mortality was 0.6% (n=10), and SCN's related mortality was 0.1% (n=1). CONCLUSIONS After a 3-year follow-up, clinical relevant symptoms occurred in a very small proportion of patients and size slowly increased in less than half. Surgical treatment should be proposed only for diagnosis remaining uncertain after complete workup, significant and related symptoms or exceptionally when exists concern with malignancy. This study supports an initial conservative management in the majority of patients with SCN. TRIAL REGISTRATION NUMBER IRB 00006477.
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206 |
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Kang H, Remington JS, Suzuki Y. Decreased resistance of B cell-deficient mice to infection with Toxoplasma gondii despite unimpaired expression of IFN-gamma, TNF-alpha, and inducible nitric oxide synthase. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:2629-34. [PMID: 10679102 DOI: 10.4049/jimmunol.164.5.2629] [Citation(s) in RCA: 193] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The role of B cells in resistance against Toxoplasma gondii was studied using B cell-deficient (muMT) mice. Following peroral infection with 10 cysts of the ME49 strain, all muMT mice survived the acute stage of the infection but died between 3 and 4 wk after infection. In contrast, all control mice were alive at 8 wk after infection. At the stage during which muMT animals succumbed to the infection, parasite replication and pathology were most evident in their brains; small numbers of tachyzoites were also detectable in their lungs. Significantly greater numbers of T. gondii cysts and areas of inflammation associated with tachyzoites were observed in brains of muMT than in control mice. Large areas of necrosis associated with numerous tachyzoites were observed only in brains of muMT mice. Anti-T. gondii IgG Abs were detected only in sera of control mice, whereas similar levels of IFN-gamma were detected in sera of both strains of mice. Amounts of mRNA for IFN-gamma, IL-10, and inducible NO synthase in the brain did not differ between infected muMT and control mice. Expression of mRNA for TNF-alpha was increased in brains of muMT mice. Administration of polyclonal rabbit anti-T. gondii IgG Ab prevented early mortality and pathology associated with tachyzoites in the brain in the infected muMT mice. These results indicate that B cells play an important role, most likely through their production of specific Abs, in resistance to persistent active (tachyzoite) infection with T. gondii in mice, especially in the brain and lung.
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MESH Headings
- Animals
- Antibodies, Protozoan/administration & dosage
- Antibodies, Protozoan/biosynthesis
- Antibodies, Protozoan/blood
- Antigens, Protozoan
- B-Lymphocytes/enzymology
- B-Lymphocytes/parasitology
- B-Lymphocytes/pathology
- Brain/immunology
- Brain/metabolism
- Brain/parasitology
- Female
- Immunity, Innate/genetics
- Immunization, Passive
- Immunoglobulin G/administration & dosage
- Injections, Intraperitoneal
- Interferon-gamma/biosynthesis
- Interferon-gamma/blood
- Interferon-gamma/genetics
- Killer Cells, Natural/cytology
- Lymphocyte Count
- Lymphopenia/genetics
- Lymphopenia/immunology
- Lymphopenia/mortality
- Lymphopenia/pathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitric Oxide Synthase/biosynthesis
- Nitric Oxide Synthase/genetics
- Nitric Oxide Synthase Type II
- Protozoan Proteins/genetics
- RNA, Messenger/metabolism
- Spleen/cytology
- T-Lymphocyte Subsets/cytology
- Toxoplasma/genetics
- Toxoplasma/immunology
- Toxoplasmosis, Animal/genetics
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/mortality
- Toxoplasmosis, Animal/pathology
- Tumor Necrosis Factor-alpha/biosynthesis
- Tumor Necrosis Factor-alpha/genetics
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193 |
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Korte M, Kang H, Bonhoeffer T, Schuman E. A role for BDNF in the late-phase of hippocampal long-term potentiation. Neuropharmacology 1998; 37:553-9. [PMID: 9704996 DOI: 10.1016/s0028-3908(98)00035-5] [Citation(s) in RCA: 192] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The neurotrophin family of growth factors has received enormous attention recently for its role in modulating synaptic strength in the developing and adult nervous system. Several recent studies have indicated a role for brain-derived neurotrophic factor (BDNF) in long-term potentiation (LTP), a form of long-lasting plasticity observed at synapses in the hippocampus and other brain areas. The late-phase (L-LTP; e.g. > 2 h) of LTP has been shown to require the synthesis of new proteins. We have examined whether BDNF or other TrkB ligands participate in L-LTP in two ways: by examining transgenic mice which lack BDNF or by acutely blocking TrkB function using function-blocking antibodies. Slices from BDNF knock-out animals or slices treated with TrkB antibodies failed to exhibit L-LTP, indicating that TrkB ligands participate in extending synaptic enhancement from a short-lasting to a long-lasting form.
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27 |
192 |
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Su J, Chen X, Huang Y, Li W, Li J, Cao K, Cao G, Zhang L, Li F, Roberts AI, Kang H, Yu P, Ren G, Ji W, Wang Y, Shi Y. Phylogenetic distinction of iNOS and IDO function in mesenchymal stem cell-mediated immunosuppression in mammalian species. Cell Death Differ 2013; 21:388-96. [PMID: 24162664 PMCID: PMC3921585 DOI: 10.1038/cdd.2013.149] [Citation(s) in RCA: 185] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 08/20/2013] [Accepted: 09/02/2013] [Indexed: 12/13/2022] Open
Abstract
Mammalian mesenchymal stem cells (MSCs) have been shown to be strongly immunosuppressive in both animal disease models and human clinical trials. We have reported that the key molecule mediating immunosuppression by MSCs is species dependent: indoleamine 2,3-dioxygenase (IDO) in human and inducible nitric oxide synthase (iNOS) in mouse. In the present study, we isolated MSCs from several mammalian species, each of a different genus, and investigated the involvement of IDO and iNOS during MSC-mediated immunosuppression. The characterization of MSCs from different species was by adherence to tissue culture plastic, morphology, specific marker expression, and differentiation potential. On the basis of the inducibility of IDO and iNOS by inflammatory cytokines in MSCs, the tested mammalian species fall into two distinct groups: IDO utilizers and iNOS utilizers. MSCs from monkey, pig, and human employ IDO to suppress immune responses, whereas MSCs from mouse, rat, rabbit, and hamster utilize iNOS. Interestingly, based on the limited number of species tested, the iNOS-utilizing species all belong to the phylogenetic clade, Glires. Although the evolutionary significance of this divergence is not known, we believe that this study provides critical guidance for choosing appropriate animal models for preclinical studies of MSCs.
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Research Support, Non-U.S. Gov't |
12 |
185 |
13
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Suzuki Y, Sher A, Yap G, Park D, Neyer LE, Liesenfeld O, Fort M, Kang H, Gufwoli E. IL-10 is required for prevention of necrosis in the small intestine and mortality in both genetically resistant BALB/c and susceptible C57BL/6 mice following peroral infection with Toxoplasma gondii. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 164:5375-82. [PMID: 10799901 DOI: 10.4049/jimmunol.164.10.5375] [Citation(s) in RCA: 172] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The role for IL-10 in the immunopathogenesis of acute toxoplasmosis following peroral infection was examined in both genetically susceptible C57BL/6 and resistant BALB/c mice. C57BL/6-background IL-10-targeted mutant (IL-10-/-) mice all died in 2 wk after infection with 20 cysts of the ME49 strain, whereas only 20% of control mice succumbed. Histological studies revealed necrosis in the small and large intestines and livers of infected IL-10-/- mice. The necrosis in the small intestine was the most severe pathologic response and was not observed in control mice. Treatment of infected IL-10-/- mice with either anti-CD4 or anti-IFN-gamma mAb prevented intestinal pathology and significantly prolonged time to death. Treatment of these animals with anti-IL-12 mAb also prevented the pathology. Significantly greater amounts of IFN-gamma mRNA were detected in the lamina propria lymphocytes obtained from the small intestine of infected IL-10-/- mice than those from infected control mice. In common with C57BL/6-background IL-10-/- mice, BALB/c-background IL-10-/- mice all died developing intestinal pathology after infection. Control BALB/c mice all survived even after infection with 100 cysts and did not develop the intestinal lesions. Treatment with anti-IFN-gamma mAb prevented the pathology and prolonged time to death of the infected IL-10-/- mice. These results strongly suggest that IL-10 plays a critical role in down-regulating IFN-gamma production in the small intestine following sublethal peroral infection with Toxoplasma gondii and that this down-regulatory effect of IL-10 is required for prevention of development of IFN-gamma-mediated intestinal pathology and mortality in both genetically resistant BALB/c and susceptible C57BL/6 mice.
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MESH Headings
- Administration, Oral
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antigens, Protozoan/administration & dosage
- Antigens, Protozoan/immunology
- CD4 Antigens/immunology
- Dose-Response Relationship, Immunologic
- Female
- Genetic Predisposition to Disease
- Immunity, Innate
- Injections, Intraperitoneal
- Interferon-gamma/biosynthesis
- Interferon-gamma/immunology
- Interleukin-10/deficiency
- Interleukin-10/genetics
- Interleukin-10/physiology
- Interleukin-12/immunology
- Intestinal Diseases, Parasitic/genetics
- Intestinal Diseases, Parasitic/immunology
- Intestinal Diseases, Parasitic/mortality
- Intestinal Diseases, Parasitic/pathology
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Intestine, Small/immunology
- Intestine, Small/metabolism
- Intestine, Small/pathology
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Necrosis
- Survival Analysis
- Time Factors
- Toxoplasma/immunology
- Toxoplasmosis, Animal/genetics
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/mortality
- Toxoplasmosis, Animal/pathology
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Comparative Study |
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172 |
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Xu T, Naraghi M, Kang H, Neher E. Kinetic studies of Ca2+ binding and Ca2+ clearance in the cytosol of adrenal chromaffin cells. Biophys J 1997; 73:532-45. [PMID: 9199815 PMCID: PMC1180952 DOI: 10.1016/s0006-3495(97)78091-3] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The Ca2+ binding kinetics of fura-2, DM-nitrophen, and the endogenous Ca2+ buffer, which determine the time course of Ca2+ changes after photolysis of DM-nitrophen, were studied in bovine chromaffin cells. The in vivo Ca2+ association rate constants of fura-2, DM-nitrophen, and the endogenous Ca2+ buffer were measured to be 5.17 x 10(8) M-1 s-1, 3.5 x 10(7) M-1 s-1, and 1.07 x 10(8) M-1 s-1, respectively. The endogenous Ca2+ buffer appeared to have a low affinity for Ca2+ with a dissociation constant around 100 microM. A fast Ca2+ uptake mechanism was also found to play a dominant role in the clearance of Ca2+ after flashes at high intracellular free Ca2+ concentrations ([Ca2+]), causing a fast [Ca2+]i decay within seconds. This Ca2+ clearance was identified as mitochondrial Ca2+ uptake. Its uptake kinetics were studied by analyzing the Ca2+ decay at high [Ca2+]i after flash photolysis of DM-nitrophen. The capacity of the mitochondrial uptake corresponds to a total cytosolic Ca2+ load of approximately 1 mM.
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research-article |
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168 |
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Shinnar S, Berg AT, Moshé SL, Kang H, O'Dell C, Alemany M, Goldensohn ES, Hauser WA. Discontinuing antiepileptic drugs in children with epilepsy: a prospective study. Ann Neurol 1994; 35:534-45. [PMID: 8179299 DOI: 10.1002/ana.410350506] [Citation(s) in RCA: 160] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In a prospective study, antiepileptic drugs were discontinued in 264 children with epilepsy after a mean seizure-free interval of 2.9 years. They were then followed for a mean of 58 months to ascertain whether seizures recurred. Seizures recurred in 95 (36%) of the children. Etiology was a significant predictor of outcome (relative risk [RR] = 1.81). On multivariable analysis, significant factors in the idiopathic group included age at onset above 12 years (RR = 5.4), a family history of seizures (RR = 3.1), the presence of slowing on the electroencephalogram prior to medication withdrawal (RR = 2.4), and a history of atypical febrile seizures (RR = 2.8). Specific epileptic syndromes such as juvenile myoclonic epilepsy and benign rolandic epilepsy were also significant predictors of outcome. In the remote symptomatic group, significant predictors of outcome included age at onset older than 12 years (RR = 3.6), moderate to severe mental retardation (IQ < 50) (RR = 2.8), a history of atypical febrile seizures (RR = 2.0), and a history of absence seizures (RR = 0.4). The majority of children with epilepsy in remission while on antiepileptic drug therapy will remain seizure free when medications are withdrawn. A few readily available parameters distinguish those with a good prognosis from those in whom seizures are likely to recur. These data provide the framework for the clinical decision making for withdrawal of medications in these children.
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160 |
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Chung CH, Guthrie VB, Masica DL, Tokheim C, Kang H, Richmon J, Agrawal N, Fakhry C, Quon H, Subramaniam RM, Zuo Z, Seiwert T, Chalmers ZR, Frampton GM, Ali SM, Yelensky R, Stephens PJ, Miller VA, Karchin R, Bishop JA. Genomic alterations in head and neck squamous cell carcinoma determined by cancer gene-targeted sequencing. Ann Oncol 2015; 26:1216-1223. [PMID: 25712460 PMCID: PMC4516044 DOI: 10.1093/annonc/mdv109] [Citation(s) in RCA: 148] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2014] [Revised: 01/23/2015] [Accepted: 02/18/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND To determine genomic alterations in head and neck squamous cell carcinoma (HNSCC) using formalin-fixed, paraffin-embedded (FFPE) tumors obtained through routine clinical practice, selected cancer-related genes were evaluated and compared with alterations seen in frozen tumors obtained through research studies. PATIENTS AND METHODS DNA samples obtained from 252 FFPE HNSCC were analyzed using next-generation sequencing-based (NGS) clinical assay to determine sequence and copy number variations in 236 cancer-related genes plus 47 introns from 19 genes frequently rearranged in cancer. Human papillomavirus (HPV) status was determined by presence of the HPV DNA sequence in all samples and corroborated with high-risk HPV in situ hybridization (ISH) and p16 immunohistochemical (IHC) staining in a subset of tumors. Sequencing data from 399 frozen tumors in The Cancer Genome Atlas and University of Chicago public datasets were analyzed for comparison. RESULTS Among 252 FFPE HNSCC, 84 (33%) were HPV positive and 168 (67%) were HPV negative by sequencing. A subset of 40 tumors with HPV ISH and p16 IHC results showed complete concordance with NGS-derived HPV status. The most common genes with genomic alterations were PIK3CA and PTEN in HPV-positive tumors and TP53 and CDKN2A/B in HPV-negative tumors. In the pathway analysis, the PI3K pathway in HPV-positive tumors and DNA repair-p53 and cell cycle pathways in HPV-negative tumors were frequently altered. The HPV-positive oropharynx and HPV-positive nasal cavity/paranasal sinus carcinoma shared similar mutational profiles. CONCLUSION The genomic profile of FFPE HNSCC tumors obtained through routine clinical practice is comparable with frozen tumors studied in research setting, demonstrating the feasibility of comprehensive genomic profiling in a clinical setting. However, the clinical significance of these genomic alterations requires further investigation through application of these genomic profiles as integral biomarkers in clinical trials.
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Research Support, N.I.H., Extramural |
10 |
148 |
17
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Kang H, Freund C, Duke-Cohan JS, Musacchio A, Wagner G, Rudd CE. SH3 domain recognition of a proline-independent tyrosine-based RKxxYxxY motif in immune cell adaptor SKAP55. EMBO J 2000; 19:2889-99. [PMID: 10856234 PMCID: PMC203341 DOI: 10.1093/emboj/19.12.2889] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Src-homology 3 (SH3) domains recognize PXXP core motif preceded or followed by positively charged residue(s). Whether SH3 domains recognize motifs other than proline-based sequences is unclear. In this study, we report SH3 domain binding to a novel proline-independent motif in immune cell adaptor SKAP55, which is comprised of two N-terminal lysine and arginine residues followed by two tyrosines (i.e. RKxxYxxY). Domains capable of binding to class I proline motifs bound to the motif, while the class II domains failed to bind. Peptide precipitation, alanine scanning and in vivo co-expression studies demonstrated a requirement for the arginine, lysine and tandem tyrosines of the motif. Two-dimensional NMR analysis of the peptide bound FYN-SH3 domain showed overlap with the binding site of a proline-rich peptide on the charged surface of the SH3 domain, while resonance signals for other residues (W119, W120, Y137) were not perturbed by the RKGDYASY based peptide. Expression of the RKGDYASY peptide potently inhibited TcRzeta/CD3-mediated NF-AT transcription in T cells. Our findings extend the repertoire of SH3 domain binding motifs to include a tyrosine-based motif and demonstrate a regulatory role for this motif in receptor signaling.
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Kang H, Jouvet C, Dedonder-Lardeux C, Martrenchard S, Grégoire G, Desfrançois C, Schermann JP, Barat M, Fayeton JA. Ultrafast deactivation mechanisms of protonated aromatic amino acids following UV excitation. Phys Chem Chem Phys 2005; 7:394-8. [PMID: 19785164 DOI: 10.1039/b414986f] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wolf H, Ringsdorf H, Delamarche E, Takami T, Kang H, Michel B, Gerber C, Jaschke M, Butt HJ, Bamberg E. End-Group-Dominated Molecular Order in Self-Assembled Monolayers. ACTA ACUST UNITED AC 2002. [DOI: 10.1021/j100018a050] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Liesenfeld O, Kang H, Park D, Nguyen TA, Parkhe CV, Watanabe H, Abo T, Sher A, Remington JS, Suzuki Y. TNF-alpha, nitric oxide and IFN-gamma are all critical for development of necrosis in the small intestine and early mortality in genetically susceptible mice infected perorally with Toxoplasma gondii. Parasite Immunol 1999; 21:365-76. [PMID: 10417671 DOI: 10.1046/j.1365-3024.1999.00237.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We previously reported that genetic susceptibility of mice to peroral infection with T. gondii is associated with CD4+ T cell-dependent, interferon (IFN)-gamma-mediated necrosis of their small intestine. We examined the role of tumour necrosis factor (TNF)-alpha and nitric oxide (NO), in addition to IFN-gamma. At 7 days after infection, a marked increase in CD4+ T cells was observed in lamina propria mononuclear cells (LPC) of the small intestine as compared with normal mice, and significantly greater amounts of mRNA for IFN-gamma, TNF-alpha, and inducible NO synthase (iNOS) were detected in LPC of the small intestine of infected than uninfected animals. Treatment of infected mice with anti-TNF-alpha monoclonal antibody (mAb) or the iNOS inhibitor, aminoguanidine, prevented necrosis and prolonged time to death. Infected iNOS-targeted mutant mice did not develop the disease whereas infected, control mice did. Treatment with anti-TNF-alpha mAb did not affect the expression of IFN-gamma in the LPC but inhibited expression of iNOS in the infected mice, indicating the role of TNF-alpha in the induction of iNOS. These results suggest that NO induced by a combination of IFN-gamma and TNF-alpha through activation of iNOS is a critical mediator of intestinal pathology and contributes to early mortality in genetically susceptible mice.
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Oh SK, Kang H, Shin DH, Yang J, Chow KS, Yeang HY, Wagner B, Breiteneder H, Han KH. Isolation, characterization, and functional analysis of a novel cDNA clone encoding a small rubber particle protein from Hevea brasiliensis. J Biol Chem 1999; 274:17132-8. [PMID: 10358068 DOI: 10.1074/jbc.274.24.17132] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Biochemical evidence reported so far suggests that rubber synthesis takes place on the surface of rubber particles suspended in the latex of Hevea brasiliensis. We have isolated and characterized a cDNA clone that encodes a protein tightly bound on a small rubber particle. We named this protein small rubber particle protein (SRPP). Prior to this study, this protein was known as a latex allergen, and only its partial amino acid sequence was reported. Sequence analysis revealed that this protein is highly homologous to the rubber elongation factor and the Phaseolus vulgaris stress-related protein. Southern and Northern analyses indicate that the protein is encoded by a single gene and highly expressed in latex. An allergenicity test using the recombinant protein confirmed that the cloned cDNA encodes the known 24-kDa latex allergen. Neither ethylene stimulation nor wounding changed the transcript level of the SRPP gene in H. brasiliensis. An in vitro rubber assay showed that the protein plays a positive role in rubber biosynthesis. Therefore, it is likely that SRPP is a part of the rubber biosynthesis machinery, if not the rubber polymerase, along with the rubber elongation factor.
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Liu J, Kang H, Raab M, da Silva AJ, Kraeft SK, Rudd CE. FYB (FYN binding protein) serves as a binding partner for lymphoid protein and FYN kinase substrate SKAP55 and a SKAP55-related protein in T cells. Proc Natl Acad Sci U S A 1998; 95:8779-84. [PMID: 9671755 PMCID: PMC21153 DOI: 10.1073/pnas.95.15.8779] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/1998] [Accepted: 05/19/1998] [Indexed: 02/08/2023] Open
Abstract
TcRzeta/CD3 ligation initiates a signaling cascade involving CD4/CD8-p56(lck), p59(fyn), and ZAP-70, as well as lymphoid downstream proteins VAV, SLP-76, and FYB/SLAP. A current question concerns the nature of the downstream binding partner(s) of FYB in T cells. In this study, using a two-hybrid screen with FYB as bait, we have identified eight clones, four of which correspond to the recently published lymphoid protein SKAP55, and two which correspond to a related protein with some 44% homology to SKAP55 (termed SKAP55-related protein, SKAP55R). The SKAP55 clones showed only minor differences (two substitutions and one residue deletion) from SKAP55. SKAP55R has the same overall structure as SKAP55 except for the presence of a unique N terminus with a well-defined coiled-coil domain. Both SKAP55 and SKAP55R were found to bind FYB through their SH3 domains and to act as substrates for the FYN kinase in T cells. Furthermore, immunofluorescence confocal microscopy showed that FYB and SKAP55 colocalize in the perinuclear region of cells. SKAP55 also colocalizes with another FYB binding protein, SLP-76. Taken together, these observations demonstrate that FYB is part of an interactive matrix with SKAP55 and a SKAP55-related protein.
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Le Pogam S, Seshaadri A, Kosaka A, Chiu S, Kang H, Hu S, Rajyaguru S, Symons J, Cammack N, Najera I. Existence of hepatitis C virus NS5B variants naturally resistant to non-nucleoside, but not to nucleoside, polymerase inhibitors among untreated patients. J Antimicrob Chemother 2008; 61:1205-16. [DOI: 10.1093/jac/dkn085] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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Abstract
We observed acute cerebral blindness and encephalopathy complicating cyclosporin A (CyA) toxicity in a 5-year-old transplantation patient. Serum CyA level was 1,704 ng/ml (normal, less than 300 ng/ml). Additional neurologic complications of CyA toxicity will be reviewed.
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