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1.
Acta Endocrinol (Buchar) ; 16(4): 426-436, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34084233

RESUMO

CONTEXT: The grey mullet, Mugil cephalus, is an edible fish of high economic importance. Breeding biology with reference to hormonal/growth factor regulation of oocyte maturation needs to be known for its commercial production. OBJECTIVE: The present study was conducted to examine the potency of maturation inducing hormones, chorionic gonadotropin (hCG), bovine-insulin, and insulin like growth factor1 (h-IGF-1) I on ovarian steroidogenesis and oocyte maturation. DESIGN: The role of hormones and growth factors on steroidogenesis and oocyte maturation was investigated using specific inhibitors, Wortmannin for phosphatidylinositol-3 (PI3) kinase, trilostane for 3ß-hydroxysteroid dehydrogenase, 1-octanol and 1-heptanol for gap junctions, actinomycin D for transcription and cycloheximide for translation of signal molecules. METHODS: Actions of hormonal and growth factors were examined for steroidogenesis, by radioimmunoassay and oocyte maturation by germinal vesicle breakdown (GVBD). Specific inhibitors were used to determine the cell signaling pathways, PI3 kinase. RESULTS: All the inhibitors attenuated the hCG-induced oocyte maturation (GVBD%), steroidogenesis including transcription, translation, gap junctions and PI3 kinase signaling. These inhibitors failed to inhibit h-IGF-I and b-insulin-induced oocyte maturation, steroidogenesis, translation and PI3 kinase signaling. CONCLUSION: hCG induces oocyte maturation via steroid dependent pathway involving gap junctions, transcription, translation and PI3 kinase signaling, unlike h-IGF-I and b-insulin in the mullet.

2.
Environ Monit Assess ; 190(4): 217, 2018 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-29541935

RESUMO

An attempt has been made to study the effect of elevated temperature on soil hydrothermal regimes and winter wheat growth under simulated warming in temperature gradient tunnel (TGT). Results showed that bulk density (BDs) of 0, 0.9, and 2.5 °C were significantly different whereas BDs of 2.8 and 3.5 °C were not significantly different. Water filled pore space (WFPS) was maximum at 3.5 °C temperature rise and varied between 43.80 and 98.55%. Soil surface temperature (ST) at different dates of sowing increased with rise in sensor temperature and highest ST was observed at S5 sensors (3.5 °C temperature rise). Temperature and its difference were high for the top soil, and were stable for the deep soil. Photosynthesis rate (µmol CO2 m-2 s-1) of wheat was lower at higher temperature in different growth stages of wheat. In wheat, stomatal conductance declined from 0.67 to 0.44 mol m-2 s-1 with temperature rise. Stomatal conductance decreased with increase in soil temperature and gravimetric soil moisture content (SWC). In TGT, 0 °C temperature rise showed highest root weight density (RWD) (5.95 mg cm-3); whereas, 2.8 and 3.5 °C showed lowest RWD (4.90 mg cm-3). Harvest index was maximum (0.37) with 0 °C temperature rise, and it decreased with increase in temperature, which indicated that both grain and shoot biomass decreased with increase in temperature. Intensive studies are needed to quantify the soil hydrothermal regimes inside TGT along with the crop growth parameters.


Assuntos
Monitoramento Ambiental , Solo/química , Temperatura , Triticum/fisiologia , Biomassa , Dióxido de Carbono/análise , Grão Comestível/química , Fotossíntese , Raízes de Plantas/química , Estações do Ano , Triticum/crescimento & desenvolvimento , Água
3.
Ann Oncol ; 28(9): 2179-2184, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28911093

RESUMO

BACKGROUND: We investigated early outcomes for patients receiving chemotherapy followed by consolidative proton therapy (PT) for the treatment of Hodgkin lymphoma (HL). PATIENTS AND METHODS: From June 2008 through August 2015, 138 patients with HL enrolled on either IRB-approved outcomes tracking protocols or registry studies received consolidative PT. Patients were excluded due to relapsed or refractory disease. Involved-site radiotherapy field designs were used for all patients. Pediatric patients received a median dose of 21 Gy(RBE) [range 15-36 Gy(RBE)]; adult patients received a median dose of 30.6 Gy(RBE) [range, 20-45 Gy(RBE)]. Patients receiving PT were young (median age, 20 years; range 6-57). Overall, 42% were pediatric (≤18 years) and 93% were under the age of 40 years. Thirty-eight percent of patients were male and 62% female. Stage distribution included 73% with I/II and 27% with III/IV disease. Patients predominantly had mediastinal involvement (96%) and bulky disease (57%), whereas 37% had B symptoms. The median follow-up was 32 months (range, 5-92 months). RESULTS: The 3-year relapse-free survival rate was 92% for all patients; it was 96% for adults and 87% for pediatric patients (P = 0.18). When evaluated by positron emission tomography/computed tomography scan response at the end of chemotherapy, patients with a partial response had worse 3-year progression-free survival compared with other patients (78% versus 94%; P = 0.0034). No grade 3 radiation-related toxicities have occurred to date. CONCLUSION: Consolidative PT following standard chemotherapy in HL is primarily used in young patients with mediastinal and bulky disease. Early relapse-free survival rates are similar to those reported with photon radiation treatment, and no early grade 3 toxicities have been observed. Continued follow-up to assess late effects is critical.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Doença de Hodgkin/radioterapia , Terapia com Prótons , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Quimiorradioterapia/efeitos adversos , Criança , Feminino , Doença de Hodgkin/diagnóstico por imagem , Doença de Hodgkin/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
Acta Endocrinol (Buchar) ; 13(4): 400-409, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31149208

RESUMO

BACKGROUND: People chew betel nut (Areca catechu) for physical work and stress reduction, but it contains arecoline, which has both therapeutic value and untoward effects on endocrine and gonadal functions. OBJECTIVE: Aim of the present study is to investigate its role on adrenal with its target in metabolic stress in mice. MATERIALS AND METHODS: Mice were deprived of water / food, each for 5 days / treated with arecoline (10 mg / kg body wt daily for 5 days) / arecoline after water or food deprivation, for 5 days each. RESULTS: Water or food-deprivation caused adrenocortical hyperactivity, evident from abundance of enlarged mitochondria and smooth endoplasmic reticulum (SER) with elevation of corticosterone level (C: 68.31 ± 2.30, WD: 159.31 ± 4.10 / FD: 194.12 ± 3.40 µg/ mL). Arecoline treatment alone or in water deprivation (C: 68.31 ± 2.30, AR: 144.50 ± 4.33, AR+WD: 194.42 ± 3.35 µg/ mL) / food deprivation (AR + FD: 180.89 ± 4.51 µg/ mL) stress also stimulated adrenocortical activity as recorded in metabolic stress. In contrast, adrenomedullary activity was not altered following water/ food deprivation. Arecoline treatment alone or in metabolic stress suppressed adrenomedullary activity by showing depletion of chromaffin granules (E/NE?), epinephrine (E) and norepinephrine (NE) concentrations. Both the stress decreased blood glucose and liver glycogen levels. Arecoline treatment decreased blood glucose level, with a rise in liver glycogen level, but elevated blood glucose level in water deprivation unlike in starvation. CONCLUSION: Arecoline alone or in metabolic stress involves adrenal and probably other endocrine glands (pancreas, posterior pituitary and rennin-angiotensin system) to maintain homeostasis in metabolic stress in mice.

5.
Nanotechnology ; 27(49): 495706, 2016 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-27831935

RESUMO

Gold cluster (Au8) coated CdS hybrid nanorods (HNRs), synthesized using a sonication assisted assembly route, exhibit phonon assisted coherent mixing of excitons. As observed from optical absorption, Raman scattering, x-ray diffraction and transmission electron microscopic studies, the Au8 modulates the crystal-and electronic-structure of the CdS nanorods, effecting enhancement of exciton-phonon (e-p) interactions. The e-p interaction and entropy effect mediated phase matching of the excitonic transitions, leading-via cooperative and coherent mixing of the excitons' color-to the emission of white light, has been confirmed from room temperature and time resolved photoluminescence measurements.

6.
Analyst ; 139(7): 1796-800, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24551870

RESUMO

In the present work we have grown highly textured, ultra-thin, nano-crystalline zinc oxide thin films using a metal organic chemical vapor deposition technique and addressed their selectivity towards hydrogen, carbon dioxide and methane gas sensing. Structural and microstructural characteristics of the synthesized films were investigated utilizing X-ray diffraction and electron microscopy techniques respectively. Using a dynamic flow gas sensing measurement set up, the sensing characteristics of these films were investigated as a function of gas concentration (10-1660 ppm) and operating temperature (250-380 °C). ZnO thin film sensing elements were found to be sensitive to all of these gases. Thus at a sensor operating temperature of ~300 °C, the response% of the ZnO thin films were ~68, 59, and 52% for hydrogen, carbon monoxide and methane gases respectively. The data matrices extracted from first Fourier transform analyses (FFT) of the conductance transients were used as input parameters in a linear unsupervised principal component analysis (PCA) pattern recognition technique. We have demonstrated that FFT combined with PCA is an excellent tool for the differentiation of these reducing gases.

7.
Iran J Vet Res ; 23(3): 237-246, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36425605

RESUMO

Background: Dogs are the favorite companion animals among humans. The close interaction between dogs and people increases the risk of antibiotic resistance spreading. Surveillance for antimicrobial resistance and the identification of ESBL-producing Escherichia coli as an indicator bacterium is an important tool for managing antimicrobial drug therapy. Aims: The present study targeted to identify and characterize ESBL-producing E. coli among dogs suffering from diarrhea in and around Kolkata. Methods: Isolation and identification of E. coli from dogs suffering from diarrhea (n=70) along with screening for the production of both ESBL and AmpC. The isolates were further characterized through antimicrobial resistance profiling, resistance genes (bla CTX-M, bla TEM, and bla SHV) screening, and phylogenetic group study. Results: Among the 70 isolates, 21 (30%) were confirmed ESBL producers. An antibiogram typing of ESBL-producing E. coli revealed that the majority of them were resistant to norfloxacin (85.7%) followed by tetracycline (61.90%), doxycycline (57.14%), piperacillin/tazobactam (52.38%), cotrimoxazole (47.62%), gentamicin (42.62%), amikacin (23.81%), and chloramphenicol (19.05%). Major resistance genes included bla CTX-M (100%), bla TEM (28.57%), and bla SHV (9.50%). The predominant phylogenetic groups were phylogroup A (76%) followed by phylogroup D (24%). Conclusion: The current investigation reported a high prevalence of both ESBL and AmpC ß-lactamase (AmpC) producing E. coli, co-resistance to a distinct group of antibiotics, and co-existence of different ESBL genes in dogs. Our findings highlight the importance of diagnostic antimicrobial susceptibility testing for proper antimicrobial therapy and to prevent antimicrobial resistance from spreading to humans from dogs in Kolkata and the surrounding area.

8.
Ann R Coll Surg Engl ; 103(7): e212-e215, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34192501

RESUMO

We present a case of a man with a background of myasthenia gravis who presented with a neck lump, which was diagnosed as thyrolipomatosis in continuity with a very large thymolipoma. Following removal of these lesions, the patient's myaesthenic symptoms improved. While thymolipomas are often seen in the context of myasthenia gravis, thyrolipomatosis is a rare entity and to our knowledge the concurrent finding of both lesions with myasthenia gravis has never been reported. We highlight the important imaging features of both entities and the clinical importance of recognising them.


Assuntos
Lipoma/cirurgia , Lipomatose/cirurgia , Miastenia Gravis/terapia , Neoplasias do Timo/cirurgia , Doenças da Glândula Tireoide/cirurgia , Adulto , Humanos , Lipoma/diagnóstico , Lipoma/patologia , Lipomatose/diagnóstico , Lipomatose/patologia , Masculino , Miastenia Gravis/etiologia , Prednisolona/uso terapêutico , Brometo de Piridostigmina/uso terapêutico , Timectomia , Timo/diagnóstico por imagem , Timo/patologia , Timo/cirurgia , Neoplasias do Timo/diagnóstico , Neoplasias do Timo/patologia , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/patologia , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/patologia , Glândula Tireoide/cirurgia , Tireoidectomia , Tomografia Computadorizada por Raios X , Resultado do Tratamento
9.
Ann R Coll Surg Engl ; 103(2): e44-e47, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33559561

RESUMO

Surgical tracheostomy is a high aerosol-generating procedure that is an essential aid to the recovery of patients who are critically ill with COVID-19 pneumonia. We present a single-centre case series of 16 patients with COVID-19 pneumonia who underwent tracheostomy. We recommend that the patient selection criteria for achieving a favourable outcome should be based on fraction of inspired oxygen together with prone-position ventilation. As with any challenging situation, the importance of effective communication is paramount. The critical modifications in the surgical steps are clearly explained. Timely tracheostomy also leads to an earlier freeing up of ventilator space during a period of a rapidly escalating pandemic. The outcomes in terms of swallow and speech function were also assessed. The study has also helped to remove the anxiety around open a tracheostomy in patients who are COVID-19 positive.


Assuntos
COVID-19/terapia , Traqueostomia/métodos , Adulto , Idoso , Extubação , COVID-19/prevenção & controle , COVID-19/transmissão , Feminino , Humanos , Controle de Infecções , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Masculino , Pessoa de Meia-Idade , Respiradores N95 , Equipamento de Proteção Individual , Respiração Artificial , SARS-CoV-2 , Resultado do Tratamento
10.
Lancet ; 371(9622): 1435-42, 2008 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-18440425

RESUMO

BACKGROUND: India has the highest burden of acute coronary syndromes in the world, yet little is known about the treatments and outcomes of these diseases. We aimed to document the characteristics, treatments, and outcomes of patients with acute coronary syndromes who were admitted to hospitals in India. METHODS: We did a prospective registry study in 89 centres from 10 regions and 50 cities in India. Eligible patients had suspected acute myocardial infarction with definite electrocardiograph changes (whether elevated ST [STEMI] or non-STEMI or unstable angina), or had suspected myocardial infarction without ECG changes but with prior evidence of ischaemic heart disease. We recorded a range of clinical outcomes, and all-cause mortality at 30 days. FINDINGS: We enrolled 20,937 patients. Of the 20,468 patients who were given a definite diagnosis, 12,405 (60.6%) had STEMI. The mean age of these patients was 57.5 (SD 12.1) years; patients with STEMI were younger (56.3 [12.1] years) than were those with non-STEMI or unstable angina (59.3 [11.8] years). Most patients were from lower middle 10,737 (52.5%) and poor 3999 (19.6%) social classes. The median time from symptoms to hospital was 360 (IQR 123-1317) min, with 50 (25-68) min from hospital to thrombolysis. 6226 (30.4%) patients had diabetes; 7720 (37.7%) had hypertension; and 8242 (40.2%) were smokers. Treatments for STEMI differed from those for non-STEMI or unstable angina. More patients with STEMI than with non-STEMI were given anti-platelet drugs (98.2%vs 97.4%); angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARB) (60.5%vs 51.2%); and percutaneous coronary interventions (8.0%vs 6.7%, p<0.0001 for all comparisons). Thrombolytics (96.3% streptokinase) were used for 58.5% of patients with STEMI. Conversely, fewer patients with STEMI than those with non-STEMI or unstable angina were given beta blockers (57.5%vs 61.9%); lipid-lowering drugs (50.8%vs 53.9%); and coronary bypass graft surgery (1.9%vs 4.4%, p<0.0001 for all comparisons). The 30-day outcomes for patients with STEMI were death (8.6%), reinfarction (2.3%), and stroke (0.7%). Outcomes for those with non-STEMI or unstable angina were better: death (3.7%), reinfarction (1.2%), and stroke (0.3%, p<0.0001 for all comparisons). Use of key treatments also differed by socioeconomic status: more rich patients than poor patients were given thrombolytics (60.6%vs 52.3%), beta blockers (58.8%vs 49.6%), lipid-lowering drugs (61.2%vs 36.0%), ACE inhibitors or ARB (63.2%vs 54.1%), percutaneous coronary intervention (15.3%vs 2.0%), and coronary artery bypass graft surgery (7.5%vs 0.7%, p<0.0001 for all comparisons). Mortality was higher for poor patients than for rich patients (8.2%vs 5.5%, p<0.0001). Adjustment for treatments (but not risk factors and baseline characteristics) eliminated this difference in mortality. INTERPRETATION: Patients in India who have acute coronary syndromes have a higher rate of STEMI than do patients in developed countries. Since most of these patients were poor, less likely to get evidence-based treatments, and had greater 30-day mortality, reduction of delays in access to hospital and provision of affordable treatments could reduce morbidity and mortality.


Assuntos
Cardiotônicos/uso terapêutico , Doença das Coronárias/tratamento farmacológico , Idoso , Doença das Coronárias/mortalidade , Doença das Coronárias/fisiopatologia , Eletrocardiografia , Feminino , Hospitalização/economia , Hospitalização/estatística & dados numéricos , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sistema de Registros , Fatores de Risco , Classe Social , Resultado do Tratamento
11.
Ann R Coll Surg Engl ; 100(6): e139-e141, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29607722

RESUMO

Distant metastasis in advanced breast cancer is not uncommon; however, spread to the paranasal sinuses is extremely rare. We present a case of a woman who presented to our ophthalmology colleagues with worsening unilateral proptosis secondary to a tumour mass within her ethmoid sinuses. Biopsy of the ethmoid tumour showed adenocarcinoma of unknown origin. Whole-body positron emission computed tomography demonstrated a breast primary lesion. The patient was treated with palliative chemotherapy, and the patient remains well at this point. The importance of specialist head and neck radiological interpretation of imaging cannot be underestimated. Early tissue diagnosis is essential before ascribing patients with orbital symptoms to non-malignant process.


Assuntos
Adenocarcinoma/secundário , Neoplasias da Mama/patologia , Seio Etmoidal , Neoplasias dos Seios Paranasais/secundário , Adenocarcinoma/diagnóstico , Neoplasias da Mama/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias dos Seios Paranasais/diagnóstico
12.
Heliyon ; 4(10): e00838, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30294688

RESUMO

The ability of calcined magnesite for Methylene Blue (MB), Direct Red 81 (DR81), Methyl Orange (MO) and Crystal Violet (CV) dye removal was evaluated in this study. The experiments were designed to test the hypothesis that alkaline earth carbonates can remove dyes from water through a combination of sorption and coagulative reactions involving Mg2+. To achieve that, several operational factors like residence time, dosage, adsorbent concentration and temperature were appraised. The batch study proved that calcined magnesite is effective in the treatment of MB, DR81, CV and MO contaminated water and moreover it performed well in terms of color removal. The adsorption equilibrium data were analysed by the Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherm models, and the Dubinin-Radushkevich and Temkin models were found to be the most appropriate fit to MB and MO dyes respectively. The adsorption kinetics process primarily followed the Elovich and Pseudo-second order model, a possible indication that chemisorption was the rate limiting step during the dye uptake process. With the adsorption-desorption cycle repeated four times, the calcined magnesite regeneration efficiency for DR81 and MO loaded dyes remained very high. According to the results of this study, it can be concluded that calcined magnesite can be used effectively for the adsorption of MB, DR81, CV and MO from wastewater.

13.
Mol Cell Biol ; 17(9): 4967-78, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9271375

RESUMO

The c-Myc protein is a helix-loop-helix leucine zipper oncogenic transcription factor that participates in the regulation of cell proliferation, differentiation, and apoptosis. The biochemical function of c-Myc has been well described, yet the identities of downstream effectors are just beginning to emerge. We describe the identification of a set of c-Myc-responsive genes in the Rat1a fibroblast through the application of cDNA representational difference analysis (RDA) to cDNAs isolated from nonadherent Rat1a and Rat1a-myc cells. In this system, c-Myc overexpression is sufficient to induce the transformed phenotype of anchorage-independent growth. We identified 20 differentially expressed cDNAs, several of which represent novel cDNA sequences. We further characterized one of the novel cDNAs identified in this screen, termed rcl. rcl expression is (i) directly stimulated by c-Myc; (ii) stimulated in the in vivo growth system of regenerating rat liver, as is c-myc; and (iii) elevated in human lymphoid cells that overexpress c-myc. By using an anti-Rcl antibody, immunoblot analysis, and immunofluorescence microscopy, the Rcl protein was found to be a 23-kDa nuclear protein. Ectopic expression of the protein encoded by the rcl cDNA induces anchorage-independent growth in Rat1a fibroblasts, albeit to a diminished extent compared to ectopic c-Myc expression. These data suggest a role for rcl during cellular proliferation and c-Myc-mediated transformation.


Assuntos
N-Glicosil Hidrolases/fisiologia , Proteínas Nucleares/genética , Proteínas Proto-Oncogênicas c-myc/fisiologia , Proteínas Proto-Oncogênicas , Sequência de Aminoácidos , Animais , Células COS , Adesão Celular , Divisão Celular/genética , Linhagem Celular , Fibroblastos/citologia , Citometria de Fluxo , Regulação da Expressão Gênica , Humanos , Camundongos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Ratos , Ribonucleases/metabolismo , Alinhamento de Sequência
14.
Vet Parasitol ; 143(3-4): 371-4, 2007 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-17029790

RESUMO

Twelve isolates of Echinococcus granulosus, collected from domestic animals, including cattle, buffalo and sheep were analysed for DNA nucleotide sequence variation within mitochondrial cytochrome c oxidase I (coxI), NADH dehydrogenase subunit I (nadI) and internal transcribed spacer gene I (ITS1). After analysis of sequence information this was found that the fragment size of ITS1 of buffalo isolate was more in comparison to cattle and sheep isolates. Based on the nadI genotype this was found that Indian cattle, buffalo and sheep isolates could be grouped into E. granulosus sensu stricto. Based on coxI genotype two sheep isolates and one buffalo isolate were homologous to G2 genotype. Rests of the isolates were microvariants of G2 genotype. Presence of G2 genotype in buffalo is the first report of this genotype from this host.


Assuntos
Búfalos/parasitologia , Doenças dos Bovinos/parasitologia , DNA de Helmintos/química , Equinococose/veterinária , Echinococcus granulosus/genética , Doenças dos Ovinos/parasitologia , Animais , Sequência de Bases , Bovinos , Citocromos c1/genética , DNA de Helmintos/análise , DNA Intergênico/genética , Equinococose/parasitologia , Echinococcus granulosus/classificação , Echinococcus granulosus/isolamento & purificação , Marcadores Genéticos , Genótipo , Dados de Sequência Molecular , NADH Desidrogenase/genética , Filogenia , Homologia de Sequência , Ovinos
15.
Cancer Res ; 60(20): 5879-86, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11059786

RESUMO

Glioblastomas are highly vascular malignant brain tumors that often overexpress vascular endothelial growth factor (VEGF). They also frequently overexpress epidermal growth factor receptor (EGFR) and contain regions of hypoxia, both conditions that can induce VEGF. We examined VEGF regulation in U87 MG human glioblastoma cells and in U87/T691 cells, a clonal derivative that contains a truncated erbB2/Neu receptor that interferes with EGFR signaling through the formation of nonfunctional heterodimeric receptor complexes. U87/T691 cells contained approximately one-half as much VEGF mRNA as did U87 MG cells under normoxic conditions (21% oxygen). Pharmacological inhibition of EGFR, Ras, or PI(3) kinase, but not MAP kinase, led to a significant decrease in VEGF mRNA levels in U87 MG cells. VEGF promoter activity in transient transfections was decreased by either pharmacological or genetic inhibition of EGFR, Ras, or phosphatidylinositol 3'-kinase [PI(3) kinase]. However, inhibition of PI(3) kinase or EGFR did not completely abolish induction of VEGF mRNA by hypoxia (0.2% oxygen). Likewise, VEGF mRNA expression was induced 3-fold by hypoxia in EGFR-inhibited U87/T691 cells, comparable with the fold induction seen in parental U87 MG cells, although the absolute level of message under hypoxia was higher in U87 MG cells. In transient transfections, a luciferase reporter construct containing a 1.2-kb fragment of the VEGF promoter, lacking the known hypoxic-responsive element (HRE), showed up-regulation after EGF stimulation to the same degree as the full-length, 1.5-kb VEGF promoter construct retaining the HRE. Furthermore, activity of the HRE-deleted, 1.2-kb promoter luciferase reporter was down-regulated by PI(3) kinase inhibition. Therefore, in glioblastoma cells, transcriptional regulation of the VEGF promoter by EGFR appears to involve Ras/PI(3) kinase and to be distinct from signals induced by hypoxia.


Assuntos
Fatores de Crescimento Endotelial/biossíntese , Receptores ErbB/fisiologia , Glioblastoma/metabolismo , Linfocinas/biossíntese , Metionina/análogos & derivados , Fosfatidilinositol 3-Quinases/metabolismo , Hipóxia Celular/fisiologia , Regulação para Baixo , Fatores de Crescimento Endotelial/genética , Inibidores Enzimáticos/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica/fisiologia , Glioblastoma/genética , Humanos , Linfocinas/genética , Metionina/farmacologia , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase , Regiões Promotoras Genéticas/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor ErbB-2/genética , Transdução de Sinais/fisiologia , Transcrição Gênica , Células Tumorais Cultivadas , Regulação para Cima , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular , Proteínas ras/antagonistas & inibidores
16.
Cancer Res ; 57(4): 753-8, 1997 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-9044856

RESUMO

Irradiation of tumor cells results in a G2 delay, which has been postulated to allow DNA repair and cell survival. The G2 delay after irradiation is marked in HeLa and other cells by delayed expression of cyclin B1. To test whether this depression of cyclin B1 contributes to the G2 delay, we induced cyclin B1 expression in irradiated HeLa cells using a dexamethasone-inducible promoter. Induction of cyclin B1 after radiation abrogated the G2 delay by approximately doubling the rate at which the cells reentered mitosis, whereas dexamethasone itself had no effect. However, overexpression of cyclin B1 did not eliminate the G2 delay in irradiated cells. In unirradiated cells, overexpression of cyclin B1 had no effect on cell cycle progression. Confirmation that reduction of cyclin B1 levels would prolong G2 was provided using antisense oligonucleotides to cyclin B1. These results demonstrate that cyclin B1 levels control the length of the G2 delay following irradiation in HeLa cells but do not exclude additional mechanisms controlling the mitotic delay after irradiation.


Assuntos
Ciclina B , Ciclinas/metabolismo , Fase G2/efeitos da radiação , Biomarcadores , Ciclina B1 , Ciclinas/genética , Dexametasona/farmacologia , Fase G2/efeitos dos fármacos , Fase G2/genética , Vetores Genéticos , Glucocorticoides/farmacologia , Células HeLa/metabolismo , Células HeLa/efeitos da radiação , Humanos , Mitose , Oligonucleotídeos Antissenso/farmacologia , RNA Mensageiro/metabolismo , Transfecção
17.
Oncogene ; 13(8): 1647-57, 1996 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-8895510

RESUMO

Exposure of cells to DNA damaging agents results in a G2 arrest. Exposure of HeLa cells to camptothecin, etoposide or nitrogen mustard for 1 h in S phase resulted in delayed expression of cyclin B1 mRNA during the G2 arrest. Initially the levels of cyclin B1 protein were low as well; however, with extended time the cells blocked in G2 regained higher levels of cyclin B1 protein. In the case of cells treated with nitrogen mustard the higher levels coincided with cells exiting the G2 block into G1. However, with camptothecin or etoposide treatment, while the accumulation of cyclin B1 protein was delayed, its levels eventually surpassed peak levels seen in control cells, in spite of the fact that cells were still blocked in G2. These cells did not continue to progress through the cell cycle indicating further complexity to the mechanisms underlying the G2 block. Decreased transcription and stability of cyclin B1 mRNA were shown to occur after treatment with these DNA damaging agents. These results indicate that suppression of cyclin B1 mRNA expression is one consequence of DNA damage in HeLa cells.


Assuntos
Ciclina B , Ciclinas/genética , Dano ao DNA , Fase G2 , Antineoplásicos/farmacologia , Camptotecina/farmacologia , Ciclina B1 , Etoposídeo/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Mecloretamina/farmacologia , Regiões Promotoras Genéticas , RNA Mensageiro/genética
18.
Oncogene ; 12(2): 237-45, 1996 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-8570201

RESUMO

Primary fibroblasts, after serum withdrawal or after irradiation, do not undergo apoptosis. Myc-transfected fibroblasts, in contrast, undergo apoptosis upon serum withdrawal and after irradiation. We have studied the relationship of apoptosis induction to effects on the G2 phase cell cycle in a series of rat embryo cells transformed by rasH plus myc or immortalized by myc alone. In this system, while the presence of rasH had little effect on the extent of apoptosis induction by serum withdrawal, rasH greatly suppressed the apoptotic response of myc-transfected cells to X-rays. The cells into which rasH had been introduced showed a profound G2 arrest associated with suppression of cyclin B1 mRNA expression. In contrast, cells with myc alone had a minimal G2 delay after irradiation and no suppression of cyclin B1 mRNA expression. We hypothesize that rasH, by influencing the G2 response of cells to X-rays, exerts an anti-apoptotic effect. In support of this hypothesis; we found that treatment of cells with caffeine, an agent that relieves the G2 delay after irradiation resulted in increased apoptosis in the irradiated cells, but not in control cells.


Assuntos
Apoptose/efeitos da radiação , Ciclina B , Fase G2/efeitos da radiação , Genes ras/fisiologia , Animais , Cafeína/farmacologia , Linhagem Celular , Ciclina B1 , Ciclinas/genética , Dano ao DNA , Fibroblastos , RNA Mensageiro/análise , Ratos , Transfecção , Raios X
19.
J Clin Oncol ; 10(6): 929-35, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1588371

RESUMO

PURPOSE: In an effort to minimize complications related to high-dose radiotherapy (RT), children with Hodgkin's disease are often treated with low-dose RT (less than 25 Gy) plus chemotherapy. We performed a retrospective study comparing the results in these children with those from children treated with higher doses of RT (30 to 40 Gy) with or without chemotherapy. PATIENTS AND METHODS: From 1970 to 1988, 121 patients younger than 18 years of age with newly diagnosed Hodgkin's disease were treated at the Children's Hospital of Philadelphia (CHOP) and the Hospital of the University of Pennsylvania (HUP). Before 1977, most children underwent laparotomy and received high-dose RT with or without chemotherapy. Since then, high-dose RT alone has been reserved for pathologic stage IA and IIA postpubertal children without large mediastinal masses. In general, most postpubertal children with stage IIB through IVB disease or large mediastinal masses and all prepubertal children have received low-dose RT plus chemotherapy without laparotomy. RESULTS: The 10-year actuarial survival for all children was 86%, and the event-free survival (EFS) was 67% (median follow-up, 6.6 years). For 58 children treated with low-dose RT plus chemotherapy, 10-year survival and EFS (median follow-up, 6.8 years) were 88% and 67%, respectively. The corresponding figures for 10-year survival and EFS in 48 children treated with high-dose RT with or without chemotherapy were 88% and 66%, respectively. In children receiving combined modality therapy, the in-field failure rate was 7% for sites given between 17.5 and 22.5 Gy and 2% for sites given more than 32.5 Gy. In children receiving RT alone, the failure rate was 5% for sites given more than 32.5 Gy. CONCLUSION: We conclude that low-dose RT plus chemotherapy has yielded results comparable to those with higher doses of RT with or without chemotherapy.


Assuntos
Doença de Hodgkin/radioterapia , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante , Criança , Pré-Escolar , Feminino , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/mortalidade , Humanos , Masculino , Dosagem Radioterapêutica , Estudos Retrospectivos , Taxa de Sobrevida
20.
Carbohydr Polym ; 115: 617-28, 2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25439940

RESUMO

This study reports the microwave-assisted synthesis of gum-ghatti (Gg)-grafted poly(acrylamide-co-methacrylic acid) (AAm-co-MAA) hydrogels for the development of biodegradable flocculants and adsorbents. The synthesized hydrogels were characterized using TGA, FTIR and SEM. TGA studies revealed that the synthesized hydrogels were thermally more stable than pristine Gg and exhibited maximum swelling capacity of 1959% at 60°C in neutral pH. The optimal Gg-cl-P(AAm-co-MAA) hydrogel was successfully employed for the removal of saline water from various petroleum fraction-saline emulsions. The maximum flocculation efficiency was achieved in an acidic clay suspension with a 15 mg polymer dose at 40°C. Moreover, the synthesized hydrogel adsorbed 94% and 75% of Pb(2+) and Cu(2+), respectively, from aqueous solutions. Finally, the Gg-cl-P(AAm-co-MAA) hydrogel could be degraded completely within 50 days. In summary, the Gg-cl-P(AAm-co-MAA) hydrogel was demonstrated to have potential for use as flocculants and heavy metal absorbents for industrial waste water treatment.


Assuntos
Hidrogéis/química , Gomas Vegetais/química , Ácidos Polimetacrílicos/química , Adsorção , Bactérias/metabolismo , Cobre/química , Floculação , Hidrogéis/metabolismo , Concentração de Íons de Hidrogênio , Caulim/química , Chumbo/química , Microscopia Eletrônica de Varredura , Petróleo , Gomas Vegetais/metabolismo , Ácidos Polimetacrílicos/metabolismo , Microbiologia do Solo , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
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