Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(27K+)
Patents
Grants
Pathways
Clinical trials
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
June/19/2007
Abstract
Multiple sclerosis (MS) is the leading cause of neurological disability in young adults, affecting some two million people worldwide. Traditionally, MS has been considered a chronic, inflammatory disorder of the central white matter in which ensuing demyelination results in physical disability [Frohman EM, Racke MK, Raine CS (2006) N Engl J Med 354:942-955]. More recently, MS has become increasingly viewed as a neurodegenerative disorder in which neuronal loss, axonal injury, and atrophy of the CNS lead to permanent neurological and clinical disability. Although axonal pathology and loss in MS has been recognized for >100 years, very little is known about the underlying molecular mechanisms. Progressive axonal loss in MS may stem from a cascade of ionic imbalances initiated by inflammation, leading to mitochondrial dysfunction and energetic deficits that result in mitochondrial and cellular Ca2+ overload. In a murine disease model, experimental autoimmune encephalomyelitis (EAE) mice lacking cyclophilin D (CyPD), a key regulator of the mitochondrial permeability transition pore (PTP), developed EAE, but unlike WT mice, they partially recovered. Examination of the spinal cords of CyPD-knockout mice revealed a striking preservation of axons, despite a similar extent of inflammation. Furthermore, neurons prepared from CyPD-knockout animals were resistant to reactive oxygen and nitrogen species thought to mediate axonal damage in EAE and MS, and brain mitochondria lacking CyPD sequestered substantially higher levels of Ca2+. Our results directly implicate pathological activation of the mitochondrial PTP in the axonal damage occurring during MS and identify CyPD, as well as the PTP, as a potential target for MS neuroprotective therapies.
Publication
Journal: Neuron
May/19/2004
Abstract
Highwire (Hiw), a putative RING finger E3 ubiquitin ligase, negatively regulates synaptic growth at the neuromuscular junction (NMJ) in Drosophila. hiw mutants have dramatically larger synaptic size and increased numbers of synaptic boutons. Here we show that Hiw binds to the Smad protein Medea (Med). Med is part of a presynaptic bone morphogenetic protein (BMP) signaling cascade consisting of three receptor subunits, Wit, Tkv, and Sax, in addition to the Smad transcription factor Mad. When compared to wild-type, mutants of BMP signaling components have smaller NMJ size, reduced neurotransmitter release, and aberrant synaptic ultrastructure. BMP signaling mutants suppress the excessive synaptic growth in hiw mutants. Activation of BMP signaling, which in wild-type does not cause additional growth, in hiw mutants does lead to further synaptic expansion. These results reveal a balance between positive BMP signaling and negative regulation by Highwire, governing the growth of neuromuscular synapses.
Publication
Journal: Magnetic Resonance in Medicine
January/3/2000
Abstract
The lack of a standard image intensity scale in MRI causes many difficulties in image display and analysis. A two-step postprocessing method is proposed for standardizing the intensity scale in such a way that for the same MR protocol and body region, similar intensities will have similar tissue meaning. In the first step, the parameters of the standardizing transformation are "learned" from a set of images. In the second step, for each MR study these parameters are used to map their histogram into the standardized histogram. The method was tested quantitatively on 90 whole-brain studies of multiple sclerosis patients for several protocols and qualitatively for several other protocols and body regions. Measurements using mean squared difference showed that the standardized image intensities have statistically significantly (P < 0.01) more consistent range and meaning than the originals. Fixed gray level windows can be established for the standardized images and used for display without the need of per case adjustment. Preliminary results also indicate that the method facilitates improving the degree of automation of image segmentation. Magn Reson Med 42:1072-1081, 1999.
Publication
Journal: Pain
February/6/2003
Abstract
A previous meta-analysis of clinical analgesic trial studies showed generally low magnitudes of placebo analgesia (N. Engl. J. Med. 344 (2001) 1594). However, as studies included in their analysis used only placebo as a control condition, we conducted two meta-analyses, one in which 23 studies used only placebo as a control condition, and one in which 14 studies investigated placebo analgesic mechanisms. Magnitudes of placebo analgesic effects were much higher in the latter (mean effect size=0.95) as compared to the former (mean effect size=0.15) and were significantly different (P=0.003). This difference as well as differences in effect sizes within studies of placebo mechanisms may be parsimoniously explained by differences in expected pain levels produced by placebo suggestions and by conditioning. Furthermore, some of the studies of placebo analgesic mechanisms indicate that the magnitude of placebo analgesia is higher when the placebo analgesic effect is induced via suggestion combined with conditioning than via suggestion alone or conditioning alone. Based on these findings, we suggest that placebo analgesic effects are most optimally conceptualized in terms of perception of the placebo agent, and therefore a new definition of placebo response is proposed.
Publication
Journal: Academic Medicine
August/8/1993
Abstract
The purpose of this review is to synthesize all available evaluative research from 1970 through 1992 that compares problem-based learning (PBL) with more traditional methods of medical education. Five separate meta-analyses were performed on 35 studies representing 19 institutions. For 22 of the studies (representing 14 institutions), both effect-size and supplementary vote-count analyses could be performed; otherwise, only supplementary analyses were performed. PBL was found to be significantly superior with respect to students' program evaluations (i.e., students' attitudes and opinions about their programs)--dw (standardized differences between means, weighted by sample size) = +.55, CI.95 = +.40 to +.70 - and measures of students' clinical performance (dw = +.28, CI.95 = +.16 to +.40). PBL and traditional methods did not differ on miscellaneous tests of factual knowledge (dw = -.09, CI.95 = +.06 to -.24) and tests of clinical knowledge (dw = +.08, CI.95 = -.05 to +.21). Traditional students performed significantly better than their PBL counterparts on the National Board of Medical Examiners Part I examination--NBME I (dw = -.18, CI.95 = -.10 to -.26). However, the NBME I data displayed significant overall heterogeneity (Qt = 192.23, p < .001) and significant differences among programs (Qb = 59.09, p < .001), which casts doubt on the generality of the findings across programs. The comparative value of PBL is also supported by data on outcomes that have been studied less frequently, i.e., faculty attitudes, student mood, class attendance, academic process variables, and measures of humanism. In conclusion, the results generally support the superiority of the PBL approach over more traditional methods. Acad. Med. 68 (1993):550-563.
Publication
Journal: Cancer Research
August/15/2001
Abstract
The development of new therapeutic strategies is essential for the management of gliomas, one of the most malignant forms of cancer. We have shown previously that the growth of the rat glioma C6 cell line is inhibited by psychoactive cannabinoids (I. Galve-Roperh et al., Nat. Med., 6: 313-319, 2000). These compounds act on the brain and some other organs through the widely expressed CB(1) receptor. By contrast, the other cannabinoid receptor subtype, the CB(2) receptor, shows a much more restricted distribution and is absent from normal brain. Here we show that local administration of the selective CB(2) agonist JWH-133 at 50 microg/day to Rag-2(-/-) mice induced a considerable regression of malignant tumors generated by inoculation of C6 glioma cells. The selective involvement of the CB(2) receptor in this action was evidenced by: (a) the prevention by the CB(2) antagonist SR144528 but not the CB(1) antagonist SR141716; (b) the down-regulation of the CB(2) receptor but not the CB(1) receptor in the tumors; and (c) the absence of typical CB(1)-mediated psychotropic side effects. Cannabinoid receptor expression was subsequently examined in biopsies from human astrocytomas. A full 70% (26 of 37) of the human astrocytomas analyzed expressed significant levels of cannabinoid receptors. Of interest, the extent of CB(2) receptor expression was directly related with tumor malignancy. In addition, the growth of grade IV human astrocytoma cells in Rag-2(-/-) mice was completely blocked by JWH-133 administration at 50 microg/day. Experiments carried out with C6 glioma cells in culture evidenced the internalization of the CB(2) but not the CB(1) receptor upon JWH-133 challenge and showed that selective activation of the CB(2) receptor signaled apoptosis via enhanced ceramide synthesis de novo. These results support a therapeutic approach for the treatment of malignant gliomas devoid of psychotropic side effects.
Publication
Journal: Annals of Behavioral Medicine
July/12/2011
Abstract
The multiphase optimization strategy (MOST) is a new methodological approach for building, optimizing, and evaluating multicomponent interventions. Conceptually rooted in engineering, MOST emphasizes efficiency and careful management of resources to move intervention science forward steadily and incrementally. MOST can be used to guide the evaluation of research evidence, develop an optimal intervention (the best set of intervention components), and enhance the translation of research findings, particularly type II translation. This article uses an ongoing study to illustrate the application of MOST in the evaluation of diverse intervention components derived from the phase-based framework reviewed in the companion article by Baker et al. (Ann Behav Med, in press, 2011). The article also discusses considerations, challenges, and potential benefits associated with using MOST and similar principled approaches to improving intervention efficacy, effectiveness, and cost-effectiveness. The applicability of this methodology may extend beyond smoking cessation to the development of behavioral interventions for other chronic health challenges.
Publication
Journal: Journal of Biological Chemistry
December/13/2004
Abstract
Annexin 2 is a profibrinolytic co-receptor for plasminogen and tissue plasminogen activator that stimulates activation of the major fibrinolysin, plasmin, at cell surfaces. In human subjects, overexpression of annexin 2 in acute promyelocytic leukemia leads to a bleeding diathesis reflective of excessive cell surface annexin 2-dependent generation of plasmin (Menell, J. S., Cesarman, G. M., Jacovina, A. T., McLaughlin, M. A., Lev, E. A., and Hajjar, K. A. (1999) N. Engl. J. Med. 340, 994-1004). In addition, mice completely deficient in annexin 2 display fibrin accumulation within blood vessels and impaired clearance of injury-induced thrombi (Ling Q., Jacovina, A.T., Deora, A.B., Febbraio, M., Simantov, R., Silverstein, R. L., Hempstead, B. L., Mark, W., and Hajjar, K. A. (2004) J. Clin. Investig. 113, 38-48). Here, we show that endothelial cell annexin 2, a protein that lacks a typical signal peptide, translocates from the cytoplasm to the extracytoplasmic plasma membrane in response to brief temperature stress both in vitro and in vivo in the absence of cell death or cell lysis. This regulated response is independent of new protein or mRNA synthesis and does not require the classical endoplasmic reticulum-Golgi pathway. Temperature stress-induced annexin 2 translocation is dependent on both expression of protein p11 (S100A10) and tyrosine phosphorylation of annexin 2 because annexin 2 release is completely eliminated on depletion of p11, inactivation of tyrosine kinase, or mutation of tyrosine 23. Translocation of annexin 2 to the cell surface dramatically increases tissue plasminogen activator-dependent plasminogen activation potential and may represent a novel stress-induced protein secretion pathway.
Publication
Journal: Journal of Virology
March/14/2002
Abstract
We previously reported that high-titered neutralizing antibodies directed against the human immunodeficiency virus type 1 (HIV-1) envelope can block the establishment of a simian immunodeficiency virus (SIV)/HIV chimeric virus (SHIV) infection in two monkeys following passive transfer (R. Shibata et al., Nat. Med. 5:204-210, 1999). In the present study, increasing amounts of neutralizing immunoglobulin G (IgG) were administered to 15 pig-tailed macaques in order to obtain a statistically valid protective neutralization endpoint titer in plasma. Using an in vitro assay which measures complete neutralization of the challenge SHIV, we correlated the titers of neutralizing antibodies in plasma at the time of virus inoculation (which ranged from 1:3 to 1:123) with the establishment of infection in virus-challenged animals. Ten of 15 monkeys in the present experiment were virus free as a result of neutralizing IgG administration as monitored by DNA PCR (peripheral blood mononuclear cells and lymph node cells), RNA PCR (plasma), virus isolation, and the transfer of lymph node cell suspensions (10(8) cells) plus 8 ml of whole blood from protected animals to naïve macaques. The titer of neutralizing antibodies in the plasma calculated to protect 99% of virus-challenged monkeys was 1:38.
Publication
Journal: BMC Research Notes
July/13/2011
Abstract
BACKGROUND
The application of mobile computing and communication technology is rapidly expanding in the fields of health care and public health. This systematic review will summarise the evidence for the effectiveness of mobile technology interventions for improving health and health service outcomes (M-health) around the world.
RESULTS
To be included in the review interventions must aim to improve or promote health or health service use and quality, employing any mobile computing and communication technology. This includes: (1) interventions designed to improve diagnosis, investigation, treatment, monitoring and management of disease; (2) interventions to deliver treatment or disease management programmes to patients, health promotion interventions, and interventions designed to improve treatment compliance; and (3) interventions to improve health care processes e.g. appointment attendance, result notification, vaccination reminders.A comprehensive, electronic search strategy will be used to identify controlled studies, published since 1990, and indexed in MEDLINE, EMBASE, PsycINFO, Global Health, Web of Science, the Cochrane Library, or the UK NHS Health Technology Assessment database. The search strategy will include terms (and synonyms) for the following mobile electronic devices (MEDs) and a range of compatible media: mobile phone; personal digital assistant (PDA); handheld computer (e.g. tablet PC); PDA phone (e.g. BlackBerry, Palm Pilot); Smartphone; enterprise digital assistant; portable media player (i.e. MP3 or MP4 player); handheld video game console. No terms for health or health service outcomes will be included, to ensure that all applications of mobile technology in public health and health services are identified. Bibliographies of primary studies and review articles meeting the inclusion criteria will be searched manually to identify further eligible studies. Data on objective and self-reported outcomes and study quality will be independently extracted by two review authors. Where there are sufficient numbers of similar interventions, we will calculate and report pooled risk ratios or standardised mean differences using meta-analysis.
CONCLUSIONS
This systematic review will provide recommendations on the use of mobile computing and communication technology in health care and public health and will guide future work on intervention development and primary research in this field.
Publication
Journal: Seminars in Cell and Developmental Biology
July/13/2006
Abstract
Histopathological examination of solid tumors frequently reveals pronounced tumor cell heterogeneity with regards to cell organization, cell morphology, cell size, nuclei morphology, etc. Analyses of gene expression patterns by immunohistochemistry or in situ hybridization techniques further strengthen the actual presence of phenotypic heterogeneity, often demonstrating substantial diversity within a given tumor. The molecular mechanisms underlying the phenotypic heterogeneity are very complex with genetic, epigenetic and environmental components. Hypoxia, shortage in oxygen, greatly influences cellular phenotypes by altering the expression of specific genes, and is an important contributor to intra- and inter-tumor cell diversity as revealed by the pronounced but non-uniform expression of hypoxia-driven genes in solid tumors (reviewed in [Semenza GL. Targeting HIF-1 for cancer therapy. Nat Rev Cancer 2003;3:721-32; Harris AL. Hypoxia--a key regulatory factor in tumour growth. Nat Rev Cancer 2002;2:38-47.]). The oxygen pressure in solid tumors is generally lower than in the surrounding non-malignant tissues, and tumors exhibiting extensive hypoxia have been shown to be more aggressive than corresponding tumors that are better oxygenized [Vaupel P. Oxygen transport in tumors: characteristics and clinical implications. Adv Exp Med Biol 1996;388:341-51; Vaupel P, Thews O, Hoeckel M. Treatment resistance of solid tumors: role of hypoxia and anemia. Med Oncol 2001;18:243-59.]. We recently observed that hypoxic neuroblastoma cells and breast cancer cells lose their differentiated gene expression patterns and develop stem cell-like phenotypes [Jögi A, Øra I, Nilsson H, Lindeheim A, Makino Y, Poellinger L, et al. Hypoxia alters gene expression in human neuroblastoma cells toward an immature and neural crest-like phenotype. Proc Natl Acad Sci USA 2002;99:7021-6; Helczynska K, Kronblad A, Jögi A, Nilsson E, Beckman S, Landberg G, et al. Hypoxia promotes a dedifferentiated phenotype in ductal breast carcinoma in situ. Cancer Res 2003;63:1441-4.]. As low stage of differentiation in neuroblastoma and in breast cancer is linked to poor prognosis, hypoxia-induced dedifferentiation will not only contribute to tumor heterogeneity but could also be one mechanism behind increased aggressiveness of hypoxic tumors. The effect(s) of hypoxia on tumor cell differentiation status is the focus of this review.
Publication
Journal: Journal of Clinical Investigation
June/23/1997
Abstract
Using a cell line (termed BCBL-1) derived from a peripheral effusion (body cavity-based) lymphoma latently infected with Kaposi's sarcoma-associated herpesvirus (KSHV), we recently reported the successful induction of KSHV replication in culture (Renne, R., W. Zhong, B. Herndier, M. McGrath, N. Abbey, D. Kedes, and D. Ganem. 1996. Nat. Med. 2:342-346). Here we report the first use of this system for establishing the susceptibility of KSHV to available antiviral drugs. Latently infected BCBL-1 cells were induced to lytic replication with phorbol esters; such cells secrete large numbers of KSHV virions into the culture medium. We assayed the ability of the antivirals to block KSHV production, as measured by the release of encapsidated viral DNA. The results show that KSHV replication is insensitive to acyclovir (9-[(2-hydroxyethoxy)-methyl]guanine) (50% inhibitory concentration [IC50] = 60-80 microM), but sensitive to ganciclovir (9-[1,3-dihydroxy-2-propoxymethyl]guanine) (IC50 = 2.7-4 microM), foscarnet (trisodium phosphonoformate hexahydrate) (IC50 = 80-100 microM), and cidofovir (1-[(S)-3-hydroxy-2-(phosphonomethoxy)propyl]cytosine) (IC50 = 0.5-1 microM).
Publication
Journal: Journal of Bacteriology
June/15/1980
Abstract
The proteins of the outer membrane of Neisseria gonorrhoeae play an important role in the serotyping system defined by K. H. Johnston et al. (J. Exp. Med. 143:741-758, 1976). This study attempted to delineate the molecular arrangement of the major proteins of the outer membrane of the gonococcus by using three approaches. First, natural protein-protein relationships were demonstrated by symmetrical, two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Second, proteins exposed on the surface of outer membrane vesicles were cross-linked by using the bifunctional reagents dimethyl-3,3'-dithiobispropionimidate and dithiobis[succinimidyl propionate]. Third, specific antigen-antibody interactions on the surface of membrane vesicles were analyzed by radioautographic techniques. The major proteins of the outer membrane of the gonococcus were defined, and a nomenclature was devised to take into account the effects of heat and reducing agents on the resolution of these proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results of cross-linking experiments strongly suggest that two of the major proteins of the gonococcal outer membrane (proteins 1 and 3) form a hydrophobically associated trimeric unit in situ which can be stabilized by selective cross-linking reagents. Results substantiated that these proteins are responsible for imparting serotypic specificity.
Publication
Journal: Journal of Biological Chemistry
July/4/1989
Abstract
The Lex determinant (Gal beta 1----4[Fuc alpha 1----3]GlcNAc-beta 1----R) has been implicated as having a role in mediating compaction of the mouse embryo at the morula stage (Fenderson, B., Zehavi, U., and Hakomori, S. (1984) J. Exp. Med. 160, 1591-1596). Here, we present evidence suggesting a role for Lex in F9 embryonal carcinoma cell adhesion and a mechanism for Lex recognition based on carbohydrate-carbohydrate interaction. Homotypic aggregation of F9 cells was inhibited by lacto-N-fucopentaose III, and F9 cells showed a preferential interaction with Lex liposomes. The following observations suggest that the structure capable of recognizing Lex per se on F9 cells is Lex: (i) Cell surface-labeled components solubilized in octylglucoside, affinity-bound on an Lex-octyl-Sepharose column, contained glycoproteins reactive with anti-Lex antibody. (ii) Liposomes containing Lex showed significant interaction with Lex glycolipid, but not other glycolipids, coated on a plastic surface. (iii) Liposomes containing Lex glycolipid were found to self-aggregate, whereas liposomes containing paragloboside (nLc4) or sialylparagloboside (IV3NeuAcnLc4) did not. (iv) The diffusibility of 3H-labeled lacto-N-fucopentaitol III (but not I or II), incubated with Lex liposome, from the lower to the upper Boyden chamber through a semipermeable membrane was inhibited. In all these experiments (i-iv), the interaction of Lex to Lex (or Lex to lacto-N-fucopentaose III) was clearly observed only in the presence of Ca2+ and Mg2+ and was enhanced by the presence of Mn2+. These interactions were inhibited by EDTA. The results suggest the novel hypothesis that carbohydrate-carbohydrate interactions may play an important role in controlling cell recognition during F9 cell aggregation and during embryonic development.
Publication
Journal: International Journal of Radiation Oncology Biology Physics
January/31/2007
Abstract
OBJECTIVE
Primary medulloblastoma and glioblastoma multiforme tumor cells that express the surface marker CD133 are believed to be enriched for brain tumor stem cells because of their unique ability to initiate or reconstitute tumors in immunodeficient mice. This study sought to characterize the radiobiological properties and marker expression changes of CD133+ vs. CD133- cells of an established medulloblastoma cell line.
METHODS
Daoy and D283 Med cell lines were stained with fluorescently labeled anti-CD133 antibody and sorted into CD133+ and CD133- populations. The effect of oxygen (2% vs. 20%) on CD133 expression was measured. Both populations were analyzed for marker stability, cell cycle distribution, and radiosensitivity.
RESULTS
CD133+ Daoy cells restored nearly native CD133+ and CD133- populations within 18 days, whereas CD133- cells remained overwhelmingly CD133-. Culturing Daoy cells in 2% oxygen rather than the standard 20% oxygen increased their CD133 expression 1.6-fold. CD133+ Daoy cells were radioresistant via the beta-parameter of the linear-quadratic model relative to CD133- Daoy cells, although their alpha-parameters and cell cycle distributions were identical.
CONCLUSIONS
Restoration of the original CD133+ and CD133- populations from CD133+ Daoy cells in serum is further evidence that CD133+ cells are functionally distinct from CD133- cells. The radioresistance of CD133+ compared with CD133- Daoy cells is consistent with better repair of sublethal damage. Enlargement of the CD133+ sector is a new feature of the hypoxic response.
Publication
Journal: Archives of internal medicine
November/20/2000
Abstract
BACKGROUND
Recognition and medical record documentation of dementia in the primary care setting are thought to be poor. To our knowledge, previous studies have not examined these issues in private practice office settings within the United States.
OBJECTIVE
To determine the rate of unrecognized and undocumented dementia in a primary care internal medicine private practice.
METHODS
This was a cross-sectional study of 297 ambulatory persons aged 65 years and older attending an internal medicine private group practice within an Asian American community of Honolulu, Hawaii. Of the subjects, 95% had been with their current primary care physician for at least 1 year. Each subject's primary care physician noted the presence or absence of dementia by questionnaire at the time of an office visit. An investigating physician (V.G.V.) subsequently assessed cognitive function using the Cognitive Abilities Screening Instrument, and confirmed the presence of dementia and its severity, if present, using Benson and Cummings' criteria and the Clinical Dementia Rating Scale, respectively. A trained research assistant completed telephone interviews to proxy informants for collateral information concerning cognition, behavior, and occupational or social function. Subjects' outpatient medical records were reviewed for documentation of problems with cognition.
RESULTS
Twenty-six cases of dementia were identified. Of these 26, 17 (65%) (95% confidence interval, 44.3-82.8) were not documented in outpatient medical records; of 18 patients, 12 (67%) (95% confidence interval, 40.9-86.7) were not thought to have dementia by their physicians at the time of the office visit. Recognition and documentation rates increased with advancing stage of disease.
CONCLUSIONS
Dementia is often unrecognized and undocumented in private practice settings. Arch Intern Med. 2000;160:2964-2968
Publication
Journal: Journal of Biological Chemistry
September/4/1997
Abstract
The malic enzyme (ME) gene is a target for both thyroid hormone receptors and peroxisome proliferator-activated receptors (PPAR). Within the ME promoter, two direct repeat (DR)-1-like elements, MEp and MEd, have been identified as putative PPAR response elements (PPRE). We demonstrate that only MEp and not MEd is able to bind PPAR/retinoid X receptor (RXR) heterodimers and mediate peroxisome proliferator signaling. Taking advantage of the close sequence resemblance of MEp and MEd, we have identified crucial determinants of a PPRE. Using reciprocal mutation analyses of these two elements, we show the preference for adenine as the spacing nucleotide between the two half-sites of the PPRE and demonstrate the importance of the two first bases flanking the core DR1 in 5'. This latter feature of the PPRE lead us to consider the polarity of the PPAR/RXR heterodimer bound to its cognate element. We demonstrate that, in contrast to the polarity of RXR/TR and RXR/RAR bound to DR4 and DR5 elements respectively, PPAR binds to the 5' extended half-site of the response element, while RXR occupies the 3' half-site. Consistent with this polarity is our finding that formation and binding of the PPAR/RXR heterodimer requires an intact hinge T region in RXR while its integrity is not required for binding of the RXR/TR heterodimer to a DR4.
Publication
Journal: Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N.Y.)
December/22/1997
Abstract
In 1988, insulin-like growth factor-binding protein-1 (IGFBP-1) became the first characterized member of a group of structurally related soluble proteins which specifically bind and modulate the actions of the IGFs. Since then, a wealth of information has accumulated regarding the physiology of this dynamic serum protein. In this review, we update our 1993 summary (Lee PDK et al. Proc Soc Exp Biol Med 204:4-29) of the status of IGFBP-1 research. The IGFBP-1 protein sequence contains 12 N-terminal and 6 C-terminal cysteine residues which are conserved in other mammalian IGFBP-1 sequences and amongst other IGFBPs; both of the cysteine-rich regions are required for optimal IGF binding. The nonconserved IGFBP-1 midregion may act as both a hinge which defines ligand binding characteristics and as a specific target for protease activity. Integrin-binding and phosphorylation sites within the IGFBP-1 sequence have functional significance in vitro, but their physiologic relevance in vivo have not been defined. The human IGFBP-1 and IGFBP-3 genes are contiguous and located in close proximity to the homeobox A (HOXA) gene cluster on chromosome 7. The other IGFBP genes, located on chromosomes 2, 12, and 17, are also associated with HOX clusters, suggesting evolutionary linkage of the IGFBP and HOX gene families. Similarities between the hIGFBP-1 and phosphoenolpyruvate kinase (PEPCK) promoters, including regions conferring insulin, glucocorticoid, and cyclic adenosine-monophosphate responses, are consistent with our previous hypothesis that IGFBP-1 is involved in regulation of glucose metabolism. The tissue-specific patterns of IGFBP-1 gene expression in liver, kidney, decidua, and ovary may be due to stimulation of IGFBP-1 transcription by hepatic nuclear factor 1 (HNF1) proteins. Clinical and basic studies of IGFBP-1 physiology have been aided by several recently developed assay methods. Numerous investigations have confirmed that insulin, via inhibition of IGFBP-1 transcription, is the primary determinant of IGFBP-1 expression both in vitro and in vivo. IGF-I and IGF-II also have specific inhibitory effects on IGFBP-1 expression. Glucocorticoids and cAMP stimulate IGFBP-1 transcription, but these effects are observed only in conditions of low or absent insulin effect. Other stimulants of IGFBP-1 expression include thyroid hormones and epidermal growth factor. Phorbol ester stimulation of IGFBP-1 expression can supersede the effects of insulin in vitro;however, the mechanism and in vivo correlates of this effect have not been determined. Cytokines and, perhaps, growth hormones may affect IGFBP-1 expression, perhaps by altering the regulatory actions of insulin; this effect may have important clinical relevance. IGFBP-1 expression is upregulated in liver and (nonhuman) kidney during postinjury regeneration. The IGF-inhibitory actions of IGFBP-1 has been confirmed by numerous in vitro studies and several in vivo animal investigations, including administration of recombinant IGFBP-1 and IGFBP-1 transgenic models. IGFBP-1 has been shown to inhibit somatic linear growth, weight gain, tissue growth, and glucose metabolism. Moreover, IGFBP-1 appears to be a primary determinant of free IGF-I levels in serum. Excess levels of IGFBP-1 may contribute to growth failure in intrauterine growth restriction and in pediatric chronic renal failure, while low IGFBP-1 levels are associated with obesity and with cardiovascular risk factors in insulin resistance syndromes. Serum IGFBP-1 measurements may be useful biochemical marker in these pathologic conditions. IGFBP-1 is expressed in decidualized stromal cells of the uterine endometrium and in ovarian granulosa cells. IGFBP-1, together with IGFs, insulin, ovarian steroids, cytokines, and other factors, is involved in a complex system which regulates menstrual cycles, ovulation, decidualization, blastocyst implantation, and fetal growth. (ABSTRACT TRUNCATED)
Publication
Journal: Genetics in Medicine
August/7/2012
Abstract
OBJECTIVE
The aim of this study was to explore specific conditions and types of genetic variants that specialists in genetics recommend should be returned as incidental findings in clinical sequencing.
METHODS
Sixteen specialists in clinical genetics and/or molecular medicine selected variants in 99 common conditions to return to the ordering physician if discovered incidentally through whole-genome sequencing. For most conditions, the specialists independently considered three molecular scenarios for both adults and minor children: a known pathogenic mutation, a truncating variant presumed pathogenic (where other truncating variants are known to be pathogenic), and a missense variant predicted in silico to be pathogenic.
RESULTS
On average, for adults and children, respectively, each specialist selected 83.5 and 79.0 conditions or genes of 99 in the known pathogenic mutation categories, 57.0 and 53.5 of 72 in the truncating variant categories, and 33.4 and 29.7 of 72 in the missense variant categories. Concordance in favor of disclosure within the adult/known pathogenic mutation category was 100% for 21 conditions or genes and 80% or higher for 64 conditions or genes.
CONCLUSIONS
Specialists were highly concordant for the return of findings for 64 conditions or genes if discovered incidentally during whole-exome sequencing or whole-genome sequencing.Genet Med 2012:14(4):405-410.
Publication
Journal: Molecular and Cellular Biology
May/1/2003
Abstract
Transcriptional activators interact with multisubunit coactivators that modify chromatin structure or recruit the general transcriptional machinery to their target genes. Budding yeast cells respond to amino acid starvation by inducing an activator of amino acid biosynthetic genes, Gcn4p. We conducted a comprehensive analysis of viable mutants affecting known coactivator subunits from the Saccharomyces Genome Deletion Project for defects in activation by Gcn4p in vivo. The results confirm previous findings that Gcn4p requires SAGA, SWI/SNF, and SRB mediator (SRB/MED) and identify key nonessential subunits of these complexes required for activation. Among the numerous histone acetyltransferases examined, only that present in SAGA, Gcn5p, was required by Gcn4p. We also uncovered a dependence on CCR4-NOT, RSC, and the Paf1 complex. In vitro binding experiments suggest that the Gcn4p activation domain interacts specifically with CCR4-NOT and RSC in addition to SAGA, SWI/SNF, and SRB/MED. Chromatin immunoprecipitation experiments show that Mbf1p, SAGA, SWI/SNF, SRB/MED, RSC, CCR4-NOT, and the Paf1 complex all are recruited by Gcn4p to one of its target genes (ARG1) in vivo. We observed considerable differences in coactivator requirements among several Gcn4p-dependent promoters; thus, only a subset of the array of coactivators that can be recruited by Gcn4p is required at a given target gene in vivo.
Publication
Journal: Genetics in Medicine
September/21/2017
Abstract
The accurate interpretation of variation in Mendelian disease genes has lagged behind data generation as sequencing has become increasingly accessible. Ongoing large sequencing efforts present huge interpretive challenges, but they also provide an invaluable opportunity to characterize the spectrum and importance of rare variation.
We analyzed sequence data from 7,855 clinical cardiomyopathy cases and 60,706 Exome Aggregation Consortium (ExAC) reference samples to obtain a better understanding of genetic variation in a representative autosomal dominant disorder.
We found that in some genes previously reported as important causes of a given cardiomyopathy, rare variation is not clinically informative because there is an unacceptably high likelihood of false-positive interpretation. By contrast, in other genes, we find that diagnostic laboratories may be overly conservative when assessing variant pathogenicity.
We outline improved analytical approaches that evaluate which genes and variant classes are interpretable and propose that these will increase the clinical utility of testing across a range of Mendelian diseases.Genet Med 19 2, 192-203.
Publication
Journal: Magnetic Resonance in Medicine
September/12/2001
Abstract
It is shown that diffusion tensor MR imaging (DTI) can discretely delineate the microstructure of white matter and gray matter in embryonic and early postnatal mouse brains based on the existence and orientation of ordered structures. This order was found not only in white matter but also in the cortical plate and the periventricular zone, which are precursors of the cerebral cortex. This DTI-based information could be used to accomplish the automated spatial definition of the cortical plate and various axonal tracts. The DTI studies also revealed a characteristic evolution of diffusion anisotropy in the cortex of the developing brain. This ability to detect changes in the organization of the brain during development will greatly enhance morphological studies of transgenic and knockout models of cortical dysfunction. Magn Reson Med 46:18-23, 2001.
Publication
Journal: Journal of Virology
May/26/1998
Abstract
The recently identified human herpesvirus 8 (HHV-8, or Kaposi's sarcoma-associated herpesvirus) has been implicated in the etiology of both Kaposi's sarcoma (KS) and primary effusion (body cavity-based) lymphoma (PEL) (Y. Chang et al., Science 266:1865-1869, 1994; P. S. Moore et al., J. Virol. 70:549-558, 1996). An important feature of the association of HHV-8 with these malignancies is the expression of an abundant, latency-associated 0.7-kb transcript, T0. 7 (W. Zhong et al., Proc. Natl. Acad. Sci. USA 93:6641-6646, 1996). T0.7 is found in all stages in nearly all KS tumors of different epidemiologic origin, including AIDS-associated, African endemic, and classical KS (K. A. Staskus et al., J. Virol. 71:715-719, 1997), as well as in a body cavity-based lymphoma-derived cell line, BCBL-1, that is latently infected with HHV-8 (R. Renne et al., Nat. Med. 2:342-346, 1996). T0.7 encodes a unique HHV-8 open reading frame, K12, also known as kaposin. In this study, we report that the kaposin gene induced tumorigenic transformation. Constructs with kaposin expressed either from its endogenous promoter or from a heterologous promoter induced focal transformation upon transfection into Rat-3 cells. All transformed Rat-3 cell lines containing kaposin sequences produced high-grade, highly vascular, undifferentiated sarcomas upon subcutaneous injection of athymic nu/nu mice. Tumor-derived cell lines expressed kaposin mRNA, suggesting a role in the maintenance of the transformed phenotype. Furthermore, kaposin protein was detected in transformed and tumor-derived cells by immunofluorescence and localized to the cytoplasm. More importantly, expression of kaposin protein was also detected in the PEL cell lines BCBL-1 and KS-1. These findings demonstrate the oncogenic potential of kaposin and suggest its possible role in the development of KS and other HHV-8-associated malignancies.
Publication
Journal: Metabolism: Clinical and Experimental
May/1/2006
Abstract
Values for body surface area (BSA) are commonly used in medicine, particularly to calculate doses of chemotherapeutic agents and index cardiac output. Various BSA formulas have been developed over the years. The DuBois and DuBois (Arch Intern Med 1916;17:863-71) BSA equation is the most widely used, although derived from only 9 subjects. More recently, Mosteller (N Engl J Med 1987;317:1098) produced a simple formula, [weight (kg) x height (cm)/3600](1/2), which could be easily remembered and evaluated on a pocket calculator, but validation data in adults are rare. The purpose of the present study was to examine the BSA based on Mosteller's formula in normal-weight (body mass index [BMI], 20-24.9 kg/m(2)), overweight (BMI, 25-29.9 kg/m(2)), and obese (BMI,>>/=30 kg/m(2)) adults (>18 years old) in comparison with other empirically derived formulas (DuBois and DuBois, Boyd [The growth of the surface area of the human body. Minneapolis: University of Minnesota Press; 1935], Gehan and George [Cancer Chemother Rep 1970;54:225-35], US Environmental Protection Agency [Development of statistical distributions or ranges of standard factors used in exposure assessments Washington, EPA/600/8-85-010. Office of Health and Environmental Assessment; 1985), Haycock et al [J Pediatr 1978;93:62-6], Mattar [Crit Care Med 1989;17:846-7], Livingston and Scott [Am J Physiol Endocrinol Metab 2001;281:E586-91]) and with the new 3-dimensional-derived formula of Yu et al (Appl Ergon. 2003;34:273-8). One thousand eight hundred sixty-eight patients were evaluated (397 normal weight [BMI, 23 +/- 1 kg/m(2); age, 50 +/- 14 years; M/F, 289/108], 714 overweight [BMI, 27 +/- 1 kg/m(2); age, 52 +/- 11 years; M/F, 594/120], and 757 obese [BMI, 36 +/- 6 kg/m(2); age, 53 +/- 11 years; M/F, 543/215]). The overall BSA was 2.04 +/- 0.24 m(2): 1.81 +/- 0.19 m(2) in normal-weight, 1.99 +/- 0.16 m(2) in overweight, and 2.21 +/- 0.22 m(2) in obese subjects. These values were significantly higher in overweight and obese patients compared with the values using the DuBois-DuBois formula (overall, 2.00 +/- 0.22 m(2), P < .01; normal weight, 1.81 +/- 0.19 m(2), P = .93; overweight, 1.97 +/- 0.16 m(2), P < .01; obese, 2.14 +/- 0.21 m(2), P < .001). We could show an excellent correlation between the results obtained from each formula, with all correlations of 0.97 or higher (between 0.971 and 0.999). Body surface area prediction with the commonly used DuBois formula underestimated BSA in obese patients by as much as 3% (male) to 5% (female). Based on the formula of Yu et al, however, BSA is overestimated when these traditional formulas are used. Although Mosteller's formula is recommended based on its simplicity and suitability for laboratory and clinical work in adults, accuracy studies in whites with 3-dimensional one-pass whole-body scanning are needed.
load more...