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Yuan M, Konstantopoulos N, Lee J, Hansen L, Li ZW, Karin M, Shoelson SE. Reversal of obesity- and diet-induced insulin resistance with salicylates or targeted disruption of Ikkbeta. Science 2001; 293:1673-7. [PMID: 11533494 DOI: 10.1126/science.1061620] [Citation(s) in RCA: 1420] [Impact Index Per Article: 59.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We show that high doses of salicylates reverse hyperglycemia, hyperinsulinemia, and dyslipidemia in obese rodents by sensitizing insulin signaling. Activation or overexpression of the IkappaB kinase beta (IKKbeta) attenuated insulin signaling in cultured cells, whereas IKKbeta inhibition reversed insulin resistance. Thus, IKKbeta, rather than the cyclooxygenases, appears to be the relevant molecular target. Heterozygous deletion (Ikkbeta+/-) protected against the development of insulin resistance during high-fat feeding and in obese Lep(ob/ob) mice. These findings implicate an inflammatory process in the pathogenesis of insulin resistance in obesity and type 2 diabetes mellitus and identify the IKKbeta pathway as a target for insulin sensitization.
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Hansen L, Salmon D, Galasko D, Masliah E, Katzman R, DeTeresa R, Thal L, Pay MM, Hofstetter R, Klauber M. The Lewy body variant of Alzheimer's disease: a clinical and pathologic entity. Neurology 1990; 40:1-8. [PMID: 2153271 DOI: 10.1212/wnl.40.1.1] [Citation(s) in RCA: 538] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Thirty-six clinically diagnosed and pathologically confirmed Alzheimer's disease (AD) patients included 13 with cortical and subcortical Lewy bodies (LBs). The patients with LBs appeared to constitute a distinct neuropathologic and clinical subset of AD, the Lewy body variant (LBV). The LBV group showed gross pallor of the substantia nigra, greater neuron loss in the locus ceruleus, substantia nigra, and substantia innominata, lower neocortical ChAT levels, and fewer midfrontal tangles than did the pure AD group, along with a high incidence of medial temporal lobe spongiform vacuolization. Analysis of neuropsychological tests from 9 LBV subjects and 9 AD patients matched for age and degree of dementia revealed greater deficits in attention, fluency, and visuospatial processing in the LBV group. Similar comparisons of neurologic examinations showed a significant increase in masked facies; in addition there was an increase in essential tremor, bradykinesia, mild neck rigidity, and slowing of rapid alternating movements in the LBV group. Extremity rigidity, flexed posture, resting tremor, or other classic parkinsonian features were not characteristic of the LBV patient. In some cases, it may be possible to diagnose LBV premortem on the basis of the clinical and neuropsychological features.
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538 |
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Hansen L, Deacon CF, Orskov C, Holst JJ. Glucagon-like peptide-1-(7-36)amide is transformed to glucagon-like peptide-1-(9-36)amide by dipeptidyl peptidase IV in the capillaries supplying the L cells of the porcine intestine. Endocrinology 1999; 140:5356-63. [PMID: 10537167 DOI: 10.1210/endo.140.11.7143] [Citation(s) in RCA: 358] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The insulinotropic hormone glucagon-like peptide-1 (GLP-1) is stored in the intestinal L cell in an active form, GLP-1-(7-36)amide, but more than half of the endogenous peptide circulates in an inactive, N-terminally truncated form, GLP-1-(9-36)amide. This study examined the GLP-1 newly secreted from the porcine ileum, in vitro (isolated perfused preparation) and in vivo (anesthetized pig), to determine where this conversion occurs. Although the GLP-1 extractable from the porcine ileum is predominantly the intact peptide (94.6+/-1.7%), a large proportion of the GLP-1 that is secreted has already been degraded to the truncated form both in vitro (53.8+/-0.9% intact) and in vivo (32.9+/-10.8% intact). In the presence of a specific dipeptidyl peptidase IV (DPP IV) inhibitor (valine-pyrrolidide), the proportion of intact GLP-1 released from the perfused ileum was increased under both basal (99% intact; P < 0.05) and stimulated (86-101% intact; P < 0.05) conditions. Immunohistochemical and histochemical studies revealed specific DPP IV staining in the brush border epithelium as well as in the capillary endothelium. Double staining showed juxtapositioning of DPP IV-positive capillaries and GLP-1-containing L cells. From these results, we suggest that GLP-1 is degraded as it enters the DPP IV containing blood vessels draining the intestinal mucosa.
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358 |
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Masliah E, Alford M, DeTeresa R, Mallory M, Hansen L. Deficient glutamate transport is associated with neurodegeneration in Alzheimer's disease. Ann Neurol 1996; 40:759-66. [PMID: 8957017 DOI: 10.1002/ana.410400512] [Citation(s) in RCA: 347] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The mechanisms of synapse damage in Alzheimer's disease (AD) are not fully understood. Deficient functioning of glutamate transporters might be involved in synaptic pathology and neurodegeneration by failing to clear excess glutamate at the synaptic cleft. In AD, glutamate transporter activity as assessed by D-[3H]aspartate binding is decreased; however, it is not clear to what extent it is associated with the neurodegenerative process and cognitive alterations. For this purpose, levels of D- and L-[3H]aspartate binding in midfrontal cortex were correlated with synaptophysin levels, brain spectrin degradation product levels, and clinical and neuropathological indicators of AD. Compared to control brains, AD brains displayed a 34% decrease in levels of D-[3H]aspartate binding, a 30% decrease in L-[3H]aspartate binding, and a 48% loss of synaptophysin immunoreactivity. Increased levels of brain spectrin degradation products correlated with a decrease in levels of D-[3H] and L-[3H]aspartate binding, and decreased levels of synaptophysin immunoreactivity. Levels of L-[3H]aspartate binding correlated with levels of synaptophysin immunoreactivity. These results suggest that decreased glutamate transporter activity in AD is associated with increased excitotoxicity and neurodegeneration, supporting the possibility that abnormal functioning of this system might be involved in the pathogenesis of synaptic damage in AD.
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347 |
5
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Mooney D, Hansen L, Vacanti J, Langer R, Farmer S, Ingber D. Switching from differentiation to growth in hepatocytes: control by extracellular matrix. J Cell Physiol 1992; 151:497-505. [PMID: 1295898 DOI: 10.1002/jcp.1041510308] [Citation(s) in RCA: 322] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Studies were carried out to analyze how different extracellular matrix (ECM) molecules regulate hepatocyte growth and differentiation. Freshly isolated rat hepatocytes were cultured on non-adhesive plastic dishes that were pre-coated with defined densities of either laminin, fibronectin, type I collagen, or type IV collagen. Sparse cell plating densities were used to minimize cell-cell contact formation and all studies were carried out in chemically defined medium that contained a saturating amount of soluble growth factors. Dishes coated with a low ECM density (1 ng/cm2) supported hepatocyte attachment, but did not promote cell spreading or growth. Computerized image analysis confirmed that over 80% of cells remained free of contact with other cells under these conditions. Yet, these round cells maintained high levels of albumin gene expression as well as elevated secretion rates for multiple liver-specific proteins (albumin, transferrin, and fibrinogen), regardless of the type of ECM molecule used for cell attachment. When ECM coating densities were raised from 1 to 1,000 ng/cm2, cell spreading, expression of histone mRNA, DNA synthesis, and cell proliferation all increased in parallel. Activation of growth by high ECM densities was also accompanied by a concomitant down-regulation of differentiated functions and again, dishes coated with all four types of ECM molecules produced similar effects. Thus, the ability to switch hepatocytes from differentiation to growth (i.e., between different genetic programs) is not limited to a single ECM molecule, a distinct three dimensional ECM geometry, or due to alteration of cell-cell interactions. Rather, the regulatory signals conveyed by immobilized ECM molecules depend on the density at which they are presented and thus, on their ability to either prohibit or support cell spreading.
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Masliah E, Mallory M, Hansen L, DeTeresa R, Terry RD. Quantitative synaptic alterations in the human neocortex during normal aging. Neurology 1993; 43:192-7. [PMID: 8423884 DOI: 10.1212/wnl.43.1_part_1.192] [Citation(s) in RCA: 303] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We quantified the synaptic population density in the frontal cortex of 25 individuals without dementia 16 to 98 years old, using sections double-immunolabeled for beta/A4 amyloid and for synaptophysin, and found a significant inverse correlation between the presynaptic terminal (PT) counts and age (r = -0.7, p < 0.001). Individuals older than 60 years had an average 20% decrease in PT density compared with individuals younger than 60 years. There were no significant correlations between the age and the number of beta/A4 amyloid-positive plaques or between synaptic density and the number of amyloid plaques. Further analysis of the digitized serial optical images showed focal areas of synapse loss and distended synaptophysin-containing boutons in the mature plaques of the normal aged cases. However, we found no microscopic changes in the synaptic content inside and outside the diffuse plaques. We suggest that a loss of synaptic input in the neocortex is an age-dependent factor that contributes to the overall synaptic loss in Alzheimer's disease, but that this might be largely independent of the beta/A4-amyloid deposition.
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303 |
7
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Wiley CA, Masliah E, Morey M, Lemere C, DeTeresa R, Grafe M, Hansen L, Terry R. Neocortical damage during HIV infection. Ann Neurol 1991; 29:651-7. [PMID: 1909852 DOI: 10.1002/ana.410290613] [Citation(s) in RCA: 298] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Clinical and pathological evidence of subcortical central nervous system (CNS) damage is observed commonly in patients with human immunodeficiency virus (HIV) encephalitis. Whether other CNS regions are also affected has not been well studied. We report neocortical damage in patients with HIV encephalitis. Using quantitative techniques, we demonstrate statistically significant thinning of the neocortex, with a loss of large cortical neurons. Qualitative and quantitative assessments of neocortical neuropil reveal a loss of synaptic density and vacuolation of dendritic processes. Failure to demonstrate an association of these changes with the presence of HIV antigens suggests that neocortical damage may be an indirect effect of HIV infection of the CNS.
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298 |
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Ingber DE, Dike L, Hansen L, Karp S, Liley H, Maniotis A, McNamee H, Mooney D, Plopper G, Sims J. Cellular tensegrity: exploring how mechanical changes in the cytoskeleton regulate cell growth, migration, and tissue pattern during morphogenesis. INTERNATIONAL REVIEW OF CYTOLOGY 1994; 150:173-224. [PMID: 8169080 DOI: 10.1016/s0074-7696(08)61542-9] [Citation(s) in RCA: 286] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Review |
31 |
286 |
9
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Conrad C, Andreadis A, Trojanowski JQ, Dickson DW, Kang D, Chen X, Wiederholt W, Hansen L, Masliah E, Thal LJ, Katzman R, Xia Y, Saitoh T. Genetic evidence for the involvement of tau in progressive supranuclear palsy. Ann Neurol 1997; 41:277-81. [PMID: 9029080 DOI: 10.1002/ana.410410222] [Citation(s) in RCA: 274] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A dinucleotide repeat polymorphism in a tau intron was identified and used in a case-control study to analyze the genetic association of tau with several neurodegenerative diseases with tau pathology. Subjects with the homozygous tau AO alleles were excessively represented in the progressive supranuclear palsy (PSP) group, compared with the age-matched healthy control group. Consequently, this allele is more frequently found in PSP than in a group of healthy subjects. This trend was not found in Alzheimer's disease or parkinsonism-dementia complex of Guam, both of which are accompanied by major tau pathology. The result suggests a possible involvement of tau in the pathogenesis of PSP.
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28 |
274 |
10
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Masliah E, Hansen L, Adame A, Crews L, Bard F, Lee C, Seubert P, Games D, Kirby L, Schenk D. Abeta vaccination effects on plaque pathology in the absence of encephalitis in Alzheimer disease. Neurology 2005; 64:129-31. [PMID: 15642916 DOI: 10.1212/01.wnl.0000148590.39911.df] [Citation(s) in RCA: 268] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors report a patient with Alzheimer disease (AD) without encephalitis who was immunized with AN-1792 (an adjuvanted formulation of Abeta-42). There were no amyloid plaques in the frontal cortex and abundant Abeta-immunoreactive macrophages, but tangles and amyloid angiopathy were present. The white matter appeared normal and minimal lymphocytic infiltration in the leptomeninges was observed. This case illustrates the effects of an Abeta-based immunization on AD pathogenesis in the absence of overt meningoencephalitis and leukoencephalopathy.
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Research Support, U.S. Gov't, P.H.S. |
20 |
268 |
11
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Masliah E, Mallory M, Hansen L, DeTeresa R, Alford M, Terry R. Synaptic and neuritic alterations during the progression of Alzheimer's disease. Neurosci Lett 1994; 174:67-72. [PMID: 7970158 DOI: 10.1016/0304-3940(94)90121-x] [Citation(s) in RCA: 254] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Extensive synaptic and neuritic alterations in the neocortex and limbic system are characteristically found in Alzheimer's disease (AD). However, it is not known how early in the development of the disease these alterations occur. For the present study, we compared the synaptic and neuritic alterations among cases classified clinically and neuropathologically as early, mild and advanced AD. In early AD there was a 20% loss of synaptophysin-immunoreactive presynaptic terminals in the outer molecular layer of the hippocampal dentate gyrus (but not in the neocortex and entorhinal cortex), accompanied by increased amyloid precursor protein (APP) and Alz50 immunoreactivity in hippocampal and entorhinal cortex pyramidal neurons. These results suggest that abnormal neuronal expression of APP and cytoskeletal proteins in early stages might be involved in the mechanisms of synaptic pathology in AD.
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31 |
254 |
12
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Masliah E, Mallory M, Hansen L, Alford M, Albright T, DeTeresa R, Terry R, Baudier J, Saitoh T. Patterns of aberrant sprouting in Alzheimer's disease. Neuron 1991; 6:729-39. [PMID: 1827266 DOI: 10.1016/0896-6273(91)90170-5] [Citation(s) in RCA: 187] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Alzheimer's disease (AD) is characterized by extensive synaptic and neuronal loss and by plaque formation in the cortex, but the mechanisms responsible for synaptic plasticity in the neocortex are still not completely understood. To analyze the sprouting response in AD cortex, we compared the patterns of GAP-43 with synaptophysin immunoreactivity. In AD, GAP-43 immunohistochemistry revealed extensive sprouting in the hippocampal molecular layer, stratum polymorphous, CA1 region, and prosubiculum. These regions presented abundant anti-GAP-43-immunoreactive coiled fibers and dystrophic neurites in association with plaques. Some of these sprouting structures were colocalized with anti-synapto-physin- and anti-neurofilament-positive neurites. The AD neocortex was characterized by an overall decrease in GAP-43 immunoreactivity accompanied by sprouting neurites in the areas of synaptic pathology. We conclude that GAP-43 might be involved in the mechanisms of synaptic plasticity in the AD cortex, as well as in the process of aberrant sprouting in the neuritic plaques.
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187 |
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Robles AI, Rodriguez-Puebla ML, Glick AB, Trempus C, Hansen L, Sicinski P, Tennant RW, Weinberg RA, Yuspa SH, Conti CJ. Reduced skin tumor development in cyclin D1-deficient mice highlights the oncogenic ras pathway in vivo. Genes Dev 1998; 12:2469-74. [PMID: 9716400 PMCID: PMC317082 DOI: 10.1101/gad.12.16.2469] [Citation(s) in RCA: 177] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/1998] [Accepted: 07/02/1998] [Indexed: 11/24/2022]
Abstract
Cyclin D1 is part of a cell cycle control node consistently deregulated in most human cancers. However, studies with cyclin D1-null mice indicate that it is dispensable for normal mouse development as well as cell growth in culture. Here, we provide evidence that ras-mediated tumorigenesis depends on signaling pathways that act preferentially through cyclin D1. Cyclin D1 expression and the activity of its associated kinase are up-regulated in keratinocytes in response to oncogenic ras. Furthermore, cyclin D1 deficiency results in up to an 80% decrease in the development of squamous tumors generated through either grafting of retroviral ras-transduced keratinocytes, phorbol ester treatment of ras transgenic mice, or two-stage carcinogenesis.
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research-article |
27 |
177 |
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Walker GM, Hansen L, Hanna JA, Allen SJ. Kinetics of a reactive dye adsorption onto dolomitic sorbents. WATER RESEARCH 2003; 37:2081-2089. [PMID: 12691893 DOI: 10.1016/s0043-1354(02)00540-7] [Citation(s) in RCA: 158] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A novel wastewater treatment technique has been investigated, for reactive dye removal, in batch kinetic systems. These experimental studies have indicated that charred dolomite has the potential to act as an adsorbent for the removal of Brilliant Red reactive dye from aqueous solution. The effect of initial dye concentration, adsorbent mass:liquid volume ratio, and agitation speed on dye removal have been determined with the experimental data mathematically described using empirical external mass transfer and intra-particle diffusion models. The experimental data show conformity with an adsorption process, with the removal rate heavily dependent on both external mass transfer and intra-particle diffusion.
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158 |
15
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Clausen JO, Hansen T, Bjørbaek C, Echwald SM, Urhammer SA, Rasmussen S, Andersen CB, Hansen L, Almind K, Winther K. Insulin resistance: interactions between obesity and a common variant of insulin receptor substrate-1. Lancet 1995; 346:397-402. [PMID: 7623569 DOI: 10.1016/s0140-6736(95)92779-4] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We previously discovered two aminoacid polymorphisms in codons 513 and 972 of the protein insulin receptor substrate-1 (IRS-1), which is important in cellular insulin action. We have investigated whether these polymorphisms are associated with changes in insulin sensitivity in a random sample of young healthy adults. Insulin sensitivity and secretion were measured during a combined intravenous glucose and tolbutamide tolerance test in 380 unrelated white subjects aged 18-32. IRS-1 polymorphisms were examined by single-strand conformation polymorphism and verified by restriction-enzyme digestion. No homozygous carrier of the codon-513 variant was identified, but one non-obese man had the codon-972 mutation on both alleles. He had low fasting-serum insulin and C-peptide concentrations and low insulin sensitivity and glucose effectiveness. During a 24 h dexamethasone test, he developed transient diabetes. In their heterozygous forms the codon-513 and codon-972 variants of IRS-1 were found in 3% and 9% of the subjects. Non-obese carriers of either polymorphism had similar insulin sensitivity and pancreatic beta-cell function to non-obese wild-type subjects (no known variants of IRS-1). Analysis of variance showed, however, a significant interaction between obesity (body-mass index > or = 25 kg/m2) and the heterozygous form of the codon-972 variant (p < 0.003); obese polymorphism carriers had lower insulin sensitivity than obese non-carriers (mean 6.0 [SD 3.3] vs 12.3 [9.5] x 10(-5) L min-1 pmol-1). The obese carriers of the codon-972 variant were also characterised by a clustering of metabolic cardiovascular risk factors, with raised fasting concentrations of plasma glucose, serum triglyceride, and plasma tissue-plasminogen-activator and its fast-acting inhibitor. With adjustment for known modulators of insulin sensitivity, multivariate analyses showed that the combination of obesity and the codon-972 variant was associated with a 50% reduction in insulin sensitivity (p = 0.0008). Our results suggest that the codon-972 IRS-1 gene variant may interact with obesity in the pathogenesis of common insulin-resistant disorders.
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141 |
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Fink-Jensen A, Suzdak PD, Swedberg MD, Judge ME, Hansen L, Nielsen PG. The gamma-aminobutyric acid (GABA) uptake inhibitor, tiagabine, increases extracellular brain levels of GABA in awake rats. Eur J Pharmacol 1992; 220:197-201. [PMID: 1425991 DOI: 10.1016/0014-2999(92)90748-s] [Citation(s) in RCA: 141] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of systemic administration of the gamma-aminobutyric acid (GABA) uptake inhibitor, R(-)N-(4,4-di(3-methyl-thien-2-yl)-but-3-enyl) nipecotic acid, hydrochloride (tiagabine) (previously NO-328), on extracellular GABA levels in the globus pallidus, ventral pallidum and substantia nigra of awake Sprague-Dawley rats was investigated using in vivo microdialysis. Tiagabine was administered in doses of 11.5 or 21.0 mg/kg i.p. (ED50 and ED85 doses, respectively, for inhibiting pentylenetetrazole-induced tonic seizures). Tiagabine increased the extracellular concentrations of GABA in globus pallidus with peak values 310% of basal level (after 21 mg/kg) and 240% of basal level (after 11.5 mg/kg). A significant increase in extracellular GABA levels was also found in the ventral pallidum (280% increase after 11.5 mg/kg and 350% increase after 21 mg/kg) and in the substantia nigra where the ED85 dose of tiagabine (21 mg/kg) produced a peak value of 200% compared to the basal level. Thus, tiagabine acts as a GABA uptake inhibitor in vivo also.
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Masliah E, Ellisman M, Carragher B, Mallory M, Young S, Hansen L, DeTeresa R, Terry RD. Three-dimensional analysis of the relationship between synaptic pathology and neuropil threads in Alzheimer disease. J Neuropathol Exp Neurol 1992; 51:404-14. [PMID: 1619440 DOI: 10.1097/00005072-199207000-00003] [Citation(s) in RCA: 133] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Recent studies have shown that the Alzheimer disease (AD) neocortex is characterized by a loss of large neurons, the presence of dilated terminal axons, widespread loss of synapses, and a disruption of the dendritic cytoskeleton which is manifested as Tau immunoreactive threads. In the present study we have investigated the relationship between synaptic and dendritic abnormalities in the neocortex of Alzheimer patients and examined the extent to which these structural alterations correlate with the severity of cognitive impairment in AD. Quantitative neuroanatomical data were obtained from immunofluorescence-labeled specimens using a laser-scanning confocal microscope, computer-assisted image processing and serial section reconstruction techniques. We found that the AD cases showed a 34% loss in the number of presynaptic terminals per 100 square (sq) microns, many of which showed structural abnormalities. The AD neuropil had an average of 10 +/- 7 dendritic threads per 1,000 sq microns, with the average thread measuring 2 sq microns. Severe AD cases had thicker threads compared with mild to moderate AD cases. Three-dimensional analysis showed clustering of synapses around threads, as well as presynaptic boutons apposed to dendritic neuropil threads. Statistical analysis showed that the strongest correlation was between synapse density and Blessed score of cognitive impairment. Thread counts did not correlate with either but were correlated with tangle counts. Stepwise multiple regression analysis showed that tangle counts, but not threads, strengthened the correlation between Blessed score and synapses. We conclude that synaptic damage may precede dendritic thread and tangle formation, and that threads do not necessarily induce synaptic pathology. Instead, dendrite sprouting in the denervated regions could be associated with increased accumulation of cytoskeletal proteins observed in the dendritic threads.
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133 |
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Masliah E, Hansen L, Albright T, Mallory M, Terry RD. Immunoelectron microscopic study of synaptic pathology in Alzheimer's disease. Acta Neuropathol 1991; 81:428-33. [PMID: 1903014 DOI: 10.1007/bf00293464] [Citation(s) in RCA: 123] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Alzheimer's disease (AD) is characterized by an extensive loss of neurons and synapses in the neocortex which correlates strongly with psychometric tests of dementia. To characterize the ultrastructural changes in presynaptic terminals in AD, we studied biopsy material from the frontal cortex. We also examined, at the ultrastructural level, abnormal neurites scattered in the AD neuropil and in the plaque region using sections from autopsy material immunolabeled with anti-synaptophysin. We found that, regardless of amyloid deposits, some presynaptic terminals were distended and contained swollen vesicles and dense bodies. These altered synaptic organelles were similar to those found in dystrophic neurites. The latter structures displayed synaptophysin immunoreactivity, mostly localized to outer membranes of synaptic vesicles and dense bodies. The present study supports the hypothesis of progressive synaptic pathology in AD neocortex and favors the notion that the dystrophic process originates from presynaptic terminals.
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123 |
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Hager J, Hansen L, Vaisse C, Vionnet N, Philippi A, Poller W, Velho G, Carcassi C, Contu L, Julier C. A missense mutation in the glucagon receptor gene is associated with non-insulin-dependent diabetes mellitus. Nat Genet 1995; 9:299-304. [PMID: 7773293 DOI: 10.1038/ng0395-299] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Non-insulin-dependent diabetes mellitus (NIDDM) affects about 5% of the world population. The disease presents a polygenic mode of inheritance, but mechanisms and genes involved in late-onset NIDDM are largely unknown. We report the association of a single heterozygous Gly to Ser missense mutation in the glucagon receptor gene with late-onset NIDDM. This mutation was highly associated with NIDDM in a pooled set of French and Sardinian patients (chi 2 = 14.4, P = 0.0001) and showed some evidence for linkage to diabetes in 18 sibships from 9 French pedigrees (chi 2 = 6.63, P < 0.01). Receptor binding studies using cultured cells expressing the Gly40Ser mutation demonstrate that this mutation results in a receptor which binds glucagon with a three-fold lower affinity compared to the wild type receptor.
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20
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Lendon CL, Lynch T, Norton J, McKeel DW, Busfield F, Craddock N, Chakraverty S, Gopalakrishnan G, Shears SD, Grimmett W, Wilhelmsen KC, Hansen L, Morris JC, Goate AM. Hereditary dysphasic disinhibition dementia: a frontotemporal dementia linked to 17q21-22. Neurology 1998; 50:1546-55. [PMID: 9633693 DOI: 10.1212/wnl.50.6.1546] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE The clinical and pathologic features of hereditary dysphasic disinhibition dementia (HDDD) are described to determine whether it is a variant of known dementias. BACKGROUND Several dementing disorders have clinical and pathologic similarities with AD, Pick's disease, and the "nonspecific" dementias. A detailed description of clinical and pathologic presentation will aid classification, but ultimately the discovery of causative gene(s) will define these disorders. METHODS The authors performed a clinical assessment: gross and microscopic pathologic evaluation of brain tissue, genetic linkage studies, and sequence analyses. RESULTS HDDD is an autosomal-dominant frontotemporal dementia with many similarities to Pick's disease. Salient clinical features are global dementia with disproportionate dysphasia and "frontotemporal" symptoms. A linkage between HDDD and 17q21-22 was shown, with a maximum lod score of 3.68 at zero recombination. CONCLUSIONS Several dementias have been linked to the same region and have been termed frontotemporal dementia with parkinsonism linked to chromosome 17. These disorders may represent phenotypic variants arising from mutations within a common gene.
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Case Reports |
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104 |
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Ek J, Andersen G, Urhammer SA, Hansen L, Carstensen B, Borch-Johnsen K, Drivsholm T, Berglund L, Hansen T, Lithell H, Pedersen O. Studies of the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) gene in relation to insulin sensitivity among glucose tolerant caucasians. Diabetologia 2001; 44:1170-6. [PMID: 11596673 DOI: 10.1007/s001250100629] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
AIMS/HYPOTHESIS We examined whether the Pro12-Ala polymorphism of the human peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) gene was related to altered insulin sensitivity among glucose-tolerant subjects or a lower accumulated incidence or prevalence of IGT and Type II (non-insulin-dependent) diabetes mellitus among Scandinavian Caucasians. METHODS The Pro12Ala polymorphism was examined using PCR-RFLP Whole-body insulin sensitivity measured under hyperinsulinaemic-euglycaemic conditions was estimated in a population-based sample of 616 glucose tolerant Swedish Caucasian men at age 70. In addition, insulin sensitivity index was measured using IVGTT and Bergman minimal modelling in a population-based sample of 364 young healthy Danish Caucasians. Finally, we evaluated whether the polymorphism predicted Type II diabetes and IGT in 841 seventy-year-old Swedish men. A case-control study was carried out in 654 unrelated Danish Type II diabetic patients and 742 Danish glucose tolerant subjects matched for age and sex. RESULTS Whole-body insulin sensitivity was significantly improved in carriers compared with non-carriers of the Ala-allele of the codon 12 polymorphism in Swedish Caucasian men (6.0+/-2.5 vs 5.6+/-2.5 mg kg(-1) x min(-1) x mU/l](-1) x 100, p = 0.044). The same tendency, but not significant, was observed in the insulin sensitivity index among the group of young healthy Danish Caucasians. The incidence of Type II diabetes and IGT among the Swedish subjects at the age of 70 was similar in the three genotype-groups of the Pro12Ala variant and the Ala-allele was not related to a lower prevalence of Type II diabetes in Danish Caucasians. CONCLUSION/INTERPRETATION The Ala-allele of the PPAR-gamma2 polymorphism is associated with improved whole body insulin sensitivity among Swedish Caucasians.
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Eiberg H, Hansen L, Kjer B, Hansen T, Pedersen O, Bille M, Rosenberg T, Tranebjaerg L. Autosomal dominant optic atrophy associated with hearing impairment and impaired glucose regulation caused by a missense mutation in the WFS1 gene. J Med Genet 2006; 43:435-40. [PMID: 16648378 PMCID: PMC2649014 DOI: 10.1136/jmg.2005.034892] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Autosomal dominant optic atrophy (ADOA) is genetically heterogeneous, with OPA1 on 3q28 being the most prevalently mutated gene. Additional loci are OPA3, OPA4, and OPA5, located at 19q13.2, 18q12.2, and 22q12.1-q13.1, respectively. Mutations in the WFS1 gene, at 4p16.3, are associated with either optic atrophy (OA) as part of the autosomal recessive Wolfram syndrome or with autosomal dominant progressive low frequency sensorineural hearing loss (LFSNHL) without any ophthalmological abnormalities. Linkage and sequence mutation analyses of the ADOA candidate genes OPA1, OPA3, OPA4, and OPA5, including the genes WFS1, GJB2, and GJB6 associated with recessive inherited OA or dominant LFSNHL, were performed. We identified one novel WFS1 missense mutation E864K, c.2590G-->A in exon 8 that co-segregates with ADOA combined with hearing impairment and impaired glucose regulation. This is the first example of autosomal dominant optic atrophy and hearing loss associated with a WFS1 mutation, supporting the notion that mutations in WFS1 as well as in OPA1 may lead to ADOA combined with impaired hearing.
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Research Support, Non-U.S. Gov't |
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Izatt RM, Rytting JH, Hansen LD, Christensen JJ. Thermodynamics of proton dissociation in dilute aqueous solution. V. An entropy titration study of adenosine, pentoses, hexoses, and related compounds. J Am Chem Soc 1966; 88:2641-5. [PMID: 5941265 DOI: 10.1021/ja00964a003] [Citation(s) in RCA: 100] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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Hansen L, Hartmann B, Bisgaard T, Mineo H, Jørgensen PN, Holst JJ. Somatostatin restrains the secretion of glucagon-like peptide-1 and -2 from isolated perfused porcine ileum. Am J Physiol Endocrinol Metab 2000; 278:E1010-8. [PMID: 10827002 DOI: 10.1152/ajpendo.2000.278.6.e1010] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Suspecting that paracrine inhibition might influence neuronal regulation of the endocrine L cells, we studied the role of somatostatin (SS) in the regulation of the secretion of the proglucagon-derived hormones glucagon-like peptide-1 and -2 (GLP-1 and GLP-2). This was examined using the isolated perfused porcine ileum stimulated with acetylcholine (ACh, 10(-6) M), neuromedin C (NC, 10(-8) M), and electrical nerve stimulation (NS) with or without alpha-adrenergic blockade (phentolamine 10(-5) M), and perfusion with a high-affinity monoclonal antibody against SS. ACh and NC significantly increased GLP secretion, whereas NS had little effect. SS immunoneutralization increased GLP secretion eight- to ninefold but had little influence on the GLP responses to ACh, NC, and NS. Basal SS secretion (mainly SS28) was unaffected by NS alone. Phentolamine + NS and NC abstract strongly stimulated release mainly of SS14, whereas ACh had little effect. Infused intravascularly, SS14 weakly and SS28 strongly inhibited GLP secretion. We conclude that GLP secretion is tonically inhibited by a local release of SS28 from epithelial paracrine cells, whereas SS14, supposedly derived from enteric neurons, only weakly influences GLP secretion.
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Galasko D, Katzman R, Salmon DP, Hansen L. Clinical and neuropathological findings in Lewy body dementias. Brain Cogn 1996; 31:166-75. [PMID: 8811993 DOI: 10.1006/brcg.1996.0040] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We compared clinical features in three groups of pathologically defined patients evaluated for dementia during life: (i) Alzheimer's disease (AD); (ii) Lewy body variant of Alzheimer's Disease (LBV), with Lewy bodies (LB) and AD; (iii) diffuse Lewy body disease (DLBD), with LB alone. All three groups had similar initial cognitive symptoms. LBV and DLBD had Parkinsonian signs, though resting tremor was extremely rare. Delusions and hallucinations were relatively more frequent in LBV and DLBD than in AD. On neuropsychological testing, the LBV group had relatively greater impairment than AD on visuospatial and executive tests. LB therefore contribute to the clinical picture of dementia.
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Comparative Study |
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