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1.
Genes (Basel) ; 9(4)2018 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29597328

RESUMO

Closely related to the model plant Arabidopsis thaliana, the genus Boechera is known to contain both sexual and apomictic species or accessions. Boechera retrofracta is a diploid sexually reproducing species and is thought to be an ancestral parent species of apomictic species. Here we report the de novo assembly of the B. retrofracta genome using short Illumina and Roche reads from 1 paired-end and 3 mate pair libraries. The distribution of 23-mers from the paired end library has indicated a low level of heterozygosity and the presence of detectable duplications and triplications. The genome size was estimated to be equal 227 Mb. N50 of the assembled scaffolds was 2.3 Mb. Using a hybrid approach that combines homology-based and de novo methods 27,048 protein-coding genes were predicted. Also repeats, transfer RNA (tRNA) and ribosomal RNA (rRNA) genes were annotated. Finally, genes of B. retrofracta and 6 other Brassicaceae species were used for phylogenetic tree reconstruction. In addition, we explored the histidine exonuclease APOLLO locus, related to apomixis in Boechera, and proposed model of its evolution through the series of duplications. An assembled genome of B. retrofracta will help in the challenging assembly of the highly heterozygous genomes of hybrid apomictic species.

2.
Colloids Surf B Biointerfaces ; 148: 600-606, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27694049

RESUMO

Food preservation is an important field of research. It extends the shelf life of major food products. Our current study is based on food preservation through TiO2 and ZnO nanoparticles. TiO2 and ZnO are biocompatible nanomaterial. The biocompatibility of the materials were established through toxicity studies on cell lines. Titanium dioxide and Zinc Oxide nanoparticle were synthesized by wet chemical process. They are characterized by X-Ray diffraction and TEM. The antibacterial activities of both the materials were analysed to ensure their effectiveness as food preservative against Salmonella typhi, Klebsiella pneumoniae and Shigella flexneri. The results indicates that TiO2 and ZnO nanoparticle inhibits Salmonella, Klebsiella and Shigella. The mode of action is by the generation of ROS in cases of Salmonella, Klebsiella. Mode of action in Shigella is still unclear. It was also proved that TiO2 and ZnO nanoparticle are biocompatible materials.


Assuntos
Antibacterianos/química , Conservantes de Alimentos/química , Nanopartículas Metálicas/química , Titânio/química , Óxido de Zinco/química , Antibacterianos/toxicidade , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Fragmentação do DNA/efeitos dos fármacos , Microbiologia de Alimentos , Conservantes de Alimentos/farmacologia , Conservantes de Alimentos/toxicidade , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/crescimento & desenvolvimento , Nanopartículas Metálicas/toxicidade , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Transmissão , Nanoestruturas/química , Nanoestruturas/toxicidade , Nanoestruturas/ultraestrutura , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Salmonella typhi/efeitos dos fármacos , Salmonella typhi/genética , Salmonella typhi/crescimento & desenvolvimento , Shigella flexneri/efeitos dos fármacos , Shigella flexneri/genética , Shigella flexneri/crescimento & desenvolvimento , Difração de Raios X
3.
Cell Death Differ ; 23(10): 1592-601, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27233083

RESUMO

The stress-induced p38 mitogen-activated protein kinase (MAPK) pathway plays an essential role in multiple physiological processes, including cancer. In turn, p38MAPK phosphorylation at Thr180 and Tyr182 is a key regulatory mechanism for its activation and functions. Here we show that this mechanism is actively regulated through isomerisation of Pro224. Different cyclophilins can isomerise this proline residue and modulate the ability of upstream kinases to phosphorylate Thr180 and Tyr182. In vivo mutation of Pro224 to Ile in endogenous p38MAPK significantly reduced its phosphorylation and activity. This resulted in attenuation of p38MAPK signalling, which in turn caused an enhanced apoptosis and sensitivity to a DNA-damaging drug, cisplatin. We further found a reduction in size and number of lesions in homozygous mice carrying the p38MAPK P224I substitution in a K-ras model of lung tumorigenesis. We propose that cyclophilin-dependent isomerisation of p38MAPK is an important novel mechanism in regulating p38MAPK phosphorylation and functions. Thus, inhibition of this process, including with drugs that are in clinical trials, may improve the efficacy of current anti-cancer therapeutic regimes.


Assuntos
Prolina/química , Prolina/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Linhagem Celular Tumoral , Cisplatino/farmacologia , Ciclofilinas/metabolismo , Ativação Enzimática/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Isomerismo , Camundongos , Mutação/genética , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Relação Estrutura-Atividade
4.
Cardiol Young ; 25(1): 154-7, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24423896

RESUMO

Ascending aortic aneurysm is uncommon in the paediatric population, and because of the rarity the aetiology, natural progression, and prognosis of the disease remain unknown. A 7-year-old boy with ascending thoracic aortic aneurysm (60×67 mm) underwent graft anastomosis from the sinotubular junction to the undersurface of the arch. Analytical determinations including karyotyping and genetic mapping were all normal. To our knowledge, idiopathic aneurysm of the ascending aorta in children is very rare.


Assuntos
Aorta/cirurgia , Aneurisma da Aorta Torácica/cirurgia , Procedimentos Cirúrgicos Vasculares/métodos , Aneurisma da Aorta Torácica/diagnóstico , Criança , Ecocardiografia , Eletrocardiografia , Humanos , Masculino , Tomografia Computadorizada por Raios X
5.
Artigo em Inglês | MEDLINE | ID: mdl-21703915

RESUMO

4-[(1E)-3-(biphenyl-4-yl)buta-1,3-dien-1-yl]phenyl prop-2-enoate (ACH) and 4-[(1E)-3-(biphenyl-4-yl)buta-1,3-dien-1-yl]phenyl 2-methylprop-2-enoate (MCH) was synthesized from biphenyl in three steps and their structures were confirmed by elemental analysis, IR, NMR (1H, 13C, DEPT135, 1H-1H COSY, 1H-13C HSQC and 1H-13C HMBC) spectroscopic techniques. In this present study, various physicochemical characteristics we demonstrate solubility, color, absorbance and fluorescence property of novel biphenyl based acrylate and methacrylate measured in different solvents like benzene, dichloromethane, tetrahydrofuran, acetonitrile, dimethylsulfoxide and ethanol.


Assuntos
Acrilatos/síntese química , Compostos de Bifenilo/química , Fluorescência , Metacrilatos/síntese química , Fenóis/química , Propionatos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Solventes , Espectrofotometria Infravermelho
6.
Horm Metab Res ; 41(10): 741-6, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19764107

RESUMO

High intake of dietary fructose has been shown to exert a number of adverse metabolic eff ects in humans and experimental animals. The present study was designed to investigate the eff ect of the aqueous extract of Tinospora cordifolia stem (TCAE) on the adverse eff ects of fructose loading toward carbohydrate and lipid metabolism in rats. Adult male Wistar rats of body weight around 200 g were divided into four groups, two of which were fed with starch diet and the other two with high fructose (66 %) diet. Plant extract of TC (400 mg/kg/day) was administered orally to each group of the starch fed rats and the highfructose fed rats. At the end of 60 days of experimental period, biochemical parameters related to carbohydrate and lipid metabolism were assayed. Hyperglycemia, hyperinsulinemia, hypertriglyceridemia, insulin resistance, and elevated levels of hepatic total lipids, cholesterol, triglycerides, and free fatty acids (p < 0.05) observed in fructose-fed rats were completely prevented with TCAE treatment. Alterations in the activities of enzymes of glucose metabolism (hexokinase, phosphofructokinase, pyruvate kinase, glucose-6-phosphatase, fructose-1,6-bisphosphatase, and glucose-6-phosphate dehydrogenase) and lipid metabolism (fatty acid synthetase, lipoprotein lipase, and malic enzyme) as observed in the high fructose-fed rats were prevented with TCAE administration. In conclusion, our fi ndings indicate improvement of glucose and lipid metabolism in high-fructose fed rats by treatment with Tinospora cordifolia, and suggest that the plant can be used as an adjuvant for the prevention and/or management of insulin resistance and disorders related to it.


Assuntos
Tecido Adiposo/metabolismo , Frutose/metabolismo , Fígado/metabolismo , Extratos Vegetais/farmacologia , Tinospora/metabolismo , Tecido Adiposo/enzimologia , Animais , Glicemia/análise , Colesterol/sangue , Ácido Graxo Sintases/análise , Ácidos Graxos não Esterificados/sangue , Frutose-Bifosfatase/análise , Glucose-6-Fosfatase/análise , Glucosefosfato Desidrogenase/análise , Hexoquinase/análise , Insulina/sangue , Lipase Lipoproteica/análise , Fígado/enzimologia , Malato Desidrogenase/análise , Masculino , Fosfofrutoquinase-1 Hepática/análise , Fosfolipídeos/sangue , Caules de Planta/metabolismo , Piruvato Quinase/análise , Distribuição Aleatória , Ratos , Ratos Wistar , Triglicerídeos/sangue
7.
Indian J Pharmacol ; 41(2): 64-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20336219

RESUMO

OBJECTIVE: Increased levels of oxidative stress may be implicated in the etiology of many pathological conditions. Protective antioxidant action imparted by many plant extracts and plant products make them promising therapeutic drugs for free radical induced pathologies. In this study we assessed the antioxidant potential of Phyllanthus amarus (Euphorbiaceae). MATERIALS AND METHODS: EXPERIMENTAL RATS WERE DIVIDED INTO TWO GROUPS: Control and Phyllanthus amarus (P. amarus) treated. Treated rats received P. amarus aqueous extract (PAAEt) at a dose of 200 mg/kg body wt/day for 8 weeks. After the treatment period of 8 weeks lipid peroxidation (LPO), vitamin C, uric acid and reduced glutathione (GSH) were estimated in plasma and antioxidant enzymes: Glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) were also assayed. Genotoxicity of PAAEt was assessed by single cell gel electrophoresis (SCGE) of lymphocytes under both in vitro and in vivo conditions. The protective role of PAAEt against hydrogen peroxide (H(2)O(2)), streptozotocin (STZ) and nitric oxide generating system induced lymphocyte DNA damage was also assessed by SCGE. RESULTS: PAAEt treated rats showed a significant decrease in plasma LPO and a significant increase in plasma vitamin C, uric acid, GSH levels and GPx, CAT and SOD activities. SCGE experiment reveals that PAAEt was devoid of genotoxicity and had a significant protective effect against H(2)O(2), STZ and nitric oxide (NO) induced lymphocyte DNA damage. CONCLUSION: The results suggest the non-toxic nature of PAAEt and consumption of PAAEt can be linked to improved antioxidant status and reduction in the risk of oxidative stress.

8.
Horm Metab Res ; 40(1): 44-9, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18085503

RESUMO

The study was aimed to examine if oral administration of the aqueous extract of the whole plant OCIMUM SANCTUM (OS) protects against the development of insulin resistance in fructose fed rats. Male Wister rats were randomly divided into four groups of eight animals each: group-S (starch diet), group-F (fructose diet), group-F+OS (fructose diet along with OCIMUM SANCTUM extract at a dose of 200 mg/kg), group-S+OS (starch diet along with OCIMUM SANCTUM). During the experimental period of 60 days body weight, plasma glucose, insulin, and triglycerides were measured at an interval of 15 days. Insulin sensitivity was assessed at the end of experimental period by measuring glucose-insulin index, which is the product of the areas under the curve of glucose and insulin during oral glucose tolerance test. The nontoxic nature of OS was revealed by unaltered body weight, plasma glucose, insulin, and triglyceride levels in group-S+OS when compared with group-S. A significant gain in body weight, hyperglycemia, hyperinsulinemia, hypertriglyceridemia, and insulin resistance were observed in group-F when compared with group-S. OS treatment prevented the observed fructose induced alterations in group-F+OS. In conclusion, our results suggests that oral administration of OS aqueous extract could delay the development of insulin resistance in rats and may be used as an adjuvant therapy for treating diabetic patients with insulin resistance.


Assuntos
Frutose/administração & dosagem , Frutose/farmacologia , Resistência à Insulina/fisiologia , Ocimum/metabolismo , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Jejum , Teste de Tolerância a Glucose , Insulina/sangue , Masculino , Fitoterapia , Ratos , Ratos Wistar , Fatores de Tempo , Triglicerídeos/sangue
9.
Indian J Exp Biol ; 45(5): 480-5, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17569293

RESUMO

Antioxidant potential of leaves of three different species of Annona was studied by using different in vitro models eg., 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothizoline-6-sulphonate) (ABTS), nitric oxide, superoxide, hydroxy radical and lipid peroxidation. The ethanolic extract of A. muricata at 500 microg/ml showed maximum scavenging activity (90.05%) of ABTS radical cation followed by the scavenging of hydroxyl radical (85.88%) and nitric oxide (72.60%) at the same concentration. However, the extract showed only moderate lipid peroxidation inhibition activity. In contrast, the extract of A. reticulata showed better activity in quenching DPPH (89.37%) and superoxide radical (80.88%) respectively. A.squamosa extract exhibited least inhibition in all in vitro antioxidant models excepting hydroxyl radical (79.79%). These findings suggest that the extracts of A. muricata possess potent in vitro antioxidant activity as compared to leaves of A. squamosa and A. reticulata suggesting its role as an effective free radical scavenger, augmenting its therapeutic


Assuntos
Annona/química , Antioxidantes/análise , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta/química , Animais , Compostos de Bifenilo/metabolismo , Sequestradores de Radicais Livres/farmacologia , Radicais Livres/metabolismo , Cabras , Hidrazinas/metabolismo , Técnicas In Vitro , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Concentração Osmolar , Picratos , Extratos Vegetais/química
10.
Clin Chim Acta ; 341(1-2): 185-92, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14967175

RESUMO

BACKGROUND: The reticulocyte maturation process is an ideal model for the study of biochemical alterations seen during final stage of erythropoiesis under disease conditions. In this study, determined whether type 2 diabetes has any effect on membrane lipids and protein-bound carbohydrates during the maturation of reticulocytes to erythrocytes. SUBJECTS AND METHODS: Lipids (cholesterol and phospholipids) and protein-bound carbohydrates (hexose, hexosamine and sialic acid) were extracted and estimated in plasma, membrane of reticulocytes and erythrocytes from 20 treated but uncontrolled type 2 diabetic volunteers and age matched controls. RESULTS: Plasma, membranes of reticulocytes and erythrocytes of diabetics showed increase in cholesterol (35.7%, 8.7% and 16.4%); phospholipids (43.4%, 18.8% and 8.2%); hexose (34.1%, 19.3% and 8.2%) and decrease in hexosamine (11.9%, 7.3% and 14.7%); and sialic acid (34.1%, 19.3% and 32.0%) compared to controls. As reticulocytes matured to erythrocytes, cholesterol, phospholipids, hexosamine and sialic acid levels were decreased; C/P ratio and hexose levels were increased in both controls and diabetics. However, these alterations were more intensified in diabetics. CONCLUSION: These alterations in diabetic patients may indicate the existence of one or both of the following conditions: acceleration of maturation processes and/or decreased red blood cell life span.


Assuntos
Carboidratos/sangue , Diabetes Mellitus Tipo 2/sangue , Eritrócitos/metabolismo , Lipídeos de Membrana/sangue , Reticulócitos/metabolismo , Adulto , Colesterol/sangue , Eritrócitos/química , Feminino , Hexosaminas/sangue , Hexoses/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Fosfolipídeos/sangue , Ligação Proteica , Reticulócitos/química , Ácidos Siálicos/sangue
11.
Free Radic Biol Med ; 35(2): 133-9, 2003 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-12853069

RESUMO

Free radical-induced lipid peroxidation has been associated with numerous disease processes including diabetes mellitus. The extent of lipid peroxidation (LPO) and antioxidant defense system [i.e., levels of glutathione (GSH), glucose-6-phosphate dehydrogenase (G6PDH), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase (CAT)] were evaluated in reticulocytes and erythrocytes of type 2 diabetic males and age-matched controls. Type 2 diabetics have shown increased lipid peroxidation and decreased levels of GSH, GR, GPx, G6PDH, and GST both in reticulocytes and erythrocytes compared to controls, indicating the presence of oxidative stress and defective antioxidant systems in these patients. CAT activity is found to be enhanced in both the reticulocytes and erythrocytes of diabetics, with a greater percentage enhancement in reticulocytes. The extent of increase in lipid peroxidation is greater in erythrocytes compared to reticulocytes in these patients. Furthermore, the maturation of reticulocytes to erythrocytes resulted in decreased GSH and decreased activities of all antioxidant enzymes (except CAT) both in normals and type 2 diabetes individuals, indicating decreased scavenging capacity as reticulocytes mature to erythrocytes. These maturational alterations are further intensified in type 2 diabetics. The present study reveals that the alterations in lipid peroxidation and antioxidant system lean toward early senescence of erythrocytes in type 2 diabetic patients.


Assuntos
Antioxidantes/análise , Diabetes Mellitus/sangue , Diabetes Mellitus/metabolismo , Eritrócitos/citologia , Eritrócitos/metabolismo , Reticulócitos/citologia , Reticulócitos/metabolismo , Adulto , Diabetes Mellitus/enzimologia , Eritrócitos/enzimologia , Glutationa/metabolismo , Humanos , Peroxidação de Lipídeos , Masculino , Pessoa de Meia-Idade , Reticulócitos/enzimologia
12.
Biomed Sci Instrum ; 37: 457-62, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11347434

RESUMO

The production of L-Glutamic acid has been studied using coimmobilized whole cells of pseudomonas reptilivora and micrococcus glutamicus in a three phase fluidized bed bioreactor with selected production medium enriched with glucose. The effect of initial substrate concentration, temperature, pH and aeration rate on the yield of glutamic acid has been investigated. It has been found that the acid production increases exponentially with substrate concentration and mass transfer co-efficient varied linearly with temperature and aeration rate. The optimum temperature and pH are 31 degree Celsius and 7.2 respectively.


Assuntos
Reatores Biológicos , Ácido Glutâmico/biossíntese , Micrococcus/metabolismo , Pseudomonas/metabolismo , Células Imobilizadas , Técnicas de Cocultura , Concentração de Íons de Hidrogênio , Micrococcus/crescimento & desenvolvimento , Pseudomonas/crescimento & desenvolvimento , Temperatura
13.
Int J Dev Biol ; 44(5): 491-8, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11032184

RESUMO

Spatial gradients of sequestered and free cellular calcium (Ca2+) exist in the slug of Dictyostelium discoideum (Maeda and Maeda, 1973; Tirlapur et al., 1991; Azhar et al., 1995; Cubitt et al., 1995). When we vary intracellular Ca2+ with the help of calcium buffers and the ionophore Br-A23187, there are striking effects on slug morphology, patterning and cell differentiation. In the presence of a calcium ionophore, high external Ca2+ levels lead to an increase of intracellular sequestered and free Ca2+, the formation of long slugs, a decrease in the fraction of genetically defined prespore cells and 'stalky' fruiting bodies. Conversely, a lowering of external Ca2+ levels results in a decrease of intracellular Ca2+, the formation of short slugs, an increase in the prespore fraction and 'spory' fruiting bodies. We infer that Ca2+ plays a significant morphogenetic role in D. discoideum development, by selectively promoting the prestalk pathway relative to the prespore pathway.


Assuntos
Cálcio/metabolismo , Dictyostelium/metabolismo , Animais , Calcimicina/farmacologia , Diferenciação Celular , Linhagem da Célula , Corantes/farmacologia , Corantes Fluorescentes/farmacologia , Ionóforos/farmacologia , Cinética , Transformação Genética
14.
Neurotoxicol Teratol ; 22(4): 593-602, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10974598

RESUMO

The present investigation was carried out to study the effects of in utero exposure to low-level gamma radiation (0.25, 0.35, or 0.50 Gy) on the postnatal neurophysiology and neurochemistry of the mouse. Pregnant Swiss albino mice were irradiated on days 11.5, 12.5, 14.5, or 17.5 post coitus (PC) and allowed to deliver. Locomotor and exploratory activities, learning and memory functions, and emotional activities were tested at 3 months of age using behavior tests. A representative group of animals was killed and hippocampal biogenic amines, noradrenaline, dopamine, serotonin (5-HT), and 5-HT's metabolite 5-hydroxy indoleactetic acid (5-HIAA), were measured. Exposure to 0.25 Gy at any of the gestation days did not produce any significant impairment in brain functions. However, an increase in gamma irradiation to 0.50 Gy on all the gestation days produced significant impairment in locomotor (open-field test) and anxiolytic (light and dark area test) activities, learning (hole board test), memory functions (active avoidance test), and emotional activity (rearings). The late fetal period is relatively resistant to radiation-induced impairment of brain functions. Both of the organogenesis gestation days showed a higher sensitivity than the fetal gestation days studied. Even a lower dose of 0.35 Gy when exposed on the late organogenesis days 11.5 and 12.5 PC, produced significant reduction in locomotor and exploratory activities. Day 11.5 PC showed a higher sensitivity than the other PC days studied. Biogenic amines did not show significant change after any of the exposures on any of the gestation days. The results suggest a threshold between 0.25 to 0.35 Gy for postnatal neurobehavior changes.


Assuntos
Comportamento Animal/efeitos da radiação , Efeitos Tardios da Exposição Pré-Natal , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Aminas Biogênicas/efeitos da radiação , Condicionamento Psicológico/efeitos dos fármacos , Relação Dose-Resposta à Radiação , Comportamento Exploratório/efeitos da radiação , Feminino , Raios gama , Idade Gestacional , Masculino , Memória/efeitos dos fármacos , Camundongos , Atividade Motora/efeitos da radiação , Gravidez
15.
Cancer Res ; 60(9): 2345-7, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10811105

RESUMO

Sinonasal lymphoma is one of the constituents of lethal midline granuloma, which is a clinical term for progressive, destructive lesions affecting the midline of the face. The majority of sinonasal lymphomas, especially those showing polymorphous patterns of proliferation and thus termed polymorphic reticulosis, recently were categorized as sinonasal natural killer/T-cell lymphomas. They are more prevalent in Asia than Europe or North America and are associated with EBV infection. Twenty-three cases with sinonasal natural killer/T-cell lymphomas were collected from two high-incidence regions: Beijing, China (14 cases) and Osaka, Japan (9 cases). c-kit mutations were analyzed on paraffin-embedded specimens by PCR-single-strand conformation polymorphism followed by direct sequencing; the c-kit proto-oncogene encodes a receptor of tyrosine kinase, which plays an important role in the regulation of normal and neoplastic hematopoiesis by the interaction with its specific ligand, termed stem cell factor. Twelve single nucleotide substitution mutations were seen in 23 cases. Ten of 14 Chinese cases (71.4%) had mutations at exon 11 or exon 17, whereas only two of nine Japanese cases (22.2%) had mutations, showing a significant difference in frequency between Chinese and Japanese cases. Furthermore, seven of eight mutations (92%) in exon 17 occurred at codon 825 and three of four mutations (75%) in exon 11 occurred at codon 561. Such a specificity has not been reported before, and these results, taken together, suggest that location-specific differences in etiological factors cause specific mutations in c-kit gene.


Assuntos
Células Matadoras Naturais/metabolismo , Linfoma de Células T/genética , Mutação , Neoplasias dos Seios Paranasais/genética , Proteínas Proto-Oncogênicas c-kit/genética , Adolescente , Adulto , Idoso , Linhagem Celular , China , Éxons , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Mutagênese Sítio-Dirigida , Mutação de Sentido Incorreto , Necrose , Mutação Puntual , Proto-Oncogene Mas , Transfecção
16.
Nature ; 404(6773): 91-4, 2000 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-10716449

RESUMO

Little is known about the timing of the maternal-to-zygotic transition during seed development in flowering plants. Because plant embryos can develop from somatic cells or microspores, maternal contributions are not considered to be crucial in early embryogensis. Early-acting embryo-lethal mutants in Arabidopsis, including emb30/gnom which affects the first zygotic division, have fuelled the perception that both maternal and paternal genomes are active immediately after fertilization. Here we show that none of the paternally inherited alleles of 20 loci that we tested is expressed during early seed development in Arabidopsis. For genes that are expressed at later stages, the paternally inherited allele becomes active three to four days after fertilization. The genes that we tested are involved in various processes and distributed throughout the genome, indicating that most, if not all, of the paternal genome may be initially silenced. Our findings are corroborated by genetic studies showing that emb30/gnom has a maternal-effect phenotype that is paternally rescuable in addition to its zygotic lethality. Thus, contrary to previous interpretations, early embryo and endosperm development are mainly under maternal control.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação/genética , Alelos , Arabidopsis , Inativação Gênica , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Sementes
17.
Cancer Lett ; 127(1-2): 55-61, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9619858

RESUMO

Esophageal achalasia (EA) is a rare disease in man and animals and there are many discussions on its higher risk of esophageal cancer. N-Amyl-N-methylnitrosamine (AMN) which specifically induces esophageal tumors in mice and rats was given to three mutant mouse strains, i.e. 101/N, STX/Le and BXH-8, which develop a high incidence of EA. The incidence of EA in 101/N, STX/Le, BXH-8 and normal C57BL/6J mice was 38.5% (110/286), 30.1% (43/143), 91.8% (190/207) and 0% (0/167), respectively. The average numbers of AMN-induced esophageal tumors in EA(+) were significantly higher than those of EA(-) in all of the 101/N, STX/Le and BXH-8 mice. Furthermore, significantly larger size tumors and invasive squamous cell carcinomas were found in EA(+) mice than in EA(-) mice. These results indicate the higher sensitivity of EA for both tumor induction and promotion, possibly due to the longer retention of AMN. In fact, relaxation of the lower esophagus by a smooth muscle relaxing calcium-channel blocker, nicardipine hydrochloride, significantly prevented the induction of esophageal tumors.


Assuntos
Carcinoma de Células Escamosas/induzido quimicamente , Acalasia Esofágica/etiologia , Neoplasias Esofágicas/complicações , Nicardipino/farmacologia , Administração Oral , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Carcinógenos , Neoplasias Esofágicas/induzido quimicamente , Neoplasias Esofágicas/prevenção & controle , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Nitrosaminas , Risco
18.
Indian J Exp Biol ; 34(9): 887-90, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9014528

RESUMO

Abdominal region of pregnant Swiss mice were exposed to 0.25, 0.35 or 0.50 Gy of gamma radiation on days 11.5, 12.5, 14.5 or 17.5 post coitus (pc). Changes in locomotory activity and learning performance, and hippocampal biogenic amines (noradrenaline, NA; dopamine, DA; 5-hydroxytryptomine, 5-HT; and 5-HTs metabolite 5-hydroxyindolacetic acid, 5-HIAA) were studied at 12 (adult) and 18 months (old) of age. Significant change in locomotory activity and learning performance was observed after exposure to 0.50 Gy at late organogenesis day (11.5 pc), when tested at 12 months of age, but not observed much change at 18 months. Biogenic amines did not show any significant change after any exposure dose at any of the gestation days. It was inferred from the results that gamma irradiation (0.50 Gy) at the late organogenesis (day 11.5 pc) can impair the brain functions in adults when normal faculties are functional.


Assuntos
Raios gama , Efeitos Tardios da Exposição Pré-Natal , Animais , Monoaminas Biogênicas/metabolismo , Feminino , Hipocampo/metabolismo , Hipocampo/efeitos da radiação , Aprendizagem/efeitos da radiação , Camundongos , Atividade Motora/efeitos da radiação , Gravidez
19.
Indian J Exp Biol ; 34(9): 895-7, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9014530

RESUMO

Pregnant Swiss albino mice were exposed to diagnostic ultrasound (3.5 MHz, 65mw, ISPTP = 1 W/cm2, ISATA = 240 W/cm2) for 10 min on day 14, 16 or 17 of gestation to assess any changes in physiological reflexes (pinna detachment, eye opening and fur development) and postnatal mortality. Changes in locomotor activity by open field test and dark/bright arena test and learning and memory by hole board test were also recorded. No change was observed in physiological reflexes and postnatal mortality. However there were significant alterations in behavior in all the three exposed groups. These results demonstrate that ultrasound exposure during the late fetal period can impair brain function in adult mouse.


Assuntos
Comportamento Animal , Ultrassonografia/efeitos adversos , Animais , Feminino , Camundongos , Gravidez
20.
Int J Radiat Biol ; 70(1): 45-52, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8691034

RESUMO

The abdominal region of pregnant Swiss albino mice was exposed to single dose of 0.5 Gy gamma-radiation at gestation days from 1.5 to 17.5 days post-coitus (p.c). The animals were sacrificed on day 18 p.c. and foetuses were examined for resorption and embryonic death, foetal death, growth retardation, small head, low brain weight, micro-phthalmia and any other gross morphological abnormalities. The period of maximum sensitivity for each effect varied. The only demonstrable effect of irradiation during the pre-implantation period was an increase in prenatal mortality. Resorptions were maximal after exposure between days 2 and 4 p.c. The pre-implantation irradiated embryos which survived did not show any major foetal abnormalities. These results confirm earlier mouse studies using higher doses of X-rays. Small head, low brain weight and microphthalmia were prominent after exposure during the late organogenesis period, especially between days 9 and 13 p.c. But no other externally visible anomalies were detected. These findings demonstrate that mouse organogenesis is very sensitive to radiation-induced retardation of development, even at doses < 1 Gy. One exencephaly, one cleft palate and two cases of open eyelids were observed in the foetuses exposed on days 14.5 and 15.5 p.c.; the number of these cases was too small to indicate a causal relationship with exposure.


Assuntos
Feto/efeitos da radiação , Anormalidades Induzidas por Radiação , Animais , Encéfalo/efeitos da radiação , Feminino , Raios gama , Idade Gestacional , Masculino , Camundongos , Microftalmia/etiologia , Tamanho do Órgão/efeitos da radiação , Gravidez
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