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1.
Sci Adv ; 6(41)2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33036964

RESUMO

Food security in a warming world is a grave concern for rapidly growing impoverished populations. Low-latitude inland fisheries provide protein for millions of rural poor, yet the impacts of high-frequency climate oscillations on these aquatic ecosystems are unknown. Here, we present a sub-annual-to-annual resolution paleolimnological reconstruction of upwelling, productivity, and algal composition at Lake Tanganyika, one of Africa's largest landlocked fisheries. The data reveal increases in diatom production at centennial-scale solar irradiance maxima, and interannual variability in upwelling linked to La Niña. Our study shows that interactions between global climatic controls and El Niño-Southern Oscillation teleconnections exert profound influences on the foundation of Lake Tanganyika's food web. Adapting long-term management practices to account for high-frequency changes in algal production will help safeguard inland fish resources.

2.
J Health Sci Educ ; 3(4): 1-7, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-37538301

RESUMO

Preparing lay Community Health Ambassadors (CHA) to assess, document and monitor physical activity using standardized instruments can be daunting. Administering some instruments needs specialized training. System for Observing Play and Recreation in Communities (SOPARC) is a standardized instrument requiring extensive training. The question guiding this project was: Can lay Community Health Ambassadors (CHA) be trained to administer SOPARC at Racial and Ethnic Approaches to Community Health (REACH) physical activity fitness sites? This manuscript presents the process undertaken to train Community Health Ambassadors (CHAs) and some preliminary results. Preliminary results are that fifty-six (56) Community Health Ambassadors (CHAs) representing four (4) community partner groups were certified in the SOPARC training. These CHAs successfully documented pre/post data for 20 different physical activity sites. Additionally, the results support the premise that Community Health Ambassadors are a viable liaison in community health delivery.

3.
Transl Psychiatry ; 6(9): e900, 2016 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-27676441

RESUMO

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder most commonly associated with repetitive traumatic brain injury (TBI) and characterized by the presence of neurofibrillary tangles of tau protein, known as a tauopathy. Currently, the diagnosis of CTE can only be definitively established postmortem. However, a new positron emission tomography (PET) ligand, [18F]T807/AV1451, may provide the antemortem detection of tau aggregates, and thus various tauopathies, including CTE. Our goal was to examine [18F]T807/AV1451 retention in athletes with neuropsychiatric symptoms associated with a history of multiple concussions. Here we report a 39-year-old retired National Football League player who suffered 22 concussions and manifested progressive neuropsychiatric symptoms. Emotional lability and irritability were the chief complaints. Serial neuropsychological exams revealed a decline in executive functioning, processing speed and fine motor skills. Naming was below average but other cognitive functions were preserved. Structural analysis of longitudinally acquired magenetic resonance imaging scans revealed cortical thinning in the left frontal and lateral temporal areas, as well as volume loss in the basal ganglia. PET with [18F]florbetapir was negative for amyloidosis. The [18F]T807/AV1451 PET showed multifocal areas of retention at the cortical gray matter-white matter junction, a distribution considered pathognomonic for CTE. [18F]T807/AV1451 standard uptake value (SUV) analysis showed increased uptake (SUVr⩾1.1) in bilateral cingulate, occipital, and orbitofrontal cortices, and several temporal areas. Although definitive identification of the neuropathological underpinnings basis for [18F]T807/AV1451 retention requires postmortem correlation, our data suggest that [18F]T807/AV1451 tauopathy imaging may be a promising tool to detect and diagnose CTE-related tauopathy in living subjects.

4.
Phys Rev Lett ; 116(9): 092501, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26991171

RESUMO

We report the first use of the effective quark-meson coupling (QMC) energy density functional (EDF), derived from a quark model of hadron structure, to study a broad range of ground state properties of even-even nuclei across the periodic table in the nonrelativistic Hartree-Fock+BCS framework. The novelty of the QMC model is that the nuclear medium effects are treated through modification of the internal structure of the nucleon. The density dependence is microscopically derived and the spin-orbit term arises naturally. The QMC EDF depends on a single set of four adjustable parameters having a clear physics basis. When applied to diverse ground state data the QMC EDF already produces, in its present simple form, overall agreement with experiment of a quality comparable to a representative Skyrme EDF. There exist, however, multiple Skyrme parameter sets, frequently tailored to describe selected nuclear phenomena. The QMC EDF set of fewer parameters, derived in this work, is not open to such variation, chosen set being applied, without adjustment, to both the properties of finite nuclei and nuclear matter.

5.
Am J Transplant ; 16(1): 121-36, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26260101

RESUMO

Identification of biomarkers that assess posttransplant risk is needed to improve long-term outcomes following heart transplantation. The Clinical Trials in Organ Transplantation (CTOT)-05 protocol was an observational, multicenter, cohort study of 200 heart transplant recipients followed for the first posttransplant year. The primary endpoint was a composite of death, graft loss/retransplantation, biopsy-proven acute rejection (BPAR), and cardiac allograft vasculopathy (CAV) as defined by intravascular ultrasound (IVUS). We serially measured anti-HLA- and auto-antibodies, angiogenic proteins, peripheral blood allo-reactivity, and peripheral blood gene expression patterns. We correlated assay results and clinical characteristics with the composite endpoint and its components. The composite endpoint was associated with older donor allografts (p < 0.03) and with recipient anti-HLA antibody (p < 0.04). Recipient CMV-negativity (regardless of donor status) was associated with BPAR (p < 0.001), and increases in plasma vascular endothelial growth factor-C (OR 20; 95%CI:1.9-218) combined with decreases in endothelin-1 (OR 0.14; 95%CI:0.02-0.97) associated with CAV. The remaining biomarkers showed no relationships with the study endpoints. While suboptimal endpoint definitions and lower than anticipated event rates were identified as potential study limitations, the results of this multicenter study do not yet support routine use of the selected assays as noninvasive approaches to detect BPAR and/or CAV following heart transplantation.


Assuntos
Biomarcadores/metabolismo , Doença da Artéria Coronariana/diagnóstico , Rejeição de Enxerto/diagnóstico , Cardiopatias/cirurgia , Transplante de Coração/efeitos adversos , Adulto , Western Blotting , Estudos de Casos e Controles , Ensaios Clínicos como Assunto , Doença da Artéria Coronariana/etiologia , Doença da Artéria Coronariana/metabolismo , Endotelina-1/metabolismo , Feminino , Perfilação da Expressão Gênica , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator A de Crescimento do Endotélio Vascular
6.
AJNR Am J Neuroradiol ; 36(3): E12-23, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25655872

RESUMO

The past decade has seen impressive advances in the types of neuroimaging information that can be acquired in patients with traumatic brain injury. However, despite this increase in information, understanding of the contribution of this information to prognostic accuracy and treatment pathways for patients is limited. Available techniques often allow us to infer the presence of microscopic changes indicative of alterations in physiology and function in brain tissue. However, because histologic confirmation is typically lacking, conclusions reached by using these techniques remain solely inferential in almost all cases. Hence, a need exists for validation of these techniques by using data from large population samples that are obtained in a uniform manner, analyzed according to well-accepted procedures, and correlated with closely monitored clinical outcomes. At present, many of these approaches remain confined to population-based research rather than diagnosis at an individual level, particularly with regard to traumatic brain injury that is mild or moderate in degree. A need and a priority exist for patient-centered tools that will allow advanced neuroimaging tools to be brought into clinical settings. One barrier to developing these tools is a lack of an age-, sex-, and comorbidities-stratified, sequence-specific, reference imaging data base that could provide a clear understanding of normal variations across populations. Such a data base would provide researchers and clinicians with the information necessary to develop computational tools for the patient-based interpretation of advanced neuroimaging studies in the clinical setting. The recent "Joint ASNR-ACR HII-ASFNR TBI Workshop: Bringing Advanced Neuroimaging for Traumatic Brain Injury into the Clinic" on May 23, 2014, in Montreal, Quebec, Canada, brought together neuroradiologists, neurologists, psychiatrists, neuropsychologists, neuroimaging scientists, members of the National Institute of Neurologic Disorders and Stroke, industry representatives, and other traumatic brain injury stakeholders to attempt to reach consensus on issues related to and develop consensus recommendations in terms of creating both a well-characterized normative data base of comprehensive imaging and ancillary data to serve as a reference for tools that will allow interpretation of advanced neuroimaging tests at an individual level of a patient with traumatic brain injury. The workshop involved discussions concerning the following: 1) designation of the policies and infrastructure needed for a normative data base, 2) principles for characterizing normal control subjects, and 3) standardizing research neuroimaging protocols for traumatic brain injury. The present article summarizes these recommendations and examines practical steps to achieve them.


Assuntos
Lesões Encefálicas , Bases de Dados Factuais , Neuroimagem , Lesões Encefálicas/patologia , Feminino , Humanos , Masculino
7.
Phys Rev Lett ; 109(3): 032504, 2012 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-22861842

RESUMO

The nucleus 49Sc, having a single f(7/2) proton outside doubly magic 48Ca (Z=20, N=28), is one of the very few isotopes which makes possible testing of the fundamental theory of nuclear magnetism. The magnetic moment has been measured by online ß NMR of nuclei oriented at milli-Kelvin temperatures to be (+)5.616(25) µ(N). The result is discussed in terms of a detailed theory of the structure of the magnetic moment operator, showing excellent agreement with calculated departure from the f(7/2) Schmidt limit extreme single-particle value. The measurement completes the sequence of moments of Sc isotopes with even numbers of f(7/2) neutrons: the first such isotopic chain between two major shells for which a full set of moment measurements exists. The result further completes the isotonic sequence of ground-state moments of nuclei with an odd number of f(7/2) protons coupled to a closed subshell of f(7/2) neutrons. Comparison with a recent shell-model calculation of the latter sequence is made.

8.
Arthritis Care Res (Hoboken) ; 64(11): 1720-9, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22674883

RESUMO

OBJECTIVE: The interleukin-6 pathway is up-regulated in giant cell arteritis (GCA), Takayasu arteritis (TA), and polymyalgia rheumatica (PMR). We retrospectively assessed the outcomes of 10 patients with relapsing/refractory GCA, TA, or PMR treated with tocilizumab (TCZ). METHODS: Patients with GCA (n = 7), TA (n = 2), and PMR (n = 1) received TCZ. Seven subjects had failed at least 1 second-line agent. The outcomes evaluated were symptoms of disease activity, inflammatory markers, ability to taper glucocorticoids, and cross-sectional imaging when indicated clinically. RESULTS: The mean followup time of this cohort since diagnosis was 27 months (range 16-60 months). The patients were treated with TCZ for a mean period of 7.8 months (range 4-12 months). Before TCZ therapy, the patients experienced an average of 2.4 flares/year. All patients entered and maintained clinical remission during TCZ therapy. The mean daily prednisone dosages before and after TCZ initiation were 20.8 mg/day (range 7-34.3 mg/day) and 4.1 mg/day (range 0-10.7 mg/day), respectively (P = 0.0001). The mean erythrocyte sedimentation rate declined from 41.5 mm/hour (range 11-68 mm/hour) to 7 mm/hour (range 2.2-11.3 mm/hour; P = 0.0001). The adverse effects of TCZ included mild neutropenia (n = 4) and transaminitis (n = 4). One patient flared 2 months after TCZ discontinuation. An autopsy on 1 patient who died from a postoperative myocardial infarction following elective surgery revealed persistent vasculitis of large and medium-sized arteries. CONCLUSION: TCZ therapy led to clinical and serologic improvement in patients with refractory/relapsing GCA, TA, or PMR. The demonstration of persistent large-vessel vasculitis at autopsy of 1 patient who had shown a substantial response requires close scrutiny in larger studies.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Arterite de Células Gigantes/tratamento farmacológico , Imunossupressores/administração & dosagem , Polimialgia Reumática/tratamento farmacológico , Arterite de Takayasu/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Seguimentos , Glucocorticoides/administração & dosagem , Humanos , Pessoa de Meia-Idade , Prednisona/administração & dosagem , Receptores de Interleucina-6/antagonistas & inibidores , Estudos Retrospectivos , Resultado do Tratamento
9.
Phys Rev Lett ; 103(14): 142501, 2009 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-19905565

RESUMO

We report the first confirmation of the predicted inversion between the pi2p3/2 and pi1f5/2 nuclear states in the nu(g)9/2 midshell. This was achieved at the ISOLDE facility, by using a combination of in-source laser spectroscopy and collinear laser spectroscopy on the ground states of 71,73,75Cu, which measured the nuclear spin and magnetic moments. The obtained values are mu(71Cu)=+2.2747(8)mu(N), mu(73Cu)=+1.7426(8)mu(N), and mu(75Cu)=+1.0062(13)mu(N) corresponding to spins I=3/2 for 71,73Cu and I=5/2 for 75Cu. The results are in fair agreement with large-scale shell-model calculations.

10.
Phys Rev Lett ; 94(19): 192501, 2005 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-16090167

RESUMO

Following Coulomb excitation of the radioactive ion beam (RIB) 132Te at HRIBF we report the first use of the recoil-in-vacuum (RIV) method to determine the g factor of the 2(+)(1) state: g(973.9 keV 2(+) 132Te) = (+)0.35(5). The advantages offered by the RIV method in the context of RIBs and modern detector arrays are discussed.

11.
Cladistics ; 19(6): 565-566, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34905859

RESUMO

Formulas for nonalgorithmically calculating probabilities for completely pectinate and symmetric cladograms are presented.

12.
Phys Rev Lett ; 88(4): 041803, 2002 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-11801107

RESUMO

Additional evidence for the rare kaon decay K+-->pi+nu(nu) has been found in a new data set with comparable sensitivity to the previously reported result. One new event was observed in the pion momentum region examined, 211pi+nu(nu)) = 1.57(+1.75)(-0.82)x10(-10).

13.
J Immunol ; 167(10): 5994-6001, 2001 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-11698479

RESUMO

Using a heterotopic model of transplantation, we investigated the role of T cell activation in vivo during allograft rejection in I-kappaB(DeltaN)-transgenic mice that express a transdominant inhibitor of NF-kappaB in T cells. Our results show indefinite prolongation of graft survival in the I-kappaB(DeltaN)-transgenic recipients. Interestingly, at the time of rejection of grafts in wild-type recipients, histology of grafts in the I-kappaB(DeltaN)-transgenic recipients showed moderate rejection; nevertheless, grafts in the I-kappaB(DeltaN) recipients survived >100 days. Analysis of acute phase cytokines, chemokine, chemokine receptors, and immune responses shows that the blockade of NF-kappaB activation in T cells inhibits up-regulation of many of these parameters. Interestingly, our data also suggest that the T cell component of the immune response exerted positive feedback regulation on the expression of multiple chemokines that are produced predominantly by non-T cells. In conclusion, our studies indicate NF-kappaB activation in T cells is necessary for acute allograft rejection.


Assuntos
Facilitação Imunológica de Enxerto , Rejeição de Enxerto/imunologia , Ativação Linfocitária , NF-kappa B/antagonistas & inibidores , Linfócitos T/imunologia , Reação de Fase Aguda/imunologia , Animais , Quimiocinas/biossíntese , Quimiocinas/genética , Citocinas/biossíntese , Citocinas/genética , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Proteínas I-kappa B/genética , Isoantígenos/imunologia , Cinética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , NF-kappa B/fisiologia , RNA Mensageiro/biossíntese , Receptores de Quimiocinas/biossíntese , Receptores de Quimiocinas/genética
14.
Exp Neurol ; 172(2): 320-31, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11716556

RESUMO

Traumatic axonal injury (TAI) contributes to morbidity and mortality following traumatic brain injury (TBI). Single-label immunocytochemical studies employing antibodies to neurofilament compaction (NFC), RM014, and antibodies to APP, a marker of impaired axonal transport (AxT), have shown that TAI involves both NFC and disruption of AxT. Although it may be hypothesized that both events occur within the same injured axon, this has not been confirmed. To determine the relationship between NFC and impaired AxT, dual-label immunofluorescence was employed. To compare and contrast specific changes associated with these two markers of TAI, single-label electron microscopy was also used. Rats were subjected to an impact acceleration injury (30 min-6 h survival), and their brains were prepared for dual-label immunofluorescence and single-label electron microscopy. APP and RM014 were consistently found in two distinct classes of TAI. One, which showed only RM014 immunoreactivity, was thin and elongate, was sometimes vacuolated, and revealed little progressive change over time. The second was distinguished by focal axonal swellings containing APP immunoreactivity alone in small-caliber axons or in combination with RM014 immunoreactivity in large-caliber axons. These swellings were localized to either nodal or internodal loci and underwent progressive swelling over time, ultimately leading to secondary axotomy. Ultrastructural examination of these two classes of TAI revealed NFC together with mitochondrial dilation without organelle pooling in the RM014 single-labeled axons. However, the APP single-labeled small-caliber axons and APP/RM014 dual-labeled large-caliber axons revealed a progressive accumulation of organelles associated with increased axonal swelling over time. In contrast to previous thought, it now appears that NFC may occur independent of impaired AxT in TAI. This finding underscores the complexity of TAI, suggesting the need for multiple immunocytochemical approaches to fully assess the overall axonal response to TBI.


Assuntos
Axônios/patologia , Edema Encefálico/etiologia , Edema Encefálico/patologia , Lesões Encefálicas/complicações , Lesão Axonal Difusa/complicações , Fibras Nervosas/patologia , Ferimentos não Penetrantes/complicações , Animais , Imuno-Histoquímica , Masculino , Microscopia Eletrônica , Tratos Piramidais/patologia , Ratos , Ratos Sprague-Dawley , Valores de Referência
15.
Circulation ; 104(21): 2525-32, 2001 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-11714645

RESUMO

BACKGROUND: The mechanisms of extracellular matrix changes accompanying myxomatous valvular degeneration are uncertain. METHODS AND RESULTS: To test the hypothesis that valvular interstitial cells mediate extracellular matrix degradation in myxomatous degeneration by excessive secretion of catabolic enzymes, we examined the functional characteristics of valvular interstitial cells in 14 mitral valves removed for myxomatous degeneration from patients with mitral regurgitation and in 11 normal mitral valves obtained at autopsy. Immunohistochemical staining assessed (1) cell phenotype using antibodies to alpha-actin (microfilaments), vimentin and desmin (intermediate filaments), smooth muscle myosin (SM1), and SMemb (a nonmuscle myosin produced by activated mesenchymal cells) and (2) the expression of proteolytic activity using antibodies to collagenases (matrix metalloproteinase [MMP]-1, MMP-13), gelatinases (MMP-2, MMP-9), cysteine endoproteases (cathepsin S and K), and interleukin-1beta, a cytokine that can induce secretion of proteolytic enzymes. Although interstitial cells in normal valves stained positively for vimentin, but not alpha-actin or desmin, cells in myxomatous valves contained both vimentin and alpha-actin or desmin (characteristics of myofibroblasts). Moreover, cells in myxomatous valves strongly expressed SMemb, MMPs, cathepsins, and interleukin-1beta, which were weakly stained in controls. Nevertheless, interstitial cells in both groups strongly expressed procollagen-I mRNA (in situ hybridization), suggesting preserved ability to synthesize collagen in myxomatous valves. CONCLUSIONS: Interstitial cells in myxomatous valves have features of activated myofibroblasts and express excessive levels of catabolic enzymes, without altered levels of interstitial collagen mRNA. We conclude that valvular interstitial cells regulate matrix degradation and remodeling in myxomatous mitral valve degeneration.


Assuntos
Matriz Extracelular/metabolismo , Fibroblastos/fisiologia , Neoplasias Cardíacas/metabolismo , Insuficiência da Valva Mitral/etiologia , Valva Mitral/citologia , Mixoma/metabolismo , Adulto , Idoso , Catepsinas/metabolismo , Colágeno Tipo I/biossíntese , Colágeno Tipo I/genética , Feminino , Fibroblastos/enzimologia , Neoplasias Cardíacas/complicações , Neoplasias Cardíacas/enzimologia , Neoplasias Cardíacas/patologia , Humanos , Masculino , Metaloproteinases da Matriz/metabolismo , Pessoa de Meia-Idade , Valva Mitral/metabolismo , Valva Mitral/patologia , Modelos Cardiovasculares , Mixoma/complicações , Mixoma/enzimologia , Mixoma/patologia , RNA Mensageiro/biossíntese
17.
Exp Neurol ; 172(1): 199-210, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11681852

RESUMO

Our laboratory has shown that traumatically induced axonal injury (TAI) is significantly reduced by posttraumatic hypothermia followed by slow rewarming. Further, TAI can be exacerbated by rapid rewarming, and the damaging consequences of rapid rewarming can be reversed by cyclosporin A, which is believed to protect via blunting mitochondrial permeability transition (MPT). In this communication, we continue investigating the damaging consequences of rapid posthypothermic rewarming and the protective role of immunophilin ligands using another member of the immunophilin family, FK506, which does not affect MPT but rather inhibits calcineurin. Rats were subjected to impact-acceleration brain injury followed by the induction of hypothermia with subsequent rapid or slow posthypothermic rewarming. During rewarming, animals received either FK506 or its vehicle. Three hours postinjury, animals were prepared for the visualization of TAI via antibodies targeting impaired axoplasmic transport (APP) and/or overt neurofilament alteration (RMO-14). Rapid rewarming exacerbated TAI, which was attenuated by FK506. This protection was statistically significant for the APP-immunoreactive fibers but not for the RMO-14-positive fibers. Combined labeling, using one chromagen to visualize both axonal changes, suggested that these two immunoreactive profiles revealed two distinct pathologies not occurring along the same axon. Collectively, these studies confirmed previous observations identifying the adverse consequences of rapid rewarming while also showing the complexity of the pathobiology of TAI. Additionally, the demonstration that FK506 is protective suggests that calcineurin may be a major target for neuroprotection.


Assuntos
Axônios/efeitos dos fármacos , Lesões Encefálicas/prevenção & controle , Hipotermia Induzida , Imunofilinas , Reaquecimento/efeitos adversos , Tacrolimo/farmacologia , Animais , Transporte Axonal/efeitos dos fármacos , Axônios/metabolismo , Axônios/patologia , Pressão Sanguínea , Temperatura Corporal , Lesões Encefálicas/patologia , Inibidores de Calcineurina , Contagem de Células , Imuno-Histoquímica , Imunofilinas/antagonistas & inibidores , Imunossupressores/farmacologia , Ligantes , Masculino , Fármacos Neuroprotetores/farmacologia , Ratos , Ratos Sprague-Dawley , Reaquecimento/métodos , Fatores de Tempo
18.
Mol Biol Evol ; 18(9): 1764-70, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11504856

RESUMO

Although the evolution of protein-coding sequences within genomes is well understood, the same cannot be said of the cis-regulatory regions that control transcription. Yet, changes in gene expression are likely to constitute an important component of phenotypic evolution. We simulated the evolution of new transcription factor binding sites via local point mutations. The results indicate that new binding sites appear and become fixed within populations on microevolutionary timescales under an assumption of neutral evolution. Even combinations of two new binding sites evolve very quickly. We predict that local point mutations continually generate considerable genetic variation that is capable of altering gene expression.


Assuntos
Evolução Molecular , Mutação Puntual/genética , Sequências Reguladoras de Ácido Nucleico/genética , Animais , Sítios de Ligação/genética , Simulação por Computador , DNA/genética , DNA/metabolismo , Bases de Dados Factuais , Humanos , Fatores de Transcrição/metabolismo
19.
J Neurotrauma ; 18(6): 607-14, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11437083

RESUMO

The immunophilin ligand, cyclosporin A (CsA), is effective in reducing the axonal damage associated with traumatic brain injury (TBI). Based upon extensive ultrastructural and immunohistochemical studies, the neuroprotection afforded by CsA appeared to be mediated via mitochondrial protection, specifically, the prevention of mitochondrial swelling and inhibition of mitochondrial permeability transition (MPT). However, the potential that CsA could also be neuroprotective via the immunophilin-mediated inhibition of the protein phosphatase, calcineurin (CN) has not been directly assessed. To address this issue, the current study assessed the ability of FK506, another immunophilin ligand that inhibits CN with no effect on MPT, to attenuate axonal damage in a rat impact-acceleration model of TBI. Traumatic axonal injury (TAI), detected via an antibody against beta-amyloid precursor protein (APP), a specific marker of axonal injury, was significantly reduced at 24 hr postinjury in Sprague-Dawley rats receiving intravenous FK506 (2 mg/kg; n = 5) 30 min prior to injury compared to vehicle controls (n = 3). While not rejecting the established efficacy of CsA in providing neuroprotection via its targeting of MPT, this study does underscore the potential importance of CN in the progressive pathobiology of TAI, suggesting that CN may constitute another important therapeutic target.


Assuntos
Axônios/patologia , Lesões Encefálicas/tratamento farmacológico , Imunossupressores/uso terapêutico , Tacrolimo/uso terapêutico , Aceleração , Animais , Gasometria , Encéfalo/metabolismo , Lesões Encefálicas/patologia , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Imunossupressores/farmacocinética , Injeções Intravenosas , Masculino , Ratos , Ratos Sprague-Dawley , Tacrolimo/farmacocinética
20.
Biosystems ; 61(1): 33-9, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11448524

RESUMO

The application of elementary equations from information theory to the elements involved in cladistic analysis is formalized mathematically. An equation is derived that quantifies the amount of information obtained by constructing a cladogram from a cladistic data matrix. Given particular conditions, the amount of information obtained increases monotonically with increases of the number of taxa involved and, so, may be used directly as a comparative measure of species richness for sister groups; in general, however, the amount of information obtained is related to the distribution of character states on the cladogram(s) deduced. An example is presented in which clades representing 11 phyla in the animal kingdom are compared in terms of information yielded. The amount of information obtained is consistent for different numbers of taxa and characters used in classifications. Speculative evolutionary explanations are presented for differences of information yielded among the phyla analyzed.


Assuntos
Classificação , Teoria da Informação , Animais
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