Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Prostate Cancer Prostatic Dis ; 16(4): 346-51, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23939133

RESUMEN

BACKGROUND: In prostate cancer patients treated with androgen deprivation therapy (ADT) and radiation therapy (RT), a pre-RT PSA level 0.5 ng ml(-1), determined after neoadjuvant ADT and before RT, predicts for worse survival measures. The present study sought to identify patient, tumor and treatment characteristics associated with the pre-RT PSA in prostate cancer patients. METHODS: We reviewed the charts of all patients diagnosed with intermediate- and high-risk prostate cancer and treated with a combination of neoadjuvant (median, 2.2 and 2.5 months, respectively), concurrent, and adjuvant ADT and RT between 1990 and 2011. RESULTS: A total of 170 intermediate- and 283 high-risk patients met inclusion criteria. On multivariate analysis, both intermediate- and high-risk patients with higher pre-treatment PSA (iPSA) were significantly less likely to achieve a pre-RT PSA <0.5 ng ml(-1) (iPSA 10.1-20 ng ml(-1): P=0.005 for intermediate risk; iPSA 10.1-20 ng ml(-1): P=0.005, iPSA >20 ng ml(-1): P<0.001 for high risk). High-risk patients undergoing total androgen blockade were more likely to achieve a pre-RT PSA <0.5 ng ml(-1) (P=0.031). We observed an interaction between race and type of neoadjuvant ADT (P=0.074); whereas African-American men on total androgen blockade reached pre-RT PSA <0.5 ng ml(-1) as frequently as other men on total androgen blockade (P=0.999), African-American men on luteinizing hormone-releasing hormone (LH-RH) agonist monotherapy/orchiectomy were significantly less likely to reach pre-RT PSA <0.5 ng ml(-1) compared with other men on LH-RH monotherapy/orchiectomy (P=0.001). CONCLUSIONS: Our findings suggest that total androgen blockade in the neoadjuvant period may be beneficial compared with LH-RH monotherapy for achieving a pre-RT PSA <0.5 ng ml(-1) in African-American men with high-risk prostate cancer. In addition, men with higher iPSA are more likely to have a pre-RT PSA greater than 0.5 ng ml(-1) in response to neoadjuvant ADT and are therefore candidates for clinical trials testing newer, more aggressive hormone-ablative therapies.


Asunto(s)
Antagonistas de Andrógenos/uso terapéutico , Antineoplásicos Hormonales/uso terapéutico , Neoplasias de la Próstata/tratamiento farmacológico , Anciano , Anciano de 80 o más Años , Humanos , Masculino , Persona de Mediana Edad , Terapia Neoadyuvante , Clasificación del Tumor , Estadificación de Neoplasias , Antígeno Prostático Específico/genética , Antígeno Prostático Específico/metabolismo , Neoplasias de la Próstata/metabolismo , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/radioterapia , Factores de Riesgo , Resultado del Tratamiento
2.
Mol Plant Microbe Interact ; 21(12): 1549-60, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18986251

RESUMEN

We compare genome sequences of three closely related soft-rot pathogens that vary in host range and geographical distribution to identify genetic differences that could account for lifestyle differences. The isolates compared, Pectobacterium atrosepticum SCRI1043, P. carotovorum WPP14, and P. brasiliensis 1692, represent diverse lineages of the genus. P. carotovorum and P. brasiliensis genome contigs, generated by 454 pyrosequencing ordered by reference to the previously published complete circular chromosome of P. atrosepticum genome and each other, account for 96% of the predicted genome size. Orthologous proteins encoded by P. carotovorum and P. brasiliensis are approximately 95% identical to each other and 92% identical to P. atrosepticum. Multiple alignment using Mauve identified a core genome of 3.9 Mb conserved among these Pectobacterium spp. Each core genome is interrupted at many points by species-specific insertions or deletions (indels) that account for approximately 0.9 to 1.1 Mb. We demonstrate that the presence of a hrpK-like type III secretion system-dependent effector protein in P. carotovorum and P. brasiliensis and its absence from P. atrosepticum is insufficient to explain variability in their response to infection in a plant. Additional genes that vary among these species include those encoding peptide toxin production, enzyme production, secretion proteins, and antibiotic production, as well as differences in more general aspects of gene regulation and metabolism that may be relevant to pathogenicity.


Asunto(s)
Cromosomas Bacterianos/genética , Genoma Bacteriano , Genómica , Pectobacterium/genética , Mapeo Contig , ADN Bacteriano/genética , Genes Bacterianos , Mutación INDEL , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia de ADN , Especificidad de la Especie
3.
Environ Technol ; 29(8): 837-46, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18724638

RESUMEN

A high-rate activated sludge (HRAS) bioreactor with high shear venturi aeration was operated in the laboratory at various organic loading rates to evaluate chemical oxygen demand (COD) removal efficiency and sludge production. Organic loading rates two orders of magnitude higher than conventional activated sludge loading were investigated in the modified HRAS reactor for a period of 41 weeks. Filtered COD removal efficiency varied from 81 to 92 % for organic loading rates of 3 to 85 kg COD m(-3) d(-1). Observed sludge yield was determined to be 0.10-0.25 g TSS produced g(-1) COD removed, under hydraulic and solids retention times (SRTs) approaching less than two hours and two days, respectively. Observed sludge yield actually declined as loading increased and SRT decreased. It was concluded that high-shear forces created in the reactor due to intense aeration at high volumetric organic loading rates increased substrate utilization rate, improved filtered COD removal efficiency, and kept sludge yields relatively low (despite the very low operating SRTs).


Asunto(s)
Reactores Biológicos , Eliminación de Residuos Líquidos/instrumentación , Compuestos Orgánicos/metabolismo , Oxígeno/metabolismo , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos
4.
Theor Appl Genet ; 108(7): 1193-9, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-14727034

RESUMEN

Silene latifolia is a key plant model in the study of sex determination and sex chromosome evolution. Current studies have been based on genetic mapping of the sequences linked to sex chromosomes with analysis of their characters and relative positions on the X and Y chromosomes. Until recently, very few DNA sequences have been physically mapped to the sex chromosomes of S. latifolia. We have carried out multicolor fluorescent in situ hybridization (FISH) analysis of S. latifolia chromosomes based on the presence and intensity of FISH signals on individual chromosomes. We have generated new markers by constructing and screening a sample bacterial artificial chromosome (BAC) library for appropriate FISH probes. Five newly isolated BAC clones yielded discrete signals on the chromosomes: two were specific for one autosome pair and three hybridized preferentially to the sex chromosomes. We present the FISH hybridization patterns of these five BAC inserts together with previously described repetitive sequences (X-43.1, 25S rDNA and 5S rDNA) and use them to analyze the S. latifolia karyotype. The autosomes of S. latifolia are difficult to distinguish based on their relative arm lengths. Using one BAC insert and the three repetitive sequences, we have constructed a standard FISH karyotype that can be used to distinguish all autosome pairs. We also analyze the hybridization patterns of these sequences on the sex chromosomes and discuss the utility of the karyotype mapping strategy presented to study sex chromosome evolution and Y chromosome degeneration.


Asunto(s)
Mapeo Cromosómico , Cromosomas de las Plantas/genética , Cromosomas Sexuales/genética , Silene/genética , Southern Blotting , Cromosomas Artificiales Bacterianos , Marcadores Genéticos/genética , Hibridación Fluorescente in Situ , Cariotipificación , Secuencias Repetitivas de Ácidos Nucleicos/genética
5.
Biochem Biophys Res Commun ; 274(3): 803-10, 2000 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-10924357

RESUMEN

Recent work from this laboratory both in rat primary cardiomyocytes and in ventricular tissue of transgenic mouse models of induced hypertrophy has identified two Ca(2+)/calmodulin-dependent nuclear signaling cascades. The first involves the phosphatase calcineurin (CaN). The second is the CaM kinase kinase cascade which involves CaM kinase I and CaM kinase IV. Each of these signaling cascades strongly up-regulate transcription of hypertrophy-sensitive genes in the rat ventricular cardiomyocyte. We have documented that over-expression of an active form of CaM kinase II silenced transcriptional induction of hypertrophy-sensitive genes. The purpose of this study was to generate an inducible CaM kinase II expression system and correlate its expression with the silencing of hypertrophic-sensitive reporters. A truncated form of CaM KII, CaM KII (1-290) was subcloned downstream and proximal to a promoter under transcriptional control (induction) of the tetracycline-regulated transcription factor, tet-TransActivator (tTA). Hypertrophy-sensitive reporter activity in primary cardiomyocytes was silenced when tet-inducible CaM KII was co-expressed with plasmids harboring active forms of CaN, CaM KI or CaM KIV. For instance, induced CaM KII expression silenced CaN, CaM kinase I, or CaM kinase IV driven ANF reporter activity 4.9-, 2.9-, and 6.9-fold below their maximal values, respectively. Myocyte exposure to doxycycline (DOX) blocked tTA-driven CaM KII expression and restored CaN/CaM KI or CaN/CaM KIV driven reporter activation. This study demonstrates, for the first time, that active CaM KII silences Ca(2+)-sensitive nuclear signaling cascades for transcriptional up-regulation of cardiomyocyte hypertrophy.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/fisiología , Miocardio/metabolismo , Miocardio/patología , Inhibidores de la Síntesis de la Proteína/farmacología , Tetraciclina/farmacología , Animales , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina , Tamaño de la Célula/fisiología , Células Cultivadas , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/fisiología , Ratones , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos
6.
J Clin Invest ; 105(10): 1395-406, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10811847

RESUMEN

Hypertrophic growth is an adaptive response of the heart to diverse pathological stimuli and is characterized by cardiomyocyte enlargement, sarcomere assembly, and activation of a fetal program of cardiac gene expression. A variety of Ca(2+)-dependent signal transduction pathways have been implicated in cardiac hypertrophy, but whether these pathways are independent or interdependent and whether there is specificity among them are unclear. Previously, we showed that activation of the Ca(2+)/calmodulin-dependent protein phosphatase calcineurin or its target transcription factor NFAT3 was sufficient to evoke myocardial hypertrophy in vivo. Here, we show that activated Ca(2+)/calmodulin-dependent protein kinases-I and -IV (CaMKI and CaMKIV) also induce hypertrophic responses in cardiomyocytes in vitro and that CaMKIV overexpressing mice develop cardiac hypertrophy with increased left ventricular end-diastolic diameter and decreased fractional shortening. Crossing this transgenic line with mice expressing a constitutively activated form of NFAT3 revealed synergy between these signaling pathways. We further show that CaMKIV activates the transcription factor MEF2 through a posttranslational mechanism in the hypertrophic heart in vivo. Activated calcineurin is a less efficient activator of MEF2-dependent transcription, suggesting that the calcineurin/NFAT and CaMK/MEF2 pathways act in parallel. These findings identify MEF2 as a downstream target for CaMK signaling in the hypertrophic heart and suggest that the CaMK and calcineurin pathways preferentially target different transcription factors to induce cardiac hypertrophy.


Asunto(s)
Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Cardiomegalia/etiología , Cardiomegalia/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas Nucleares , Factores de Transcripción/metabolismo , Animales , Factor Natriurético Atrial/genética , Calcineurina/metabolismo , Proteína Quinasa Tipo 4 Dependiente de Calcio Calmodulina , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Cardiomegalia/genética , Regulación de la Expresión Génica , Genes Reporteros , Humanos , Luciferasas/genética , Factores de Transcripción MEF2 , Ratones , Ratones Transgénicos , Miocardio/metabolismo , Factores Reguladores Miogénicos , Cadenas Pesadas de Miosina/genética , Factores de Transcripción NFATC , Regiones Promotoras Genéticas , Ratas , Transducción de Señal
7.
BJOG ; 107(4): 481-5, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10759266

RESUMEN

OBJECTIVE: To assess management and outcome of pregnancies with anti-Kell in the West Midlands in the UK over 13 years. DESIGN: A retrospective review of casenotes. SETTING: A regional referral clinic for red cell alloimmune disease and fetal medicine unit at a university hospital. POPULATION: Sixty-five pregnancies were identified in 52 Kell-sensitised women with Kell positive partners from the records of the Birmingham Blood Transfusion Centre. METHODS: Information from the casenotes was entered on a database and comparisons were made using the SPSS for Windows statistics package. MAIN OUTCOME MEASURES: Mode of sensitisation, degree of fetal or neonatal anaemia, need for transfusion, gestation at delivery, birthweight and pregnancy outcome. RESULTS: Alloimmunisation was transfusion-related in 29 pregnancies and pregnancy-induced in 33. The cause could not be identified in three cases. There were 22 proven Kell positive fetuses, of which 18 were affected, in which alloimmunisation was pregnancy-related in 12 cases and transfusion-related in five. Antibody titres and amniotic fluid OD450 were not helpful in management. Severe or very severe disease occurred in 50% of the affected pregnancies (9/18). There was no difference in pregnancy outcome between transfusion or pregnancy induced sensitisation. CONCLUSIONS: Anti-Kell alloimmunisation is an uncommon cause of serious anaemia in a significant proportion of affected pregnancies. There appears to be no difference between that caused by pregnancy or transfusion. Estimation of fetal haemoglobin concentration by cordocentesis is recommended, as antibody titres and amniocentesis are not helpful.


Asunto(s)
Anemia Neonatal/sangre , Incompatibilidad de Grupos Sanguíneos/complicaciones , Sistema del Grupo Sanguíneo de Kell , Complicaciones del Embarazo/sangre , Resultado del Embarazo , Adolescente , Adulto , Anemia Neonatal/etiología , Peso al Nacer , Inglaterra , Femenino , Edad Gestacional , Humanos , Recién Nacido , Masculino , Embarazo , Complicaciones del Embarazo/etiología , Estudios Retrospectivos
8.
Prenat Diagn ; 20(1): 51-5, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10701852

RESUMEN

A review of sacrococcygeal teratomas diagnosed in the antenatal period in the West Midlands region over a six year interval is reported. The aim of the study was to assess the contribution of ultrasound scanning to the management of cases and to determine the outcome of prenatally diagnosed sacrococcygeal teratomas. A retrospective review of 10 cases was performed to obtain pregnancy details, ultrasound scan data and outcome information. Two fetuses were electively aborted. Perinatal mortality was 62.5% in the remaining cases with all stillbirths and neonatal deaths occurring in babies delivered preterm (at or before 34 weeks' gestation). Marked increase in tumour size (mainly vascular/solid) was observed in five of the fetuses, which was often associated with local compression effects and the development of hydrops. Eight out of 10 cases were delivered vaginally, one following aspiration of the large cystic tumour. Three of the four neonates surviving to surgery underwent successful resection of their benign tumours. As well as guiding prognosis, serial ultrasound scans may also allow the mode of delivery to be planned more effectively. The importance of a multidisciplinary team approach to these difficult cases is emphasized.


Asunto(s)
Enfermedades Fetales/diagnóstico por imagen , Resultado del Embarazo , Región Sacrococcígea , Teratoma/diagnóstico por imagen , Ultrasonografía Prenatal , Aborto Inducido , Adolescente , Adulto , Femenino , Enfermedades Fetales/mortalidad , Edad Gestacional , Humanos , Recién Nacido , Embarazo , Estudios Retrospectivos , Teratoma/mortalidad , Teratoma/cirugía
9.
Plant J ; 20(3): 371-8, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10571898

RESUMEN

We combined single pollen typing with laser-mediated manipulation. After drilling a hole in the wall of a pollen grain from a dioecious plant (Silene latifolia) with a UV-laser microbeam, the single pollen grain was recovered directly in the cap of a PCR tube, using a non-contact method called laser pressure catapulting. The entire genome of the single pollen grain was then amplified with improved primer-extension-preamplification PCR (I-PEP PCR). Nested PCR with sequence tagged site (STS)-specific primers was used to analyze several loci in the haploid genome. The single copy gene MROS1 was detected in most of the single pollen grains analyzed. Bgl10, which is localized on the Y chromosome, was detected in approximately half of the pollen grains. MROS3 is reported to be localized on the X chromosome. Using inverse PCR, we isolated two genomic clones of MROS3: MROS3A and MROS3B. The single pollen analysis using nested PCR showed that MROS3A and MROS3B are derived from different loci that are not located on the X chromosome. Single pollen typing not only reveals sex chromosome-linkage within the haploid genome, but can also discriminate between alleles and different loci. This method should also be useful for measuring recombination frequencies without genetic crossover analysis.


Asunto(s)
Genoma de Planta , Rayos Láser , Proteínas de Plantas/genética , Polen/genética , Genotipo , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
11.
Cell ; 93(2): 215-28, 1998 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-9568714

RESUMEN

In response to numerous pathologic stimuli, the myocardium undergoes a hypertrophic response characterized by increased myocardial cell size and activation of fetal cardiac genes. We show that cardiac hypertrophy is induced by the calcium-dependent phosphatase calcineurin, which dephosphorylates the transcription factor NF-AT3, enabling it to translocate to the nucleus. NF-AT3 interacts with the cardiac zinc finger transcription factor GATA4, resulting in synergistic activation of cardiac transcription. Transgenic mice that express activated forms of calcineurin or NF-AT3 in the heart develop cardiac hypertrophy and heart failure that mimic human heart disease. Pharmacologic inhibition of calcineurin activity blocks hypertrophy in vivo and in vitro. These results define a novel hypertrophic signaling pathway and suggest pharmacologic approaches to prevent cardiac hypertrophy and heart failure.


Asunto(s)
Calcineurina/fisiología , Cardiomegalia/genética , Miocardio/patología , Proteínas Nucleares , Transducción de Señal/fisiología , Activación Transcripcional/fisiología , Angiotensina II/farmacología , Animales , Animales Recién Nacidos , Factor Natriurético Atrial/genética , Calcineurina/genética , Cardiomegalia/enzimología , Cardiomegalia/prevención & control , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Factor de Transcripción GATA4 , Inmunosupresores/farmacología , Ratones , Ratones Transgénicos , Miocardio/metabolismo , Factores de Transcripción NFATC , Péptido Natriurético Encefálico , Fenilefrina/farmacología , Regiones Promotoras Genéticas/genética , Ratas , Proteínas Recombinantes de Fusión , Factores de Transcripción/metabolismo , Transcripción Genética , Dedos de Zinc
12.
Plant J ; 12(3): 515-26, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9351239

RESUMEN

To investigate the genetics of male sex determination and stamen development in the dioecious plant Silene latifolia (white campion), male-specific transcripts were isolated from developing flowers by cDNA subtraction. One of the cDNAs identified, STA1, had high DNA and amino acid sequence homology to the male sex determining gene of Zea mays (maize), TASSELSEED2. Both genes are expressed in male and not in female flowers, However, they do not share the same expression pattern. The TASSELSEED2 gene product is expressed in the gynoecium primordia of male maize flowers where it is necessary for pistil abortion. STA1 is not expressed in the gynoecium primordia of male white campion and therefore its gene product cannot perform the same function in sex determination that TASSELSEED2 performs in maize. STA1 is expressed in tapetal cells of white campion male flowers and of white campion hermaphroditic mutants. A homologous gene is also expressed in the tapetum of hermaphroditic Silene species. Tapetal expression of a homologous gene (named ATA1) was also found in Arabidopsis thaliana. The similarity in primary sequence and expression pattern of STA1 and ATA1 indicate that these genes have a conserved role in tapetum development.


Asunto(s)
Proteínas de Arabidopsis , Genes de Plantas , Proteínas de Plantas/genética , Plantas/genética , Alelos , Secuencia de Aminoácidos , Arabidopsis/genética , Arabidopsis/fisiología , Secuencia de Consenso , Datos de Secuencia Molecular , Proteínas de Plantas/química , Proteínas de Plantas/fisiología , Transcripción Genética , Zea mays/genética
13.
Genetics ; 144(4): 1893-901, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8978072

RESUMEN

The genomic subtraction method representational difference analysis (RDA) was used to identify male-specific restriction fragments in the dioecious plant Silene latifolia. Male-specific restriction fragments are linked to the male sex chromosome (the Y chromosome). Four RDA-derived male-specific restriction fragments were used to identify polymorphisms in a collection of X-ray-generated mutant plants with either hermaphroditic or asexual flowers. Some of the mutants have cytologically detectable deletions in the Y chromosome that were correlated with loss of male-specific restriction fragments. One RDA-derived probe detected a restriction fragment present in all mutants, indicating that each has retained Y chromosomal DNA. The other three probes detected genomic fragments that were linked in a region deleted in some hermaphroditic and some asexual mutants. Based on the mutant phenotypes and the correlation of cytologically visible deletions with loss of male-specific restriction fragments, these markers were assigned to positions on the Y chromosome close to the carpel suppression locus. This RDA mapping also revealed a Y-linked locus, not previously described, which is responsible for early stamen development.


Asunto(s)
ADN de Plantas/genética , Plantas/genética , Cromosoma Y , Regulación de la Expresión Génica de las Plantas , Análisis de Secuencia de ADN , Diferenciación Sexual
14.
Mol Gen Genet ; 241(1-2): 153-60, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8232198

RESUMEN

TNPA, one of the two transposition proteins encoded by the En/Spm transposable elements of Zea mays, suppresses the expression of genes that contain an appropriate cis element. Suppression can be monitored in tobacco protoplasts in a transient expression assay as follows. The plant promoter-driven expression of the Escherichia coli-glucuronidase (GUS)-encoding gene, uidA, is repressed in the presence of TNPA if the GUS gene contains a functional cis element in the untranslated RNA leader sequence. Earlier, we found that the minimal cis element is composed of two 12 bp sequences in a tail-to-tail inverted orientation. Each 12 bp sequence is sufficient to bind TNPA in vitro and can be thought of as a half-site in the cis element. Here, we investigated the sequence requirements of the minimal cis element. Our observations support our expectations that a functional cis element must provide a template to which two TNPA molecules can bind in the correct orientation. Sequences within the half-sites can be altered as long as the eight bases that make up the consensus binding sites are not changed. However, we found the following unexpected sequence specificities. Firstly, some changes to the consensus binding sequence can be tolerated in one half-site, as long as the other site matches the consensus. Secondly, although the region between the half-sites can vary in sequence and in length between two and four bases, a thymidine residue is not tolerated directly 5' preceding the second half-site.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Elementos Transponibles de ADN , Proteínas de Unión al ADN , Regulación de la Expresión Génica , Proteínas de Plantas/genética , Secuencias Reguladoras de Ácidos Nucleicos , Proteínas Represoras , Zea mays/genética , Secuencia de Bases , Sitios de Unión , ADN , Glucuronidasa/genética , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Proteínas de Plantas/metabolismo , Plásmidos
15.
Protein Expr Purif ; 3(4): 313-21, 1992 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1422225

RESUMEN

The cDNA for the human chemotactic interleukin, IL-8, was subcloned from a bacterial source into the eucaryotic vector expression system baculovirus. Recombinant human IL-8 (rhIL-8) was synthesized and secreted from Sf9 cells derived from Spodoptera frugiperda following infection of a recombinant virus harboring the full-length IL-8 structural gene. Infected Sf9 cells produced rhIL-8 in a range from 0.5 to 2.0 mg of rhIL-8/liter of postinfection cell culture media. The recombinant interleukin was purified (greater than 600-fold) to homogeneity using preparative HPLC. rhIL-8 retained all of the physical, immunological, and biochemical properties observed for the natural product, monocyte-derived IL-8. rhIL-8 was assessed for biological efficacy by three criteria: (a) ability to induce chemotaxis in human neutrophils, (b) ability to induce oxygen burst metabolism, and (c) ability to be recognized by purified rabbit antibody generated against monocyte-derived IL-8. Antibody generated against monocyte-derived IL-8 recognized rhIL-8 isolated during all stages of the purification protocol. rhIL-8 was strongly chemotactic for human neutrophils and exhibited a chemotactic index comparable to that reported for other strong chemotactic peptides. rhIL-8 was identified following sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a single silver-stained band having an estimated molecular weight of 9.2 kDa and displayed amino acid residue molar abundance homology predicted for the mature form of the interleukin. Baculovirus vector expression coupled to preparative HPLC proved to be a very efficient method for large-scale recombinant interleukin production.


Asunto(s)
Interleucina-8/biosíntesis , Interleucina-8/genética , Aminoácidos/análisis , Baculoviridae/genética , Quimiotaxis de Leucocito , Clonación Molecular , Vectores Genéticos , Humanos , Interleucina-8/inmunología , Interleucina-8/aislamiento & purificación , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Estallido Respiratorio
16.
Protein Expr Purif ; 1(1): 9-12, 1990 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-2152189

RESUMEN

A new method for the isolation of homogeneous triosephosphate isomerase (TPI, EC 5.3.1.1) has been developed. The method utilizes high-performance liquid chromatography on DEAE 5PW and Hydrophase-polyethyleneimine columns, which results in the rapid isolation and essentially quantitative recovery of the enzyme. The procedure is superior to previous methods with respect to specificity, recovery, and time. In addition, this rapid process minimizes the potential for postsynthetic modifications of the protein. Milligram quantities of TPI can be isolated from 100 g of tissue.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Triosa-Fosfato Isomerasa/aislamiento & purificación , Animales , Pollos , Electroforesis en Gel de Poliacrilamida , Músculos/enzimología
17.
EMBO J ; 9(7): 2029-35, 1990 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-2162760

RESUMEN

The En/Spm encoded suppressor function has been reconstituted in transgenic tobacco protoplasts. The suppressor affects genes which contain an En/Spm responsive transposable element in the transcribed sequences. The En/Spm encoded protein tnpA binds a defined cis element in the inserted transposon, repressing expression of the adjacent gene. This was shown by monitoring transient expression of a bacterial marker gene (GUS) expressed from a strong plant viral promoter. Suppressible variants of the marker gene were produced by inserting I element sequences into the untranslated sequences of the GUS transcript. Comparison of transient expression of these variants in wildtype tobacco protoplasts with their expression in protoplasts transgenic for tnpA protein demonstrates that tnpA is the suppressor. In addition, the minimal cis element required for suppression has been defined as a dimer consisting of two 12 bp tnpA binding sequences in a particular inverted orientation. One of these dimers occurs in each En/Spm end close to the characteristic 13 bp terminal inverted repeat. TnpA binding sites in different arrangements do not respond as well to tnpA. The implications of this observation are discussed. This system can be used to analyse tnpA-DNA interactions involved in gene regulation further.


Asunto(s)
Elementos Transponibles de ADN , Proteínas de Unión al ADN , Nicotiana/genética , Proteínas de Plantas/genética , Plantas Tóxicas , Proteínas Represoras , Supresión Genética , Zea mays/genética , Alelos , Secuencia de Bases , Exones , Expresión Génica , Genotipo , Intrones , Datos de Secuencia Molecular , Fenotipo , Plásmidos , Protoplastos/metabolismo
18.
Mol Gen Genet ; 217(2-3): 324-31, 1989 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2770697

RESUMEN

We report here the existence and initial characterization of a genetic locus (imp) that inhibits maintenance of SLP1-derived plasmids as extrachromosomal replicons in a manner distinct from normal incompatibility between autonomous SLP1 replicons. The trans-acting imp function has been localized to a 1.8 kb Eco47III restriction fragment present on integrated SLP1 elements. At least part of this DNA segment is absent from SLP1-derived plasmids. DNA sequence analysis of the imp region indicates that it contains three overlapping open reading frames (ORFs) that may constitute a polycistronic operon. The effects of insertions within the imp region indicate that uninterrupted transcription through all three ORFs is necessary for imp activity.


Asunto(s)
Plásmidos , Streptomyces/genética , Secuencia de Aminoácidos , Secuencia de Bases , Deleción Cromosómica , ADN Bacteriano/genética , Proteínas de Unión al ADN/genética , Genes Bacterianos , Datos de Secuencia Molecular , Replicón , Mapeo Restrictivo
19.
Arch Oral Biol ; 33(2): 115-20, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-2971345

RESUMEN

Such stimulation of rat parotid acinar cells in vitro modulated the rate of processing of N-linked oligosaccharides in a high-molecular weight (220 kdalton) secretory glycoprotein. Conversion of polymannose-type oligosaccharides to complex-type oligosaccharides was evaluated by sensitivity to endoglucosaminidase H and alpha-mannosidase, and with a specific inhibitor of glucosidases I/II. Oligosaccharide maturation in the 220 kdalton glycoprotein required one-third to half less time in cells exposed to the beta-adrenergic agonist isoproterenol than in controls.


Asunto(s)
Glicoproteínas/metabolismo , Isoproterenol/farmacología , Oligosacáridos/metabolismo , Glándula Parótida/efectos de los fármacos , 1-Desoxinojirimicina , Animales , Glucosamina/análogos & derivados , Glucosamina/farmacología , Masculino , Glándula Parótida/metabolismo , Ratas , Ratas Endogámicas
20.
J Immunol ; 137(7): 2210-4, 1986 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-3093567

RESUMEN

Quiescent normal human B cells have been shown to require an activation step before proliferating in response to B cell growth factor (BCGF) of 12,000 m.w. (12 kd). One effect of cell activation has been the putative acquisition of specific cell surface growth factor receptors. In this report, the existence of such receptors has been confirmed by using purified radioiodinated BCGF-12 kd. BCGF-12 kd receptors on activated B cells have been shown to be distinct form those interacting with IL 2. Scatchard analysis revealed both high affinity receptor sites with an apparent Kd of 28.6 pM and low affinity receptor sites with Kd of 1.2 nM on freshly prepared, anti-IgM activated peripheral blood B cells. Human B cells grown in culture for extended periods of time in the presence of BCGF-12 kd also displayed high affinity receptor sites (Kd, 41.4 pM) and low affinity receptor sites (Kd, 0.9 nM). The action of BCGF-12 kd therefore appears to be mediated by binding to its lineage-specific receptors on the cell surface.


Asunto(s)
Linfocitos B/metabolismo , Sustancias de Crecimiento/metabolismo , Linfocinas/metabolismo , Receptores Mitogénicos/metabolismo , Anticuerpos Antiidiotipos , Unión Competitiva , Humanos , Inmunoglobulina M/inmunología , Interleucina-2/metabolismo , Interleucina-4 , Cinética , Activación de Linfocitos , Peso Molecular , Receptores Inmunológicos/metabolismo , Receptores de Interleucina-2 , Receptores de Interleucina-4 , Receptores Mitogénicos/inmunología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...