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1.
J Econ Entomol ; 105(4): 1261-7, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22928305

RESUMO

Strong market demand for canola, Brassica napus L., has prompted some western Canadian producers to increase the frequency of this crop in rotations with other crop species, but the impact of this practice on canola insect pests has not been determined. Here, we investigate 12 cropping sequences involving canola over a 3-yr period (2008-2010 inclusive) at five locations across western Canada. Cropping sequences varied from continuous production of two herbicide-tolerant canola varieties, to production in two of 3 yr, to canola production in one of the 3 yr. Treatments analyzed were the frequency and timing of canola within the rotational sequence. Damage by larvae of root maggots (Diptera: Anthomyiidae: Delia spp.) to canola taproots increased as the study progressed, particularly in 2010 after canola had been grown continuously for 3 yr. Yield declined with continuous canola production, and differences were greatest in 2010. At mean canola crop prices for 2010, the yield reduction from continuous production amounted to economic losses of approximately Can$282-$377/ha. Crop quality, in terms of oil and protein concentrations of harvested seed, was affected more by crop variety than cropping sequence. Crop sequence effects for root maggot damage, yield, and seed quality were relatively stable in the presence of environmental (location) variation. Results of our study suggest that continuous canola production could be unsustainable over the long-term even though market forces currently provide incentive for this practice.


Assuntos
Agricultura , Brassica napus/parasitologia , Brassica rapa/parasitologia , Dípteros/fisiologia , Raízes de Plantas/parasitologia , Animais , Biomassa , Interações Hospedeiro-Parasita , Larva/fisiologia , Sementes/crescimento & desenvolvimento
2.
Environ Entomol ; 41(1): 72-80, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22525061

RESUMO

Diversity and abundance of ground beetles (Coleoptera: Carabidae) can be enhanced in vegetable and field intercropping systems, but the complexity of polycultures precludes the application of generalized assumptions of effects for novel intercropping combinations. In a field experiment conducted at Lacombe and Ellerslie, Alberta, Canada, in 2005 and 2006, we investigated the effects of intercropping canola (Brassica napus L.) with wheat (Triticum aestivum L.) on the diversity and community structure of carabid beetles, and on the activity density responses of individual carabid species. Shannon-Wiener diversity index scores and species evenness increased significantly as the proportion of wheat comprising total crop plant populations increased in one site-year of the study, indicating a positive response to enhanced crop plant species evenness in the intercrops, and in that same site-year, ground beetle communities in intercrops shifted to more closely approximate those in wheat monocultures as the percentage of wheat in the intercrops increased. Individual carabid species activity densities showed differing responses to intercropping, although activity densities of some potential root maggot (Delia spp.) (Diptera: Anthomyiidae) predators were greater in intercrops with high proportions of wheat than in canola monocultures. The activity density of Pterostichus melanarius (Illiger), the most abundant species collected, tended to be greater in canola monocultures than high-wheat intercrops or wheat monocultures. We conclude that intercrops of canola and wheat have the potential to enhance populations of some carabid species, therefore possibly exerting increased pressure on some canola insect pests.


Assuntos
Agentes de Controle Biológico , Biota , Besouros/fisiologia , Agricultura/métodos , Alberta , Animais , Brassica napus , Cadeia Alimentar , Densidade Demográfica , Estações do Ano , Triticum
3.
J Econ Entomol ; 102(1): 219-28, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19253640

RESUMO

Reductions in oviposition and subsequent damage by root maggots (Diptera: Anthomyiidae, Delia spp.) to brassicaceous crops in the presence of nonhost plants has been demonstrated, but such investigations have not been conducted using intercrops of species commonly grown in the large-scale agricultural production systems of western Canada. A field experiment was conducted at three sites in Alberta, Canada, in 2005 and 2006 to determine interactions between root maggots and the various proportions of canola (Brassica napus L.) making up the total crop plant populations in intercrops with wheat (Triticum aestivum L.). The effect of a neonicotinoid seed treatment also was investigated. Root maggot damage to canola taproots decreased with increasing proportions of wheat in the intercrops. The presence of wheat in the intercrops had little effect on root maggot adult abundance in any single site-by-year combination or when data were combined over all sites and years, with different Delia species and sexes responding differently. Similarly, per plant root maggot egg populations were unaffected by intercropping, although egg populations were reduced on a per unit land area basis in intercrops compared with monocultures. Insecticidal seed treatment did not affect root maggot egg populations or canola root damage. Variable abundances and phenologies of the principal root maggot species infesting canola at different sites and years may influence their responses to canola-wheat intercrops. Intercropping canola and wheat may provide an opportunity for reducing crop damage from root maggot attack without compromising environmental sustainability.


Assuntos
Agricultura/métodos , Brassica napus/parasitologia , Dípteros/fisiologia , Controle de Insetos/métodos , Triticum , Animais , Brassica napus/crescimento & desenvolvimento , Comportamento Alimentar , Feminino , Interações Hospedeiro-Parasita , Larva , Masculino , Oviposição , Raízes de Plantas/parasitologia , Densidade Demográfica , Triticum/crescimento & desenvolvimento
4.
J Econ Entomol ; 99(5): 1665-74, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17066797

RESUMO

Several agronomic benefits can result from fall seeding of canola (Brassica spp.), but extensive research data are lacking on the potential impact of this practice on infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae), which are major pests of the crop in western Canada. Field experiments making up 13 location by year combinations were conducted in central Alberta, Canada, from 1998 to 2001 to determine the effect of fall versus spring seeding of canola on root maggot damage. Depending on the experiment, interactions with seeding rate, seed treatment, timing of weed removal, and canola species (cultivar) also were investigated. Root maggot damage declined with an increase in seeding rate for plots seeded in May but not in fall or April. Susceptibility to infestation was greater for plants of Brassica rapa L. than Brassica napus L., but seed treatment had no effect on damage by these pests. Combined analysis using data from all experiment by location by year combinations indicated that seeding date had no significant effect on root maggot damage. The extended emergence of Delia spp. adults, which spans the appearance of crop stages vulnerable to oviposition regardless of seeding date, prevented reduced root maggot attack. Covariance analysis demonstrated the importance of increasing seeding rate for reducing root maggot infestations, a practice that can be especially beneficial for May-seeded canola when growing conditions limit the ability of plants to compensate for root maggot damage. Results determined with the small plot studies described here should be validated in larger plots or on a commercial field scale, but both the combined and covariance analyses indicate that seeding canola in fall does not predispose plants to greater damage by larval root maggots than seeding in spring.


Assuntos
Agricultura/métodos , Brassica napus/parasitologia , Brassica rapa/parasitologia , Dípteros/fisiologia , Estações do Ano , Animais , Brassica napus/crescimento & desenvolvimento , Brassica rapa/crescimento & desenvolvimento , Meio Ambiente , Larva/fisiologia , Raízes de Plantas/parasitologia , Sementes , Fatores de Tempo
5.
J Agric Food Chem ; 48(7): 2986-90, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10898653

RESUMO

Under controlled-environment conditions, ethametsulfuron-methyl doses that inhibited growth by 50% (ED(50)) were >100 and <1 g of active ingredient (ai) ha(-)(1) for ethametsulfuron-methyl-resistant (R) and -susceptible (S) wild mustard, respectively. There were no differences between the two biotypes with regard to absorption and translocation of the herbicide. Three days after treatment, approximately 90, 5, and 2% of the applied [(14)C]ethametsulfuron-methyl was found in the treated leaf, foliage, and roots of each biotype, respectively. Acetolactate synthase extracted from the two biotypes was equally sensitive to both ethametsulfuron-methyl and chlorsulfuron. These results indicate that resistance was not due to differences in the target site, absorption, or translocation. However, ethametsulfuron-methyl was metabolized more rapidly in the R than the S biotype. Approximately 82, 73, 42, 30, and 17% of the recovered radioactivity remained as ethametsulfuron-methyl in R wild mustard 3, 6, 18, 48, and 72 h after treatment, respectively. Conversely, 84, 79, 85, and 73% of the (14)C was ethametsulfuron-methyl in the S biotype 12, 24, 48, and 72 h after treatment, respectively. On the basis of these results, it is proposed that resistance is due to enhanced metabolism of ethametsulfuron-methyl in the R biotype.


Assuntos
Benzoatos/farmacologia , Herbicidas/farmacologia , Mostardeira/metabolismo , Plantas Medicinais , Triazinas/farmacologia , Absorção , Cromatografia Líquida de Alta Pressão , Resistência a Medicamentos , Mostardeira/efeitos dos fármacos
6.
Gynecol Oncol ; 73(3): 424-9, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10366472

RESUMO

BACKGROUND: Paraneoplastic syndromes are rare conditions associated with cancer that result in serious disease states at unique sites. In 1982, a report of bilateral diffuse uveal melanocytic proliferation associated with nonocular cancers which resulted in blindness was reported. We present a case of a woman with recurrent ovarian cancer who developed this paraneoplastic syndrome. CASE: A 55-year-old woman had been diagnosed in 1990 with an ocular melanoma of her right eye and in 1994 with clear cell carcinoma of the ovary. With recurrence of ovarian cancer, new eye lesions were identified in both eyes. After enulcleation of her right eye, an ocular melanoma and diffuse bilateral melanocytic proliferation (BDUMP) were found. The sight in her left eye continued to deteriorate as other signs of BDUMP occurred in the eye. Within 1 month of diagnosis, the patient was blind. She subsequently succumbed to progression of ovarian cancer. CONCLUSION: Recurrent ovarian cancer is usually an intraabdominal disease that results in gastrointestinal dysfunction. This case illustrates a rare paraneoplastic syndrome associated with ovarian cancer that mimics metastatic disease to the eye, but has a different pathophysiology.


Assuntos
Adenocarcinoma de Células Claras/diagnóstico , Cegueira/diagnóstico , Neoplasias Oculares/diagnóstico , Melanoma/diagnóstico , Neoplasias Ovarianas/diagnóstico , Síndromes Paraneoplásicas/diagnóstico , Feminino , Humanos , Pessoa de Meia-Idade
7.
J Magn Reson Imaging ; 8(2): 467-72, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9562077

RESUMO

The reproducibility of a semiautomated method of volumetric analysis allowing estimates of left ventricular (LV) parameters in approximately 5 minutes of analysis time is reported. Twenty normal volunteers underwent cine breath-hold cardiac MRI on two occasions with two observers using this new semiautomated method to estimate LV parameters. Reproducibility of this technique was comparable to published data with a variability of less than approximately 10% for all LV parameters calculated. Using this technique, the 95% confidence limits for change for left ventricular end diastolic volume (LVEDV) = +/-15 ml, left ventricular end systolic volume (LVESV) = +/-8 ml, LV mass = +/-24 g, and left ventricular ejection fraction (LVEF) = +/-6%. This new method also compared favorably to established manual methods. This new method permits estimation of LV parameters with acceptable reproducibility in a time that may permit routine quantitation of cardiac MR studies.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Imagem Cinética por Ressonância Magnética , Função Ventricular Esquerda , Adulto , Automação , Estudos de Avaliação como Assunto , Feminino , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes
8.
Gynecol Oncol ; 64(3): 533-40, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9062166

RESUMO

Metastatic ovarian cancer to the breast is a rare condition. The diagnosis must be made quickly and efficiently to minimize patients' physical and emotional trauma. Three patients with metastatic ovarian cancer to the breast are presented. Fine-needle aspiration of the breast was used in all patients in an attempt to obtain a diagnosis. Correlation of the cytomorphology from the primary tumor and metastatic lesion allowed proper diagnosis in two of the three patients. This study shows that it is imperative for the clinician to work closely with the cytopathologist to obtain a correct diagnosis.


Assuntos
Biópsia por Agulha , Neoplasias da Mama/patologia , Neoplasias da Mama/secundário , Neoplasias Ovarianas/patologia , Adulto , Feminino , Humanos , Pessoa de Meia-Idade
9.
Gynecol Oncol ; 61(2): 249-52, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8626142

RESUMO

The objective of this study was to evaluate the activity of the combination of 5-fluorouracil (5-FU) and leucovorin in women with platinum-resistant recurrent or advanced ovarian cancer. A retrospective study was conducted of consecutive patients treated with weekly intravenous 5-FU and leucovorin, both at 500 mg/m2. Sixty-one cycles were administered to 28 women between 1989 and 1995. The median age of the patients was 58 years and median number of previous chemotherapy regimens was 2. No patient had a complete response. There was 1 partial response (PR) among 8 patients with measurable disease, and 4 PR among 20 women with evaluable disease; 2 had stable disease and 21 progressed on treatment for a response rate of 18% (95% confidence interval, 3-33%). Duration of response was 2 to 14 months, median 5 months. Survival from the start of 5-FU/leucovorin ranged from 1 to 78 months, median 5.5 months, and a mean of 10 +/- 15 months (mean +/- SD). The combination of 5-FU/leucovorin had minimal activity in this patient population. Only 2 women achieved resolution of their ascites and experienced a significant palliation.


Assuntos
Antídotos/uso terapêutico , Antimetabólitos Antineoplásicos/uso terapêutico , Fluoruracila/uso terapêutico , Leucovorina/uso terapêutico , Neoplasias Ovarianas/tratamento farmacológico , Adulto , Idoso , Antimetabólitos Antineoplásicos/efeitos adversos , Antígeno Ca-125/metabolismo , Quimioterapia Combinada , Feminino , Fluoruracila/efeitos adversos , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/metabolismo , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
10.
Gynecol Oncol ; 55(1): 36-40, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7959263

RESUMO

Nine massively obese patients underwent excision of a large abdominal panniculus in conjunction with pelvic surgery. The most frequent indication for surgery was endometrial cancer. The charts of the patients were reviewed with careful attention to the outcome of the operation and the postoperative course. Comparison was made to previously reported data. The patients ranged in age from 48 to 72 years (mean 56). Weight range was 216 to 325 pounds (mean 261) and averaged more than twice ideal body weight. The weight of the resected abdominal wall was 3900 to 11,000 grams (mean 6247). Hospital stay ranged from 6 to 18 days (mean 8.2). Postoperative complications were chiefly those associated with the dead space created by the large resection without flap undermining (seromas in 2 and wound infections in 3). Four patients required prolonged wound drainage as outpatients. The average length of time to complete wound healing was 40.3 days (range 10 to 65). There were no dehiscences, pulmonary emboli, or operative mortalities. No patients required reoperation. Our study demonstrates that it is possible to safely combine plastic and gynecologic surgery without significantly increasing operative time, blood loss, postoperative complications, or hospital stay.


Assuntos
Abdome/cirurgia , Tecido Adiposo/cirurgia , Obesidade Mórbida/cirurgia , Pelve/cirurgia , Idoso , Peso Corporal , Neoplasias do Endométrio/cirurgia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Segurança , Cirurgia Plástica
11.
Gynecol Oncol ; 55(1): 87-90, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7959274

RESUMO

We evaluated the accuracy and interobserver variability of intraoperative tumor measurements in ovarian cancer. Thirty-four obstetrician-gynecologists, 26 gynecologic oncologists, and 12 residents estimated the size of a primary ovarian cancer and four metastases in a simulated patient at laparotomy. The validity of the model was rated from 1 (poor) to 10 (excellent) as 6.9 +/- 1.3 (range 4-10). Actual diameters and range of estimates were, respectively, primary ovarian tumor, 13 cm and 4 to 20 cm; plaque right pelvic sidewall, 8.5 cm and 0 to 12 cm; paraaortic nodes, 2 cm and 0 to 5 cm; right hemidiaphragm, 1 cm and 0.3 to 3 cm; and left hemidiaphragm, 5 cm and 2 to 7 cm. There was no significant difference in measurements between the three groups of surgeons. More surgeons underestimated than overestimated tumor diameters. Tumor measurements in individual patients are highly variable; interpretation of the surgical literature and ovarian cancer treatment protocols based on tumor volume are subject to significant measurement error.


Assuntos
Neoplasias Ovarianas/patologia , Análise de Variância , Feminino , Cirurgia Geral , Ginecologia , Humanos , Internato e Residência , Pessoa de Meia-Idade , Variações Dependentes do Observador , Obstetrícia , Médicos , Reprodutibilidade dos Testes
12.
Obstet Gynecol ; 83(6): 1011-4, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8190415

RESUMO

OBJECTIVE: To explore the association between the use of the Cavitron Ultrasonic Surgical Aspirator for cytoreduction of ovarian cancer and the intraoperative development of disseminated intravascular coagulation (DIC). METHODS: A retrospective chart review was performed of all patients undergoing surgery for ovarian cancer from September 1991 to February 1993. Data were extracted to correlate clinical and hematologic evidence of DIC with and without intraoperative use of the Cavitron Ultrasonic Surgical Aspirator. Statistical analyses were done by chi 2 and analysis of variance. RESULTS: Fifty-one patients underwent surgery for ovarian cancer; 33 had stage IIIB, IIIC, IV, or recurrent disease and could be evaluated for this study. Nineteen patients were treated with the surgical aspirator, five of whom developed an intraoperative coagulopathy, as compared to none of 14 patients treated with conventional cytoreduction (P < .04, chi 2). The duration of use of the surgical aspirator correlated with the risk of coagulopathy (P < .001, analysis of variance). CONCLUSION: These data suggest a potential risk of developing DIC after extended use of the Cavitron Ultrasonic Surgical Aspirator for cytoreduction of ovarian cancer.


Assuntos
Coagulação Intravascular Disseminada/etiologia , Complicações Intraoperatórias , Neoplasias Ovarianas/cirurgia , Terapia por Ultrassom/efeitos adversos , Feminino , Humanos , Estudos Retrospectivos , Sucção/instrumentação , Terapia por Ultrassom/instrumentação
13.
Anal Quant Cytol Histol ; 16(2): 85-9, 1994 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7913806

RESUMO

Sources of variability in quantitating proliferative cell nuclear antigen (PCNA) by image analysis were evaluated in paraffin sections of 18 ovarian tumors of low malignant potential (LMP) and grade 1 (G1) carcinomas. The correlation coefficient of reliability (R) was calculated to determine how reliable a single observation was for representing a "true" tumor value. Reliability of 61% was obtained when interobserver and intraobserver variability were assessed. Threshold settings for positive nuclear and antibody signals minimally affected the overall reliability. The reliability of a single block of tumor for representing true tumor value was R = 0.61. These sources of variability render this technique impractical for evaluating proliferative characteristics in LMP and G1 common epithelial ovarian tumors with PCNA staining.


Assuntos
Antígenos de Neoplasias/análise , Carcinoma/química , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Proteínas Nucleares/análise , Neoplasias Ovarianas/química , Análise de Variância , Carcinoma/patologia , Feminino , Humanos , Variações Dependentes do Observador , Neoplasias Ovarianas/patologia , Antígeno Nuclear de Célula em Proliferação , Reprodutibilidade dos Testes
14.
Gynecol Oncol ; 50(3): 379-83, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8406206

RESUMO

Supernumerary breasts on the vulva are a rare occurrence. There have been 26 cases previously reported and only 4 case reports of primary mammary carcinoma of the vulva. This is the fifth case report of mammary carcinoma of the vulva and the second report using tamoxifen for adjuvant treatment.


Assuntos
Neoplasias da Mama , Mama , Carcinoma Ductal de Mama , Coristoma , Doenças da Vulva , Idoso , Carcinoma Ductal de Mama/secundário , Carcinoma de Apêndice Cutâneo , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Vulvares/secundário
15.
Gynecol Oncol ; 50(2): 249-53, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8375740

RESUMO

Malignant lipoid cell tumors of the ovary are rare lesions that are frequently associated with endocrinologic abnormalities. A case of a woman with this lesion who developed Cushing's syndrome with progression of tumor is presented. Neither aggressive medical therapy with ketoconazole nor multiagent chemotherapy was beneficial in controlling tumor growth or physical and biochemical manifestations of Cushing's syndrome.


Assuntos
Síndrome de Cushing/etiologia , Neoplasias Ovarianas/complicações , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Cisplatino/administração & dosagem , Síndrome de Cushing/complicações , Síndrome de Cushing/tratamento farmacológico , Feminino , Humanos , Hipopotassemia/tratamento farmacológico , Hipopotassemia/etiologia , Cetoconazol/uso terapêutico , Metotrexato/administração & dosagem , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Vimblastina/administração & dosagem
16.
Gynecol Oncol ; 47(1): 110-3, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1427389

RESUMO

A patient with squamous cell carcinoma of the vulva treated with a radical vulvectomy and bilateral inguinal and femoral lymphadenectomies utilizing separate groin incisions, subsequently developed a recurrence in the skin bridge between the vulvar and groin excisions. Following groin irradiation with chemosensitization, the tumor progressed to involve the superior public ramus and femoral vessels. A left hip disarticulation and resection of a portion of the superior pubic ramus was performed. The patient has been free of disease for 3 years. The advantages of this procedure over a hemipelvectomy include shorter operative time, reduced blood loss, better fascial closure of the abdomen, and the creation of a stump which is more amendable to prosthetic fitting.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Desarticulação , Articulação do Quadril/cirurgia , Neoplasias Vulvares/cirurgia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Terapia Combinada , Feminino , Virilha , Humanos , Pessoa de Meia-Idade , Neoplasias Vulvares/tratamento farmacológico , Neoplasias Vulvares/radioterapia
17.
Gynecol Oncol ; 46(2): 255-8, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1323525

RESUMO

One of four patients who underwent lymph node excision at exploration for ovarian serous borderline epithelial tumor (OSBT) at Baystate Medical Center was found to have FIGO Stage III C lesion associated with extensive ovarian external (surface) papillary growth, peritoneal implants in the omentum and cul-de-sac, and involvement of multiple pelvic and periaortic lymph nodes by the tumor. Histologically, the lymph nodes showed an admixture of endosalpingeal glandular inclusions with neoplastic tissue identical to the ovarian tumor. The exact histogenesis and the prognostic significance of the nodal involvement by OSBT are still not fully understood. Although there is a small number of reported cases of lymph node involvement associated with OSBT, they are described as examples of nodal metastases or independent primary foci of malignant transformation. This paper presents an interesting association of OSBT with extensive pelvic and periaortic nodal involvement and reviews the relevant literature.


Assuntos
Transformação Celular Neoplásica/patologia , Corpos de Inclusão/patologia , Neoplasias Ovarianas/patologia , Ovário/patologia , Adulto , Aorta , Epitélio/patologia , Feminino , Humanos , Metástase Linfática , Omento/patologia , Pelve , Neoplasias Peritoneais/secundário
18.
Nucleic Acids Res ; 19(14): 3867-73, 1991 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-1861979

RESUMO

We report the sequence and expression of a single-copy gene from Dictyostelium discoideum which encodes the homolog of yeast ribosomal protein S4, a protein located on the small ribosomal subunit and known to play an important role in maintaining translational fidelity. Over a highly conserved central region, the Dictyostelium protein has 78% sequence similarity to the yeast protein and 83% sequence similarity to mammalian S4 protein homologs, the LLRep3 proteins. The Dictyostelium gene encodes a polypeptide 28,717 Da in size and hence this ribosomal protein has been named rp29. The N-terminal sequence of the Dictyostelium rp29 protein is extended by 61 amino acids and 14 amino acids compared to the mammalian and yeast proteins, respectively, and the C-terminus is correspondingly 15 amino acids or 2 amino acids shorter. Although the coding region of the rp29 gene is present on a single exon, a 157bp intron interrupts the 5' untranslated region and unusually contains four direct repeats of the sequence TCAATCT. The gene is expressed maximally during vegetative growth but a second peak of expression also occurs late in development which is restricted to prestalk cells; rp29 is the first Dictyostelium ribosomal protein gene reported which shows prestalk-specific developmental expression. During each round of expression, only a single 0.9kb transcript is produced which is similar in size to the yeast S4 ribosomal protein transcript (0.8kb) but markedly smaller than the mammalian LLRep3 mRNA (1.7kb) due to a much shorter 5' untranslated region.


Assuntos
Dictyostelium/genética , Proteínas/genética , Proteínas Ribossômicas/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Evolução Biológica , Códon , DNA Fúngico , Dictyostelium/crescimento & desenvolvimento , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Humanos , Camundongos , Dados de Sequência Molecular , Poli A/genética , Biossíntese de Proteínas , Proteínas de Ligação a RNA , Mapeamento por Restrição , Homologia de Sequência do Ácido Nucleico , Regiões Terminadoras Genéticas
19.
Mol Microbiol ; 5(2): 427-32, 1991 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1645841

RESUMO

The 7E gene is expressed late in normal development of Dictyostelium discoideum after pseudoplasmodium formation. After disaggregation of the developing cells, transcription of this gene depends entirely on exogenous 3'5' cyclic AMP (cAMP). The 5' flanking region of the 7E gene contains two TATA box-oligo (dT) promoter motifs but analysis of 7E gene expression by primer extension shows only a single primary transcript with transcription initiating immediately after the most proximal promoter motif during development or in disaggregated cells in the presence of exogenous cAMP. Four C-rich sequences lie within 350bp upstream of the cap site, analogous to the upstream elements implicated in the cAMP regulation of several other Dictyostelium genes expressed in development.


Assuntos
AMP Cíclico/metabolismo , Dictyostelium/genética , Regulação Fúngica da Expressão Gênica , Composição de Bases , Sequência de Bases , Southern Blotting , DNA Fúngico , Dictyostelium/crescimento & desenvolvimento , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Mapeamento por Restrição , TATA Box , Transcrição Gênica
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