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Structural alterations in adult rat carotid bodies exposed to hyperbaric oxygenation

LEITE, M. S.; DAMACENO-RODRIGUES, N. R.; SIMONE, M. R. P. T.; SANTOS, A. B. G.; BUENO, H. M. S.; BATTLEHNER, C. N.; MAUAD, T.; CALDINI, E. G.; SALDIVA, P. H. N.
Fonte: UNDERSEA & HYPERBARIC MEDICAL SOC INC Publicador: UNDERSEA & HYPERBARIC MEDICAL SOC INC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
46.06%
Inhibition of carotid body (CB) function is the main mechanism involved in the attenuation of respiratory drive observed during hyperoxia However, only a few studies at 5 0 atmospheres absolutes (ATA) have analyzed carotid body structure or function in hyperbaric oxygenation (HBO(2)) situations We hypothesized that rats will present CB structural alterations when exposed to different lower hyperbaric oxygen doses enough to alter their chemosensory response to hypoxia Methods - Twenty-one adult male Wistar rats, divided into three groups, were maintained in room air or exposed to O(2) at 2 4 or 3 0 ATA for six hours Histological, ultrastructural and immunohistochemical analyses for neuronal nitric oxide synthase (nNOS) and F2-isoprostane were performed in the excised CBs Results - Histological analyses revealed signs of intracellular edema in animals exposed to both conditions, but this was more marked in the 3 0 ATA group, which showed ultrastructural alterations at the mitochondrial level There was a significant increase in the volume density of intraglomic-congested capillaries in the 3 0 ATA group associated with an arteriolar vasoconstriction In the 2 4 ATA group, there was a relative increase of glomic light cells and a decrease of glomic progenitor cells Additionally...

Alterações estruturais de corpos carotídeos de ratos expostos à hiperoxigenação hiperbárica; Structural alterations of rat carotid body exposed to hyperbaric oxygenation

Leite, Magno Santos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 07/11/2006 PT
Relevância na Pesquisa
45.96%
Procurou-se confirmar a existência de alterações estruturais em corpos carotídeos de ratos expostos à hiperóxia que pudessem explicar a atenuação da resposta fisiológica à hipóxia nessas condições descrita na literatura. Também testamos a hipótese de haver um desvio de fluxo sanguíneo para os capilares intraglômicos em situações de hiperoxigenação hiperbárica.15 ratos machos Wistar adultos foram divididos em 3 grupos e expostos a 2,4 ATA por 6 horas, a 3,0 ATA por 6 horas e a ar ambiente (grupo controle). Os resultados obtidos através de análise histológica e morfométrica mostraram: a) nenhuma alteração da arquitetura dos corpos carotídeos, mas as células expostas à dose mais elevada apresentaram-se com citoplasma desarranjado, confirmado pela microscopia eletrônica; b) um aumento significativo da densidade volumétrica de capilares preenchidos por hemácias, mas não do estroma intersticial, no grupo exposto à dose mais elevada de O2 c) uma vasoconstricção significativa das arteríolas maiores em todas as doses de oxigênio empregadas no estudo e das arteríolas menores na dose mais elevada de O2; d) variações significativas na proporção das variantes de células glômicas no grupo exposto a menor dose de O2; e) mitocôndrias com poucas cristas...

Efeitos do treinamento físico aeróbio sobre as alterações vasculares estruturais, mecânicas e funcionais de ratos espontaneamente hipertensos: mecanismos implicados; Effects of aerobic exercise trining on the vascular structural mechanical and functional alterations of spontaneously hipertensive rats: mechanisms involved

Redondo, Fernanda Roberta Roque
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/07/2010 PT
Relevância na Pesquisa
46.08%
A hipertensão arterial (HA) é um importante problema de saúde pública e representa um dos fatores de risco mais relevantes na etiologia das doenças cardiovasculares. O incremento na resistência vascular periférica (RVP) é a principal característica da HA e está diretamente associado a alterações vasculares estruturais, mecânicas e funcionais. O aumento do estresse oxidativo tem sido considerado um importante fator que contribui para o desenvolvimento e estabelecimento da HA. A prática regular de exercício físico aeróbio, utilizada como medida não farmacológica para o tratamento da HA, tem se mostrado efetiva em reduzir os valores de pressão arterial através da promoção de diversas adaptações cardiovasculares. Este estudo teve como objetivo avaliar os efeitos do treinamento físico (TF) aeróbio sobre as alterações vasculares de artérias coronárias e mesentéricas de resistência induzidas pela HA. Para isso ratos espontaneamente hipertensos (SHR) foram submetidos a um protocolo de TF aeróbio. Este TF promoveu alterações estruturais, avaliadas através de um miógrafo de pressão, como o remodelamento vascular em coronárias e redução de colágeno com aumento na área das fenestras da elastina em mesentéricas...

Idade pulmonar está relacionada à alterações estruturais carotídeas em pacientes hipertensos = : Lung age is related to carotid structural alterations in hypertensive subjects; Lung age is related to carotid structural alterations in hypertensive subjects

Tatiana Alves Kiyota
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 11/07/2014 PT
Relevância na Pesquisa
46.01%
Pacientes hipertensos exibem aumento do risco para desenvolvimento de eventos cardiovasculares e redução da função pulmonar quando comparados com a população geral. Contudo, ainda não está claro se esta associação se origina da coexistência de doenças altamente prevalentes ou de ações diretas ou indiretas de mecanismos fisiopatológicos em comum. Este estudo investigou a associação entre características das artérias carótidas e função pulmonar em hipertensos não fumantes com função pulmonar supostamente normal. Pacientes hipertensos (n=67) foram avaliados transversalmente por análises clínicas, hemodinâmicas, laboratoriais e ultrassom de carótidas. A capacidade vital forçada (CVF), o volume expiratório forçado no primeiro segundo (VEF1) e no sexto segundo (VEF6) e a idade pulmonar foram medidos por espirometria. Os indivíduos com anormalidades ventilatórias de acordo com o consenso da American Thoracic Society/ European Respiratory Society foram excluídos. Análises bivariadas mostraram que a idade pulmonar e o percentual do previsto para parâmetros espirométricos correlacionaram-se com espessura íntima-média, diâmetro e rigidez da artéria carótida comum. Níveis séricos de Proteína C-reativa e metaloproteinases 2 e 9 não influenciaram esta relação. Na análise de regressão tipo stepwise...

alpha-Globin genes: thalassemic and structural alterations in a Brazilian population

Wenning,M.R.S.C.; Kimura,E.M.; Costa,F.F.; Saad,S.T.O.; Gervásio,S.; de Jorge,S.B.; Borges,E.; Silva,N.M.; Sonati,M.F.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2000 EN
Relevância na Pesquisa
56.11%
Seven unrelated patients with hemoglobin (Hb) H disease and 27 individuals with alpha-chain structural alterations were studied to identify the alpha-globin gene mutations present in the population of Southeast Brazil. The -alpha3.7, --MED and -(alpha)20.5 deletions were investigated by PCR, whereas non-deletional alpha-thalassemia (alphaHphalpha, alphaNcoIalpha, aaNcoI, alphaIcalpha and alphaTSaudialpha) was screened with restriction enzymes and by nested PCR. Structural alterations were identified by direct DNA sequencing. Of the seven patients with Hb H disease, all of Italian descent, two had the -(alpha)20.5/-alpha3.7 genotype, one had the --MED/-alpha3.7 genotype, one had the --MED/alphaHphalpha genotype and three showed interaction of the -alpha3.7 deletion with an unusual, unidentified form of non-deletional alpha-thalassemia [-alpha3.7/(aa)T]. Among the 27 patients with structural alterations, 15 (of Italian descent) had Hb Hasharon (alpha47Asp->His) associated with the -alpha3.7 deletion, 4 (of Italian descent) were heterozygous for Hb J-Rovigo (alpha53Ala->Asp), 4 (3 Blacks and 1 Caucasian) were heterozygous for Hb Stanleyville-II (alpha78Asn->Lys) associated with the alpha+-thalassemia...

Structural alterations of nerve during cuff compression.

Dyck, P J; Lais, A C; Giannini, C; Engelstad, J K
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /12/1990 EN
Relevância na Pesquisa
46.07%
Whether compression nerve injury is due to ischemia, direct mechanical injury, or both remains unsettled. To assess structural changes of nerve during compression, peroneal nerves of rats were compressed at various pressures for different times, and the structural alterations were stopped by simultaneous in situ and perfusion fixation. The structural changes observed during a few minutes of compression cannot be explained by ischemic injury because the pathologic alterations characteristic of ischemia take many hours to develop and in any case are different from the ones found here. The pressure- and time-related structural changes observed in the present study under the cuff were (i) decrease in fascicular area and increase in fiber density due to expression of endoneurial fluid; (ii) compression and expression of axoplasm, sometimes to the point of fiber transection; (iii) lengthening of internodes; and (iv) obscuration of nodes of Ranvier due to cleavage and displacement of myelin and overlapping of nodes by displaced loops of myelin. At the edges of the cuff the changes were (i) increase of fascicular area probably from expressed endoneurial fluid; (ii) widening of nodal gaps, perhaps mainly from translocated axonal fluid; and (iii) disordered structure of axoplasm. We suggest that the process of paranodal demyelination and axonal transection are linked...

Functional changes in temperature-sensitive mutants of the adenovirus single-stranded DNA-binding protein are accompanied by structural alterations.

Tsuji, M; Kitchingman, G R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1992 EN
Relevância na Pesquisa
46.01%
Adenovirus requires the virus-encoded single-stranded DNA-binding protein (DBP) to replicate its DNA. We have previously shown (M. Tsuji, P. C. van der Vliet, and G. R. Kitchingman, J. Biol. Chem. 266:16178-16187, 1991) that the inability of three temperature-sensitive (ts) mutant DBPs (Ad2+ ND1ts23, Ad2ts111A, and Ad5ts125) to support DNA replication at the nonpermissive temperature was associated with impaired ability to bind to DNA. In this study, we examined these mutant proteins for structural alterations that might be linked to the functional changes. All three ts mutants, but not the wild-type protein, showed different proteolytic cleavage patterns before and after heating at 40 degrees C (the nonpermissive temperature), suggesting a possible conformational change during heating. The Ad2+ND1ts23 and Ad2ts111A DBPs have single amino acid changes located in a putative zinc finger subdomain (positions 282 and 280). In the presence of zinc ions, these ts mutants showed significantly increased resistance to inactivation at 40 degrees C. Surprisingly, however, the stabilizing effect of zinc was also observed with the Ad5ts125DBP, which contains a mutation located more than 100 amino acids from the zinc finger. Other related metal ions...

Structural alterations to the pulmonary circulation in fulminant hepatic failure.

Williams, A; Trewby, P; Williams, R; Reid, L
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1979 EN
Relevância na Pesquisa
45.98%
Like patients with chronic liver disease, those with coma due to fulminant hepatic failure may show arterial hypoxaemia even in the absence of pulmonary complications, and in both it is attributed to increased intrapulmonary arteriovenous admixture. This study is concerned with the structural alterations in the pulmonary circulation of patients who have died from fulminant hepatic failure. Precise quantitative morphometric techniques applied to the injected and inflated lung have shown the major abnormality to be a diffuse dilatation of the pulmonary vascular bed affecting arteries and veins of all structural types. At an intra-acinar level the diameter of arteries accompanying respiratory bronchioles was 232.97 micron (+/-SD 46.35) compared with 177.76 micron (+/-SD 30.43) in controls (P less than 0.01). In two-thirds of the patients pleural spider naevi were seen and, throughout the lung, similar significant dilatation of precapillary vessels; but in only one patient were precapillary anastomoses shown. While intrapulmonary venous admixture undoubtedly contributes to hypoxia in fulminant hepatic failure, its exact relation to the structural changes is not yet determined.

Gray Matter Structural Alterations in Obsessive-Compulsive Disorder: Relationship to Neuropsychological Functions

Christian, Christopher J.; Lencz, Todd; Robinson, Delbert G.; Burdick, Katherine E.; Ashtari, Manzar; Malhotra, Anil K.; Betensky, Julia D.; Szeszko, Philip R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.01%
Numerous magnetic resonance (MR) studies have examined gray matter structural alterations in patients with obsessive-compulsive disorder (OCD). Few, however, have used automated, highly reliable techniques such as voxel-based morphometry (VBM) to examine the entire brain in contrast to selected regions of interest. Moreover, few studies have examined the functional correlates of gray matter abnormalities in OCD. We used VBM to evaluate regional gray matter differences between 21 OCD patients and 21 age- and sex-matched healthy volunteers. All patients had comprehensive neuropsychological assessments. MR images were normalized to a customized template and segmented using optimized VBM. OCD patients had significantly (P < 0.001; uncorrected) more gray matter in the left thalamus compared to healthy volunteers. OCD patients without major depression had significantly more gray matter in the thalamus (bilaterally) and left orbitofrontal cortex as well as an unpredicted region of more right dorsolateral prefrontal gray matter, which remained significant after correction for multiple comparisons, compared to healthy volunteers. In the subgroup of patients without depression greater right hemisphere thalamic and dorsolateral prefrontal gray matter correlated significantly with worse motor functioning and processing speed...

Structural alterations within native amyloidogenic immunoglobulin light chains

Randles, Edward G.; Thompson, James R.; Martin, Douglas J.; Ramirez-Alvarado, Marina
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.05%
Amyloid diseases are characterized by the misfolding of a precursor protein that leads to amyloid fibril formation. Despite the fact that there are different precursors, some commonalities in the misfolding mechanism are thought to exist. In light chain amyloidosis (AL), the immunoglobulin light chain (LC) forms amyloid fibrils that deposit in the extracellular space of vital organs. AL proteins are thermodynamically destabilized compared to non-amyloidogenic proteins and some studies have linked this instability to increased fibril formation rates. Here we present the crystal structures of two highly homologous AL proteins, AL-12 and AL-103. This structural study shows that these proteins retain the canonical germline dimer interface. We highlight important structural alterations in two loops flanking the dimer interface and correlate these results with the somatic mutations present in AL-12 and AL-103. We suggest that these alterations are informative structural features that are likely contributing to protein instability that leads to conformational changes involved in the initial events of amyloid formation.

Rapid structural alterations of the active zone lead to sustained changes in neurotransmitter release

Matz, Jacob; Gilyan, Andrew; Kolar, Annette; McCarvill, Terrence; Krueger, Stefan R.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46%
The likelihood with which an action potential elicits neurotransmitter release, the release probability (pr), is an important component of synaptic strength. Regulatory mechanisms controlling several steps of synaptic vesicle (SV) exocytosis may affect pr, yet their relative importance in determining pr and eliciting temporal changes in neurotransmitter release at individual synapses is largely unknown. We have investigated whether the size of the active zone cytomatrix is a major determinant of pr and whether changes in its size lead to corresponding alterations in neurotransmitter release. We have used a fluorescent sensor of SV exocytosis, synaptophysin-pHluorin, to measure pr at individual synapses with high accuracy and employed a fluorescently labeled cytomatrix protein, Bassoon, to quantify the amount of active zone cytomatrix present at these synapses. We find that, for synapses made by a visually identified presynaptic neuron, pr is indeed strongly correlated with the amount of active zone cytomatrix present at the presynaptic specialization. Intriguingly, active zone cytomatrices are frequently subject to synapse-specific changes in size on a time scale of minutes. These spontaneous alterations in active zone size are associated with corresponding changes in neurotransmitter release. Our results suggest that the size of the active zone cytomatrix has a large influence on the reliability of synaptic transmission. Furthermore...

NAD+ administration significantly attenuates synchrotron radiation X-ray-induced DNA damage and structural alterations of rodent testes

Sheng, Caibin; Chen, Heyu; Wang, Ban; Liu, Tengyuan; Hong, Yunyi; Shao, Jiaxiang; He, Xin; Ma, Yingxin; Nie, Hui; Liu, Na; Xia, Weiliang; Ying, Weihai
Fonte: e-Century Publishing Corporation Publicador: e-Century Publishing Corporation
Tipo: Artigo de Revista Científica
Publicado em 01/03/2012 EN
Relevância na Pesquisa
45.94%
Synchrotron radiation (SR) X-ray has great potential for its applications in medical imaging and cancer treatment. In order to apply SR X-ray in clinical settings, it is necessary to elucidate the mechanisms underlying the damaging effects of SR X-ray on normal tissues, and to search for the strategies to reduce the detrimental effects of SR X-ray on normal tissues. However, so far there has been little information on these topics. In this study we used the testes of rats as a model to characterize SR X-ray-induced tissue damage, and to test our hypothesis that NAD+ administration can prevent SR X-ray-induced injury of the testes. We first determined the effects of SR X-ray at the doses of 0, 0.5, 1.3, 4 and 40 Gy on the biochemical and structural properties of the testes one day after SR X-ray exposures. We found that 40 Gy of SR X-ray induced a massive increase in double-strand DNA damage, as assessed by both immunostaining and Western blot of phosphorylated H2AX levels, which was significantly decreased by intraperitoneally (i.p.) administered NAD+ at doses of 125 and 625 mg/kg. Forty Gy of SR X-ray can also induce marked increases in abnormal cell nuclei as well as significant decreases in the cell layers of the seminiferous tubules one day after SR X-ray exposures...

Dissect: detection and characterization of novel structural alterations in transcribed sequences

Yorukoglu, Deniz; Hach, Faraz; Swanson, Lucas; Collins, Colin C.; Birol, Inanc; Sahinalp, S. Cenk
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
45.94%
Motivation: Computational identification of genomic structural variants via high-throughput sequencing is an important problem for which a number of highly sophisticated solutions have been recently developed. With the advent of high-throughput transcriptome sequencing (RNA-Seq), the problem of identifying structural alterations in the transcriptome is now attracting significant attention.

Direct Observation of Single DNA Structural Alterations at Low Forces with Surface-Enhanced Raman Scattering

Rao, Satish; Raj, Saurabh; Cossins, Benjamin; Marro, Monica; Guallar, Victor; Petrov, Dmitri
Fonte: The Biophysical Society Publicador: The Biophysical Society
Tipo: Artigo de Revista Científica
Publicado em 08/01/2013 EN
Relevância na Pesquisa
46.01%
DNA experiences numerous mechanical events, necessitating single-molecule force spectroscopy techniques to provide insight into DNA mechanics as a whole system. Inherent Brownian motion limits current force spectroscopy methods from observing possible bond level structural changes. We combine optical trapping and surface-enhanced Raman scattering to establish a direct relationship between DNA’s extension and structure in the low force, entropic regime. A DNA molecule is trapped close to a surface-enhanced Raman scattering substrate to facilitate a detectable Raman signal. DNA Raman modes shift in response to applied force, indicating phosphodiester mechanical alterations. Molecular dynamic simulations confirm the local structural alterations and the Raman sensitive band identified experimentally. The combined Raman and force spectroscopy technique, to our knowledge, is a novel methodology that can be generalized to all single-molecule studies.

Is there a correlation between structural alterations and retinal sensitivity in morphological patterns of diabetic macular edema?

Kothari, Abhishek R; Raman, Rajiv P G; Sharma, Tarun; Gupta, Muneesawar; Laxmi, G
Fonte: Medknow Publications & Media Pvt Ltd Publicador: Medknow Publications & Media Pvt Ltd
Tipo: Artigo de Revista Científica
Publicado em /05/2013 EN
Relevância na Pesquisa
46.01%
Spectral domain optical coherence tomography (SDOCT) enables enhanced visualization of retinal layers and delineation of structural alterations in diabetic macular edema (DME). Microperimetry (MP) is a new technique that allows fundus-related testing of local retinal sensitivity. Combination of these two techniques would enable a structure-function correlation with insights into pathomechanism of vision loss in DME. To correlate retinal structural derangement with retinal sensitivity alterations in cases with diabetic macular edema, using SDOCT and MP. Prospective study of 34 eyes of 30 patients with DME. All patients underwent comprehensive ophthalmic examination, fluorescein angiography, microperimetry and SDOCT. Four distinct morphological patterns of DME were identified- diffuse retinal thickening (DRT), cystoid macular edema (CME), schitic retinal thickening (SRT) and neourosensory detachment (NSD) of fovea. Some retinal loci presented with a mixture of above patterns There was significant difference in retinal thickness between groups (P<0.001). Focal retinal sensitivity measurement revealed relatively preserved retinal sensitivity in areas with DRT (13.8 dB), moderately reduced sensitivity (7.9 dB) in areas with CME, and gross retinal sensitivity loss in areas with SRT (1.2 dB) and NSD (4.7 dB) (P<0.001). Analysis of regional scotoma depth demonstrated similar pattern. Retinal sensitivity showed better correlation to OCT pattern (r=-0.68...

Age-related structural alterations in human skeletal muscle fibers and mitochondria are sex specific: relationship to single-fiber function

Callahan, Damien M.; Bedrin, Nicholas G.; Subramanian, Meenakumari; Berking, James; Ades, Philip A.; Toth, Michael J.; Miller, Mark S.
Fonte: American Physiological Society Publicador: American Physiological Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
45.96%
Age-related loss of skeletal muscle mass and function is implicated in the development of disease and physical disability. However, little is known about how age affects skeletal muscle structure at the cellular and ultrastructural levels or how such alterations impact function. Thus we examined skeletal muscle structure at the tissue, cellular, and myofibrillar levels in young (21–35 yr) and older (65–75 yr) male and female volunteers, matched for habitual physical activity level. Older adults had smaller whole muscle tissue cross-sectional areas (CSAs) and mass. At the cellular level, older adults had reduced CSAs in myosin heavy chain II (MHC II) fibers, with no differences in MHC I fibers. In MHC II fibers, older men tended to have fewer fibers with large CSAs, while older women showed reduced fiber size across the CSA range. Older adults showed a decrease in intermyofibrillar mitochondrial size; however, the age effect was driven primarily by women (i.e., age by sex interaction effect). Mitochondrial size was inversely and directly related to isometric tension and myosin-actin cross-bridge kinetics, respectively. Notably, there were no intermyofibrillar or subsarcolemmal mitochondrial fractional content or myofilament ultrastructural differences in the activity-matched young and older adults. Collectively...

The structural impact of DNA mismatches

Rossetti, Giulia; Dans, Pablo D.; Gomez-Pinto, Irene; Ivani, Ivan; Gonzalez, Carlos; Orozco, Modesto
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
46.02%
The structure and dynamics of all the transversion and transition mismatches in three different DNA environments have been characterized by molecular dynamics simulations and NMR spectroscopy. We found that the presence of mismatches produced significant local structural alterations, especially in the case of purine transversions. Mismatched pairs often show promiscuous hydrogen bonding patterns, which interchange among each other in the nanosecond time scale. This therefore defines flexible base pairs, where breathing is frequent, and where distortions in helical parameters are strong, resulting in significant alterations in groove dimension. Even if the DNA structure is plastic enough to absorb the structural impact of the mismatch, local structural changes can be propagated far from the mismatch site, following the expected through-backbone and a previously unknown through-space mechanism. The structural changes related to the presence of mismatches help to understand the different susceptibility of mismatches to the action of repairing proteins.

Brain structural alterations associated with young women with subthreshold depression

Li, Haijiang; Wei, Dongtao; Sun, Jiangzhou; Chen, Qunlin; Zhang, Qinglin; Qiu, Jiang
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 18/05/2015 EN
Relevância na Pesquisa
46.01%
Neuroanatomical abnormalities in patients with major depression disorder (MDD) have been attracted great research attention. However, the structural alterations associated with subthreshold depression (StD) remain unclear and, therefore, require further investigation. In this study, 42 young women with StD, and 30 matched non-depressed controls (NCs) were identified based on two-time Beck Depression Inventory scores. Whole-brain voxel-based morphometry (VBM) and region of interest method were used to investigate altered gray matter volume (GMV) and white matter volume (WMV) among a non-clinical sample of young women with StD. VBM results indicated that young women with StD showed significantly decreased GMV in the right inferior parietal lobule than NCs; increased GMV in the amygdala, posterior cingulate cortex, and precuneus; and increased WMV in the posterior cingulate cortex and precuneus. Together, structural alterations in specific brain regions, which are known to be involved in the fronto-limbic circuits implicated in depression may precede the occurrence of depressive episodes and influence the development of MDD.

THE RENAL LESIONS OF ELECTROLYTE IMBALANCE : I. THE STRUCTURAL ALTERATIONS IN POTASSIUM-DEPLETED RATS

Oliver, Jean; MacDowell, Muriel; Welt, L. G.; Holliday, M. A.; Hollander, W.; Winters, R. W.; Williams, T. F.; Segar, W. E.
Fonte: The Rockefeller University Press Publicador: The Rockefeller University Press
Tipo: Artigo de Revista Científica
Publicado em 30/09/1957 EN
Relevância na Pesquisa
46.14%
Renal tubular lesions during the early phases of progressive potassium depletion in rats were found in nephrons isolated by microdissection in two locations, the collecting tubules and the proximal convolutions. All other portions of the nephron, in particular the "distal tubule," i.e. ascending limbs of Henle's loop and distal convolutions, showed no structural alterations except the passive effects of dilatation and cellular compression which developed as a result of primary disturbances lower in the tubular system. The alterations affected all the collecting tubules uniformly and took two forms; the more severe, a swelling and hyperplasia of the tubular epithelium and the lesser, an intracellular accumulation of granule droplets. The former was limited to the outer zone of the medulla, the latter to its inner zone. In the proximal convolution the structural alteration began in its middle third and extended downward towards the medulla; only occasional nephrons were affected. The essential nature of the more severe epithelial lesion was similar in both collecting tubule and proximal convolution, beginning as a swelling of cell bodies, increasing to protoplasmic disturbances with disintegration of the mitochondrial pattern, followed by rupture of cells and nuclear disappearance. These retrogressive alterations were followed by prolific regenerative hyperplasia. In the collecting tubules of the outer zone these epithelial alterations were present in both the clear and the intercalcated cells; in the latter the swelling of the cells was not prominent...

Chromosomal breakpoints and structural alterations of the c-myc locus differ in endemic and sporadic forms of Burkitt lymphoma.

Pelicci, P G; Knowles, D M; Magrath, I; Dalla-Favera, R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /05/1986 EN
Relevância na Pesquisa
46.09%
We have examined the position of the chromosomal breakpoint relative to the human c-myc gene (MYC) and the presence of other structural alterations of the same locus in 19 fresh samples of Burkitt lymphoma (BL) and 13 BL-derived cell lines. This panel includes the two pathogenetic forms of BL: the endemic (African-type) BL (eBL) and sporadic (American-type) BL (sBL). In all cases tested, including fresh samples and cell lines, structural alterations of the 5' portion of the gene were detected, suggesting that they may be necessary for c-myc activation. However, the site of chromosomal breakpoint and the type of structural alterations differ in eBL and sBL. In 16 of 18 sBL cases, chromosomal translocation truncates the gene within a 5' region that includes the first intron, the first exon, and 5' flanking sequences. Conversely, in 14 of 14 eBL samples, the chromosomal breakpoint is located outside the c-myc locus, yet the same 5' sequences are affected by several mutations identifiable by restriction enzyme polymorphisms. Different genetic mechanisms may therefore be involved in chromosomal translocation/c-myc activation, and these differences may be a function of differences in the stage of differentiation of eBL versus sBL.