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1.
Rev Med Interne ; 34(9): 515-21, 2013 Sep.
Artigo em Francês | MEDLINE | ID: mdl-23523077

RESUMO

PURPOSE: Recent data show that the quality of anticoagulation evaluated in patients receiving vitamin K antagonists (VKA) is not optimal in France. The aim of this retrospective study was to estimate the performances of six French anticoagulant clinics that manage VKA treatments over a 3-year period, from 2009 to 2011. METHODS: All clinics used the same rule based software. We determined the time spent in the therapeutic range (TTR), a surrogate end-point of quality of treatment with VKA. RESULTS: The overall duration of follow-up was 2755 patient-years concerning 2385 patients. The time spent in the therapeutic range 2 to 3 assigned for 89% of the patients, was 73%. On the other hand the time spent in the therapeutic range for the other two INR ranges (2.5-3.5 and 3-4.5) concerning 11% of patients with prosthetic heart valve was lower (63.7% and 68.8% respectively) with an imbalance in favour of the time below the range. In this study, warfarin (Coumadine(®)) and fluindione (Previscan(®)) allowed an equivalent quality of anticoagulation. The 1728 patients of age ranged from 60 to 100 years spent more time in TTR than the 651 younger patients. The percentage of time spent with an INR greater than 5 was extremely reduced which is a guarantee of safety. CONCLUSION: These results prove that anticoagulant clinics in France have the same good performances as their counterparts abroad. It can be assumed that a high TTR contributes to a low incidence of both bleedings and thrombosis.


Assuntos
4-Hidroxicumarinas/uso terapêutico , Instituições de Assistência Ambulatorial , Anticoagulantes/uso terapêutico , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Indenos/uso terapêutico , Vitamina K/antagonistas & inibidores , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial/estatística & dados numéricos , Transtornos da Coagulação Sanguínea/epidemiologia , Criança , Feminino , França/epidemiologia , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Prática Profissional , Estudos Retrospectivos , Vitamina K/uso terapêutico , Adulto Jovem
2.
Rev Med Interne ; 30(7): 567-72, 2009 Jul.
Artigo em Francês | MEDLINE | ID: mdl-19299042

RESUMO

INTRODUCTION: Anticoagulation clinics and computerized management of chronic oral anticoagulation increase the time spent in the therapeutic range with both mortality and morbidity reduction. Usually, anticoagulation clinics are hospital-based medical care centers. We report the five-year results from a general medicine center (CSCTA) using a computer-assisted management. METHODS: A prospective cohort observational study of 530 primary care patients that were receiving long term oral anticoagulation. RESULTS: Cardiac arrhythmia (55%), heart valve disease and venous thrombo-embolic disease (30%) represented the most common indications of oral anticoagulation. Patients received fluindione, warfarin and acenocoumarol in 80%, 13% and 7%, respectively. The duration of treatment was at least one year in 54% of the cases, and was at least three years in 25% of the cases. The rate of patients that were in average within the therapeutic range (INR 2-3) was 72%, while 12% were under and 16% over the therapeutic range. Corresponding rates were 82, 17 and 1% respectively for all anticoagulation targets (INR 1.5-4.5). Twenty-six bleeding events (4.9 per 100 patient-years) and four thrombotic complications (0.75 per 100 patient-years) occurred. Life-threatening hemorrhage occurred in 1.3 per 100 patient-years. After the equilibration of the anticoagulation, the average delay of control between two consecutive INR was 19 days. CONCLUSION: The results obtained with CSCTA were similar to those reported by other anticoagulation clinics regarding hemorrhagic complications and time spent in the therapeutic range. In contrast, thrombotic events were less frequent. Because of the absence of a control group, a medico-economic analysis could not be performed.


Assuntos
Anticoagulantes/uso terapêutico , Administração Oral , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , França , Humanos , Coeficiente Internacional Normatizado , Masculino , Pessoa de Meia-Idade , Ambulatório Hospitalar , Estudos Prospectivos , Adulto Jovem
3.
Oncol Rep ; 18(1): 235-40, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17549373

RESUMO

Gastric carcinogenesis is a multistep process progressing from chronic gastritis, through glandular atrophy (GA), intestinal metaplasia (IM) and dysplasia. We have previously demonstrated that minority patients at New York City hospitals are infected with a relatively virulent strain of H. pylori (Hp) and that Hp infection is associated with an increased incidence of precancerous changes in the gastric mucosa. Nevertheless, precancerous changes are not observed in every Hp-infected individual, suggesting that environmental and genetic factors may also play a role in the formation and appearance of precancerous lesions. In the present study, the association between polymorphisms in the promoter regions of human myeloperoxidase (MPO -463G--> A) and catalase (CAT -262C-->T) genes and the appearance of precancerous changes in the gastric mucosa of our patient population were examined. Patients enrolled in this study were undergoing endoscopy for gastrointestinal complaints. Samples were collected from 126 patients at Kings County Hospital in Brooklyn and St. John's Episcopal Hospital in Queens. One antral biopsy was taken for genotyping, while additional biopsies were taken from the antrum and fundic region for histological analysis and were scored with respect to acute and chronic inflammation, GA, IM and Hp infestation according to the Sydney classification. MPO and CAT genotypes were determined by PCR and RFLP. CAT genotypes did not influence the incidence or severity of precancerous lesions in the fundic or antral regions of the stomach, whereas the MPO -463A allele was associated with an increase in intensity of gastric atrophy in the fundic mucosa. In Hp-infected individuals, the MPO -463G/G genotype was associated with an increase in the incidence of IM in the antrum, whereas the A allele was associated with an increase in IM in the fundic region. These paradoxical findings suggest that different MPO genotypes are associated with the appearance of IM in distinct anatomical regions of the stomach. However, since the majority of gastric cancer (GC) cases in our patient population occurred in the antrum, the MPO -463G/G genotype, which is associated with increased MPO expression and antral IM, may be considered a risk factor for GC.


Assuntos
Catalase/genética , Mucosa Gástrica/patologia , Neoplasias Intestinais/genética , Peroxidase/genética , Polimorfismo Genético , Lesões Pré-Cancerosas/genética , Neoplasias Gástricas/genética , DNA Viral/genética , Feminino , Gastrite Atrófica/genética , Gastrite Atrófica/microbiologia , Gastrite Atrófica/patologia , Genótipo , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Infecções por Helicobacter/patologia , Helicobacter pylori , Hospitais Urbanos , Humanos , Incidência , Neoplasias Intestinais/microbiologia , Neoplasias Intestinais/patologia , Masculino , Metaplasia/genética , Metaplasia/microbiologia , Metaplasia/patologia , Pessoa de Meia-Idade , New York , Lesões Pré-Cancerosas/microbiologia , Lesões Pré-Cancerosas/patologia , Prevalência , Antro Pilórico/microbiologia , Antro Pilórico/patologia , Neoplasias Gástricas/microbiologia , Neoplasias Gástricas/patologia
4.
Dig Dis Sci ; 51(10): 1801-9, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16944298

RESUMO

Gastric carcinogenesis is a multistep process progressing from chronic gastritis, through glandular atrophy (GA), intestinal metaplasia (IM) and dysplasia. Infection of the stomach with H. pylori increases the risk of developing gastric cancer. Few studies have examined the degree to which Hp-induced changes occur in specific populations. In the present study, we examined the association between Hp infection and histological changes in the gastric mucosa of patients at two inner-city hospitals in New York. Patients enrolled in this study were undergoing endoscopy for gastrointestinal complaints. One antral biopsy was taken for detecting and genotyping Hp by PCR. Additional biopsies were taken from the antrum and fundic region for histological analysis and were scored with respect to acute and chronic inflammation, GA, IM and Hp infestation according to the Sydney classification. Hp strains infecting these patients were genotyped with respect to the expression of Hp virulence factors including VacA, CagA, and BabA2. Samples were collected from 126 patients at Kings County Hospital in Brooklyn and St. John's Episcopal Hospital in Queens. Hp infection rates were highest in Blacks (41.6%) and Hispanics (29.4%) and lowest in Caucasians (18.8%). Scores for acute and chronic inflammation and IM were higher in Hp-infected individuals in both the antrum and fundic regions, whereas Hp infection did not affect the incidence or intensity of GA. In Hp-infected individuals, the incidence of IM was greater in the antrum (Hp-infected 37.8% vs. non-infected 9.2%, p < 0.05) and fundic region (Hp-infected 15.1% vs. noninfected 1.8%, p < 0.05). Genotyping of the Hp strains infecting these patients revealed that the predominant VacA allele was s1 bm 1 and that the CagA gene was present in 69.8% of Hp-infected samples. Interestingly, the BabA2 gene was detected in only four samples (9.3%). The incidence of IM in the antrum was higher in CagA + samples when compared with CagA- samples (52.2% vs. 15.4%, respectively). Our findings indicate that the virulent Hp strain infecting minority patients treated at inner-city hospitals in New York City is associated with a high incidence of IM and that these patients may be at greater risk for developing gastric cancer than the general population.


Assuntos
Mucosa Gástrica/patologia , Gastrite Atrófica/microbiologia , Gastrite Atrófica/patologia , Infecções por Helicobacter/patologia , Helicobacter pylori , Intestinos/patologia , Estudos de Casos e Controles , Feminino , Hospitais Urbanos , Humanos , Incidência , Masculino , Metaplasia/epidemiologia , Metaplasia/microbiologia , Metaplasia/patologia , Pessoa de Meia-Idade , Cidade de Nova Iorque , Índice de Gravidade de Doença , Saúde da População Urbana
5.
Theor Appl Genet ; 113(3): 453-65, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16786342

RESUMO

Polyploidy plays a pivotal role in plant evolution. However, polyploids with polysomic inheritance have hitherto been severely underrepresented in plant population genetic studies, mainly due to a lack of appropriate molecular genetic markers. Here we report the establishment and experimental validation of six fully informative microsatellite markers in tetraploid gynodioecious Thymus praecox agg. Sequence data of 150 microsatellite alleles and their flanking regions revealed high variation, which may be characteristic for polyploids with a reticulate evolutionary history. Understanding the patterns of mutation (indels and substitutions) in microsatellite flanking-sequences was a prerequisite for the development of co-dominant markers for fragment analyses. Allelic segregation patterns among progeny arrays from ten test crosses revealed tetrasomic inheritance in T. praecox agg. No evidence of frequent double reduction was detected. Polymerase chain reaction (PCR) based dosage effects allowed for precise assignment of allelic configuration at all six microsatellite loci. The quantification of allele copy numbers in PCR was verified by comparisons of observed and expected gametic allele frequencies and heterozygosities in test crosses. Our study illustrates how PCR based markers can provide reliable estimates of heterozygosity and, thus, powerful tools for breeding system and population genetic analyses in polyploid organisms.


Assuntos
Alelos , Variação Genética , Padrões de Herança , Repetições de Microssatélites , Poliploidia , Thymus (Planta)/genética , Cruzamento , Segregação de Cromossomos , Frequência do Gene , Heterozigoto , Reação em Cadeia da Polimerase
6.
Heredity (Edinb) ; 87(Pt 3): 344-55, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11737281

RESUMO

The reconstruction of recent historical population sizes allowed us to investigate the influence of random evolutionary processes on present-day genetic diversity in populations of Dryopteris cristata. This long-lived, allotetraploid fern is rare and endangered in the study area at the southwestern border of its European distribution. Random amplified polymorphic DNA (RAPD) diversity of 280 individuals from 14 populations of D. cristata was extraordinarily low, suggesting an ancient bottleneck in the species' history. Analysis of molecular variance (AMOVA) of 25 different RAPD multiband phenotypes revealed significant genetic variation among three geographical regions (15%) and among populations within regions (34%); 51% of total variance was attributed to variation within populations. High population differentiation indicated limited gene flow among populations, and genetic divergence was not correlated with geographical distance. There was no relationship between genetic variation within population, estimated as molecular variance, and present-day population size. Populations with recent historical bottlenecks of fewer than 25 individuals showed a substantial and significant reduction in genetic variation, compared with populations without bottlenecks. Comparatively high levels of genetic variation were still maintained in small remnants (60-110 individuals) of formerly large populations. Average deviations of frequencies of widespread polymorphic markers within populations from their frequencies in the whole dataset were significantly higher in small or recently bottlenecked populations than in constantly large populations, thus providing evidence for random sampling effects during genetic bottlenecks and drift in small populations. The present investigation demonstrates the importance of population history for understanding present-day genetic diversity within natural populations, as well as for conservation biology.


Assuntos
DNA de Plantas/genética , Gleiquênias/genética , Variação Genética , Frequência do Gene , Marcadores Genéticos , Geografia , Técnica de Amplificação ao Acaso de DNA Polimórfico
8.
Acta Cytol ; 45(4): 605-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11480726

RESUMO

BACKGROUND: Mucinous cystadenocarcinoma of the salivary gland is a rare entity. Review of the literature from 1991 to 1999 revealed no previous reports on its cytologic features. CASE: A 25-year-old man had a slowly growing, painless mass in the left parotid gland. Fine needle aspiration biopsy, performed prior to surgical excision, showed clusters of minimally atypical epithelial cells in which occasional vacuolated cells containing mucin could be seen. Pathologic evaluation of the resected parotid mass showed it to be a mucinous cystadenocarcinoma. CONCLUSION: The cytologic differential diagnosis of mucinous cystadenocarcinoma is with low grade mucoepidermoid carcinoma and with mucinous adenocarcinoma. Mucinous cystadenocarcinoma must be cystic; cysts may be present in low grade mucoepidermoid carcinoma, but their size and prominence varies. Mucinous adenocarcinoma is not cystic but gelatinous. Nuclei are bland in both mucinous cystadenocarcinoma and low grade mucoepidermoid carcinoma but are atypical in mucinous adenocarcinoma. There is no squamous differentiation in either mucinous cystadenocarcinoma or mucinous adenocarcinoma, but it is subtle in low grade mucoepidermoid carcinomas. Mucinous cystadenocarcinoma should be considered a potential candidate in the differential diagnosis of mucinous lesions that can occur in the salivary gland.


Assuntos
Cistadenocarcinoma Mucinoso/patologia , Neoplasias Parotídeas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Cistadenocarcinoma Mucinoso/diagnóstico , Feminino , Humanos , Masculino , Neoplasias Parotídeas/diagnóstico
9.
Mol Ecol ; 10(2): 357-70, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11298951

RESUMO

Two main possibilities regarding glacial survival of the mountain flora of the Alps during the Quaternary have been discussed: the tabula rasa and the nunatak hypotheses. Eritrichium nanum (L.) Gaudin (Boraginaceae) is a perennial cushion plant, occurring at high elevations of the Central Alps and having a preference for extreme habitats. It belongs to a group of high-alpine plants, for which in situ glacial survival on nunataks is ecologically possible. By investigating 20 populations of E. nanum of potential nunatak and peripheral refugial regions using amplified fragment length polymorphism, considerable genetic differences between populations from the Central Alps and populations from peripheral refugia were detected; hence, the latter probably did not serve as potential sources for the re-colonization of the Central Alps after glaciation. Genetic variation was hierarchically structured (AMOVA), and three genetically distinct regions could be identified in the Central Alps. Two of these, the Penninic and Rhaetic Alps, correspond to nunatak regions proposed in the biogeographic literature. Populations from the Lepontic Alps formed a third genetic group. Genetic correlation (Mantel statistics) was highest within populations, with a modest decline among populations within specific nunatak regions and a negative correlation outside the genetic influence of specific nunatak regions. In situ glacial survival in E. nanum could be a model for the Quaternary history of other alpine plants, especially those that also occur at high elevations and in similar habitats.


Assuntos
Magnoliopsida/genética , Altitude , Interpretação Estatística de Dados , Meio Ambiente , Europa (Continente) , Genes de Plantas , Variação Genética , Genética Populacional , Magnoliopsida/classificação , Filogenia , Reação em Cadeia da Polimerase/métodos
10.
Am J Bot ; 87(4): 583-90, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10766730

RESUMO

Several alpine species have outlying populations in the lowlands and lower mountains north of the Alps. These small, isolated populations are usually described as either (1) glacial relics, (2) descendants from populations living on forelands and moraines during the ice ages, or (3) populations founded by long-distance dispersal after glaciation. A floristic survey of the historic and present distributions and an allozyme investigation were performed on one of these relic species, Saxifraga aizoides. The species was historically more abundant and had more stations in more regions of northeastern Switzerland. The former population structures within regions, nowadays destroyed, were still reflected in distinct and high regional genetic diversity and variation. There was weak evidence of increased inbreeding in outlying populations, but populations did not deviate from Hardy-Weinberg equilibrium. No geographic pattern of genetic variation above the regional scale (>10 km) was found. Based on the spatial and genetic structures found, it was not possible to discriminate between the abovementioned hypotheses. Nevertheless, the study shows how a thorough evaluation of distribution and abundance data aids the interpretation of genetic data with respect to population history, biogeography, and conservation biology.

11.
J Assoc Acad Minor Phys ; 10(4): 94-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10826016

RESUMO

Esophageal cancer in advanced stages grows to occlude the esophageal lumen; presenting symptoms include dysphagia and weight loss. Esophageal cancer rarely grows to occupy a narrow column of the esophagus or manifests neurologic symptoms. We report the case of a 58-year-old man with a history of tobacco and alcohol abuse and chronic obstructive airway disease who presented with headaches, left-sided weakness, unsteady gait, and weight loss. Physical examination showed left-sided weakness. Computed tomographic scan of the brain and chest revealed, respectively, a right frontoparietal mass and a tumor mass in the distal esophagus. The patient's weakness and headaches improved after treatment with dexamethasone and craniotomy with partial enucleation of the brain lesion. An esophagogastroduodenoscopy revealed a large, elongated mass in the esophagus. Pathologic analyses of biopsies of the esophageal mass showed mixed adenosquamous carcinoma. The brain mass histology showed poorly differentiated carcinoma. Several weeks after craniotomy, the patient developed respiratory failure and died. While it appears that the esophageal cancer metastasized to the brain, there is the possibility of other undetected primary tumor with metastasis to the brain. Nonetheless, the endoscopic appearance and clinical presentation of this case are unusual and noteworthy.


Assuntos
Carcinoma Adenoescamoso/diagnóstico , Neoplasias Esofágicas/diagnóstico , Esofagoscopia , Neoplasias Encefálicas/secundário , Carcinoma Adenoescamoso/secundário , Neoplasias Esofágicas/patologia , Evolução Fatal , Humanos , Masculino , Pessoa de Meia-Idade
12.
Am J Bot ; 85(7): 1038, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21684989

RESUMO

Debates on speciation processes in pteridophytes have revived. In order to study the evolutionary origin of an apomictic fern species, we investigated the genetic variation in the strictly agamosporous Dryopteris remota. We determined the genotypes of 22 individuals from many different locations within the species' European distribution and of 20 individuals from a Swiss population. A previous study on isozyme variation showed no intraspecific genetic variation in a similar sample set (Schneller and Holderegger, 1994, American Fern Journal 84: 94-98). In contrast to this, four out of 12 random amplified polymorphic DNA (RAPD) primers tested revealed low genetic diversity among individuals of D. remota from different locations. Intrapopulational genetic variation was also very low, but in the single population studied, a unique multiband genotype could be detected. The geographic distribution of genetic variation found in D. remota was best explained by the assumption of a single origin, the accumulation of somatic mutations during spread, and occasional, but effective, events of dispersal over large distances. The present study thus stresses the importance of long-distance dispersal in evolutionary processes and biogeography of ferns.

13.
Oecologia ; 117(1-2): 105-107, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28308475

RESUMO

Anemone nemorosa is a perennial rhizomatous plant of European woodlands. The "probability of clonal identity" method estimated the relative proportion of sexual to vegetative reproduction in this species to be 4.4% from allozyme genotype distributions. This result is congruent with investigations on the germination, short-term demography, population genetics, and breeding system of this species, and supports the hypothesis that even low levels of seedling recruitment can maintain considerable intrapopulational genetic diversity.

14.
Gynecol Oncol ; 54(1): 87-90, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8020845

RESUMO

A case of endometrial adenocarcinoma discovered incidentally in a patient who underwent an elective abortion is described here. Eleven other cases of pregnancy occurring with endometrial carcinoma were found in the literature. The presence of immature progesterone unresponsive endometrium is discussed as a possible etiology of the unusual coincidence of these two common phenomena.


Assuntos
Adenocarcinoma/patologia , Neoplasias do Endométrio/patologia , Complicações Neoplásicas na Gravidez/patologia , Aborto Induzido , Adenocarcinoma/cirurgia , Adulto , Curetagem , Neoplasias do Endométrio/cirurgia , Feminino , Humanos , Gravidez , Complicações Neoplásicas na Gravidez/cirurgia , Reoperação
15.
Cancer ; 59(7): 1307-13, 1987 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-2434207

RESUMO

Fifty-eight effusions (42 pleural and 16 ascitic fluids) from patients with and without cancer were analyzed by conventional cytology and the results compared with DNA patterns generated by flow cytometry of 10(4) nuclei and several modes of Feulgen cytophotometry. In 31 patients (24 without evidence of cancer and seven with history of cancer and cytologically negative fluids), the fluids were diploid by flow cytometry. One fluid with atypical cells from a lymphoma suspect was also diploid. Flow cytometry of 26 cytologically cancerous fluids disclosed aneuploid DNA patterns in 16 and diploid patterns in ten. Feulgen cytophotometry of 11 of these fluids (three aneuploid, eight diploid) was performed on nuclear preparations identical to those used in flow cytometry and on restrained smears used for visual analysis. The analysis was performed in two modes: as a study of 500 sequential nuclei in an automated system, mimicking flow cytometry, and visually selected large, presumably malignant nuclei. In nine of the 11 cases, the DNA content of visually selected cancer cells was aneuploid, even though this DNA pattern was not evident in the analysis of 500 sequential cells. In two cases, both diploid by flow cytometry, the Feulgen analysis confirmed the presence of cancer cells in the diploid range. In samples of 10(4) nuclei representing a mixed population of cells occurring in effusions, the presence of aneuploid cancer cells may not be disclosed by conventional flow cytometry. A larger sample of cells, a detailed analysis of DNA histograms, and perhaps sorting of select cells in the hypertetraploid range, may prove essential before flow cytometry can be accepted as a diagnostic tool in the laboratory in the assessment of effusions.


Assuntos
Líquido Ascítico/genética , Corantes , Citofotometria/métodos , Citometria de Fluxo , Derrame Pleural/genética , Corantes de Rosanilina , Coloração e Rotulagem , Aneuploidia , Contagem de Células , DNA/análise , Diploide , Humanos , Neoplasias/genética
19.
Nucleic Acids Res ; 5(12): 4579-92, 1978 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-370774

RESUMO

Mitochondrial tRNAPhe from Saccharomyces cerevisiae isolated by two-dimensional gel electrophoresis was sequenced by fingerprinting uniformly labeled 32 P-tRNA as well as by 5'-end postlabeling techniques. Its sequence was found to be: pG-C-U-U-U-U-A-U-A-G-C-U-U-A-G-D-G-G-D-A-A-A-G-C-m22G-A-U-A-A-A-phi-U-G-A-A-m1G-A-phi-U-U-A-U-U-U-A-C-A-U-G-U-A-G-U-phi-C-G-A-U-U-C-U-C-A-U-U-A-A-G-G-G-C-A-C-C-A. The secondary structure we propose, in order to maximize base pairing in the phiC stem and to allow tertiary interaction between G15 and C46, excludes U50 from base pairing giving a bulge in the phiC stem. No conclusion can be drawn concerning the endosymbiotic theory of mitochondria evolution by comparing the primary structure of mt. tRNAPhe with other sequenced tRNAsPhe. This mt.tRNAPhe lacks some of the structural elements reported to be involved in the yeast cytoplasmic phenylalanyl-tRNA ligase recognition site and cannot be aminoacylated by purified yeast cytoplasmic phenylalanyl-tRNA ligase.


Assuntos
DNA Mitocondrial/metabolismo , RNA de Transferência , Saccharomyces cerevisiae/metabolismo , Sequência de Bases , Conformação de Ácido Nucleico , Oligorribonucleotídeos/análise , Fenilalanina , RNA de Transferência/biossíntese , RNA de Transferência/isolamento & purificação , Ribonucleases
20.
C R Acad Hebd Seances Acad Sci D ; 287(8): 845-8, 1978 Oct 09.
Artigo em Francês | MEDLINE | ID: mdl-103657

RESUMO

The primary structure of mitochondrial tRNAPhe from Saccharomyces cerevisiae, purified by two-dimensional polyacrylamide gel electrophoresis, was determined using, standard procedures on in vivo 32P-labeled tRNA, as well as the new 5'-end postlabeling techniques. We propose a cloverleaf model which allows for tertiary interaction between cytosine in position 46 and guanine in position 15 and maximizes base pairing in the psi C stem, thus excluding the uracile in position 50 from base pairing in the psi C stem. Comparison of the primary structure of this tRNA with all other known procaryotic, chloroplastic or cytoplasmic tRNAsPhe sequences does not lead to any conclusion about the endosymbiotic theory of mitochondria evolution.


Assuntos
Mitocôndrias/ultraestrutura , RNA de Transferência , Saccharomyces cerevisiae/ultraestrutura , Sequência de Bases , Fenômenos Químicos , Química , Conformação de Ácido Nucleico , Fenilalanina
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