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Domjahn BT, Hlavsa MC, Anderson B, Schulkin J, Leon J, Jones JL. A survey of U.S. obstetrician-gynecologists' clinical and epidemiological knowledge of cryptosporidiosis in pregnancy. Zoonoses Public Health 2013; 61:356-63. [PMID: 24119338 DOI: 10.1111/zph.12078] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Indexed: 11/30/2022]
Abstract
Although cryptosporidiosis is frequently diagnosed in the U.S., there has been very little assessment of obstetrician-gynaecologist knowledge about this disease. In 2010, we surveyed U.S. obstetricians about the diagnosis, treatment and epidemiology of cryptosporidiosis. Data were examined through univariable analysis and multivariable regression models. Of 1000 obstetrician-gynaecologists surveyed, 431 (43.1%) responded. Only 44.4% of respondents correctly identified that prolonged, intermittent diarrhoea would lead them to consider cryptosporidiosis in a differential diagnosis. Routine ova and parasites (O&P) testing was incorrectly chosen to identify Cryptosporidium in stool by 30.4% of respondents. Questions about nitazoxanide, the only drug approved by the U.S. Food & Drug Administration (FDA) for treatment of cryptosporidiosis, were the most frequently missed questions. Only 9.0% of respondents correctly classified nitazoxanide as an FDA pregnancy Category B drug, and only 5.6% of respondents correctly indicated that FDA approved nitazoxanide for immunocompetent patients aged ≥1 years. Regarding prevention- and control-related knowledge, only 14.1% of respondents correctly indicated that alcohol-based hand sanitizers were not effective at inactivating Cryptosporidium spp., and <10% correctly indicated that cryptosporidiosis is a reportable disease in their state of practice. Multivariable analysis found that ≥19 years in practice was positively associated with O&P diagnostic testing knowledge, while rural and urban non-inner city practice location, compared with suburban practice location, was positively associated with nitazoxanide knowledge. The low level of knowledge among obstetrician-gynaecologists about cryptosporidiosis indicates a need to develop resources for physicians about all aspects of cryptosporidiosis, particularly on diagnosis, treatment and prevention strategies.
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Garcia L, Ferrandiz N, Caraballo J, Lafita M, Bretones G, Quintanilla A, Muñoz-Alonso M, Blanco R, Agell N, Leon J. 669 P21WAF1 Represses Cell Cycle Genes in K562 Cells Acting as a Transcriptional Modulator. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71314-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Caraballo Otero J, Acosta J, Gomez-Casares M, Cortes M, Batlle A, Cuadrado M, Colomer D, Leon J. 333 Myc/p27 Balance in Chronic Lymphocytic Leukemia. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)71023-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Anghel-Vasilescu P, Dorignac J, Geniet F, Leon J, Taki M. Nonlinear supratransmission in multicomponent systems. PHYSICAL REVIEW LETTERS 2010; 105:074101. [PMID: 20868047 DOI: 10.1103/physrevlett.105.074101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2010] [Indexed: 05/29/2023]
Abstract
A method is proposed to solve the challenging problem of determining the supratransmission threshold (onset of instability of harmonic boundary driving inside a band gap) in multicomponent nonintegrable nonlinear systems. It is successfully applied to the degenerate three-wave resonant interaction in a birefringent quadratic medium where the process generates spatial gap solitons. No analytic expression is known for this model showing the broad applicability of the method to nonlinear systems.
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Leon J, Bretones G, Acosta J, Caraballo J, Ferrandiz N, Perez-Roger I, Albajar M. 661 SKP2 oncogene is a MYC target gene in human leukemia cells. EJC Suppl 2010. [DOI: 10.1016/s1359-6349(10)71459-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Khomeriki R, Leon J. Chaotic spatial soliton rays in smooth two-dimensional optical lattices. OPTICS LETTERS 2009; 34:3376-3378. [PMID: 19881599 DOI: 10.1364/ol.34.003376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The light ray of a spatial soliton in an optical film whose refractive index is smoothly modulated (wavelength much larger than the typical soliton width) in both spatial directions is shown to possess chaotic regimes for which the propagation is erratic. This is interpreted as a parametric driven pendulum, obtained by what we believe to be a new perturbative approach of the Maxwell's equation. These findings are then demonstrated to compare well to the eikonal law of light ray propagation (nonlinearity compensates diffraction).
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Vasquez J, Montesinos E, Peralta J, Rojas L, DeLaRosa J, Leon J. Need for Lung Resection in Patients with Intact or Ruptured Hydatid Cysts. Thorac Cardiovasc Surg 2009; 57:295-302. [DOI: 10.1055/s-0029-1185604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Leon J, Vega JM. Effect of Immobilization on the Kinetic and Stability Properties of O-Acetyl-L-Serine Sulfhydrylase from: Chlamydomonas reinhardtii. ACTA ACUST UNITED AC 2009. [DOI: 10.3109/10242429209003659] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Vidaurre T, Olivera M, Gómez H, Pinto J, Doimi F, Velarde R, Abugattas J, Leon J, Mas L, Vigil C. Effect of dose intensity and overexpression of topoisomerase iia on survival in patients with locally advanced breast cancer treated with anthracyclines. J Clin Oncol 2008. [DOI: 10.1200/jco.2008.26.15_suppl.11512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Khomeriki R, Leon J. Driving light pulses with light in two-level media. PHYSICAL REVIEW LETTERS 2007; 99:183601. [PMID: 17995406 DOI: 10.1103/physrevlett.99.183601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2007] [Indexed: 05/25/2023]
Abstract
A two-level medium, described by the Maxwell-Bloch system, is engraved by establishing a standing cavity wave with a linearly polarized electromagnetic field that drives the medium on both ends. A light pulse, polarized along the other direction, then scatters the medium and couples to the cavity standing wave by means of the population inversion density variations. We demonstrate that control of the applied amplitudes of the grating field allows one to stop the light pulse and to make it move backward (eventually to drive it freely). A simplified limit model of the Maxwell-Bloch system with variable boundary driving is obtained as a discrete nonlinear Schrödinger equation with tunable external potential. It reproduces qualitatively the dynamics of the driven light pulse.
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Lopez LM, Olivera M, Casanova L, Santos C, Neciosup S, Gomez H, Leon J, Velarde C, Mariategui J, Vidaurre T. Gestational trophoblastic disease: 25-year experience at the Instituto Nacional de Enfermedades Neoplasicas (INEN). J Clin Oncol 2007. [DOI: 10.1200/jco.2007.25.18_suppl.16031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
16031 Background: To evaluate the clinical behavior and results of treatment of gestational trophoblastic disease at INEN between 1980 to 2005. Methods: This is a retrospective analysis of patients with gestational trophoblastic disease, clinical characteristics, results of treatment, toxicity, objective response and survival from January 1980 to December 2005. Descriptive statistics and Kaplan-Meier for survival analysis were performed. Results: Since Jan 1980 to Dec 2005. 595 patients were admitted at INEN; Hydatidiform mole 254 (42.7%) choriocarcinoma 201 (33.8%) invasive mole 41(6.8%). FIGO scoring System, high risk (score >6): 247 (41.5%), low risk (score 1–6): 348 (58.5%). Age ranged from 14 to 54 years, with 255 (44%) cases between 20 to 29 years. The sities of metastasis: lung 67.3%, vaginal 17.9%, brain 8.7%, liver 5.1%. The patients with low risks received treatment with Metotrexate 0.4mg/kg x day x 5 days po, reach disease control with a mean course of 6 (1 - 14), complete remission in 66.1% cases and 97% the overall survival rate to 20 years. Patients with high risk received treatment with: MAC 77 patients, MEC 19 patients, EMACO 48 patients and BEP 14 patients and achieved complete remission in 32.5%, 36.8%, 50% and 25% respectively. On the high risk group we detected two groups according to score > 12 and < 12, with diferent probability of survival at 20 years, for the group with score <12, 80% and the group with score >12, 48%. 98 patients were identified with score >12, and the age of these patients ranged from 15 to 51 years, with a mean age of 36.5 years. The blood B- HCG titers of these patients ranged from 198 to 6710,500. Liver and brain metastasis in 26 cases, number metastasis mayor 8 in 78 cases. Conclusions: Gestational trofhoblastic disease is highly curable. Patients of low risk achieved a 97% overall survival rate to 20 years. There are differences in the overall survival rate between patients of high risk with a score < 12 (80%) and score >12 (48%). This group presented with brain and liver metastasis, and it is important to define the best treatment for this group of patients No significant financial relationships to disclose.
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Ve Koon KT, Leon J, Marquié P, Tchofo-Dinda P. Cutoff solitons and bistability of the discrete inductance-capacitance electrical line: theory and experiments. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:066604. [PMID: 17677373 DOI: 10.1103/physreve.75.066604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2007] [Revised: 04/27/2007] [Indexed: 05/16/2023]
Abstract
A discrete nonlinear system driven at one end by a periodic excitation of frequency above the upper band edge (the discreteness induced cutoff) is shown to be a means to (1) generate propagating breather excitations in a long chain and (2) reveal the bistable property of a short chain. After detailed numerical verifications, the bistability prediction is demonstrated experimentally on an electrical transmission line made of 18 inductance-capacitance (LC) cells. The numerical simulations of the LC -line model allow us also to verify the breather generation prediction with a striking accuracy.
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Stippich C, Leon J, Akbar M, Durst A, Nennig E, Sartor K. Funktionelle Organisation des primären Motorkortex (M1) bei Patienten mit angeborener Paraplegie (Spina bifida aperta/Meningomyelocele (MMC)). ROFO-FORTSCHR RONTG 2007. [DOI: 10.1055/s-2007-977188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ordway JM, Bedell JA, Citek RW, Nunberg A, Garrido A, Kendall R, Stevens JR, Cao D, Doerge RW, Korshunova Y, Holemon H, McPherson JD, Lakey N, Leon J, Martienssen RA, Jeddeloh JA. Comprehensive DNA methylation profiling in a human cancer genome identifies novel epigenetic targets. Carcinogenesis 2006; 27:2409-23. [PMID: 16952911 DOI: 10.1093/carcin/bgl161] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Using a unique microarray platform for cytosine methylation profiling, the DNA methylation landscape of the human genome was monitored at more than 21,000 sites, including 79% of the annotated transcriptional start sites (TSS). Analysis of an oligodendroglioma derived cell line LN-18 revealed more than 4000 methylated TSS. The gene-centric analysis indicated a complex pattern of DNA methylation exists along each autosome, with a trend of increasing density approaching the telomeres. Remarkably, 2% of CpG islands (CGI) were densely methylated, and 17% had significant levels of 5 mC, whether or not they corresponded to a TSS. Substantial independent verification, obtained from 95 loci, suggested that this approach is capable of large scale detection of cytosine methylation with an accuracy approaching 90%. In addition, we detected large genomic domains that are also susceptible to DNA methylation reinforced inactivation, such as the HOX cluster on chromosome 7 (CH7). Extrapolation from the data suggests that more than 2000 genomic loci may be susceptible to methylation and associated inactivation, and most have yet to be identified. Finally, we report six new targets of epigenetic inactivation (IRX3, WNT10A, WNT6, RARalpha, BMP7 and ZGPAT). These targets displayed cell line and tumor specific differential methylation when compared with normal brain samples, suggesting they may have utility as biomarkers. Uniquely, hypermethylation of the CGI within an IRX3 exon was correlated with over-expression of IRX3 in tumor tissues and cell lines relative to normal brain samples.
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Riffel K, Nennig E, Leon J, Blatow M, Sarpaczki E, Stippich C. Clinical fMRI at 3 Tesla with reproducible and standardised tactile stimulation. AKTUELLE NEUROLOGIE 2006. [DOI: 10.1055/s-2006-953469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Nennig E, Blatow M, Sarpaczki E, Leon J, Riffel K, Stippich C. Functional magnetic resonance imaging for clinical applications: methods for automated and standardised data processing and management. AKTUELLE NEUROLOGIE 2006. [DOI: 10.1055/s-2006-953471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Khomeriki R, Leon J. Bistability in the sine-Gordon equation: the ideal switch. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:056620. [PMID: 16089681 DOI: 10.1103/physreve.71.056620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2005] [Indexed: 05/03/2023]
Abstract
The sine-Gordon equation, used as the representative nonlinear wave equation, presents a bistable behavior resulting from nonlinearity and generating hysteresis properties. We show that the process can be understood in a comprehensive analytical formulation and that it is a generic property of nonlinear systems possessing a natural band gap. The approach allows one to discover that the sine-Gordon equation can work as an ideal switch by reaching a transmissive regime with vanishing driving amplitude.
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Reiter RJ, Tan DX, Mayo JC, Sainz RM, Leon J, Bandyopadhyay D. Neurally-mediated and neurally-independent beneficial actions of melatonin in the gastrointestinal tract. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2003; 54 Suppl 4:113-25. [PMID: 15075454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/15/2003] [Accepted: 12/18/2003] [Indexed: 04/29/2023]
Abstract
Melatonin (N-acetyl-5-methoxytryptamine), originally discovered in the pineal gland, is now known also to be present in the gastrointestinal tract from the stomach to the colon. It is localized and likely synthesized in the enterochromaffin cells of the mucosal lining. Its functions in the gut generally seem to be protective of the mucosa from erosion and ulcer formation and to possibly influence movement of the gastrointestinal contents through the digestive system. In this brief review, we summarize the work documenting the function of melatonin in influencing bicarbonate secretion in the stomach and its role in preventing and repairing ulcers in the stomach and duodenum. Melatonin's actions in the control of bicarbonate secretion involve the central and peripheral sympathetic nervous systems and the actions are receptor mediated. Conversely, melatonin's actions in reducing ulcer formation also seemingly involve the ability of the indole to directly scavenge toxic oxygen-based reactants, e.g., the hydroxyl radical, and possibly to promote antioxidative enzyme activities. These same processes may be involved in the mechanisms by which melatonin promotes ulcer healing. Additionally, however, melatonin's effects on the healing of ulcers includes actions of blood flow in the margins of the ulcer and also on the sensory nerves. All indications are that melatonin has a variety of beneficial effects in the gastrointestinal tract. It is likely, however, that additional actions of melatonin on the digestive system will be uncovered.
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Perez-Amador MA, Leon J, Green PJ, Carbonell J. Induction of the arginine decarboxylase ADC2 gene provides evidence for the involvement of polyamines in the wound response in Arabidopsis. PLANT PHYSIOLOGY 2002; 130:1454-63. [PMID: 12428010 PMCID: PMC166664 DOI: 10.1104/pp.009951] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2002] [Revised: 07/12/2002] [Accepted: 08/04/2002] [Indexed: 05/19/2023]
Abstract
Polyamines are small ubiquitous molecules that have been involved in nearly all developmental processes, including the stress response. Nevertheless, no direct evidence of a role of polyamines in the wound response has been described. We have studied the expression of genes involved in polyamine biosynthesis in response to mechanical injury. An increase in the expression of the arginine decarboxylase 2 (ADC2) gene in response to mechanical wounding and methyl jasmonate (JA) treatment in Arabidopsis was detected by using DNA microarray and RNA gel-blot analysis. No induction was observed for the ADC1 gene or other genes coding for spermidine and spermine synthases, suggesting that ADC2 is the only gene of polyamine biosynthesis involved in the wounding response mediated by JA. A transient increase in the level of free putrescine followed the increase in the mRNA level for ADC2. A decrease in the level of free spermine, coincident with the increase in putrescine after wounding, was also observed. Abscisic acid effected a strong induction on ADC2 expression and had no effect on ADC1 expression. Wound-induction of ADC2 mRNA was not prevented in the JA-insensitive coi1 mutant. The different pattern of expression of ADC2 gene in wild-type and coi1 mutant might be due to the dual regulation of ADC2 by abscisic acid and JA signaling pathways. This is the first direct evidence of a function of polyamines in the wound-response, and it opens a new aspect of polyamines in plant biology.
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Geniet F, Leon J. Energy transmission in the forbidden band gap of a nonlinear chain. PHYSICAL REVIEW LETTERS 2002; 89:134102. [PMID: 12225030 DOI: 10.1103/physrevlett.89.134102] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2002] [Indexed: 05/23/2023]
Abstract
A nonlinear chain driven by one end may propagate energy in the forbidden band gap by means of nonlinear modes. For harmonic driving at a given frequency, the process occurs at a threshold amplitude by sudden large energy flow that we call nonlinear supratransmission. The bifurcation of energy transmission is demonstrated numerically and experimentally on the chain of coupled pendula (sine-Gordon and nonlinear Klein-Gordon equations) and sustained by an extremely simple theory.
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Rasko JE, Klenova EM, Leon J, Filippova GN, Loukinov DI, Vatolin S, Robinson AF, Hu YJ, Ulmer J, Ward MD, Pugacheva EM, Neiman PE, Morse HC, Collins SJ, Lobanenkov VV. Cell growth inhibition by the multifunctional multivalent zinc-finger factor CTCF. Cancer Res 2001; 61:6002-7. [PMID: 11507042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The 11-zinc finger protein CCTC-binding factor (CTCF) employs different sets of zinc fingers to form distinct complexes with varying CTCF- target sequences (CTSs) that mediate the repression or activation of gene expression and the creation of hormone-responsive gene silencers and of diverse vertebrate enhancer-blocking elements (chromatin insulators). To determine how these varying effects would integrate in vivo, we engineered a variety of expression systems to study effects of CTCF on cell growth. Here we show that ectopic expression of CTCF in many cell types inhibits cell clonogenicity by causing profound growth retardation without apoptosis. In asynchronous cultures, the cell-cycle profile of CTCF-expressing cells remained unaltered, which suggested that progression through the cycle was slowed at multiple points. Although conditionally induced CTCF caused the S-phase block, CTCF can also arrest cell division. Viable CTCF-expressing cells could be maintained without dividing for several days. While MYC is the well-characterized CTCF target, the inhibitory effects of CTCF on cell growth could not be ascribed solely to repression of MYC, suggesting that additional CTS-driven genes involved in growth-regulatory circuits, such as p19ARF, are likely to contribute to CTCF-induced growth arrest. These findings indicate that CTCF may regulate cell-cycle progression at multiple steps within the cycle, and add to the growing evidence for the function of CTCF as a tumor suppressor gene.
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Schaer M, Ginn PE, Fox LE, Leon J, Ramirez FM. Severe calcinosis cutis associated with treatment of hypoparathyroidism in a dog. J Am Anim Hosp Assoc 2001; 37:364-9. [PMID: 11450837 DOI: 10.5326/15473317-37-4-364] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 6-month-old, female border collie was referred for evaluation of hypocalcemia, hyperphosphatemia, fever, and painful ventral abdominal skin. She had recently been treated intravenously and subcutaneously (SC) with a diluted 10% calcium gluconate solution. The medical evaluation supported the diagnosis of primary hypoparathyroidism, but the subsequent hospital course was complicated by severe calcinosis cutis, which caused extensive skin necrosis and marked debilitation. This patient illustrates that administration of a calcium gluconate solution SC can be associated with extensive morbidity when administered to hyperphosphatemic patients.
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Santillana S, Leon J, Samanez C, Campana F, Wachtel A, Ferreyros G, Flores C, Vallejos C, Lopez Berestein A, Williams T. Molecular biology of acute promyelocytic leukemia (APL) in peruvian patients: PML/RAR alfa isoforms distribution in latino patients. Eur J Cancer 2001. [DOI: 10.1016/s0959-8049(01)80816-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Franco SJ, Leon J. Rural home health agencies: the impact of the Balanced Budget Act. POLICY ANALYSIS BRIEF. W SERIES 2000; 3:1-4. [PMID: 11764817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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Salvatierra J, Escames G, Hernandez P, Cantero J, Crespo E, Leon J, Salvatierra D, Acuña-Castroviejo D, Vives F. Cartilage and serum levels of nitric oxide in patients with hip osteoarthritis. J Rheumatol 1999; 26:2015-7. [PMID: 10493684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
OBJECTIVE To assess whether nitric oxide (NO) is related to cartilage deterioration resulting from osteoarthritis, NO concentrations were analyzed in normal and deteriorated areas of cartilage obtained from femur heads of patients with primary hip osteoarthritis (HOA). METHODS The concentration of NO in macroscopically deteriorated and non-deteriorated cartilage of femoral heads of patients with HOA at hip replacement surgery was analyzed spectrophotometrically. Serum NO levels were also determined in 16 ambulatory patients with hip OA and in healthy volunteers. RESULTS NO levels of non-deteriorated areas of femoral head cartilage were significantly lower (3.82+/-1.30 micromol/l; mean +/- SD) than levels of deteriorated cartilage areas (11.07+/-6.48 micromol/l; p<0.01). The surgery HOA group showed serum NO levels (2.64+/-0.32 micromol/l; p<0.0001 vs. healthy group) similar to the ambulatory HOA group levels (2.56+/-0.56 micromol/l; p<0.0001 vs. healthy group). Serum NO concentrations in healthy volunteers were 1.37+/-0.55 micromol/l. CONCLUSION This study shows increased NO levels in joint cartilage of patients with hip OA. This increase was not homogeneously distributed, but the higher NO levels were found in macroscopically deteriorated areas. The data also suggest that high NO serum levels found in patients with hip OA may be due to joint cartilage destruction.
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Carracedo C, Travezan R, Postigo J, Sanchez P, Zaharia M, Santillana S, Casanova L, Rodriguez W, Gomez H, Leon J, Vallejos C. Neoadjuvant cisplatin (P) 5-fluoracilo (5-FU) and radiation therapy (RT) for organ preservation in squamous cell carcinoma of the head and neck: a single institutional experience. Eur J Cancer 1999. [DOI: 10.1016/s0959-8049(99)81085-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Leon J, Moyer D. Potential cost savings in residential care for Alzheimer's disease patients. THE GERONTOLOGIST 1999; 39:440-9. [PMID: 10495582 DOI: 10.1093/geront/39.4.440] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Data from a 1996 cross-sectional study examining the costs of care for Alzheimer's Disease patients are used to estimate the potential cost savings that could result by substituting assisted living for nursing home care for AD residents with health profiles that appear to be manageable within assisted living facilities that specialize in dementia care. Results indicate that up to 13.9% of nursing home costs could be saved, making such a service substitution an attractive alternative in the provision of residential care for certain categories of AD patients.
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Leon J, Neumann PJ. The cost of Alzheimer's disease in managed care: a cross-sectional study. THE AMERICAN JOURNAL OF MANAGED CARE 1999; 5:867-77. [PMID: 10557408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
BACKGROUND The number of people with Alzheimer's disease (AD) is expected to grow as the US population ages. Given the increasing enrollment in managed care organizations, growth in the number of managed care patients with AD is a certainty. To our knowledge, no study to date has focused on the cost of care of community-dwelling AD patients receiving care through a health maintenance organization (HMO) system. METHODS One hundred and fifty patients were recruited from 4 managed care sites from July through December 1996. Staff at each site clinically confirmed patients' AD diagnosis, AD severity, and ascertained patients' comorbidities. Demographic, quality of life, and service utilization data were collected from proxy respondents. Costs of hospitalization, medications, doctor visits (formal costs), and caregiver assistance (informal costs) were analyzed separately. RESULTS The average total (formal and informal) per-patient costs in the 4 settings in 1996 were $18,804. Costs increased with cognitive impairment. For patients with mild, moderate, and severe AD, annual total costs were $14,904, $19,272, and $25,860, respectively. Annual direct costs were $5520, $7044 and $10,992, respectively. CONCLUSION Across all severity levels, we calculated a total annual cost of $8.8 billion for managed care enrollees older than 65 years in the United States. We did not estimate these costs for the population younger than 65 years because of the variability in AD prevalence estimates. Due to the increased costs for patients with more severe AD, interventions that would reverse or delay progression may result in significant cost savings.
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Macias A, Arce S, Leon J, Mustelier G, Bombino G, Domarco A, Perez R, Lage A. Novel cross-reactive anti-idiotype antibodies with properties close to the human intravenous immunoglobulin (IVIg). Hybridoma (Larchmt) 1999; 18:263-72. [PMID: 10475241 DOI: 10.1089/027245799315925] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The most important link between the immune network theory and clinically useful therapies so far is the use of human intravenous immunoglobulin (IVIg) in the treatment of autoimmune diseases. Although still controversial, one of the main mechanisms that has been postulated for the in vivo effects of IVIg, is the selection of immune repertoires through idiotypic interactions. We describe here anti-idiotype IgG monoclonal antibodies (MAbs), which were obtained by immunization of syngeneic mice (Balb/c) with an anti-ganglioside antibody. These anti-idiotype MAbs show multiple idiotypic connections and share some of the properties of the IVIg pool. The antiidiotype (Ab2) MAbs B7 and 34B7 showed heterogeneous binding with the idiotypes of several anti-ganglioside antibodies, MAbs obtained from splenocytes of nonimmunized newborn mice, F(ab')2 fragments of IgG human myeloma proteins, and nonimmunoglobulin antigens. The recognition pattern of the B7 MAb to the idiotypes of human immunoglobulins was also studied using a phage display library obtained from the variable region genes of an asymptomatic AIDS patient and also F(ab')2 fragments obtained from an IVIg pool of healthy human donors. We also demonstrated that these MAbs produced some of the in vitro effects reported for the human IVIg pool, such as the inhibition of cell proliferation of human B and T cell lines and of normal human lymphocytes activated with different mitogens. Another striking property of the MAb B7 was its ability to induce a dose-dependent specific antibody T-cell response in vivo in syngeneic mice. Both anti-idiotype MAbs showed anti-metastatic effect in vivo when injected intravenously to mice inoculated with MB16-F10 melanoma cells. The antimetastatic effect of the antiidiotype MAbs was not observed in athymic mice inoculated with the same tumor. This kind of antibody can become an interesting tool for further exploration of the role of idiotypic network connections in the regulation of the immune system and to study the effects of interventions on network connectivity in experimental autoimmune disease, using a reagent better chemically defined than the IVIg pool.
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MESH Headings
- Animals
- Antibodies, Anti-Idiotypic/immunology
- Antibodies, Anti-Idiotypic/therapeutic use
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/therapeutic use
- Autoimmune Diseases/immunology
- Autoimmune Diseases/therapy
- B-Lymphocytes/cytology
- B-Lymphocytes/immunology
- Cell Division
- Cell Line
- Cross Reactions
- G(M2) Ganglioside/immunology
- Humans
- Immunoglobulin G/immunology
- Immunoglobulin G/therapeutic use
- Immunoglobulin Idiotypes/immunology
- Immunoglobulins, Intravenous/immunology
- In Vitro Techniques
- Melanoma, Experimental/immunology
- Melanoma, Experimental/secondary
- Melanoma, Experimental/therapy
- Mice
- Mice, Inbred C57BL
- Mice, Nude
- T-Lymphocytes/cytology
- T-Lymphocytes/immunology
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Feldman B, Yaron Y, Critchfield G, Leon J, O'Brien JE, Johnson MP, Evans MI. Distribution of neural tube defects as a function of maternal weight: no apparent correlation. Fetal Diagn Ther 1999; 14:185-9. [PMID: 10364672 DOI: 10.1159/000020916] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Maternal nutritional deficiency is an important predisposing factor to congenital neural tube defects (NTDs). It was hypothesized that obese women may have an increased risk for NTDs. The aim of the present study was to address this question in a large cohort. METHODS A total of 72,915 consecutive cases of biochemical screening that had documented maternal weights and pregnancy outcomes were identified from the Quest Diagnostic Laboratories database. Patients were divided into five ranges of maternal weights, and the incidence of NTDs was calculated for each group. Based on the different definitions of maternal overweight, the data were also analyzed based on 2 groups only, obese and nonobese, using three cutoff points. RESULTS Seventy-nine pregnancies were complicated by NTDs (incidence of 1.08 per 1,000 pregnancies). Differences between maternal weights ranges were not found to be statistically significant (chi2 = 5.997, p = 0.19, power = 0.99). Differences between obese and nonobese mothers were not found to be statistically significant for all three analyses as well. CONCLUSIONS Our present results do not support an association between maternal obesity and NTDs.
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Neumann PJ, Hermann RC, Kuntz KM, Araki SS, Duff SB, Leon J, Berenbaum PA, Goldman PA, Williams LW, Weinstein MC. Cost-effectiveness of donepezil in the treatment of mild or moderate Alzheimer's disease. Neurology 1999; 52:1138-45. [PMID: 10214734 DOI: 10.1212/wnl.52.6.1138] [Citation(s) in RCA: 148] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To demonstrate the use of cost-effectiveness analysis to assess the economic impact of donepezil in the treatment of mild or moderate AD. BACKGROUND Cost-effectiveness analyses show the relationship between resources used (costs) and health benefits achieved (effects) for an intervention compared with an alternative strategy. METHODS We developed a model to estimate the incremental cost-effectiveness of donepezil compared with no treatment. We determined costs per quality-adjusted life-years gained, a measurement that enhances the comparability of diverse studies. The model projects the progression of AD patients into more severe disease stages and into nursing homes. Data from a randomized clinical trial of donepezil were used to assess the drug's impact on the 6-week probabilities of progression. Data on the costs and health-related quality of life associated with different disease stages and settings were taken from published estimates and our companion cross-sectional study, respectively. RESULTS Donepezil costs are partially offset by a reduction in the costs of care due to enhancement in cognitive functioning and the delay to more costly disease stages and settings. The magnitude of this cost offset and of the effect of donepezil on health-related quality of life depends on the model's assumptions about the duration of the drug effect, where controlled data are lacking. If the drug effect exceeds 2 years, the model predicts that for mild AD the drug would pay for itself in terms of cost offsets. CONCLUSIONS The results of the cost-effectiveness model presented here suggest that donepezil may be cost-effective but additional controlled data on long-term drug efficacy are needed.
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Neumann PJ, Kuntz KM, Leon J, Araki SS, Hermann RC, Hsu MA, Weinstein MC. Health utilities in Alzheimer's disease: a cross-sectional study of patients and caregivers. Med Care 1999; 37:27-32. [PMID: 10413389 DOI: 10.1097/00005650-199901000-00005] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Although the broad impacts of Alzheimer's disease (AD) are increasingly recognized, little work has focused on the overall health-related quality of life experienced by Alzheimer's disease patients and their caregivers. The study had two main objectives: (1) to test the feasibility of measuring health utilities in Alzheimer's disease with a generic preference-weighted instrument using proxy respondents and (2) to assess the utility scores of Alzheimer's disease patients (and their caregivers) in different disease stages and care setting. METHODS A cross-sectional study of 679 Alzheimer's disease patient/caregiver pairs was conducted at 13 sites in the United States: four academic medical centers, four managed care plans, two assisted living facilities, and three nursing homes. The Health Utilities Index Mark II (HUI:2) questionnaire was administered to caregivers of patients who responded both as proxies for patients and for themselves. Responses to the questionnaire were converted into a global utility score, between 0 and 1, using the HUI:2 multi-attribute utility function. RESULTS Global utility scores varied considerably across patients' Alzheimer's disease stage: for the six stages assessed (questionable, mild, moderate, severe, profound, and terminal), mean utility scores were 0.73, 0.69, 0.53, 0.38, 0.27, and 0.14, respectively. In multiple regression analyses, Alzheimer's disease stage was a negative and significant predictor of utility scores for patients; setting did not exert an independent effect. Utility scores for the caregivers were insensitive to patients' Alzheimer's disease stage and setting. CONCLUSIONS Patients' Alzheimer's disease stage had a substantial influence on health utilities, as measured by the HUI:2. More research is needed to assess the validity of using proxy respondents.
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Abstract
A cross-sectional study of 679 Alzheimer's disease patients from thirteen sites in nine states provides a unique opportunity to estimate costs of Alzheimer's disease care by disease stage and care setting and to explore potential areas of cost savings. In 1996 annual costs of caring for patients with mild, moderate, and severe Alzheimer's disease were $18,408, $30,096, and $36,132, respectively. Monthly savings of $2,029 in formal services are possible if disease progression can be slowed. Annual institutional cost savings of $9,132 also are achievable if alternative residential settings are used.
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Abstract
OBJECTIVE Determine the relative importance of potential medical, behavioral, and socioeconomic barriers to adequate protein nutrition among hemodialysis patients. DESIGN Cross-sectional study. SETTING All 22 chronic hemodialysis units in northeast Ohio. PATIENTS 298 randomly selected chronic hemodialysis patients. INTERVENTION We interviewed and abstracted the chart of each patient to assess protein nutritional status (albumin and protein catabolic rate), potential medical barriers (poor appetite, inadequate dialysis, bioincompatible dialysis membrane, difficulty chewing, and comorbid conditions), potential behavioral barriers (knowledge of protein containing foods and dietary noncompliance), and potential socioeconomic barriers (expense of protein containing foods and needing help shopping and cooking). MAIN OUTCOME MEASURE We used logistic regression to examine the relationship between protein nutritional status and potential barriers. RESULTS Albumin levels of <35 g/L were independently associated with Kt/V of <1.2 (odds ratio, 2.4), having more than three comorbid conditions (odds ratio, 4.0), inability to name any protein-containing foods (odds ratio, 2. 3), and needing help shopping and cooking (odds ratio, 2.6). Normalized protein catabolic rate of <1.0 g/kg/d was independently associated with poor appetite (odds ratio, 3.3), Kt/V of <1.2 (odds ratio, 3.1), and dietary compliance as indicated by low interdialytic fluid gain (odds ratio, 2.2). CONCLUSION Three medical factors (poor appetite, inadequate dialysis, and comorbid conditions), two behavioral factors (lack of knowledge of protein containing foods and low interdialytic fluid gain), and one socioeconomic factor (needing help shopping and cooking) are independently associated with inadequate protein nutrition among hemodialysis patients. Further work is needed to develop interventions to overcome these barriers and to determine the effect of such interventions on protein nutrition and patient mortality and morbidity.
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Yaron Y, Hamby DD, O'Brien JE, Critchfield G, Leon J, Ayoub M, Johnson MP, Evans MI. Combination of elevated maternal serum alpha-fetoprotein (MSAFP) and low estriol is highly predictive of anencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS 1998; 75:297-9. [PMID: 9475601 DOI: 10.1002/(sici)1096-8628(19980123)75:3<297::aid-ajmg14>3.0.co;2-k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Increased levels of second trimester maternal serum alpha-fetoprotein (MSAFP) have long been established as a marker for neural tube defects (NTDs). In addition, decreased levels of maternal estriol in the third trimester have been reported in pregnancies with anencephalic fetuses. The purpose of this study was to evaluate whether early second trimester unconjugated serum estriol (uE3) is an independent predictor of NTDs. The study included 57,031 patients who underwent maternal serum screening with MSAFP at 14-22 weeks gestation. Of these, 23,415 also had uE3 measurements. There were 63 cases of NTD, an overall incidence of 1.1 per 1,000. Elevated MSAFP (> or =2.5 MOM) was detected in 1,346 patients, 48 of which had NTDs. Decreased uE3 (< or =0.5) was detected in 1,437 patients, 17 of which had NTDs. The incidence of NTDs was significantly higher in patients with low uE3, compared to patients with normal/high uE3 (1.15% vs. 0.09%, P < 001). Finally, 51 patients had both increased MSAFP and decreased uE3; 16 of these had NTDs, 14 of which were anencephalics. In conclusion, both elevated MSAFP and low maternal serum estriol are predictive of NTD but have a low sensitivity. The combination of abnormally elevated MSAFP and low estriol is highly predictive of NTD in particular anencephaly.
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Burgio L, Leon J. Using patient and proxy reports as outcome measures in Alzheimer disease research. Alzheimer Dis Assoc Disord 1998; 11 Suppl 6:179-80. [PMID: 9437464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Zünd G, Lachat M, Leon J, Niederhäuser U, Vogt P, Turina M. [How to do: initial experiences with a new device in minimally invasive heart surgery]. SWISS SURGERY = SCHWEIZER CHIRURGIE = CHIRURGIE SUISSE = CHIRURGIA SVIZZERA 1998; Suppl 2:12-3. [PMID: 9757798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
A special surgical technique is required for minimal-invasive cardiac surgery. The view for the coronary artery anastomosis under beating heart conditions is important and coronary artery blood might prevent a clear view of the opened coronary artery vessel. A new system called VisoFlo promises to improve visualisation at the surgical site. VisoFlo delivers a column of air to help provide a clear view of anastomosis site and in addition has a controllable mist to help prevent desiccation of the graft and surrounding tissue. This system was tested on 45 patients with coronary-artery-bypass graft surgery under beating heart conditions and at 65 patients with standard coronary-artery-bypass graft surgery. Our conclusions are, that the VisoFlo system is easy to use, guarantees a clear view of the anastomosis site and the surgical work will not be impaired.
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Barbash I, Behar S, Battler A, Boyko V, Gottlieb S, Leon J. On-site catheterization facilities improves the outcome of unselected patients with cardiogenic shock. J Am Coll Cardiol 1998. [DOI: 10.1016/s0735-1097(98)80707-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Cardwell L, Kowalczyk CL, Krivchenia EL, Leon J, Evans MI. Urinary beta-core fragment as a predictor of abnormal pregnancy at 4-6 weeks' gestation. Fetal Diagn Ther 1997; 12:340-2. [PMID: 9475363 DOI: 10.1159/000264501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Currently, transvaginal ultrasound and serial serum beta-hCG measurements are used to differentiate normal versus abnormal gestations in the first trimester of pregnancy. These techniques have been found to be ineffective when the gestations are earlier than 6 weeks. This study was conducted to determine if urinary beta-core fragment, the urine degradation product of beta-hCG, could be used to distinguish normal from abnormal gestations between 4 and 6 weeks. Urine samples were obtained from 27 patients on initial presentation to the emergency room or outpatient settings with gestations at 4-6 weeks by sure last menstrual period. The urine was then frozen at -40 degrees C and sent for beta-core assay analysis. Eighteen women with normal intrauterine pregnancies and nine abnormal pregnancies, including ectopics and spontaneous abortions, were studied. Pearson correlations were performed with a p < 0.05 considered significant. In the normal gestations, there was a positive correlation between beta-core fragment and gestational age at 4-6 weeks (r = 0.461, p < 0.05). This correlation was not evident in abnormal gestations (r = 0.360, p = 0.34). In early pregnancy, beta-core fragment correlates positively with gestational age which is not apparent in abnormal counterparts. This finding suggests that urinary beta-core fragment may be a promising marker to differentiate normal early pregnancies from abnormal gestations.
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Wu G, Shortt BJ, Lawrence EB, Leon J, Fitzsimmons KC, Levine EB, Raskin I, Shah DM. Activation of Host Defense Mechanisms by Elevated Production of H2O2 in Transgenic Plants. PLANT PHYSIOLOGY 1997; 115:427-435. [PMID: 12223817 PMCID: PMC158500 DOI: 10.1104/pp.115.2.427] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Active oxygen species have been postulated to perform multiple functions in plant defense, but their exact role in plant resistance to diseases is not fully understood. We have recently demonstrated H2O2-mediated disease resistance in transgenic potato (Solanum tuberosum) plants expressing a foreign gene encoding glucose oxidase. In this study we provide further evidence that the H2O2-mediated disease resistance in potato is effective against a broad range of plant pathogens. We have investigated mechanisms underlying the H2O2-mediated disease resistance in transgenic potato plants. The constitutively elevated levels of H2O2 induced the accumulation of total salicylic acid severalfold in the leaf tissue of transgenic plants, although no significant change was detected in the level of free salicylic acid. The mRNAs of two defense-related genes encoding the anionic peroxidase and acidic chitinase were also induced. In addition, an increased accumulation of several isoforms of extracellular peroxidase, including a newly induced one, was observed. This was accompanied by a significant increase in the lignin content of stem and root tissues of the transgenic plants. The results suggest that constitutively elevated sublethal levels of H2O2 are sufficient to activate an array of host defense mechanisms, and these defense mechanisms may be a major contributing factor to the H2O2-mediated disease resistance in transgenic plants.
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92
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Benito A, Lerga A, Silva M, Leon J, Fernandez-Luna JL. Apoptosis of human myeloid leukemia cells induced by an inhibitor of protein phosphatases (okadaic acid) is prevented by Bcl-2 and Bcl-X(L). Leukemia 1997; 11:940-4. [PMID: 9204972 DOI: 10.1038/sj.leu.2400699] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Okadaic acid, an inhibitor of serine/threonine protein phosphatases 1 and 2A has been shown to cause mitotic arrest and cell death of HL-60 and K562 cells. HL-60 cells express Bcl-2 and little or no Bcl-X(L), while K562 expresses Bcl-X(L) but not Bcl-2. Since phosphorylation/dephosphorylation reactions have been suggested to be involved in the regulation of Bcl-2, we planned to investigate whether the expression of Bcl-2, Bcl-X(L) and Bax, a protein that antagonizes the antiapoptotic function of Bcl-2, are regulated in myeloid leukemia cell lines (K562, KU812 and HL-60) treated with okadaic acid. Our results indicate that exposure of all three leukemic cell lines to nanomolar concentrations of okadaic acid causes a loss of viability by activation of an apoptotic process accompanied by a marked decrease in the expression of Bcl-2, Bcl-X(L) and Bax at both mRNA and protein level, but not of c-fos, vimentin and epsilon-globin, ruling out a non-specific effect of okadaic acid. Furthermore, constitutive expression of either Bcl-X(L) or Bcl-2 by gene transfer inhibited apoptosis triggered by okadaic acid in K562 cells. Thus, we suggest that protein phosphatases may be involved in maintaining the expression of bcl-2 family genes as part of the survival machinery of the cell.
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93
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McGuire T, Greally J, Leon J, Luka J. Epstein-Barr virus (herpesvirus 4) types A, B and herpesvirus-6 variants A and B in patients presenting with recurrent upper respiratory inflammation, persistent paravertebral thoraco-lumbar muscle spasm and fatigue by polymerase chain reaction (PCR). In Vivo 1997; 11:23-8. [PMID: 9067769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
DNA from Epstein-Barr virus (EBV) Types A, B and Herpesvirus-6 (HHV-6) Variants A and B was detected by the Polymerase chain reaction (PCR) in the saliva of 51 non-immunocompromised donor patients and in the blood of seventy non-immunocompromised donor patients with specific signs and symptoms. The minimum selection criteria for each patient included acute or recurrent upper respiratory infection, unilateral thoracolumbar muscle spasm and fatigue. PCR DNA detection in the saliva of selected donors revealed 80% of the donors had either Type A or B EBV (41 of 51), 34.1% Type B EBV only (14 of 41), 9% Type A only (4 of 41), and 56.1% Type A and B EBV (23 of 41). HHV-6 DNA was detected in 45.0% (23 of 51). PCR for EBV in blood of selected donors revealed 68.5% Type A or B EBV (48 of 70), 0% type B EBV alone, 64.8% Type A EBV only (31 of 48) and 35.4% both Type A and B EBV (17 of 48). HHV-6 was detected in 96.4% (64 of 70). The association of Type B EBV in the pathogenesis of these patients is explored based on the PCR quantitation of B type EBV DNA present in the samples.
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Boiti M, Leon J, Pempinelli F. Nonlinear spectral characterization of discrete data. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 54:5739-5742. [PMID: 9965761 DOI: 10.1103/physreve.54.5739] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Devogelaer JP, Broll H, Correa-Rotter R, Cumming DC, Nagant de Deuxchaisnes C, Geusens P, Hosking D, Jaegar P, Kaufman JM, Leite M, Leon J, Liberman U, Menkes CJ, Meunier PJ, Reid I, Rodriguez J, Romanowicz A, Seeman E, Vermeulen A. Oral alendronate induces progressive increases in bone mass of the spine, hip and total body over 3 years in postmenopausal women with osteoporosis. Maturitas 1996. [DOI: 10.1016/0378-5122(96)81667-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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96
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Devogelaer JP, Broll H, Correa-Rotter R, Cumming DC, De Deuxchaisnes CN, Geusens P, Hosking D, Jaeger P, Kaufman JM, Leite M, Leon J, Liberman U, Menkes CJ, Meunier PJ, Reid I, Rodriguez J, Romanowicz A, Seeman E, Vermeulen A, Hirsch LJ, Lombardi A, Plezia K, Santora AC, Yates AJ, Yuan W. Oral alendronate induces progressive increases in bone mass of the spine, hip, and total body over 3 years in postmenopausal women with osteoporosis. Bone 1996; 18:141-50. [PMID: 8833208 DOI: 10.1016/8756-3282(95)00436-x] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
To determine the effects of long-term daily oral alendronate sodium (ALN) on bone mass in postmenopausal women with osteoporosis, 19 centers enrolled 516 postmenopausal women aged 45-80 years with spine bone mineral density (BMD) at least 2.5 SD below the mean for young premenopausal women in a 3-year, double-blind, placebo-controlled study. Subjects were randomly allocated to one of four treatment groups: placebo; alendronate, 5 or 10 mg/day for 3 years; or alendronate, 20 mg/day for 2 years followed by 5 mg/day for the 3rd year. All patients received 500 mg/day of supplemental calcium to ensure adequate calcium intake. BMD was measured by dual-energy X-ray absorptiometry at several skeletal sites. Nonsignificant mean decreases in BMD of the spine, femoral neck, and trochanter of 0.6, 0.7, and 0.4%, respectively, occurred in the placebo group at 3 years. Relative to placebo-treated patients, spine BMD increased by 5.4%, 7.4%, and 8.4% in the 5, 10, and 20/5 mg ALN groups, respectively. Increases at the femoral neck were 3.5%, 5.5%, and 4.3%, and those at the trochanter were 5.1%, 7.2%, and 7.2%, respectively. Thus, efficacy of 10 and 20/5 mg ALN was similar, whereas the 5 mg dose was less effective. BMD continued to increase over the entire 3-year study duration in the ALN-treated groups and, compared with the other dosage groups, 10 mg ALN produced the largest gains in BMD during the 3rd year. Changes in biochemical markers of bone turnover and mineral homeostasis confirmed the effect of ALN to decrease bone turnover to a new steady-state level. The safety and tolerability of ALN were comparable with those of placebo. In summary, 10 mg daily oral ALN given for 3 years significantly and progressively increases bone mass and is a generally well-tolerated treatment for osteoporosis in postmenopausal women.
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Ros MA, Dolores Delgado M, Leon J. Lack of correlation between c-myc expression and programmed or experimentally-induced cell death during chick limb development. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 1995; 39:1021-6. [PMID: 8901205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The protooncogene c-myc positively regulates cell death in most in vitro cell model systems under conditions of restricted proliferation, and it has been proposed that cell death is a physiological function of c-myc. To investigate possible changes in c-myc expression concomitant with programmed cell death, we have analyzed c-myc mRNA expression during chick limb development. Expression of c-myc was high in the premuscular masses at earlier stages and in the chondrogenic condensations at later stages of limb development, as demonstrated by in situ mRNA hybridization in sections and whole-mount. However, we did not detect c-myc expression in specific limb areas where massive apoptosis was occurring. Furthermore, when the apical ridge was removed from stage 20 wing buds, there was no increase in the expression of c-myc in the subridge mesoderm, despite the extensive cell death induced by this surgical manipulation. Therefore, our results show no correlation between elevated c-myc expression and either programmed or experimentally-induced apoptosis in the developing limb. These results argue against a role of c-myc in cell death occurring in vivo.
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98
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Shulaev V, Leon J, Raskin I. Is Salicylic Acid a Translocated Signal of Systemic Acquired Resistance in Tobacco? THE PLANT CELL 1995; 7:1691-1701. [PMID: 12242358 PMCID: PMC161030 DOI: 10.1105/tpc.7.10.1691] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Salicylic acid (SA) is a likely endogenous signal in the development of systemic acquired resistance (SAR) in some dicotyledonous plants. In tobacco mosaic virus (TMV)-resistant Xanthi-nc tobacco, SA levels increase systemically following the inoculation of a single leaf with TMV. To determine the extent to which systemic increases in SA result from SA export from the inoculated leaf, SA produced in TMV-inoculated or healthy leaves was noninvasively labeled with 18O2. Spatial and temporal distribution of 18O-SA indicated that most of the SA detected in the healthy tissues was synthesized in the inoculated leaf. No significant increase in the activity of benzoic acid 2-hydroxylase, the last enzyme involved in SA biosynthesis, was detected in upper uninoculated leaves, although the basal level of enzyme activity was relatively high. No increases in SA level, pathogenesis-related PR-1 gene expression, or TMV resistance in the upper uninoculated leaf were observed if the TMV-inoculated leaf was detached up to 60 hr after inoculation. Apart from the inoculated tissues, the highest increase in SA was observed in the leaf located directly above the inoculated leaf. The systemic SA increase observed during SAR may be explained by phloem transport of SA from the inoculation sites.
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Leon J, Lawton MA, Raskin I. Hydrogen Peroxide Stimulates Salicylic Acid Biosynthesis in Tobacco. PLANT PHYSIOLOGY 1995; 108:1673-1678. [PMID: 12228572 PMCID: PMC157549 DOI: 10.1104/pp.108.4.1673] [Citation(s) in RCA: 199] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Hydrogen peroxide induced the accumulation of free benzoic acid (BA) and salicylic acid (SA) in tobacco (Nicotiana tabacum L. cv Xanthi-nc) leaves. Six hours after infiltration with 300 mM H2O2, the levels of BA and SA in leaves increased 5-fold over the levels detected in control leaves. The accumulation of BA and SA was preceded by the rapid activation of benzoic acid 2-hydroxylase (BA2H) in the H2O2-infiltrated tissues. This enzyme catalyzes the formation of SA from BA. Enzyme activation could be reproduced in vitro by addition of H2O2 or cumene hydroperoxide to the assay mixture. H2O2 was most effective in vitro when applied at 6 mM. In vitro activation of BA2H by peroxides was inhibited by the catalase inhibitor 3-amino-1,2,4-triazole. We suggest that H2O2 activates SA biosynthesis via two mechanisms. First, H2O2 stimulates BA2H activity directly or via the formation of its substrate, molecular oxygen, in a catalase-mediated reaction. Second, higher BA levels induce the accumulation of BA2H protein in the cells and provide more substrate for this enzyme.
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Claude C, Ginovart F, Leon J. Nonlinear theory of transient stimulated Raman scattering and its application to long-pulse experiments. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1995; 52:767-782. [PMID: 9912301 DOI: 10.1103/physreva.52.767] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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