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1.
Kidney Int Rep ; 3(1): 142-147, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29340324

RESUMO

INTRODUCTION: Autoantibodies to M-type phospholipase A2 receptor (aPLA2R) are seen in two-thirds of patients with primary membranous nephropathy (PMN) and are associated with disease activity. However, the precise temporal dynamics between the presence and amount of aPLA2R in circulation, as well as the clinical activity, are not known. We evaluated the temporal association between disease activity and serum aPLA2R during and after treatment in PMN. METHODS: The study included all patients with PMN and elevated aPLA2R who were started on immunosuppressive therapy for persistent nephrotic syndrome at a single center between December 2014 and December 2015. Serum samples were tested for aPLA2R at baseline and at monthly intervals for 6 months. Clinical details were collected monthly for 9 months. Serological remission was defined as negative aPLA2R in 2 consecutive samples. Clinical remission was defined by standard criteria. RESULTS: A total of 30 patients with PMN were studied. Of these, 28 (93%) had elevated levels at baseline, whereas 2 (7%) became positive after 1 month. The mean age was 33.2 ± 1 (range, 13-52) years. Median baseline aPLA2R titer was 163.41 (range, 70-291.01) RU/ml. A total of 24 patients (80%) achieved serological remission by 6 months. Among all the serological responders, 54% had achieved negative aPLA2R by the end of the first month. Clinical remission was observed in 20 patients (67%). Serological and clinical remission were noted at 2.7 ± 1.71 and 5.05 ± 2.64 months, respectively. CONCLUSION: In patients with aPLA2R-associated PMN, reduction in circulating aPLA2R precedes clinical remission. Persistence of aPLA2R at the end of therapy is associated with clinical resistance.

2.
Curr Top Med Chem ; 16(28): 3133-3174, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27291985

RESUMO

This review discusses the biological and medicinal significance of one of the most important and interesting heterocyclic ring systems, the pyrimidine and its condensed derivatives. Herein, various physiologically important molecules, as well as, therapeutically used drugs having a pyrimidine or condensed pyrimidine system in their chemical structures, have been covered. The chemistry and synthesis of pyrimidines have also been briefly discussed.


Assuntos
Pirimidinas/química , Humanos
3.
Drug Dev Ind Pharm ; 39(1): 138-45, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22369145

RESUMO

Pellets, reliant on pH-sensitivity and time-dependency for drug delivery, provide one of the most versatile opportunities for targeting colon. 5-Fluorouracil (5-FU) loaded pellets were prepared by extrusion-spheronization using Avicel(®) PH101 as a spheronization aid and hydroxypropylmethylcellulose K4M (HPMC K4M) solution as a binder. A 3(2) full factorial design was employed to optimize spheronization speed and time. Obtained pellets were evaluated for flow properties, pellet size, roundness and aspect ratio. Optimized batch was coated in a bottom-spray fluidized bed processor (FBP) with an inner coat of sustained release polymer Eudragit NE30D and an outer coat of pH-sensitive polymer Eudragit FS30D. The coating levels were statistically optimized and in vitro drug release was monitored by changing pH media method. Optimized system with 15% inner and outer coating levels revealed t(50%) (time required for 50% drug release) to be about 9 h while almost complete drug was released in 24 h (98.71 ± 1.33%) with highest dissolution efficiency (DE(24h)) of 58.71%. The optimization model was validated; the predicted and experimental/actual values for validation batch (M1) were in close tolerance and the standard error (SE) was also small. Drug release was also studied at pH 7.4. Scanning electron microscopy (SEM) demonstrated average coating thickness to be 32.50 ± 3.0 µm. Hence, the present study provides constructive results for colon targeting of 5-FU pellets with industrially feasible processes.


Assuntos
Antimetabólitos Antineoplásicos/química , Preparações de Ação Retardada/química , Fluoruracila/química , Antimetabólitos Antineoplásicos/administração & dosagem , Colo , Preparações de Ação Retardada/administração & dosagem , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Estabilidade de Medicamentos , Fluoruracila/administração & dosagem , Concentração de Íons de Hidrogênio , Absorção Intestinal , Microscopia Eletrônica de Varredura , Solubilidade
4.
Colloids Surf B Biointerfaces ; 88(2): 691-6, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21862296

RESUMO

Pluronic block copolymers offer affluent phase behavioral characteristics and are extensively investigated for drug delivery applications. Hydrophobic Pluronics produce larger aggregates whereas hydrophilic Pluronics often generate small-sized micelles in aqueous milieu. To overcome the limitations and combine the advantages of different kinds of Pluronics the mixing of such two types of Pluronics is studied here, especially for hydrophobic Pluronic L81 and relatively hydrophilic Pluronic P123. Critical micelle concentration (CMC) of the developed binary mixtures was 0.032 mg/ml as evidenced from pyrene fluorescence spectroscopy and is located in between that of the individual Pluronics. Dynamic light scattering (DLS) showed very small particle sizes (∼20 nm) and low polydispersity indices for most of the mixed micelles. Transmission electron microscopy (TEM) demonstrated spherical shape of micelles. Based upon the ratio of hydrophobic and hydrophilic Pluronics, dispersions of varied stability were obtained. With 0.1/1.0 wt.% and 0.5/3.0 wt.% of Pluronic L81/P123, stable dispersions were obtained. Stability was assessed from turbidity measurement, size analysis and clarity of dispersion on standing. Micelles were also found to be stable in bovine serum albumin (BSA) solution. Mixed micelles showed fairly high entrapment efficiency, loading capacity and sustained release profile for aceclofenac (Acl), a model hydrophobe. Presence of salt lowered Acl solubilization in micelles. Thermodynamic parameters for Acl solubilization in mixed micelles revealed high partition coefficient values and spontaneity of drug solubilization. Thus, the developed novel mixed micelles hold promise in controlled and targeted drug delivery owing to their very small size, high entrapment efficiency and stability.


Assuntos
Micelas , Polímeros/química , Animais , Bovinos , Diclofenaco/administração & dosagem , Diclofenaco/análogos & derivados , Diclofenaco/química , Portadores de Fármacos/química , Interações Hidrofóbicas e Hidrofílicas , Microscopia Eletrônica de Transmissão , Soroalbumina Bovina/química , Espectrometria de Fluorescência
5.
Curr Neuropharmacol ; 5(2): 99-113, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18615181

RESUMO

Parkinson's disease (PD) is characterized clinically by resting tremor, rigidity, bradykinesia and postural instability due to progressive and selective loss of dopamine neurons in the ventral substantia nigra, with the presence of ubiquitinated protein deposits called Lewy bodies in the neurons. The pathoetiology of cell death in PD is incompletely understood and evidence implicates impaired mitochondrial complex I function, altered intracellular redox state, activation of proapoptotic factors and dysfunction of ubiquitinproteasome pathway. Now it is believed that genetic aberration, an environmental toxin or combination of both leads to a cascade of events culminating in the destruction of myelinated brainstem catecholaminergic neurons. Also the role of production of significant levels of abnormal proteins, which may misfold, aggregate and interfere with intracellular processes causing cytotoxicity has recently been hypothesized. In this article, the diverse pieces of evidence that have linked the various factors responsible for the pathophysiology of PD are reviewed with special emphasis to various candidate genes and proteins. Furthermore, the present therapeutic strategies and futuristic approaches for the pharmacotherapy of PD are critically discussed.

6.
J Biol Chem ; 276(28): 25889-93, 2001 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-11342531

RESUMO

Insulin resistance contributes to a number of metabolic disorders, including type II diabetes, hypertension, and atherosclerosis. Cytokines, such as tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6, and hormones, such as growth hormone, are known to cause insulin resistance, but the mechanisms by which they inhibit the cellular response to insulin have not been elucidated. One mechanism by which these agents could cause insulin resistance is by inducing the expression of cellular proteins that inhibit insulin receptor (IR) signaling. Suppressors of cytokine signaling (SOCS) proteins are negative regulators of cytokine signaling pathways, the expression of which is regulated by certain cytokines. SOCS proteins are therefore attractive candidates as mediators of cytokine-induced insulin resistance. We have found that SOCS-1 and SOCS-6 interact with the IR when expressed in human hepatoma cells (HepG2) or in rat hepatoma cells overexpressing the human IR. In SOCS-1-expressing cells, insulin treatment increases the extent of interaction with the IR, whereas in SOCS-6-expressing cells the association with the IR appears to require insulin treatment. SOCS-1 and SOCS-6 do not inhibit insulin-dependent IR autophosphorylation, but both proteins inhibit insulin-dependent activation of ERK1/2 and protein kinase B in vivo and IR-directed phosphorylation of IRS-1 in vitro. These results suggest that SOCS proteins may be inhibitors of IR signaling and could mediate cytokine-induced insulin resistance and contribute to the pathogenesis of type II diabetes.


Assuntos
Receptor de Insulina/fisiologia , Proteínas Repressoras/fisiologia , Linhagem Celular , Humanos , Insulina/fisiologia , Resistência à Insulina , Transdução de Sinais
7.
Int J Oncol ; 13(6): 1319-22, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9824651

RESUMO

The TEL/AML1 translocation, which is specific for pre B-cell leukemias is predictive of a favorable treatment outcome. In contrast, translocations involving the ALL1 locus which are associated with both B and non B leukemias predict a poor outcome. To determine the relative distribution of high and low risk molecular subtypes of ALL in India, we analyzed the relative frequencies of these two translocations. The study included a random selection of 46 newly diagnosed patients of childhood ALL from the Tata Memorial Hospital, Bombay, India. Similar to the frequency observed in other world regions, we found an All1 rearrangement in less than 7% (3/46) of pre B-ALL patients. In contrast to the 25% frequency reported for other regions the low risk molecular subtype characterized by the TEL/AML1 translocation represented a comparatively smaller fraction (4/46) in this study. These results provide a preliminary support for a lower frequency of molecular subgroup of leukemias with a potential for favorable clinical outcome in precursor B-ALL from India.


Assuntos
Proteínas de Neoplasias/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Proteínas Proto-Oncogênicas , Proto-Oncogenes , Proteínas Repressoras , Translocação Genética , Adolescente , Criança , Pré-Escolar , Cromossomos Humanos Par 11 , Subunidade alfa 2 de Fator de Ligação ao Core , Proteínas de Ligação a DNA/genética , Frequência do Gene , Histona-Lisina N-Metiltransferase , Humanos , Índia , Proteína de Leucina Linfoide-Mieloide , Proteínas Proto-Oncogênicas c-ets , Fatores de Transcrição/genética , Variante 6 da Proteína do Fator de Translocação ETS
8.
Mol Endocrinol ; 12(9): 1322-33, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9731701

RESUMO

The c-jun protooncogene encodes a nuclear protein, cJun, which is a major component of the AP-1 transcription factor. AP-1 regulates various aspects of cell proliferation and differentiation. As an immediate early response gene, the expression of the c-jun gene is affected by various extracellular stimuli, such as serum, phorbol esters, and glucocorticoids. In mouse L929 fibroblasts, dexamethasone (DEX) treatment caused a 60% reduction of c-jun mRNA levels. Previous studies indicated that this reduction is due to the alteration of the transcription rate of the c-jun gene. To further investigate the molecular mechanisms of transcriptional repression of c-jun by DEX, a full-length human c-jun promoter, from -1780 to +731, was amplified from genomic DNA using PCR and then linked to the luciferase reporter gene. To identify the regulatory elements responsible for the down-regulation, nested deletions spanning the promoter were generated, and the promoter/luciferase constructs were transiently transfected into L929 cells. Upon hormone treatment, basal activity of the full-length c-jun promoter was reduced by approximately 40%, which accounts for two-thirds of the overall down-regulation observed at the mRNA level. This reduction of c-jun promoter activity was abolished after deletion of the region between -1780 to -63, where two AP-1 sites (-182 and -64) are located. Site-directed deletion of these AP-1 sites reduced the basal activity of the c-jun promoter and prevented repression by DEX. Repression of the c-jun gene is due to the transrepression activity of the glucocorticoid receptor (GR), as determined using GR mutants lacking this activity. Overexpression of cJun overcame the negative effect of DEX, suggesting that down-regulation of the c-jun gene by hormone is mediated by the interaction between the GR and the cJun protein. These studies are the first to show that glucocorticoids can repress c-jun promoter activity through the AP-1 sites in the c-jun promoter in mouse fibroblast cells. They also suggest that inhibition of cell proliferation by glucocorticoids may be due not only to the interference with AP-1 activity on other cellular genes, but also because of a direct transcriptional suppression of c-jun gene expression by the GR.


Assuntos
Regulação da Expressão Gênica , Genes jun/genética , Regiões Promotoras Genéticas , Receptores de Glucocorticoides/genética , Proteínas Repressoras/metabolismo , Fator de Transcrição AP-1/metabolismo , Animais , Sítios de Ligação/genética , Células Cultivadas , Dexametasona/farmacologia , Regulação para Baixo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Mutagênese Sítio-Dirigida , RNA Mensageiro/metabolismo , Deleção de Sequência
9.
Mol Carcinog ; 22(1): 9-15, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9609096

RESUMO

Elongation factor-1 (EF-1) gamma is overexpressed in a high proportion of gastrointestinal cancers. The mechanism of overexpression has not been determined. The purpose of this study was to examine cDNA specimens from pancreatic and colorectal cancer for mutation in this gene, which would allow us to determine whether gene mutations are responsible for overexpression of EF-1gamma. In one colorectal carcinoma, we detected an A-->G transition at amino-acid codon 158 (T-->C in the sense strand) resulting in a change from a leucine to a serine. The base change was not detected in cDNA isolated from normal-appearing tissue from the same patient. We did not find mutations in another five colorectal carcinoma and five pancreatic cancer samples. Thus, although we detected a mutation in one tumor, the frequency of mutations was too low to account for the high frequency of overexpression of the EF-1gamma RNA in colorectal cancer. We also investigated other possible mechanisms of overexpression of the EF-1gamma RNA in this study. Slot-blot analysis of DNA isolated from colorectal cancers showed that the overexpression was not due to gene amplification. Using serum starvation to synchronize cultured cells, we showed that the overexpression was also not due to an increase in the number of cycling cells, as occurs in cancer. Using Southern blot analysis, we were unable to detect genome rearrangements that could have been responsible for the overexpression. In conclusion, the mechanism for overexpression of the EF-1gamma gene in colorectal and pancreatic cancer remains unknown. However, mutations in the coding sequence of the gene, gene amplification, and gene rearrangement do not account for the high frequency of overexpression of this gene, and the overexpression is not due to an increase in the number of cycling cells.


Assuntos
Adenocarcinoma/genética , Neoplasias Colorretais/genética , Neoplasias Gastrointestinais/genética , Neoplasias Pancreáticas/genética , Fatores de Alongamento de Peptídeos/genética , Mutação Puntual , Células 3T3 , Adenocarcinoma/patologia , Animais , Sequência de Bases , Ciclo Celular , Clonagem Molecular , Neoplasias Colorretais/patologia , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Camundongos , Proteínas de Neoplasias/genética , Neoplasias Pancreáticas/patologia , Fator 1 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/biossíntese , RNA Mensageiro/biossíntese , Transcrição Gênica , Células Tumorais Cultivadas
10.
Cancer ; 82(5): 816-21, 1998 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-9486568

RESUMO

BACKGROUND: Elongation factor-1 (EF-1) is a cellular protein that plays a role in protein synthesis by mediating the transfer of aminoacyl-tRNA to 80S ribosomes. It is comprised of four subunits: alpha, beta, gamma, and delta. EF-1gamma is a substrate for the maturation-promoting factor, which determines entry into the M-phase of the cell cycle in all eukaryotic cells. Previously, the authors showed that EF-1gamma RNA is overexpressed in a high proportion of colorectal carcinomas. At that time, there were no antibodies to EF-1gamma, so the EF-1gamma protein could not be examined. Because levels of RNA do not always parallel the levels of the protein it encodes, it was important to develop antibodies to EF-1gamma to examine its expression at the protein level in colorectal carcinoma. METHODS: Twenty-nine patients undergoing surgical resection for colorectal adenocarcinoma were studied. A polyclonal antibody to EF- 1gamma in rabbit was prepared. Tumors and normal-appearing mucosa distant from the tumor (> or = 10 cm) were obtained from each patient. Cytosolic proteins were extracted from the tissues and examined by Western blot analysis with the EF-1gamma antibody. Colonic tumors also were studied by immunohistochemical analysis with another EF-1gamma polyclonal antibody. RESULTS: Using Western blot analysis, the authors observed greater expression of EF-1gamma in the tumors than in the more distal normal-appearing mucosa. Overexpression was not observed in the patients with the two Dukes Stage A tumors, but was observed in four of ten patients with Dukes Stage B tumors, seven of eight patients with Dukes Stage C tumors, and six of nine patients with Dukes Stage D tumors. Overall, 17 of 29 patients (59%) were found to have overexpression of EF-1gamma. Using immunohistochemical analysis, EF-1gamma protein was shown to be located predominantly in tumor epithelium rather than the stroma or infiltrating mononuclear cells. CONCLUSIONS: Previous studies showed that EF-1gamma mRNA frequently is overexpressed in colorectal adenocarcinoma. This study showed that EF-1gamma also was overexpressed at the protein level in colorectal adenocarcinoma relative to more distal normal-appearing mucosa from the same patient. Immunohistochemical analysis demonstrated that this protein was expressed predominantly in the tumor epithelial cells and therefore was not derived from cells involved in the desmoplastic response.


Assuntos
Adenocarcinoma/genética , Neoplasias do Colo/genética , Fatores de Alongamento de Peptídeos/biossíntese , Neoplasias Retais/genética , Adenocarcinoma/patologia , Adulto , Idoso , Animais , Western Blotting , Neoplasias do Colo/patologia , Feminino , Expressão Gênica , Humanos , Mucosa Intestinal , Masculino , Pessoa de Meia-Idade , Fator 1 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/genética , RNA Mensageiro/metabolismo , Coelhos , Neoplasias Retais/patologia
11.
Am J Respir Cell Mol Biol ; 14(6): 556-68, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8652184

RESUMO

Using hyperoxia as a model of oxidant-induced lung injury in the rat, we explored the regulation of heme oxygenase-1 (HO-1) expression in vivo and in vitro. We demonstrate marked increase of HO-1 messenger ribonucleic acid (mRNA) levels in rat lungs after hyperoxia. Increased HO-1 mRNA expression correlated with increased HO-1 protein and enzyme activity. Immunohistochemical studies of the rat lung after hyperoxia showed increased HO-1 expression in a variety of cell types, including the bronchoalveolar epithelium and interstitial and inflammatory cells. We then examined the regulation of HO-1 expression in vitro after hyperoxia and observed increased HO-1 gene expression in various cultured cells including epithelial cells, fibroblasts, macrophages, and smooth muscle cells. Increased HO-1 mRNA expression correlated with increased HO-1 protein in vitro, and resulted from increased gene transcription and not from increased mRNA stability. We show that transcriptional activation of the HO-1 gene by hyperoxia requires cooperation between the HO-1 promoter and an enhancer fragment located 4 kb upstream from its transcription site. Increased HO-1 gene transcription was associated with increased activator protein-1 (AP-1) binding activity and supershift of the AP-1 complex by antibodies to c-Fos and c-Jun after hyperoxia. Taken together, our data suggest that AP-1 activation may represent one mechanism mediating hyperoxia-induced HO-1 gene transcription.


Assuntos
Heme Oxigenase (Desciclizante)/genética , Hiperóxia/fisiopatologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Células Cultivadas/química , Células Cultivadas/fisiologia , Relação Dose-Resposta a Droga , Células Epiteliais , Epitélio/química , Epitélio/fisiologia , Fibroblastos/química , Fibroblastos/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Heme Oxigenase (Desciclizante)/metabolismo , Humanos , Imuno-Histoquímica , Cinética , Pneumopatias/induzido quimicamente , Macrófagos Alveolares/química , Macrófagos Alveolares/fisiologia , Macrófagos Peritoneais/química , Macrófagos Peritoneais/fisiologia , Camundongos , Dados de Sequência Molecular , Oxigênio/efeitos adversos , Ligação Proteica/fisiologia , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Organismos Livres de Patógenos Específicos , Fator de Transcrição AP-1/metabolismo , Transcrição Gênica/fisiologia
12.
Biochem Biophys Res Commun ; 221(3): 570-6, 1996 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-8630002

RESUMO

Jun and Fos (AP-1) transcription factors were recently proposed to mediate induction of the mouse heme oxygenase-1 gene by different agents including heme and cadmium. In this report we show that the AP-1 binding sequence, TGAGTCA, is necessary but insufficient for gene activation in response to heme or cadmium. The minimal heme response element was identified as an extended AP-1 binding site, (T/C)GCTGAGTCA. In addition to the AP-1 heptad, this element also contains an interdigitated antioxidant response element, GCnnnGTCA. Specific antioxidant response elements from the NAD(P)H:quinone oxidoreductase-1 and the glutathione S-transferase Ya subunit genes were in fact responsive to heme but not all sequences that conform to the consensus antioxidant response element were activated by this agent. The heme response element resembles the consensus binding sites for the product of the maf oncogene and for the transcription factor NF-E2. The potential role of these and related transcription factors and the implication of the composite heme response element in heme oxygenase-1 gene regulation are discussed.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Heme Oxigenase (Desciclizante)/genética , Proteínas Oncogênicas Virais/metabolismo , Fator de Transcrição AP-1/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Virais , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular , Cloranfenicol O-Acetiltransferase/genética , Proteínas de Ligação a DNA/genética , Elementos Facilitadores Genéticos , Fatores de Ligação de DNA Eritroide Específicos , Camundongos , Dados de Sequência Molecular , Fator de Transcrição NF-E2 , Subunidade p45 do Fator de Transcrição NF-E2 , Proteína Oncogênica v-maf , Proteínas Oncogênicas Virais/genética , Homologia de Sequência do Ácido Nucleico , Fatores de Transcrição/genética
14.
Inflamm Bowel Dis ; 1(4): 280-3, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-23282427

RESUMO

SUMMARY: A patient with Crohn's disease who developed mucinous adenocarcinoma in chronic fistulae is reported. Malignancy may complicate chronic nonhealing Crohn's sinus tracts and fistulae, even with no mucosal involvement by carcinoma. Persistent non-remitting perianal induration and pain should alert the physician to the possibility of underlying malignancy. Prompt examination under anesthesia and biopsy or fine-needle aspiration may facilitate diagnosis and therapy of the carcinoma at an early stage.

15.
Mol Carcinog ; 7(1): 18-20, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8382068

RESUMO

While it is apparent that colorectal carcinogenesis results from a series of genetic alterations manifested phenotypically by the adenoma-to-carcinoma sequence, the early events that occur in the process of tumorigenesis have not been elucidated. We previously demonstrated that human elongation factor-1 (EF-1) gamma-hybridizing RNA was overexpressed in 25 of 29 colorectal carcinomas. To determine if the overexpression of this mRNA occurs early in tumor development, we examined 25 adenomas and corresponding normal-appearing distant mucosae from 20 patients without familial adenomatous polyposis (FAP). We observed overexpression at a level of twofold or more in 14 (56%) of the 25 adenomas, indicating that overexpression of EF-1 gamma RNA is often a relatively early event in the development of non-FAP colorectal cancer.


Assuntos
Adenoma/genética , Neoplasias Colorretais/genética , Expressão Gênica/genética , Fatores de Alongamento de Peptídeos/genética , RNA Mensageiro/genética , Polipose Adenomatosa do Colo/genética , Idoso , Idoso de 80 Anos ou mais , Northern Blotting , DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hibridização de Ácido Nucleico , Biossíntese de Proteínas/genética
16.
Plant Mol Biol ; 20(1): 123-31, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1515601

RESUMO

We have compared the fate of U.G mispairs or analogous T.G mispairs in DNA heteroduplexes transfected into tobacco protoplasts. The heteroduplex DNA consisted of tomato golden mosaic virus DNA sequences in the Escherichia coli vectors pUC118 or pUC119. After transfection, the mismatched U residues were lost with an efficiency of greater than 95%, probably as a result of the uracil-DNA glycosylase pathway for excision of U residues in any sequence context. In contrast to the preferential removal of the mispaired U residues, biased removal of T residues from analogous heteroduplexes was not seen in the transfected plant cells. Also, we investigated the effect of extensively methylating one strand of the heteroduplex DNA used for transfection. Surprisingly, such methylation resulted in highly biased loss of the mismatched base from the 5-methylcytosine-rich strand of T.G-containing heteroduplexes.


Assuntos
DNA Viral/genética , Guanina , Vírus do Mosaico/genética , Nicotiana/genética , Ácidos Nucleicos Heteroduplexes/genética , Plantas Tóxicas , Timina , Uracila , Composição de Bases , Sequência de Bases , DNA Viral/isolamento & purificação , Escherichia coli/genética , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos , Plasmídeos , Protoplastos/fisiologia , Mapeamento por Restrição , Moldes Genéticos , Transfecção
17.
Indian J Cancer ; 29(2): 82-5, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1473838

RESUMO

A 37 year old man with symptomatic multiple myeloma diagnosed in April 1968 presented with generalised bony pains, extensive skeletal osteolytic lesions, monoclonal gammopathy and 90 percent atypical plasma cells in the marrow. He was given cyclophosphamide for six months with minimal response and then initiated on melphalan for one year. He was asymptomatic for 15 years thereafter and presented again in 1985 with a relapse of the disease. Over the next four years he was given various combinations of chemotherapy including cyclophosphamide, vincristine, melphalan and carmustine. He responded well on two more occasions only to relapse again. Recently, he has developed a symptomatic relapse with 36 percent plasma cells. This case report highlights the fact that there is a subset of patients with myeloma who survive beyond ten years, but remain symptomatic and respond slowly to chemotherapy.


Assuntos
Mieloma Múltiplo , Adulto , Humanos , Masculino , Mieloma Múltiplo/tratamento farmacológico , Prognóstico
18.
Plant Mol Biol ; 18(4): 703-12, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1558945

RESUMO

The effects of methylation on plant viral DNA replication have been studied in Nicotiana tabacum protoplasts transfected with DNA of the geminivirus tomato golden mosaic virus (TGMV). The transfected cells were also used to determine whether experimentally introduced methylation patterns are maintained in extrachromosomal viral DNA. Replacement of cytosine residues with 5-methylcytosine (m5C) reduced the amount of viral DNA which accumulated in transfected protoplasts. The reduction was observed whether m5C residues were substituted for cytosine residues in vitro in either the viral strand or the complementary strand of double-stranded circular inoculum DNAs containing tandemly repeated copies of the A component of the TGMV genome. Both limited and extensive cytosine methylation of TGMV DNA sequences in vitro was not propagated in progeny viral DNA. The absence of detectable maintenance-type methylation of the transfecting TGMV DNA sequences may be related to the lack of methylation observed in double-stranded TGMV DNA isolated from infected plants.


Assuntos
Replicação do DNA , DNA Viral/metabolismo , Vírus do Mosaico/genética , Protoplastos/microbiologia , Transfecção , Southern Blotting , DNA Recombinante , DNA Viral/biossíntese , Cinética , Metilação , Mapeamento por Restrição
19.
Plant Mol Biol ; 17(1): 111-23, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1831056

RESUMO

To elucidate how methylation of specific sites in plant DNA might control transcription, we examined the effect of DNA methylation at CpG sequences on the binding of plant nuclear factors to an oligonucleotide duplex containing the consensus sequence for mammalian CREB (cAMP response element binding protein). CREB is part of the ATF (activating transcription factor) family of mammalian proteins specifically binding to 5'-TGACGTCA-3' and related sequences. Proteins recognizing the CREB-specific ligand were identified in nuclear extracts of pea seeds, wheat germ, cauliflower, and soybean leaves using electrophoretic mobility shift assays. Cytosine methylation inhibited binding of this protein in all these extracts, and so this sequence-specific DNA-binding activity is referred to as methylation-inhibited binding protein 1 (MIB-1). Sites somewhat similar to that of the CREB ligand are found in the upstream regions of a wheat histone H3 gene and tomato and pea ribulose 1,5-bisphosphate carboxylase genes. These sites were bound preferentially by distinct proteins that may be related to the previously described plant proteins HBP-1, HSBF, ASF-1, or GBF. Methylation of cytosine residues at these sites and at a site for MIB-1 located upstream of a soybean proline-rich protein gene also reduced specific binding with all the nuclear extracts tested. Similarly, substitution of the central CpG dinucleotide with TpG decreased binding.


Assuntos
Proteínas de Ligação a DNA/metabolismo , DNA/metabolismo , Fosfatos de Dinucleosídeos/metabolismo , Proteínas de Plantas/metabolismo , Plantas/genética , Sequência de Bases , Sítios de Ligação , Brassica/genética , Sequência Consenso , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico , Eletroforese em Gel de Poliacrilamida , Fabaceae/genética , Histonas/genética , Metilação , Dados de Sequência Molecular , Oligonucleotídeos/síntese química , Oligonucleotídeos/metabolismo , Plantas/metabolismo , Plantas Medicinais , Regiões Promotoras Genéticas , Glycine max/genética , Triticum/genética
20.
Virology ; 182(2): 865-9, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1850934

RESUMO

MDBP, a mammalian sequence-specific DNA-binding protein, was found to recognize two sites in the major immediate-early (IE) enhancer of human cytomegalovirus. The recognition sequence for MDBP at each of these sites was localized to 14 bp by studying the effects of limited G methylation, depurination, depyrimidination, or deoxyribose modification on the ability of these sites to bind to MDBP. In addition to the two high-affinity MDBP sites in the enhancer, one low-affinity MDBP site was detected 5 bp after the transcription initiating residue of this IE transcription unit. The possible biological significance of the two enhancer MDBP sites and the downstream MDBP site is discussed.


Assuntos
Citomegalovirus/metabolismo , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos , Regulação Viral da Expressão Gênica , Regiões Promotoras Genéticas , Sequência de Bases , Sítios de Ligação , DNA Viral/genética , DNA Viral/metabolismo , Humanos , Técnicas In Vitro , Metilação , Dados de Sequência Molecular , Sequências Reguladoras de Ácido Nucleico , Relação Estrutura-Atividade , Fatores de Transcrição
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