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1.
Haemophilia ; 23(1): 135-143, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27486060

RESUMO

INTRODUCTION AND OBJECTIVES: Intra-articular corticosteroid injections are standard of care for managing joint pain secondary to osteoarthritis or rheumatoid arthritis but are rarely used in haemophilic arthropathy. We have introduced and evaluated the efficacy and safety of ultrasound-guided corticosteroid injections for pain relief in patients with haemophilic arthropathy. PATIENTS AND METHODS: Ultrasound-guided intra-articular injections performed on haemophilia patients at UCSD between March 2012 and January 2016 were analysed. Needle placement and injection (40 mg triamcinolone; 3-5 mL lidocaine) were performed with musculoskeletal ultrasound and Power Doppler. Analysis included patient demographics, joint-specific parameters such as tissue hypervascularity and effusions, pain relief, and procedure-associated complications. RESULTS: Forty-five injections (14 ankles, 13 elbows, 18 knees) were administered in 25 patients. Advanced arthropathy with hypervascularity and/or effusions was present in 91% and 61% of joints, respectively. Ninety-one per cent of injections resulted in pain relief which was significant in 84% (>30% reduction). Median pain score was reduced from 7 of 10 to 1 of 10 (P < 0.001), usually within 24 h. Median duration of pain relief was 8 weeks (range 1-16 weeks). Haemophilia B patients experienced longer periods of relief, and high Pettersson scores were associated with shorter duration of relief. There were no procedure-associated complications. Repeat ultrasound of eight joints within 4 weeks of injection demonstrated nearly complete resolution of hypervascularity. CONCLUSIONS: Point-of-care ultrasound enabled intra-articular corticosteroid injections that provided highly effective, safe, and relatively long-lasting pain relief in haemophilic arthropathy. This approach should be used to improve pain management in haemophilic arthropathy.


Assuntos
Corticosteroides/uso terapêutico , Hemofilia A/diagnóstico por imagem , Artropatias/tratamento farmacológico , Ultrassonografia/métodos , Corticosteroides/administração & dosagem , Adulto , Feminino , Humanos , Injeções Intra-Articulares , Masculino , Pessoa de Meia-Idade , Sistemas Automatizados de Assistência Junto ao Leito , Resultado do Tratamento
2.
J Clin Pharm Ther ; 39(5): 468-70, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24912052

RESUMO

WHAT IS KNOWN AND OBJECTIVE: To date, there is no evidence to indicate the reliability of how patients self-report their own antibiotic usage in the community. Such data are fundamental in supporting antimicrobial stewardship practices, and so there is a need to determine its accuracy and reliability. COMMENT: Patients in the community (n = 476) were required to recollect their antibiotic usage in the past three months. Simultaneously, similar information was obtained by careful extraction from their respective medical notes, which was qualitatively compared with the patient's recollection. Overall, concordance was high (88·1%), but age (<20 and >80 years) and sex (female) were significant factors of reliability. WHAT IS NEW AND CONCLUSION: This study suggests that basic self-reporting of antibiotic usage amongst patients is relatively reliable, with increasing accuracy with years until 80 years. Where such information is critical, the current study can help decide who to interview and whose notes to interrogate, in the quest to obtain reliable and accurate information.


Assuntos
Antibacterianos/uso terapêutico , Padrões de Prática Médica/estatística & dados numéricos , Autorrelato , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/efeitos adversos , Antibacterianos/provisão & distribuição , Criança , Pré-Escolar , Serviços de Saúde Comunitária , Farmacorresistência Bacteriana , Feminino , Necessidades e Demandas de Serviços de Saúde , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Irlanda do Norte , Reprodutibilidade dos Testes
3.
Proc Nutr Soc ; 82(2): 186-199, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36785878

RESUMO

A high intake of fruit and vegetables (FV) has consistently been associated with a reduced risk of a number of non-communicable diseases. This evidence base is largely from prospective cohort studies, with meta-analyses demonstrating an association between increased FV intake and reduced risk of both CHD and stroke, although the evidence is less certain for cancer and diabetes. Controlled intervention trials examining either clinical or intermediate risk factor endpoints are more scarce. Therefore, evidence that FV consumption reduces the risk of disease is so far largely confined to observational epidemiology, which is hampered by some methodological uncertainties. Although increased FV intake is promoted across all dietary guidelines, national surveys confirm that dietary intakes are suboptimal and are not increasing over time. A range of barriers to increasing FV intake exist, including economic, physical and behavioural barriers that must be considered when exploring potential opportunities to change this, considering the feasibility of different approaches to encourage increased FV consumption. Such interventions must include consideration of context, for example, challenges and uncertainties which exist with the whole food system.


Assuntos
Doenças não Transmissíveis , Verduras , Humanos , Frutas , Comportamento Alimentar , Doenças não Transmissíveis/prevenção & controle , Estudos Prospectivos
4.
Gene Ther ; 17(6): 709-12, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20428213

RESUMO

Multiple sclerosis is an autoimmune disease of the central nervous system believed to be mediated by pathogenic T lymphocytes. We have developed a next-generation therapy in which cells secrete specific therapeutic molecules to silence these aberrant T cells. We have shown that fibroblasts, transduced to secrete a myelin basic protein-derived peptide, abrogate disease in the murine experimental autoimmune encephalomyelitis model of multiple sclerosis, which we hypothesized using a low-zone tolerance mechanism. To determine the efficacy (or not) of this therapy in humans, we must ensure that patients receive comparable doses of therapeutic peptide. To this end, we have used liquid chromatography coupled to tandem mass spectrometry to detect a tryptic peptide, derived from the secreted therapeutic product, at nanomolar concentrations. Success depended on growing the transduced fibroblasts in defined PC-1 medium in the presence of a cocktail of protease inhibitors.


Assuntos
Esclerose Múltipla/terapia , Fragmentos de Peptídeos/isolamento & purificação , Espectrometria de Massas em Tandem , Animais , Cromatografia Líquida , Encefalomielite Autoimune Experimental/terapia , Estudos de Viabilidade , Camundongos , Proteína Básica da Mielina/metabolismo , Transdução Genética
5.
Science ; 161(3848): 1358-9, 1968 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-17831348

RESUMO

Ancient mosaic patterns tend to be certain absolute sizes (mosaic units). There is evidence that the mosaicists had these lengths marked on rulers. A ruler such as one which an ancient mosaicist might have used has been reconstructed. It is possible that an original may still exist.

6.
Science ; 210(4474): 1137-9, 1980 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-6255561

RESUMO

An endogenous polysomal cyclic AMP-dependent protein kinase specifically phosphorylates a 150,000-dalton peptide bound to an adrenocortical polyadenylated messenger ribonucleoprotein complex. There is a possibility that this protein is a physiological substrate of cyclic AMP-dependent protein kinase and that the phosphorylation and dephosphorylation of this substrate may be important in the translation control of adrenal polyadenylated messenger RNA.


Assuntos
Córtex Suprarrenal/metabolismo , Nucleoproteínas/metabolismo , Proteínas Quinases/metabolismo , RNA Mensageiro/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Bovinos , AMP Cíclico/metabolismo , Peso Molecular , Fosforilação , Polirribossomos/metabolismo
7.
Science ; 172(3982): 495-8, 1971 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-4396320

RESUMO

Palytoxin has been isolated from the zoanthids "limu-make-o-Hana" (Tentatively identified as Palythoa sp.) as a noncrystalline, chromatographically pure entity. Apart from polypeptide and protein toxins, it is the most highly toxic substance known, with a lethal dose (LD(59)) in mice of 0.15 microgram per kilogram by intravenous injection. Unlike the potent toxins batrachotoxin, saxitoxin, and tetrodotoxin which have molecular weights of 500 or less, palytoxin has an estimated molecular weight of 3300 and contains no repetitive amino acid or sugar units.


Assuntos
Cnidários/análise , Toxinas Biológicas/análise , Toxinas Biológicas/isolamento & purificação , Animais , Cromatografia em Gel , Cromatografia em Camada Fina , Havaí , Espectroscopia de Ressonância Magnética , Biologia Marinha , Camundongos , Peso Molecular , Análise Espectral , Toxinas Biológicas/toxicidade , Raios Ultravioleta
8.
Science ; 204(4389): 193-5, 1979 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-107586

RESUMO

A highly inflammatory and vesicatory substance, lyngbyatoxin A, has been isolated from the lipid extract of a Hawaiian shallow-water variety of Lyngbya majuscula Gomont; its gross structure was determined from chemical and spectral data. Lyngbyatoxin A is closely related to teleocidin B, a poisonous substance associated with several strains of Streptomyces.


Assuntos
Alcaloides/toxicidade , Cianobactérias , Dermatite de Contato/etiologia , Dermotoxinas , Toxinas Marinhas , Animais , Indóis/toxicidade , Camundongos
9.
Science ; 202(4372): 1045-50, 1978 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-17777943

RESUMO

Radiation doses from airborne effluents of model coal-fired and nuclear power plants (1000 megawatts electric) are compared. Assuming a 1 percent ash release to the atmosphere (Environmental Protection Agency regulation) and 1 part per million of uranium and 2 parts per million of thorium in the coal (approximately the U.S. average), population doses from the coal plant are typically higher than those from pressurized-water or boiling-water reactors that meet government regulations. Higher radionuclide contents and ash releases are common and would result in increased doses from the coal plant. The study does not assess the impact of non-radiological pollutants or the total radiological impacts of a coal versus a nuclear economy.

10.
Science ; 196(4289): 538-40, 1977 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-403608

RESUMO

Chloroform extracts of several seaweeds, of the family Oscillatoriaceae, from Enewetak Atoll, Marshall Islands, display activity against P-388 lymphocytic mouse leukemia. A P-388 active compound, debromoaplysiatoxin, has been isolated from Lyngbya gracilis and characterized. This compound also has dermonecrotic activity and may be the dermatitis-producing substance in L. majuscula, the causative agent of "swimmers' itch" outbreaks in Hawaiian waters.


Assuntos
Antineoplásicos/uso terapêutico , Cianobactérias , Leucemia Experimental/tratamento farmacológico , Leucemia Linfoide/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Toxinas Biológicas/uso terapêutico , Animais , Cianobactérias/análise , Dermatite de Contato/etiologia , Camundongos , Toxinas Biológicas/isolamento & purificação
11.
Cancer Res ; 45(5): 2863-8, 1985 May.
Artigo em Inglês | MEDLINE | ID: mdl-2985250

RESUMO

Human hepatoma cells, HuH-6 Cl-5, were treated with 12-O-tetradecanoylphorbol-13-acetate at concentrations of 1 ng/ml to 10 micrograms/ml for 6 h in the presence of [35S]methionine. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the labeled proteins secreted into the medium showed that this treatment induced marked secretion of a polypeptide with a molecular weight of about 46,000 (p46). When the labeled proteins were analyzed by two-dimensional polyacrylamide gel electrophoresis, p46 was composed of three isoproteins which had different isoelectric points. The two new classes of tumor promoters, teleocidin and aplysiatoxin, also induced secretion of this protein, although the amount of p46 induced by debromoaplysiatoxin was less than that induced by 12-O-tetradecanoylphorbol-13-acetate, teleocidin, and aplysiatoxin, judging from densitometric scanning of bands on a fluorogram. The nonpromoting phorbol esters, such as 4 beta-phorbol and phorbol-13-monoacetate, did not induce p46. The induction of p46 secretion involved de novo RNA synthesis, since actinomycin D (1 microgram/ml) completely and selectively blocked the incorporation of [35S]-methionine into the protein. "Pulse-chase" experiments indicated that p46 was not a degradation product induced by these potent tumor promoters. In an attempt to identify p46, the total proteins released were treated with two kinds of rabbit anti-human whole serum antisera, but although some proteins were precipitated, p46 was not.


Assuntos
Carcinógenos , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas de Neoplasias/metabolismo , Células Cultivadas , Dactinomicina/farmacologia , Humanos , Peso Molecular , Proteínas de Neoplasias/biossíntese , Acetato de Tetradecanoilforbol , Transcrição Gênica/efeitos dos fármacos
12.
Cancer Res ; 53(6): 1343-7, 1993 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-8095179

RESUMO

Cells demonstrating the multidrug resistance phenotype because of overexpression of P-glycoprotein, a drug efflux pump, are resistant to the cytotoxic effects of most natural product drugs. To determine if P-glycoprotein confers resistance to the syctophycins, a family of natural cytotoxic macrolides recently isolated from cyanobacteria of the family Syctone-mataceae, we have characterized the effects of these compounds on drug-sensitive (SKOV3) and drug-resistant (SKVLB1) human ovarian carcinoma cells. While SKVLB1 cells demonstrated > 150- and 10,000-fold decreases in sensitivity to Adriamycin and vinblastine, respectively, they were equally sensitive as SKOV3 cells to the antiproliferative effects of tolytoxin and certain related scytophycins. The SKVKB1 cells were 4- to 11-fold resistant to other scytophycins and were 14-fold resistant to cytochalasin B. Microfilaments in SKOV3 and SKVLB1 cells were depolymerized by similar concentrations of tolytoxin, while cytochalasin B was less potent toward SKVLB1 cells than SKOV3 cells. Both tolytoxin and cytochalasin B enhanced the cytotoxicity of vinblastine toward SKVLB1 cells; however, neither compound affected the sensitivity to Adriamycin or cisplatin. Verapamil markedly increased the accumulation of [3H]vinblastine by SKLVB1 cells, while cytochalasin B caused only modest increase, and tolytoxin had no effect on [3H]vinblastine accumulation. These results suggest that some of the scytophycins, including tolytoxin, are not subject to P-glycoprotein-mediated efflux from cells exhibiting multidrug resistance due to overexpression of this transport protein. These compounds may therefore be useful for killing drug-resistant tumor cells.


Assuntos
Citoesqueleto de Actina/efeitos dos fármacos , Antineoplásicos/farmacologia , Cianobactérias/química , Resistência a Medicamentos , Glicoproteínas de Membrana/fisiologia , Piranos/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP , Actinas/análise , Citocalasina B/farmacologia , Feminino , Humanos , Neoplasias Ovarianas/patologia , Células Tumorais Cultivadas/efeitos dos fármacos , Vimblastina/metabolismo , Vimblastina/farmacologia
13.
Cancer Res ; 54(14): 3779-84, 1994 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-7913408

RESUMO

Cryptophycin is a cytotoxic dioxadiazacyclohexadecenetetrone isolated from cyanobacteria of the genus Nostoc. Incubation of L1210 leukemia cells with cryptophycin resulted in dose-dependent inhibition of cell proliferation in parallel with increases in the percentage of cells in mitosis (half-maximal effects at < 10 pM). Indirect immunofluorescence studies demonstrated that treatment of A-10 vascular smooth muscle cells with cryptophycin results in marked depletion of cellular microtubules and reorganization of vimentin intermediate filaments, similar to the effects of vinblastine. Cytochalasin B caused the depolymerization of microfilaments in these cells, while neither vinblastine nor cryptophycin affected this cytoskeletal component. Pretreatment of cells with taxol prevented microtubule depolymerization in response to either vinblastine or cryptophycin. While microtubule depolymerization in response to vinblastine was rapidly reversed by removal of the drug, cells treated with cryptophycin remained microtubule depleted for at least 24 h after removal of the compound. Combinational treatments with vinblastine and cryptophycin resulted in additive cytotoxicity. Ovarian carcinoma and breast carcinoma cells which are multiply drug resistant due to overexpression of P-glycoprotein are markedly less resistant to cryptophycin than they are to vinblastine, colchicine, and taxol. Therefore, cryptophycin is a new antimicrotubule compound which appears to be a poorer substrate for P-glycoprotein than are the Vinca alkaloids. This property may confer an advantage to cryptophycin in the chemotherapy of drug-resistant tumors.


Assuntos
Antineoplásicos/farmacologia , Resistência a Medicamentos , Microtúbulos/efeitos dos fármacos , Peptídeos Cíclicos/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Citocalasina B/farmacologia , Depsipeptídeos , Humanos , Camundongos , Índice Mitótico , Paclitaxel/farmacologia , Células Tumorais Cultivadas , Vimblastina/farmacologia
14.
Cancer Res ; 43(4): 1529-35, 1983 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-6299522

RESUMO

We have compared the activities of aplysiatoxin and debromoaplysiatoxin, two polyacetate marine algae toxins, with teleocidin, a tumor-promoting indole alkaloid from Streptomyces, with respect to inhibition of specific binding of epidermal growth factor, and phorbol-12,13-dibutyrate to their respective receptors and ability to stimulate the release of radioactivity from cells prelabeled with choline or arachidonic acid. Although these compounds have chemical structures that are quite different from the phorbol esters, both aplysiatoxin and teleocidin are essentially equipotent with the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate in all four assays. The fact that aplysiatoxin and teleocidin inhibit phorbol-12,13-dibutyrate-receptor binding suggests that their biological activities are mediated by binding to the same receptors utilized by the phorbol esters. Debromoaplysiatoxin, a debrominated form of aplysiatoxin, is about 10-fold weaker than aplysiatoxin in inhibiting epidermal growth factor and phorbol-12,13-dibutyrate-receptor binding, but is equipotent with aplysiatoxin in stimulating the release of lipid metabolites from the prelabeled cells. The results are discussed in terms of possible heterogeneity of cellular receptors for this group of compounds.


Assuntos
Alcaloides/farmacologia , Proteínas de Caenorhabditis elegans , Carcinógenos/farmacologia , Fator de Crescimento Epidérmico/metabolismo , Lactonas/farmacologia , Toxinas de Lyngbya , Toxinas Marinhas/farmacologia , Venenos de Moluscos/farmacologia , Forbóis/metabolismo , Fosfolipídeos/metabolismo , Proteína Quinase C , Receptores de Superfície Celular/metabolismo , Receptores de Droga , Acetato de Tetradecanoilforbol/metabolismo , Animais , Proteínas de Transporte , Linhagem Celular , Receptores ErbB , Cinética , Camundongos , Ratos
15.
Endocrinology ; 107(4): 1264-5, 1980 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7408774

RESUMO

Free and membrane-bound polysomes were isolated and incubated under in vitro conditions that allowed the phosphorylation of contained poly(A)mRNP complexes. The three phosphoproteins of 150,000, 67,000 and 45,000 daltons were consistently present in the free poly(A)mRNP fraction and absent in the membrane-bound particles. The major phosphoprotein contained in the membrane-bound poly(A)mRNP complexes was 105,000 daltons. This protein was also present in the free cytoplasmic poly(A)mRNP fraction. It is conceivable that protein kinases differentially regulate these two classes of poly(A)mRNP particles through specific phosphorylations of their associated proteins.


Assuntos
Córtex Suprarrenal/metabolismo , Nucleoproteínas/metabolismo , Poli A/metabolismo , Polirribossomos/metabolismo , RNA Ribossômico/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Bovinos , Membrana Celular/metabolismo , Peso Molecular , Fosforilação
16.
Am J Clin Nutr ; 43(3): 406-13, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3082177

RESUMO

We have studied 15 infants with severe protein energy malnutrition (PEM) as a model of nutritional nonthyroidal illness. Changes in circulating thyroid hormones, binding proteins, and their interrelationships were assessed before and during recovery. Serum concentrations of total thyroxine and triiodothyronine and of thyroxine-binding proteins were extremely reduced, and increased progressively during 3 wk of refeeding. The T4:TBG molar ratio was initially 0.180 +/- 0.020, and increased progressively, parallel to the increases in TT4, to 0.344 +/- 0.038 after 21 days (p less than 0.025). The changes in free T4 estimates varied according to the methods used--FTI and analogue FT4 increased, dialysis FT4 fraction decreased. Serum TSH levels increased transiently during recovery. It is concluded 1) there is reduced binding of T4 and T3 to TBG in untreated PEM which takes 2-3 wk to recover; 2) there are methodological differences in evaluating free T4 levels in PEM; 3) increased TSH secretion appears to be an integral part of the recovery from PEM.


Assuntos
Proteínas de Transporte/sangue , Kwashiorkor/metabolismo , Tiroxina/sangue , Tri-Iodotironina/sangue , Pré-Escolar , Convalescença , Eletroforese , Humanos , Lactente , Testes de Função Renal , Testes de Função Hepática , Proteínas de Ligação a Tiroxina/análise
17.
Int J Radiat Oncol Biol Phys ; 10(8): 1421-4, 1984 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6547941

RESUMO

Perfluorocarbon (PFC) emulsions, due to their favorable oxygen transporting properties, have been proposed as tumor sensitizers for application in both radiotherapy and chemotherapy. While this application is a very promising one it is by no means simple, and presently available formulations are inadequate. Intravenous administration of these emulsions can produce a severe hemodilution which tends to offset the desired effect; these emulsions can alter the pharmacokinetics of simultaneously administered drugs. Unless these variables are taken into account the risk of false negative and false positive results will be excessive. Of more serious concern are the profound disturbances produced by these emulsions in the reticuloendothelial system. Using two of the more popular PFC, Fluosol-DA and DMA/NONANE, we have shown that daily administration of these emulsions can produce 9-fold increases in liver size and 27-fold increases in spleen size. This problem appears to involve the surfactant used in both emulsions, pluronic F-68. It will be necessary to circumvent this problem before further study of their potential application can proceed.


Assuntos
Fluorocarbonos/uso terapêutico , Neoplasias Experimentais/terapia , Radiossensibilizantes/uso terapêutico , Animais , Terapia Combinada , Combinação de Medicamentos/uso terapêutico , Combinação de Medicamentos/toxicidade , Fluorocarbonos/toxicidade , Hematócrito , Derivados de Hidroxietil Amido , Fígado/efeitos dos fármacos , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/radioterapia , Tamanho do Órgão/efeitos dos fármacos , Oxigênio/farmacologia , Ratos , Ratos Endogâmicos F344 , Baço/efeitos dos fármacos
18.
Biotechniques ; 14(3): 415-9, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8457347

RESUMO

We have developed a differential screening technique, single plate one transfer (SPOT), that allows the easy detection of mRNAs induced only 2-fold to 3-fold or less above background. As a model system, we looked at the induction of mRNA by parathyroid hormone (PTH) in ROS 17/2.8 rat osteosarcoma cells. The basis for this technique is to symmetrically spot in quadruplicate, on a single plate, a large number of potentially positive plaques obtained from a primary, conventional screen. We then do only one transfer from this plate in order that there will be minimal variability in DNA transfer. This filter is cut into symmetrical strips so that all clones are multiply represented on each strip. These strips are then hybridized with different probes. Since each strip contains an approximately identical amount of DNA per plaque, it is possible to accurately detect mRNAs that are induced only slightly above background. Additionally, the large sizes of the DNA plaques, as well as spotting each clone serially, contribute to the sensitivity of the technique.


Assuntos
Clonagem Molecular/métodos , RNA Mensageiro/genética , Animais , Bacteriófago lambda/genética , DNA/genética , Vetores Genéticos , Sondas Moleculares , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/farmacologia , RNA Mensageiro/biossíntese , RNA Mensageiro/isolamento & purificação , Ratos , Teriparatida , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/metabolismo
19.
Biotechniques ; 25(2): 224-9, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9714880

RESUMO

Recent advances in long reverse transcription (RT)-PCR technology allow the copying of full-length coding regions of large mRNAs in one step. Using long RT-PCR, one can be certain that a given cDNA is derived from a single mRNA. In what to our knowledge is a novel application, we can isolate and characterize splice variants for any given mRNA in a systematic manner. We optimized long RT-PCR to copy the full-length coding region of human multidrug resistance (MDR1) mRNA or the major vault protein (MVP) mRNA in one step, so that only one full-length PCR product was synthesized in each case. Such stringent conditions are necessary to ensure that smaller than full-length products derived from total cell RNA are true splice variants. Twenty MDR1 double-stranded (ds) cDNAs, isolated from either the full-length or one prominent splice-variant DNA band, visualized on agarose gels, were cloned and sequenced. Two were full-length, wild-type in sequence as expected, and the rest were splice-variant mRNAs. Fourteen of the clones were identical and encoded a prominent splice-variant mRNA that can be detected in two tumor cell lines. This approach is shown to be generally applicable to the systematic analysis of splice-variant mRNAs derived from any gene.


Assuntos
Processamento Alternativo/genética , RNA Mensageiro/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Genes MDR/genética , Células HL-60 , Humanos , RNA Mensageiro/genética , Células U937
20.
Cancer Lett ; 96(2): 261-6, 1995 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-7585466

RESUMO

A sensitive assay for the detection of microtubule-stabilizing agents [1] was used to screen an extensive collection of cyanobacterial and microalgal extracts. The hydrophilic extract of the cyanobacterium, Plectonema radiosum (UH isolate IC-70-1), exhibited microtubule-stabilizing activity. Bioassay-directed purification of the active compound yielded tubercidin (7-deazaadenosine), a potent cytotoxic nucleoside analog. Further studies revealed that tubercidin protected a population of cellular microtubules against vinblastine-induced depolymerization, a microtubule-stabilizing, taxol-like effect. The microtubule-stabilizing effect of tubercidin is dose dependent and limited by the cytotoxicity of the agent. Tubercidin represents another natural product that interacts with microtubules and is one of the few to cause microtubule stabilization.


Assuntos
Microtúbulos/efeitos dos fármacos , Paclitaxel/farmacologia , Tubercidina/farmacologia , Vimblastina/farmacologia , Animais , Aorta , Linhagem Celular , Cianobactérias , Microtúbulos/ultraestrutura , Músculo Liso Vascular , Extratos Vegetais/farmacologia , Ratos , Sensibilidade e Especificidade , Vimblastina/antagonistas & inibidores
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