Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-37999852

RESUMO

OBJECTIVE: To establish the influence of overweight/obesity, medicated hypothyroidism, and medicated non-syndromic hypogrowth on maxillary and mandibular growth. MATERIALS AND METHODS: The relation between 10 craniofacial anthropometric measurements and hypothyroidism (n = 216), overweight/obesity (n = 108), and non-syndromic hypogrowth (n = 250) were evaluated in patients aged 1-19 years and a control group of healthy patients (n = 587). A subgroup analysis was performed at the peak growth in all groups. RESULTS: Patients with overweight/obesity and hypothyroidism showed increased craniofacial growth, while hypogrowth patients showed differences in zygomatic width and nasal base growth. Females with hypothyroidism and non-syndromic hypogrowth showed decreased head circumference at peak growth. Several anthropometric measurements were increased in patients with overweight/obesity, including head circumference. When all age groups were analyzed, overweight/obese and hypothyroidism patients showed increased zygomatic width while decreased hypogrowth. Overall, most craniofacial anthropometric measurements in overweight/obese patients were increased. Finally, the peak growth in males with hypothyroidism and subjects with non-syndromic hypogrowth was delayed compared to the control group (p < 0.05). CONCLUSIONS: Children and adolescents with overweight/obesity and endocrine disorders showed alterations in craniofacial growth. Clinicians must be aware that the growth peak in these patients may be delayed when planning maxillary and mandibular orthopedic treatment.

2.
Mech Ageing Dev ; 204: 111670, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35367225

RESUMO

Huntington disease (HD) is a neurodegenerative disorder produced by an expansion of CAG repeats in the HTT gene. Patients of HD show involuntary movements, cognitive decline and psychiatric impairment. People carrying abnormally long expansions of CAGs (more than 35 CAG repeats) produce mutant huntingtin (mHtt), which encodes tracks of polyglutamines (polyQs). These polyQs make the protein prone to aggregate and cause it to acquire a toxic gain of function. Principally affecting the frontal cortex and the striatum, mHtt disrupts many cellular functions. In addition, this protein is expressed ubiquitously, and some reports show that many other cell types are affected by the toxicity of mHtt. Several studies reported that metformin, a widely-used anti-diabetic drug, is neuroprotective in models of HD. Here, we provide a review of the benefits of this substance to treat HD. Metformin is a pleiotropic drug, modulating different targets such as AMPK, insulin signalling and many others. These molecules regulate autophagy, chaperone expression, and more, which in turn reduce mHtt toxicity. Moreover, metformin alters gut microbiome and its metabolic processes. The study of potential targets, interactions between the drug, host and microbiome, or genomic and pharmacogenomic approaches may allow us to design personalised medicine to treat HD.


Assuntos
Doença de Huntington , Metformina , Doenças Neurodegenerativas , Animais , Corpo Estriado/metabolismo , Modelos Animais de Doenças , Humanos , Doença de Huntington/tratamento farmacológico , Doença de Huntington/genética , Doença de Huntington/metabolismo , Metformina/farmacologia , Metformina/uso terapêutico , Doenças Neurodegenerativas/metabolismo , Neurônios/metabolismo
3.
Pharmacol Res ; 161: 105105, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32739430

RESUMO

Expression of abnormally long polyglutamine (polyQ) tracks is the source of a range of dominant neurodegenerative diseases, such as Huntington disease. Currently, there is no treatment for this devastating disease, although some chemicals, e.g., metformin, have been proposed as therapeutic solutions. In this work, we show that metformin, together with salicylate, can synergistically reduce the number of aggregates produced after polyQ expression in Caenorhabditis elegans. Moreover, we demonstrate that incubation polyQ-stressed worms with low doses of both chemicals restores neuronal functionality. Both substances are pleitotropic and may activate a range of different targets. However, we demonstrate in this report that the beneficial effect induced by the combination of these drugs depends entirely on the catalytic action of AMPK, since loss of function mutants of aak-2/AMPKα2 do not respond to the treatment. To further investigate the mechanism of the synergetic activity of metformin/salicylate, we used CRISPR to generate mutant alleles of the scaffolding subunit of AMPK, aakb-1/AMPKß1. In addition, we used an RNAi strategy to silence the expression of the second AMPKß subunit in worms, namely aakb-2/AMPKß2. In this work, we demonstrated that both regulatory subunits of AMPK are modulators of protein homeostasis. Interestingly, only aakb-2/AMPKß2 is required for the synergistic action of metformin/salicylate to reduce polyQ aggregation. Finally, we showed that autophagy acts downstream of metformin/salicylate-related AMPK activation to promote healthy protein homeostasis in worms.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/efeitos dos fármacos , Ativadores de Enzimas/farmacologia , Metformina/farmacologia , Neurônios/efeitos dos fármacos , Peptídeos/toxicidade , Proteínas Serina-Treonina Quinases/metabolismo , Proteostase/efeitos dos fármacos , Salicilatos/farmacologia , Proteínas Quinases Ativadas por AMP , Animais , Animais Geneticamente Modificados , Autofagia/efeitos dos fármacos , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Sinergismo Farmacológico , Ativação Enzimática , Mutação , Neurônios/enzimologia , Neurônios/patologia , Agregados Proteicos , Agregação Patológica de Proteínas , Proteínas Serina-Treonina Quinases/genética
4.
Angiología ; 69(3): 137-146, mayo.-jun. 2017. graf, ilus
Artigo em Espanhol | IBECS | ID: ibc-164475

RESUMO

Introducción: Debido a las características electromagnéticas únicas del microhilo amorfo magnetoelástico, los cambios en la presión de un fluido provocarán una variación de la tensión mecánica sobre el sensor, lo que supondrá una variación de su imanación que será detectable de forma inalámbrica. Utilizando esta tecnología, se podrá desarrollar un sistema inalámbrico para el seguimiento de procedimientos en cirugía vascular. Métodos: El sensor diseñado consiste en un anillo de microhilo magnetoelástico que se integró en un modelo in vitro con flujo pulsátil. Se simularon distintos grados de estenosis en distintas localizaciones, tanto en arteria bovina como en un segmento de PTFE. Se realizó el análisis de Fourier de las señales registradas, y se emplearon el test de correlación de Pearson y curvas COR para el análisis de la información. Resultados: Se obtuvo un índice de correlación de Pearson de 0,945 (p < 0,001) entre la presión invasiva del fluido y la potencia de la señal emitida por el microhilo magnetoelástico en arteria bovina. Se obtuvieron unas excelentes curvas COR, tanto en el caso de las estenosis preanastomóticas (AUC 0,98; IC 95%: 0,97-1) y anastomóticas (AUC 0,93; IC 95%: 0,86-0,99), como en el caso de las estenosis distales (AUC 0,88; IC 95%: 0,79-0,98), comparadas con un grupo control. Conclusiones: El microhilo magnetoelástico es capaz de detectar, localizar y cuantificar el grado de estenosis en arteria bovina, así como en una anastomosis latero-terminal, con una elevada potencia estadística. Por primera vez se ha desarrollado un sensor inalámbrico in vitro para el seguimiento postoperatorio de los procedimientos en cirugía vascular (AU)


Introduction: Due to the unique electromagnetic characteristics of the magnetoelastic microwire, the changes in the pressure of a fluid will lead to changes in the mechanical pressure on the sensor, which will then cause a variation of its magnetisation which will be detectable wirelessly. Thus, a wireless system can be developed for following-up vascular surgery procedures. Methods: The sensor consists of a magnetoelastic microwire ring which was integrated into an in vitro model with pulsatile flow. Different degrees of stenosis were simulated in different locations in bovine artery, as well as in a polytetrafluoroethylene anastomosis. A Fourier analysis of the registered signals was performed, with a statistical analysis using Pearson test and ROC curves. Results: A Pearson index of .945 (P < .001) was obtained between the invasive pressure of the fluid and the power of the signal transmitted by the sensor in bovine artery. The sensor obtained very good ROC curves in the analysis of the registered the signals, in the case of pre-anastomotic stenosis (AUC .98; 95% CI: .97-1), anastomosis (AUC .93; 95% CI: .86-.99), as well as distal (AUC .88; 95% CI: .79-.98), compared to the control group. Conclusions: The magnetoelastic microwire has shown that it is capable of detecting, locating and quantifying the degree of stenosis in bovine artery, as well as in a latero- terminal anastomosis, with a high statistical power. For the first time, a wireless in vitro sensor has been developed for the post-operative follow-up of vascular surgery procedures (AU)


Assuntos
Humanos , Procedimentos Cirúrgicos Vasculares/estatística & dados numéricos , Doença Arterial Periférica/diagnóstico , Telemetria/instrumentação , Técnicas In Vitro/métodos , Monitorização Ambulatorial/instrumentação , Seguimentos , Tecnologia sem Fio , Cuidados Pós-Operatórios/métodos
5.
Clin Otolaryngol ; 42(6): 1172-1180, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28166395

RESUMO

OBJECTIVES: To define clinical subgroups by cluster analysis in patients with unilateral Meniere disease (MD) and to compare them with the clinical subgroups found in bilateral MD. DESIGN: A cross-sectional study with a two-step cluster analysis. SETTINGS: A tertiary referral multicenter study. PARTICIPANTS: Nine hundred and eighty-eight adult patients with unilateral MD. MAIN OUTCOME MEASURES: best predictors to define clinical subgroups with potential different aetiologies. RESULTS: We established five clusters in unilateral MD. Group 1 is the most frequently found, includes 53% of patients, and it is defined as the sporadic, classic MD without migraine and without autoimmune disorder (AD). Group 2 is found in 8% of patients, and it is defined by hearing loss, which antedates the vertigo episodes by months or years (delayed MD), without migraine or AD in most of cases. Group 3 involves 13% of patients, and it is considered familial MD, while group 4, which includes 15% of patients, is linked to the presence of migraine in all cases. Group 5 is found in 11% of patients and is defined by a comorbid AD. We found significant differences in the distribution of AD in clusters 3, 4 and 5 between patients with uni- and bilateral MD. CONCLUSIONS: Cluster analysis defines clinical subgroups in MD, and it extends the phenotype beyond audiovestibular symptoms. This classification will help to improve the phenotyping in MD and facilitate the selection of patients for randomised clinical trials.


Assuntos
Doença de Meniere/classificação , Doença de Meniere/complicações , Adulto , Idoso , Doenças Autoimunes/epidemiologia , Análise por Conglomerados , Estudos Transversais , Feminino , Perda Auditiva/epidemiologia , Humanos , Masculino , Doença de Meniere/diagnóstico , Pessoa de Meia-Idade , Transtornos de Enxaqueca/epidemiologia , Fenótipo , Estudos Retrospectivos , Fatores de Tempo
10.
Eye (Lond) ; 26(2): 315-20, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22094302

RESUMO

PURPOSE: To describe ocular abnormalities in patients with Friedreich ataxia (FRDA). METHODS: Patients diagnosed with FRDA by genetic analysis were invited to participate in a prospective cohort. The patients included underwent an extensive ophthalmologic examination, including low-contrast Sloan letter charts test and retinal nerve fiber layer (RNFL) thickness analysis by optical coherence tomography (OCT). RESULTS: Twenty-three patients agreed to participate. In all, 19 patients (83%) had a visual acuity of at least 0.8 in both eyes. Fundus examination showed diffuse optic nerve pallor in four patients. However, OCT showed a decreased mean peripapillary RNFL thickness in all but three adult cases and one teenager. The RNFL thickness was found to have a positive correlation with visual acuity (P=0.001) and contrast sensitivity (P=0.001) and a negative correlation with time elapsed from diagnosis (P=0.001). CONCLUSIONS: OCT and low contrast test sensitivity show that the visual pathway is affected in FRDA. However, in most patients there is no significant visual impairment. In a small proportion of patients visual acuity declines with disease progression. This study provides a better understanding of the ophthalmic features of FRDA.


Assuntos
Sensibilidades de Contraste/fisiologia , Ataxia de Friedreich/fisiopatologia , Fibras Nervosas/patologia , Células Ganglionares da Retina/patologia , Acuidade Visual/fisiologia , Adolescente , Adulto , Criança , Feminino , Ataxia de Friedreich/complicações , Humanos , Masculino , Estudos Prospectivos , Análise de Regressão , Tomografia de Coerência Óptica , Adulto Jovem
11.
Horiz. méd. (Impresa) ; 8(1): 6-34, ene.-jul. 2008. tab
Artigo em Espanhol | LILACS, LIPECS | ID: lil-676661

RESUMO

Se realizó el estudio de la acción hipoglicemiante de Ocimum sanctus (Albahaca morada), Notholaena nivea (Cuti-Cuti), Geranuim lechleri (Pasuchaca) y Smallantus sonchifolius (Yacón), frente a la hiperglicemia aloxánica, tanto de los extractos atomizados, como del pool de alcaloides, de cada una de las plantas. Igualmente, se determinó la DL50 del extracto atomizado y de los alcaloides de las cuatro plantas evaluadas. La toxicidad aguda se determinó en ratones albinos, cepa nihs, cuyos pesos oscilaron entre 25 y 30 g. La acción hipoglicemiante, fue evaluada en ratas albinas cepa holtzman, de 200 a 250 g de peso. Tanto los extractos atomizados, como los alcaloides de Cuti-Cuti, Pasuchaca y hojas de Yacón, mostraron un excelente efecto hipoglicemiante, frente a la hiperglicemia inducida por aloxano. Las tres plantas poseen escasa toxicidad aguda, y según los criterios de Williams podrían considerarse como plantas prácticamente atóxicas. Sin embargo, solamente el pool de alcaloides de Albahaca a la dosis de 250 mg/ kg de peso, mostró una escasa acción hipoglicemiante, no mostrando eficacia la dosis de 500mg/kg, del pool de alcaloides, ni el atomizado de la planta, a la dosis de 1000 mg/kg de peso.


The study of the hypoglicemic action of Ocimum sanctum (Albahaca morada), Notholaena nivea (Cuti-Cuti), Geranuim lechleri (Pasuchaca) and Smallantus sonchifolius (Yacón), was performed on alloxan-induced hyperglicemic rats. In addition, atomized extracts and the pool of alkaloids, of the different plants were studied. To evaluate acute toxicity, DL50 of the atomized extract and of the alkaloids on the four plants were determined using albino mice, whose weights oscillated between 25 and 30 g. The hypoglycemic action, was evaluated in Holtzman albino rats, of 200 to 250 g of weight. The atomized extracts, as well as the alkaloids of Cuti-Cuti, Pasuchaca and leaves of Yacón, showed an excellent hypoglicemic effect in the hyperglicemic alloxaninduced rats. These three plants have little acute toxicity and according to the Williams` criteria they could be considered as practically non toxic. On the other hand only the pool of alkaloids of Albahaca, at the dose of 250 mg/kg showed little hypoglicemic action. No hypoglicemic effect was observed with the albahaca alkaloids at the dose of 500mg/kg nor with the atomized extract of the plant at the dose of 1000 mg/kg.


Assuntos
Diabetes Mellitus , Hiperglicemia , Ocimum sanctum , Plantas , Testes de Toxicidade Aguda
12.
Horiz. méd. (Impresa) ; 7(1): 32-38, ene.-jun. 2007. tab, ilus
Artigo em Espanhol | LILACS, LIPECS | ID: lil-706078

RESUMO

El Lepidium meyenii, “Maca” y el Lupinus Mutabilis S, “Chocho”, pertenecen al grupo de plantas conocidas como nutracáticas. El uso de la Maca, se remonta al siglo 7 AC. En la época de la conquista fue el producto más importante del agro peruano; pertenece a la familia de las Cruciferaceae (Brasicaceae). Ambas plantas son usadas, desde tiempos precolombinos, como medicinales y/o alimenticias. En el presente trabajo, evaluamos el efecto de Maca y de Lupinus, en ratas hembras Sprague Dawley, con peso corporal entre 120 y 170g, sobre los valores de hematocrito, hemoglobina, glucosa, colesterol, trigliceridos, HDL, LDL, proteínas totales, albúmina, TGO, TGP y peso corporal, después de 15 y 30 días de tratamiento. Utilizamos 60 ratas albinas distribuidas en 3 grupos de 20 animales cada uno. Al primer grupo se le administró, por 30 días, suero fisiológico (GRUPO CONTROL). Al segundo grupo se le administró cocimiento acuoso de harina de maca, a la dosis de 500 mg/Kg y al tercer grupo, cocimiento acuoso de harina de semillas de chocho, desamargado y descascarado, a las dosis de 500 mg/Kg, durante 30 días. Nuestros resultados, indican un aumento de los niveles de triglicéridos en sangre, por efecto de Lupinus (de 45.9 a 76.55 mg), a los 30 días, con respecto al control, que varió de 43.5 a 61.8 mg. Con maca, las variaciones fueron de 43,5 a 56.7 mg: asimismo, apreciamos un ligero aumento del hematocrito y la hemoglobina, a los 15 días de tratamiento, con maca. Los an lisis estadísticos entre el grupo control y los tratados, con Maca y Lupinus, no fueron significativos.


Lepidium meyenii, “Maca” and the Lupinus mutabilis S, “Chocho” belong to the group of plants known as nutraceutic plants. Maca has been used since the seventh century BC and it was the most important crop in Peruvian agriculture during the sisxteenth century, around the time when the Spanierds arrived to our territory. This plant belongs to the Cruciferaceae (Brasicaceae) family. Both plants (Maca and Chocho) were used in Peru, since pre Columbian times as part of the diet as well as for their medicinal properties. In these issue, we evaluated the effects of Maca and Lupinus on female Sprague Dawley rats (weight between 120 and 170 g), and we tested Hemoglobin, hematocrit, total proteins, albumin, TGO, TGP and corporal weight values after 15 and 30 days of trestment.We used 60 albino rats, distributed in three groups of twenty animals each one. The first group was the control and re ceived 0, 9% saline solution for 30 days. The second group received Maca flour watery solution at 500 mg/kg doses and the third group received Lupinus, watery solution at 500 mg/kg doses for thirty days.Our results showed an increase of the serum levels of triglycerides due to Lupinus (from 45.9 to 76.55mg) after 30 days in relation to the control that varied from 43.5 to 61.8mg. With Maca variations were from 43.5 to 56.7 mg. We also appeciated a slight increase of hematocrit and haemoglobin after 15 days of treatment with Maca in relation to the control group. Analyses between control and treated groups showed no statistical differences.


Assuntos
Lepidium , Lupinus , Metabolismo , Ratos
13.
Horiz. méd. (Impresa) ; 5(1): 57-61, jun. 2005. tab, graf
Artigo em Espanhol | LILACS, LIPECS | ID: lil-676645

RESUMO

Al evaluar el efecto analgésico se encontró actividad positiva del extracto metanólico de Maytenus krukovii (chuchahuasi), Alchornea castaneifolia (Hiporuro), Sambucus nigra (Saúco) y Aristeguietia discolor (Pulmonaria) a las dosis de 100 mg/kg, 250 mg/kg, 250mg/kg y 750 mg/kg, respectivamente, por vía oral; luego de una hora de administración se encontró que el efecto analgésico de Chuchuhuasi y Pulmonaria eran comparables al Ibuprofeno. Asimismo, apreciamos, en todos los extractos, una prolongación del período de latencia con respecto al control.


We evaluated the analgesic effect of four different plants, and this effect was positive for thr metanolic extracts of Maytenus krukovii (Chuchuhuasi), Alchornea castaneifolia (Hiporuro), Sambucus nigra (Saúco) y Aristeguietia discolor (Pulmonaria) in the doses of 1000 mg/g, 250 mg/kg, and 750 mg/kg, respectively administered orally to mice. After one hour of administration the analgesic effect of Chuchuhuasi and Pulmonaria were comparable to that Ibuprofene. It was also noted that all extracts delayed the latency time regarding to the control sample.


Assuntos
Animais , Analgésicos , Euphorbiaceae , Ibuprofeno/uso terapêutico , Maytenus , Pulmonaria , Camundongos , Sambucus nigra , Experimentação Animal
14.
Transplant Proc ; 36(4): 989-90, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15194343

RESUMO

INTRODUCTION: Patients with heart failure frequently develop renal failure, which increases the mortality rate among patients undergoing cardiac transplantation. PURPOSE: To determine whether preoperative renal function influenced postoperative mortality in cardiac transplantation recipients. MATERIALS AND METHODS: The measurements of plasma urea, plasma creatinine, and 24-hour creatinine clearance in patients who underwent cardiac transplantation were correlated with mortality at 30, 90, and 365 days after the procedure, using Student t test for continuous variables and the chi-square test for categorical variables. RESULTS: All variables correlated with mortality, particularly plasma creatinine at 30, 90, and 365 days (P =.029,.003, and.0029, respectively). CONCLUSION: Preoperative renal failure is a mortality indicator in cardiac transplantation recipients.


Assuntos
Transplante de Coração/mortalidade , Insuficiência Renal/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/classificação , Complicações Pós-Operatórias/mortalidade , Insuficiência Renal/mortalidade , Estudos Retrospectivos
15.
Transplant Proc ; 36(04): 989-990, 2004. tab
Artigo em Inglês | Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1068308

RESUMO

Introduction. Patients with heart failure frequently develop renal failure, which increasesthe mortality rate among patients undergoing cardiac transplantation.Purpose. To determine whether preoperative renal function influenced postoperativemortality in cardiac transplantation recipients.Materials and Methods. The measurements of plasma urea, plasma creatinine, and 24-hour creatinine clearance in patients who underwent cardiac transplantation werecorrelated with mortality at 30, 90, and 365 days after the procedure, using Student t test for continuous variables and the chi-square test for categorical variables.Results. All variables correlated with mortality, particularly plasma creatinine at 30, 90,and 365 days (P .029, .003, and .0029, respectively).Conclusion. Preoperative renal failure is a mortality indicator in cardiac transplantation recipients.


Assuntos
Creatinina , Insuficiência Cardíaca/cirurgia , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/mortalidade , Insuficiência Renal/cirurgia , Insuficiência Renal/mortalidade , Transplante de Coração/mortalidade
17.
Hum Genet ; 106(1): 86-92, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10982187

RESUMO

Friedreich's ataxia is caused by mutations in the FRDA gene that encodes frataxin, a nuclear-encoded mitochondrial protein. Most patients are homozygous for the expansion of a GAA triplet repeat within the FRDA gene, but a few patients show compound heterozygosity for a point mutation and the GAA-repeat expansion. We analyzed DNA samples from a cohort of 241 patients with autosomal recessive or isolated spinocerebellar ataxia for the GAA triplet expansion. Patients heterozygous for the GAA expansion were screened for point mutations within the FRDA coding region. Molecular analyses included the single-strand conformation polymorphism analysis, direct sequencing, and linkage analysis with FRDA locus flanking markers. Seven compound heterozygous patients were identified. In four patients, a point mutation that predicts a truncated frataxin was detected. Three of them associated classic early-onset Friedreich's ataxia with an expanded GAA allele greater than 800 repeats. The other patient associated late-onset disease at the age of 29 years with a 350-GAA repeat expansion. In two patients manifesting the classical phenotype, no changes were observed by single-strand conformation polymorphism (SSCP) analysis. Linkage analysis in a family with two children affected by an ataxic syndrome, one of them showing heterozygosity for the GAA expansion, confirmed no linkage to the FRDA locus. Most point mutations in compound heterozygous Friedreich's ataxia patients are null mutations. In the present patients, clinical phenotype seems to be related to the GAA repeat number in the expanded allele. Complete molecular definition in these patients is required for clinical diagnosis and genetic counseling.


Assuntos
Ataxia de Friedreich/genética , Proteínas de Ligação ao Ferro , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Adulto , Idade de Início , Alelos , Criança , Pré-Escolar , Análise Mutacional de DNA , Saúde da Família , Genes Recessivos , Ligação Genética , Genótipo , Heterozigoto , Humanos , Repetições de Microssatélites , Linhagem , Fenótipo , Mutação Puntual , Polimorfismo Conformacional de Fita Simples , Expansão das Repetições de Trinucleotídeos , Repetições de Trinucleotídeos
18.
Mol Biol Evol ; 17(8): 1185-93, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10908638

RESUMO

The Ty3/gypsy family of retroelements is closely related to retroviruses, and some of their members have an open reading frame resembling the retroviral gene env. Sequences homologous to the gypsy element from Drosophila melanogaster are widely distributed among Drosophila species. In this work, we report a phylogenetic study based mainly on the analysis of the 5' region of the env gene from several species of the obscura group, and also from sequences already reported of D. melanogaster, Drosophila virilis, and Drosophila hydei. Our results indicate that the gypsy elements from species of the obscura group constitute a monophyletic group which has strongly diverged from the prototypic D. melanogaster gypsy element. Phylogenetic relationships between gypsy sequences from the obscura group are consistent with those of their hosts, indicating vertical transmission. However, D. hydei and D. virilis gypsy sequences are closely related to those of the affinis subgroup, which could be indicative of horizontal transmission.


Assuntos
Drosophila/genética , Evolução Molecular , Retroelementos/genética , Retroviridae/genética , Animais , DNA/química , DNA/genética , Drosophila/classificação , Genes env/genética , Filogenia , Análise de Sequência de DNA , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...