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1.
Phys Rev Lett ; 130(17): 173001, 2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37172243

RESUMO

To test bound-state quantum electrodynamics (BSQED) in the strong-field regime, we have performed high precision x-ray spectroscopy of the 5g-4f and 5f- 4d transitions (BSQED contribution of 2.4 and 5.2 eV, respectively) of muonic neon atoms in the low-pressure gas phase without bound electrons. Muonic atoms have been recently proposed as an alternative to few-electron high-Z ions for BSQED tests by focusing on circular Rydberg states where nuclear contributions are negligibly small. We determined the 5g_{9/2}- 4f_{7/2} transition energy to be 6297.08±0.04(stat)±0.13(syst) eV using superconducting transition-edge sensor microcalorimeters (5.2-5.5 eV FWHM resolution), which agrees well with the most advanced BSQED theoretical prediction of 6297.26 eV.

2.
Phys Rev Lett ; 128(11): 112503, 2022 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-35363014

RESUMO

We have measured the 3d→2p transition x rays of kaonic ^{3}He and ^{4}He atoms using superconducting transition-edge-sensor microcalorimeters with an energy resolution better than 6 eV (FWHM). We determined the energies to be 6224.5±0.4(stat)±0.2(syst) eV and 6463.7±0.3(stat)±0.1(syst) eV, and widths to be 2.5±1.0(stat)±0.4(syst) eV and 1.0±0.6(stat)±0.3(stat) eV, for kaonic ^{3}He and ^{4}He, respectively. These values are nearly 10 times more precise than in previous measurements. Our results exclude the large strong-interaction shifts and widths that are suggested by a coupled-channel approach and agree with calculations based on optical-potential models.

3.
Phys Rev Lett ; 127(5): 053001, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34397250

RESUMO

We observed electronic K x rays emitted from muonic iron atoms using superconducting transition-edge sensor microcalorimeters. The energy resolution of 5.2 eV in FWHM allowed us to observe the asymmetric broad profile of the electronic characteristic Kα and Kß x rays together with the hypersatellite K^{h}α x rays around 6 keV. This signature reflects the time-dependent screening of the nuclear charge by the negative muon and the L-shell electrons, accompanied by electron side feeding. Assisted by a simulation, these data clearly reveal the electronic K- and L-shell hole production and their temporal evolution on the 10-20 fs scale during the muon cascade process.

4.
Diabetes Obes Metab ; 14(6): 511-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22192426

RESUMO

AIM: We recently discovered a glucose-dependent insulinotropic polypeptide (GIP) receptor antagonist, SKL-14959. GIP plays a role in the glucose and lipid metabolism, and is associated with obesity and insulin resistance. Therefore, we aimed to ascertain the inhibitory potency and glucose and lipid metabolism of SKL-14959. METHODS: SKL-14959 was evaluated for its binding affinity to each GIP, glucagon-like peptide-1 (GLP-1) and glucagon receptors by each labelled and non-labelled ligand; GIP-stimulated cyclic AMP (cAMP) production in CHO cells expressing human GIP receptor in vitro. Oral and intraperitoneal glucose tolerance tests (OGTT and IPGTT) were performed to examine the insulinotropic effect on endogenous and exogenous GIP. Oil tolerance tests were also conducted to examine the lipid metabolism and the postheparin plasma lipase activity, lipoprotein lipase (LPL) and hepatic lipase (HL). RESULT: SKL-14959 selectively bound to GIP receptor and inhibited GIP-stimulated cAMP production with the Ki value of 55 nM and an IC(50) value of 2.9 µM, respectively. SKL-14959·Na significantly increased blood glucose levels, inhibited insulin secretion in OGTT and inhibited the plasma glucose lowering of exogenous GIP in IPGTT. Furthermore, SKL-14959 increased plasma triacylglycerol (TG) levels as well as suppressed the postheparin plasma lipase activity in an oil load test. CONCLUSION: These data indicate that SKL-14959 is distinguished in the physiological phenotype of GIP following direct binding to the receptor.


Assuntos
AMP Cíclico/metabolismo , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Lipase/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Receptores dos Hormônios Gastrointestinais/antagonistas & inibidores , Receptores de Glucagon/metabolismo , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Células CHO , Cricetinae , AMP Cíclico/biossíntese , Peptídeo 1 Semelhante ao Glucagon/efeitos dos fármacos , Teste de Tolerância a Glucose , Humanos , Insulina/metabolismo , Secreção de Insulina , Lipase/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores de Glucagon/efeitos dos fármacos , Triglicerídeos/sangue
5.
Insect Mol Biol ; 20(3): 279-89, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21349119

RESUMO

Wolbachia and Cardinium are bacterial endosymbionts that are widely distributed amongst arthropods. Both cause reproductive alterations, such as cytoplasmic incompatibility, parthenogenesis and feminization. Here we studied differentially expressed genes in Wolbachia- and Cardinium-infected Bm-aff3 silkworm cells using a silkworm microarray. Wolbachia infection did not alter gene expression or induce or suppress immune responses. In contrast, Cardinium infection induced many immune-related genes, including antimicrobial peptides, pattern recognition receptors and a serine protease. Host immune responses differed, possibly because of the different cell wall structures of Wolbachia and Cardinium because the former lacks genes encoding lipopolysaccharide components and two racemases for peptidoglycan formation. A few possibly non-immune-related genes were differentially expressed, but their involvement in host reproductive alteration was unclear.


Assuntos
Bacteroidetes , Bombyx/imunologia , Bombyx/microbiologia , Regulação da Expressão Gênica , Imunidade/genética , Simbiose/imunologia , Wolbachia , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Bombyx/genética , Células Cultivadas , Citoplasma/imunologia , Citoplasma/microbiologia , Análise de Sequência com Séries de Oligonucleotídeos , Simbiose/genética
6.
J Intern Med ; 267(6): 576-87, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20141564

RESUMO

OBJECTIVE: The aim of this study was to examine whether LDL cholesterol raises the risk of coronary heart disease in a dose-response fashion in a population with low LDL-cholesterol levels. DESIGN: Population-based prospective cohort study in Japan. SUBJECTS AND MAIN OUTCOME MEASURES: A total of 30,802 men and 60,417 women, aged 40 to 79 years with no history of stroke or coronary heart disease, completed a baseline risk factor survey in 1993. Systematic mortality surveillance was performed through 2003 and 539 coronary heart disease deaths were identified. RESULTS: The mean values for LDL-cholesterol were 110.5 mg dL(-1) (2.86 mmol L(-1)) for men and 123.9 mg dL(-1) (3.20 mmol L(-1)) for women. Men with LDL-cholesterol > or =140 mg dL(-1) (> or =3.62 mmol L(-1)) had two-fold higher age-adjusted risk of mortality from coronary heart disease than did those with LDL-cholesterol <80 mg dL(-1) (<2.06 mmol L(-1)), whereas no such association for women was found. The multivariable hazard ratio for the highest versus lowest categories of LDL-cholesterol was 2.06 (95 percent confidence interval: 1.34 to 3.17) for men and 1.16 (0.64 to 2.12) for women. CONCLUSION: Higher concentrations of LDL-cholesterol were associated with an increased risk of mortality from coronary heart disease for men, but not for women, in a low cholesterol population.


Assuntos
LDL-Colesterol/sangue , Doença das Coronárias/sangue , Doença das Coronárias/mortalidade , Adulto , Idoso , Estudos de Coortes , Doença das Coronárias/etnologia , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco , Fatores Sexuais
7.
Science ; 183(4124): 543-5, 1974 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-4809566

RESUMO

The excitability of lateral geniculate cells to orthodromic volleys decreased during saccadic eye movements. This decrease was caused by retinal impulses generated by a quick displacement of the image of the visual field associated with eye movements. This may be a mechanism for saccadic suppression.


Assuntos
Potenciais Evocados , Movimentos Oculares , Corpos Geniculados/fisiologia , Potenciais de Ação , Animais , Mapeamento Encefálico , Gatos , Escuridão , Estimulação Elétrica , Eletroculografia , Luz , Quiasma Óptico/fisiologia , Retina/fisiologia , Campos Visuais , Vias Visuais/fisiologia
8.
Science ; 175(4022): 661-4, 1972 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-5009768

RESUMO

About 10 percent of the cells in the visual cortex of awake cats do not respond to stationary parallel stripes in any orientation or to stripes moving across the visual field in any direction at a moderate speed (up to 132 degrees per second), but these cells are either excited or inhibited during saccadic eye movements when the animal faces a patterned visual environment. Of nineteen such cells tested in total darkness, seven discharged in association with eye movements. For saccade-related discharges, the latency during retinal stimulation is typically shorter than the latencey in total darkness.


Assuntos
Movimentos Oculares , Córtex Visual/fisiologia , Percepção Visual , Potenciais de Ação , Animais , Gatos , Escuridão , Eletroculografia , Percepção de Forma , Luz , Percepção de Movimento , Neurônios/fisiologia
9.
Science ; 281(5377): 666-9, 1998 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-9685252

RESUMO

It was recently demonstrated that peptide bond formation can occur using an Escherichia coli naked 23S ribosomal RNA without any of the ribosomal proteins. Here, the six domains of the 23S ribosomal RNA were individually synthesized and shown to be capable, when complexed together, of stimulating the reaction. Omission and addition experiments indicated that the activity could be reconstituted solely by domain V at a concentration 10 times higher than that of the intact 23S ribosomal RNA, whereas domain VI could enhance the activity in trans. These findings suggest that fragments of an RNA molecule have the ability to associate into a functional whole.


Assuntos
Escherichia coli/metabolismo , Biossíntese Peptídica , Peptidil Transferases/metabolismo , RNA Ribossômico 23S/metabolismo , Aminoacil-RNA de Transferência/metabolismo , Catálise , Neomicina/farmacologia , Conformação de Ácido Nucleico , Inibidores da Síntese de Proteínas/farmacologia , RNA Bacteriano/química , RNA Bacteriano/metabolismo , RNA Ribossômico 23S/química , Esparsomicina/farmacologia , Transcrição Gênica
10.
Science ; 205(4407): 717-20, 1979 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-111350

RESUMO

Discharges of Purkinje cells were recorded from the vermis, lobules VI and VII, of a monkey trained to track a visual target. When the monkey tracked a sinusoidally oscillating target, cellular activity changes in phase with the velocity signal of the eye movement. When the monkey fixated a stationary point, almost identical modulation in activity occurred, reflecting the velocity signal of the motion of the retinal image of the target. The data suggest that the vermis participates in the control of smooth pursuit eye movements by providing the oculomotor system with the actual target velocity information which is the sum of eye velocity and retinal image velocity signals.


Assuntos
Movimentos Oculares , Células de Purkinje/fisiologia , Percepção Visual/fisiologia , Potenciais de Ação , Animais , Haplorrinos , Percepção de Movimento/fisiologia , Propriocepção
11.
J Med Entomol ; 46(5): 1099-108, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19769041

RESUMO

We determined nucleotide sequences of the nuclear rDNA internal transcribed spacer (ITS)1-5.8S-ITS2a-2S-ITS2 region in 103 individuals of 25 Culicoides species (Diptera: Ceratopogonidae) from 11 locations in Japan. Ribosomal RNA genes, 5.8S and 2S rDNA, were highly conserved among the species with few variations. The ITS2a region showed length variation among species. Both ITS1 and ITS2 showed highly varied sequences among species. The noticeable indel regions among ITS1 sequences are present in some Culicoides species, separating species into two types having long or short ITS1 region. However, Culicoides cylindratus Kitaoka possesses both types of ITS1 in each individual; these results seem to indicate that the ITS1-long type was the prototype and the short type was produced through deletion in many Culicoides species. One species, belonging to subgenus Avaritia, possessed an Avaritia-specific sequence in ITS1 and phylogenetically formed a monophyletic group. Geographical genotypes in a species were not clear. Species-specific sequence features were observed, enabling molecular identification of Culicoides species.


Assuntos
Ceratopogonidae/genética , DNA Espaçador Ribossômico/genética , Animais , Sequência de Bases , Ceratopogonidae/classificação , Genes de Insetos , Japão , Dados de Sequência Molecular , Filogenia
12.
Med Vet Entomol ; 23(1): 47-55, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19239613

RESUMO

Partial mitochondrial gene sequences of 16 Culicoides species were determined to elucidate phylogenetic relations among species and to develop a molecular identification method for important virus vector species. In addition, the analysis found mitochondrial gene rearrangement in several species. Sequences of the mitochondrial genome region, cox1-trnL2-cox2 (1940-3785 bp) of 16 Culicoides and additional sequences were determined in some species, including whole mitochondrial genome sequences of Culicoides arakawae. Nine species showed common organization in this region, with three genes cox1-trnL2-cox2 and a small or no intergenic region (0-30 bp) between them. The other seven species showed translocation of tRNA and protein-coding genes and/or insertion of AT-rich non-coding sequences (65-1846 bp) between the genes. The varied gene rearrangements among species within a genus is very rare for mitochondrial genome organization. Phylogenetic analyses based on the sequences of cox1+cox2 suggest a few clades among Japanese Culicoides species. No relationships between phylogenetic closeness and mitochondrial gene rearrangements were observed. Sequence data were used to establish a polymerase chain reaction tool to distinguish three important vector species from other Culicoides species, for which classification during larval stages is not advanced and identification is difficult.


Assuntos
Ceratopogonidae/genética , Genes Mitocondriais , Insetos Vetores/genética , Animais , Sequência de Bases , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genoma de Inseto , Dados de Sequência Molecular , Filogenia , Especificidade da Espécie
13.
Kyobu Geka ; 62(6): 460-3, 2009 Jun.
Artigo em Japonês | MEDLINE | ID: mdl-19522205

RESUMO

We report 2 cases of superior vena cava (SVC) syndrome inserted metallic-expanding stents into SVC after radiotherapy. Case 1: A 77-year-old man had been performed chemotherapy and radiotherapy for the adenocarcinoma of the lung since December 2000. The edema of the upper limbs, head and neck emerged in April 2002 and he was diagnosed SVC syndrome with contrasted chest computed tomography (CT). We inserted a metallic-expanding stent into SVC, and after that the symptom disappeared in 5 days. There was no recurrence of the symptom until he died 4 months later. Case 2: A 57-year-old man had undergone the right upper lobectomy for the squamous cell carcinoma of the lung in March 2003. Because of mediastinal lymph node metastasis, he had been performed radiotherapy. Head and neck edema appeared at the end of October 2004, and he was diagnosed SVC syndrome. We inserted a metallic-expanding stent into SVC on November and the symptom disappeared in 7 days. There was no recurrence of the symptom until he died 4 months later. After radiotherapy, the stent insertion to SVC should be performed promptly to relieve SVC syndrome due to relapsed lung cancer.


Assuntos
Stents , Síndrome da Veia Cava Superior/terapia , Adenocarcinoma/complicações , Idoso , Carcinoma de Células Escamosas/complicações , Evolução Fatal , Humanos , Neoplasias Pulmonares/complicações , Masculino , Pessoa de Meia-Idade , Síndrome da Veia Cava Superior/etiologia
14.
Science ; 364(6437): 252, 2019 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-30890587

RESUMO

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multicolor images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east-west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of [Formula: see text] years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu's surface supports partial dehydration due to internal heating of the asteroid's parent body.

15.
Trends Biotechnol ; 26(12): 668-73, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18976825

RESUMO

Biodiesel fuel (BDF), which refers to fatty acid alkyl esters, has attracted considerable attention as an environmentally friendly alternative fuel for diesel engines. Alkali catalysis is widely applied for the commercial production of BDF. However, enzymatic transesterification offers considerable advantages, including reducing process operations in biodiesel fuel production and an easy separation of the glycerol byproduct. The high cost of the lipase enzyme is the main obstacle for a commercially feasible enzymatic production of biodiesel fuels. To reduce enzyme associated process costs, the immobilization of fungal mycelium within biomass support particles (BSPs) as well as expression of the lipase enzyme on the surface of yeast cells has been developed to generate whole-cell biocatalysts for industrial applications.


Assuntos
Fenômenos Fisiológicos Bacterianos , Fontes de Energia Bioelétrica/tendências , Ácidos Graxos/biossíntese , Fungos/fisiologia , Gasolina/microbiologia , Melhoramento Genético/métodos , Catálise
16.
J Food Prot ; 71(7): 1460-4, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18680947

RESUMO

A total of 353 samples of 29 types of seafood were tested for Salmonella prevalence and total microbial population. Salmonella enterica serotype Weltevreden was isolated from 2 of 47 black tiger prawn samples. The contamination levels of Salmonella were in a range of <30 to 40 most probable number per 100 g. In addition, one sample of black tiger prawns and two samples of white shrimp were positive for Salmonella invA gene on PCR assay. Although the mean aerobic bacterial count was greater than 4 log CFU/g in most of the sample types, those in the two Salmonella-isolated samples of black tiger prawn were 7.48 and 5.18 log CFU/g, respectively. These results indicate the possibility that shrimp and prawns contribute to foodborne infections. The improvement of seafood quality is an important issue, and the information on contamination by pathogens should be provided as feedback to the originating country, with the aim of increasing safety.


Assuntos
Contaminação de Alimentos/análise , Salmonella/isolamento & purificação , Alimentos Marinhos/microbiologia , Frutos do Mar/microbiologia , Animais , Contagem de Colônia Microbiana/métodos , Qualidade de Produtos para o Consumidor , Microbiologia de Alimentos , Humanos , Japão , Prevalência , Salmonella/crescimento & desenvolvimento , Salmonella enterica/crescimento & desenvolvimento , Salmonella enterica/isolamento & purificação
17.
Obes Sci Pract ; 4(2): 194-203, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29670757

RESUMO

Objective: Gastric inhibitory polypeptide plays a role in glucose and lipid metabolism and is associated with obesity and insulin resistance. The objective of this study is to confirm the anti-obesity effects of the gastric inhibitory polypeptide receptor antagonist, SKL-14959, on diet-induced obesity mice. Method: Diet-induced obesity mice at 20 weeks of age were administered with or without SKL-14959 for 96 d. Body weight and food intake were monitored throughout the experiment. Mice were sacrificed, and physiological and biochemical markers were measured, and then histochemical and gene expression analyses were also performed. In further studies, mice were orally gavaged with [14C]-oleic acid to investigate the excursion of digested lipids. Results: SKL-14959 significantly suppressed weight gain without affecting food intake, decreased triacylglycerol contents in the liver and the muscle and the intensity stained with oil-red in the liver. It also improved plasma glutamic pyruvic transaminase and 3-hydroxybutyrate levels in addition to notably down-regulated relative gene expression of srebf1 and dgat1 in the liver despite not altering in the adipose tissue. Furthermore, SKL-14959 showed remarkable inhibition of lipid uptake in the adipose tissue after the oil challenge. Conclusion: SKL-14959 inhibited lipids uptake and improved lipids metabolism, results in suppression of body-weight gain.

18.
Curr Biol ; 10(13): 801-4, 2000 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-10898984

RESUMO

Despite more than half a century of research, the evolutionary origin of termites remains unresolved [1] [2] [3]. A clear picture of termite ancestry is crucial for understanding how these insects evolved eusociality, particularly because they lack the haplodiploid genetic system associated with eusocial evolution in bees, ants, wasps and thrips [4] [5]. Termites, together with cockroaches and praying mantids, constitute the order Dictyoptera, which has been the focus of numerous conflicting phylogenetic studies in recent decades [6] [7] [8] [9] [10] [11] [12]. With the aim of settling the debate over the sister-group of termites, we have determined the sequences of genes encoding 18S ribosomal RNA, mitochondrial cytochrome oxidase subunit II (COII) and endogenous endo-beta-1, 4-glucanase (EG) from a diverse range of dictyopterans. Maximum parsimony and likelihood analyses of these sequences revealed strong support for a clade consisting of termites and subsocial, wood-feeding cockroaches of the genus Cryptocercus. This clade is nested within a larger cockroach clade, implicating wood-feeding cockroaches as an evolutionary intermediate between primitive non-social taxa and eusocial termites.


Assuntos
Baratas/genética , Evolução Molecular , Isópteros/genética , Animais , Celulase/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mitocôndrias/enzimologia , Modelos Genéticos , Filogenia , RNA Ribossômico 18S/genética
19.
J Clin Invest ; 80(3): 832-40, 1987 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3040808

RESUMO

To study vascular actions of synthetic alpha-human atrial natriuretic polypeptide (alpha hANP) in man, forearm blood flow (FBF) was measured by strain-gauge plethysmograph during the continuous infusion of 100 ng/min alpha hANP dissolved in 5% dextrose into the brachial artery in healthy subjects. alpha hANP increased FBF, with the concomitant increase in ipsilateral limb venous plasma concentrations of alpha hANP. Overall, there was a significant linear correlation between the decrements of ipsilateral forearm vascular resistance (FVR) during infusions of alpha hANP and initial FVR levels (r = -0.883, P less than 0.01). Moreover, alpha hANP, at the stepwise increasing doses of 20, 100, and 500 ng/min, increased FBF in a dose-related fashion: alpha hANP elicits a concentration-dependent vasodilation of forearm vascular beds. Concomitantly, infusions of alpha hANP caused a dose-dependent increase in ipsilateral limb venous plasma cyclic guanosine monophosphate (cyclic GMP). Overall, there were direct correlations of FBF either to ipsilateral venous plasma alpha hANP (r = 0.724, P less than 0.01) or to cyclic GMP concentrations (r = 0.637, P less than 0.01). Subsequently, isoosmolar CaCl2 solution was infused into the same brachial artery at a rate of 0.09 meq/min, and then, with a 2.5 +/- 0.2-mg/dl increase in ipsilateral venous serum calcium concentrations the incremental responses of both FBF and plasma cyclic GMP to alpha hANP were severely blunted. There was also a significant positive linear correlation between FBF and venous plasma cyclic GMP during infusions of alpha hANP with the simultaneous administration of CaCl2 (r = 0.807, P less than 0.01). Finally, the addition of CaCl2 infusion did not change the slope of the regression line of the FBF-plasma cyclic GMP relationship during infusions of alpha hANP. Evidence presented suggests that alpha hANP acts directly on the forearm vascular beds in man, eliciting its vascular relaxant effect, possibly by increasing cellular levels of cyclic GMP. Moreover, modest elevations of serum calcium inhibit the alpha hANP-dependent vasodilation, possibly through the suppression of cyclic GMP activation.


Assuntos
Fator Natriurético Atrial/farmacologia , Cálcio/farmacologia , Vasodilatação/efeitos dos fármacos , Adolescente , Adulto , Artéria Braquial , GMP Cíclico/sangue , Feminino , Antebraço/irrigação sanguínea , Humanos , Injeções , Masculino , Fluxo Sanguíneo Regional/efeitos dos fármacos
20.
J Exp Clin Cancer Res ; 26(4): 521-6, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18365548

RESUMO

Sporadic colorectal cancer (SCRC) occurring in young patients represent a subset with a higher proportion of advanced tumors and a poor prognosis, however, the genetic basis of SCRCs has not yet been sufficiently studied. We assigned 16 SCRC patients aged 40 years or less to group 1, and 30 SCRCs patients aged 65 years or more to group 2. The methylation status in the promoter of 7 tumor suppressor genes regarding these two groups was then examined. The average number of hypermethylated tumor-related genes per sample in group 1 was 1.50 +/- 0.07, which was significantly lower than that in group 2 of 2.73 +/- 1.24 (p = 0.0040). The frequencies of the promoter hypermethylation of hMLH1, p15INK4b, p16INK4a, and RASSF1A in group 1 were 12.5%, 12.5%, 12.5%, 6.3%, and 0.0%, which were substantially less frequent than those same rates observed in group 2. In contrast, the frequencies of the promoter hypermethylation of APC, MGMT, p14ARF, in group 1 were 43.8%, 37.5%, and 31.3%, which were as frequent as those seen in group 2. The promoter hypermethylation of APC, MGMT, and pl4ARF is therefore considered to be closely related to the development of SCRCs in young patients, regardless of aging.


Assuntos
Neoplasias Colorretais/genética , DNA de Neoplasias/metabolismo , Genes Supressores de Tumor , Regiões Promotoras Genéticas , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Inibidor de Quinase Dependente de Ciclina p15/genética , Metilação de DNA , Feminino , Genes p16 , Humanos , Masculino , Pessoa de Meia-Idade , Proteína 1 Homóloga a MutL , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética
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