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1.
Mol Biol Rep ; 51(1): 174, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38252353

RESUMO

BACKGROUND: Cell-free DNA (cfDNA) is a source for liquid biopsy used for cancer diagnosis, therapy selection, and disease monitoring due to its non-invasive nature and ease of extraction. However, cfDNA also participates in cancer development and progression by horizontal transfer. In humans, cfDNA circulates complexed with extracellular vesicles (EV) and macromolecular complexes such as nucleosomes, lipids, and serum proteins. The present study aimed to demonstrate whether cfDNA not associated with EV induces cell transformation and tumorigenesis. METHODS: Supernatant of the SW480 human colon cancer cell line was processed by ultracentrifugation to obtain a soluble fraction (SF) and a fraction associated with EV (EVF). Primary murine embryonic fibroblast cells (NIH3T3) underwent passive transfection with these fractions, and cell proliferation, cell cycle, apoptosis, cell transformation, and tumorigenic assays were performed. Next, cfDNA was analyzed by electronic microscopy, and horizontal transfer was assessed by human mutant KRAS in recipient cells via PCR and recipient cell internalization via fluorescence microscopy. RESULTS: The results showed that the SF but not the EVF of cfDNA induced proliferative and antiapoptotic effects, cell transformation, and tumorigenesis in nude mice, which were reduced by digestion with DNAse I and proteinase K. These effects were associated with horizontal DNA transfer and cfDNA internalization into recipient cells. CONCLUSIONS: The results suggest pro-tumorigenic effects of cfDNA in the SF that can be offset by enzyme treatment. Further exploration of the horizontal tumor progression phenomenon mediated by cfDNA is needed to determine whether its manipulation may play a role in cancer therapy.


Assuntos
Ácidos Nucleicos Livres , Humanos , Animais , Camundongos , Ácidos Nucleicos Livres/genética , Camundongos Nus , Células NIH 3T3 , Carcinogênese , DNA
2.
Heliyon ; 8(11): e11378, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36406665

RESUMO

Objective: To evaluate the knowledge, attitudes and behavior regarding antibiotics, use of antibiotics, and antibiotic resistance in students and health care professionals of the district of Barranquilla, Colombia. Study design: Descriptive, cross-sectional. Methods: A sample of 399 respondents was selected, that included health professionals and medical students from 12 health institutions in the district of Barranquilla (Colombia), using an established stratified sampling method. Each of the respondent professionals completed a survey that included 43 items in the Likert scale. A descriptive analysis of the study variables was performed using the software SPSS version 25. Results: Most of the respondents were women (64.4%), aged between 26 and 35 years (47.6%); 28.8% were nurses and 26.1% general practitioners, with ≤10 years of professional experience (63.4%). Overall, the survey revealed that the participants had considerable knowledge about antibiotic use (89.5%-98% correct answers) and the spread of antibiotic resistance (67.4%-89% correct answers). Approximately 74% of the respondents agreed or fully agreed with the questions related to the management of infections and the provision of advice. Conclusions: The present study revealed that most of the health care professionals surveyed had a good knowledge about antibiotic use, although strategies must be developed to strengthen knowledge regarding the spread of antibiotic resistance. Likewise, it is important to identify opportunities for improvement related with access to the guidelines and/or materials necessary to treat infections and to provide advice on antibiotic use and antibiotic resistance.

4.
Lima; Fondo Editorial Comunicacional; 2014. 126 p. ilus.
Monografia em Inglês | HISA - História da Saúde | ID: his-42514

RESUMO

El autor, a través de este estudio analiza el impacto de una epidemia que se originó por la confluencia de factores biológicos, ambientales, culturales, sociales y políticos, que siguió su curso natural dejando a su paso muerte y desolación, pero que no logró despertar la conciencia sanitaria de los responsables de las políticas públicas. (AU)


Assuntos
Febre Amarela , Surtos de Doenças , História do Século XIX , Peru
5.
Rev. med. vet. zoot ; 60(2): 121-138, may.-ago. 2013. ilus, tab
Artigo em Espanhol | LILACS-Express | LILACS | ID: lil-695867

RESUMO

El cambio climático es un fenómeno global actual que posee diversas causas, tales como el incremento antropogénico en las emisiones de gases de efecto invernadero y su influencia en el planeta. El óxido nitroso (N2O) es un gas con un potencial de calentamiento 298 veces mayor que el CO2; es emitido por diversos sectores económicos, entre ellos la agricultura y la ganadería por el empleo de fertilizantes nitrogenados. Este uso no incrementa únicamente las emisiones de N2O, sino que afecta todos los eslabones del ciclo del nitrógeno, siendo importante reconocer las interacciones entre sus reacciones (amonificación, nitrificación, denitrificación, etc.) para comprender los efectos sobre la lixiviación de nitratos, volatilización de amoniaco y emisiones de N2O, tres compuestos naturales que afectan el medio ambiente. En Colombia, el IDEAM reportó que en 2004 el sector agropecuario nacional produjo 94,91 gigagramos (Gg) de N2O, pues los sistemas de producción agrícolas y bovinos utilizan altas cantidades de fertilizantes nitrogenados con bajos índices de asimilación. Por ello adquiere importancia implementar buenas prácticas que midan y mitiguen estas emisiones en campo, buscando mayor eficiencia en la transformación de componentes nitrogenados dentro del sistema. En este artículo se enfatiza un manejo adecuado del suelo y la utilización de inhibidores de nitrificación naturales (presentes en algunas plantas tropicales) o químicos, como la nitrapyrina, DCD y NBPT (este último como inhibidor de la amonificación), observando su forma de acción y medición, su efecto mitigador y los incrementos productivos. La presente es una revisión bibliográfica que aborda la problemática ambiental de la ganadería bovina.


Climate change is a global effect currently present with several causes, such as the increased of anthropogenic emissions of greenhouse gases and its influence on the planet. Nitrous oxide (N2O) is a gas with a global warming potential 298 times greater than CO, which comes of many sectors, one of them is the agriculture and livestock through the use of nitrogen fertilizers. This use not only increases N2O emissions, its affects all stages of the nitrogen cycle, being important to observe the interactions between their reactions (ammonification, nitrification, denitrification etc.) to understand the effects over nitrate leaching, ammonia volatilization and N2O emissions, three natural chemicals that affect the environment. In Colombia, IDEAM reports that for 2004, the national agricultural sector produced 94.91 Gg of N2O, knowing the agricultural and livestock productions use high quantities of nitrogen fertilizers, with low assimila2tion rates. Therefore, some adaptable practices and methodologies become important to measure and mitigate these emissions in the field, seeking greater efficiency in the transformation of nitrogen components in the system, being reviewed on this paper the appropriate land management or implementation of natural nitrification inhibitors (present in some tropical plants) or chemical inhibitors, such as nitrapyrina, DCD and NBPT (as an ammonification inhibitor). This is a literature review that approaches the environmental problems of livestock.

6.
Exp Parasitol ; 134(4): 422-9, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23684908

RESUMO

Chagas disease, caused by the intracellular protozoan Trypanosoma cruzi, is associated with inflammation, discomfort and pain during the acute phase. The influence of TNF-α (tumor necrosis factor) in this disease outcome is controversial. In this way, the aim of this work was to determine the role of the TNF-α blocker etanercept in the pain, discomfort, and survival during the Chagas' acute phase of mice experimentally infected with a wild virulent strain of T. cruzi. The infection with this wild strain was responsible for a severe visceral inflammation and said parasite showed a tropism in peritoneal fluid cells. Etanercept was able to restore spontaneous vertical and horizontal activities during the second week after infection and to abolish mechanical allodynia during the first week after infection. Finally, etanercept delayed the mortality without any effect on the parasitemia rates. This is the first report that correlates sickness behavior and allodynia with TNF-α and suggests that this cytokine may play an important role in the physiopathology of the acute phase.


Assuntos
Doença de Chagas/fisiopatologia , Fármacos Gastrointestinais/farmacologia , Hiperalgesia/etiologia , Imunoglobulina G/farmacologia , Trypanosoma cruzi/patogenicidade , Fator de Necrose Tumoral alfa/fisiologia , Actinas/análise , Doença Aguda , Animais , Comportamento Animal/fisiologia , Proteína C-Reativa/análise , Doença de Chagas/complicações , Doença de Chagas/tratamento farmacológico , Modelos Animais de Doenças , Etanercepte , Fármacos Gastrointestinais/uso terapêutico , Hiperalgesia/prevenção & controle , Comportamento de Doença/fisiologia , Imunoglobulina G/uso terapêutico , Inflamação/etiologia , Inflamação/prevenção & controle , Masculino , Camundongos , Reação em Cadeia da Polimerase em Tempo Real , Receptores do Fator de Necrose Tumoral/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/fisiologia , Fator de Necrose Tumoral alfa/análise , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Vísceras/patologia
7.
Rev. med. vet. zoot ; 60(1): 32-48, ene.-abr. 2013. tab
Artigo em Espanhol | LILACS-Express | LILACS | ID: lil-677529

RESUMO

La presente investigación tuvo como objetivo evaluar el uso de la leguminosa Lotus uliginosus como alternativa de inclusión dentro de las praderas en dos ecorregiones estratégicas de la Sabana de Bogotá. En cada finca se evaluaron cuatro tratamientos: 1) kikuyo solo (P. clandestinum), 2) kikuyo asociado con trébol pata de pájaro (P. clandestinum + L. uliginosus), 3) festuca alta sola (F. arundinacea) y 4) Festuca alta asociada con trébol pata de pájaro (F. arundinacea + L. uliginosus). El número de bovinos varió de acuerdo a la capacidad de carga de cada finca. Se utilizaron animales que se encontraban en el segundo tercio de lactancia durante un período experimental de siete días. En cada tratamiento se determinó la producción (L/día) y calidad de leche (% de grasa, proteína y sólidos totales); en la pastura se evaluó la composición química (MS, FDN, FDA) y la digestibilidad in vitro de la materia seca (DIVMS). Se midió el consumo voluntario. En la finca Megaleche la producción de biomasa presentó diferencias significativas (P<0,05) entre los tratamientos destacándose el tratamiento del kikuyo solo; la calidad nutricional de las pasturas también presentó diferencias (P<0,04) destacándose el tratamiento de kikuyo + trébol pata de pájaro, asociación que también se destacó en consumo voluntario (P< 0.05) y producción de leche (P<0,05). En la finca Colega el contenido de proteína del forraje presentó diferencias cuando las gramíneas se asociaron con el trébol pata de pájaro (P<0,001). Se concluyó que la introducción del Lotus en las praderas mejoró la producción de leche y consumo de materia seca en los animales.


The present research aimed to evaluate the use of the legume Lotus uliginosus alternatively inclusion into the meadows on two strategic ecoregions savannah of Bogota. In each farm four treatments: 1) only kikuyu (P. clandestinum), 2) associated kikuyo Birdsfoot trefoil (P. clandestinum + L. uliginosus), 3) single tall fescue (F. arundinacea) and 4) tall fescue associated Birdsfoot trefoil (F. arundinacea + L. uliginosus). The number of cattle varied according the load capacity of each farm. Were used animals that were in the second third of lactation during a trial period of seven days, in each treatment was determined production (L/day) and milk quality (% of fat, protein and total solids). In the pasture it was evaluated chemical composition (DM, NDF, ADF) and in vitro digestibility of matter dry (IVDMD). Voluntary intake was measured. On the farm Megaleche biomass production showed significant differences (P˂0.05) between treatments kikuyu emphasizing treatment alone nutritional quality of pastures also showed significant differences (P˂0.04) emphasizing treating kikuyu + Birdsfoot trefoil an association that was also highlighted in the voluntary intake (P˂0.05) and milk production (P˂0.05). On the farm Colega protein content of forage grasses differed when associated with Birdsfoot trefoil (P˂0.001). It was concluded that the introduction of Lotus grassland improved milk production and dry matter intake in animals.

8.
Ciudad Autónoma de Buenos Aires; Ministerio de Salud de la Nación; 2013. 1 p.
Não convencional em Espanhol | BINACIS, ARGMSAL | ID: biblio-1532820

RESUMO

INTRODUCCIÓN La violencia obstétrica se define como "aquella que ejerce el personal de salud sobre el cuerpo y los procesos reproductivos de las mujeres, expresada en un trato deshumanizado, un abuso de medicalización y patologización de los procesos naturales, de conformidad con la Ley 25.929". Sin embargo, este punto de partida conceptual presenta debilidades para su comprensión. OBJETIVOS Problematizar y delimitar el alcance de la noción de violencia obstétrica para clarificar la validez práctica de sus definiciones. Reconocer los modos de expresión de esta forma de violencia en el ejercicio de la práctica médica y establecer los dispositivos que la perpetúan y obstaculizan su erradicación. MÉTODOS Se aplicó el método etnográfico. El trabajo de campo fue realizado en hospitales de la zona norte y oeste del conurbano bonaerense y en centros privados de la Ciudad Autónoma de Buenos Aires. El estudio incluyó 98 encuestas a profesionales de la salud, grupos focales, entrevistas a profesionales y funcionarias/os, mujeres y sus familiares y activistas del parto humanizado, observaciones de campo, visitas a hospitales, visitas a usuarias fuera del hospital y registro fotográfico. Se relevaron datos estadísticos obtenidos en las instituciones y material periodístico. RESULTADOS Se reconoció una multiplicidad de dispositivos (contextuales, relacionales e institucionales) que contribuyen a la violencia obstétrica y revelan el complejo entramado que da lugar a este fenómeno. DISCUSIÓN Existen numerosas tensiones que ponen en juego la autonomía de las mujeres. La conceptualización efectuada por la ley de violencia deja interrogantes, que obligan a clarificar mejor aquello que se nombra.


Assuntos
Saúde Reprodutiva , Violência Obstétrica , Direitos Humanos
9.
J Nanosci Nanotechnol ; 10(7): 4352-6, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21128424

RESUMO

Films of small irregular-shaped aggregates composed by several layers of turbostratic graphite encapsulating iron nanoparticles, like carbon nanoshells, and quasi-isolated multi-walled carbon nanotubes (MWCNTs), were synthesized by the chemical vapor deposition method on glass substrates. Quasi-isolated MWCNTs were found emerging in different directions on the agglomerates composed of carbon nanoshells. The morphological properties of the films were characterized using scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy, whereas their optical properties were investigated using optical absorption and photoluminescence (PL) spectroscopy. The studies show a high-intensity PL signal in the infrared at room temperature. This PL signal shows several peaks, which cannot be explained by a blackbody emission. However, the overall PL signal could be a combination of the black emission and electronic transitions. Furthermore, the observed infrared PL emission could be ideal for potential applications such as in gas sensors, infrared detectors and so on.

10.
Eur J Gynaecol Oncol ; 31(4): 386-91, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20882878

RESUMO

INTRODUCTION: This trial aimed to evaluate the safety and efficacy of epigenetic therapy associated with cisplatin chemoradiation in FIGO Stage IIIB patients. METHODS: Hydralazine containing either 182 mg for rapid-, or 83 mg for slow acetylators and magnesium valproate were administered at 30 mg/kg tid. Both drugs were taken until intracavitary therapy was finished. Pelvic external beam radiation and low-dose rate brachytherapy were administered at a total cumulative dose to point A of at least 85 Gy. Weekly cisplatin at 40 mg/m2 was delivered for six cycles. RESULTS: Twenty-two patients were included and 18 (82%) patients completed treatment. Mean dose to point A was 84.6 + 2.2. Median number of cisplatin cycles was 5.5 (range, 1-6). Brachytherapy was delayed for technical reasons; the mean overall treatment time was 11.8 weeks. Grade 3 anemia, leucopenia, neutropenia, and thrombocytopenia were observed in 9%, 45%, 45%, and 9% of patients, respectively. CONCLUSIONS: Hydralazine and valproate are well-tolerated and safe when administered with cisplatin chemoradiation. Unfortunately, the suboptimal administration of brachytherapy for technical reasons in this study, precluded assessing the efficacy of epigenetic therapy. However, the tolerability of this regimen administered concurrent to radiation needs to be further tested.


Assuntos
Antineoplásicos/uso terapêutico , Braquiterapia , Cisplatino/uso terapêutico , Epigênese Genética , Neoplasias do Colo do Útero/terapia , Adulto , Idoso , Braquiterapia/efeitos adversos , Cisplatino/efeitos adversos , Terapia Combinada , Feminino , Humanos , Hidralazina/administração & dosagem , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias do Colo do Útero/genética , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia , Ácido Valproico/administração & dosagem
11.
Med Oncol ; 27(4): 1133-43, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19902390

RESUMO

Gemcitabine (2',2'-difluoro 2'deoxycytidine, dFdC) is an analog of cytosine with distinctive pharmacological properties and a wide antitumor-activity spectrum. The pharmacological characteristics of gemcitabine are unique because two main classes of genes are essential for its antitumor effects: membrane transporter protein-coding genes, whose products are responsible for drug intracellular uptake, as well as enzyme-coding genes, which catalyze its activation and inactivation. The study of the pharmacogenetics and pharmacoepigenetics of these two gene classes is greatly required to optimize the drug's therapeutic use in cancer. This review aims to provide an update of genetic and epigenetic bases that may account for interindividual variation in therapeutic outcome exhibited by gemcitabine.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Desoxicitidina/análogos & derivados , Epigenômica , Neoplasias/tratamento farmacológico , Neoplasias/genética , Farmacogenética , Desoxicitidina/uso terapêutico , Humanos , Gencitabina
12.
Acta Ortop Mex ; 24(5): 312-6, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-21246802

RESUMO

UNLABELLED: The trend in distal radius fracture is towards open reduction and internal fixation; however, treatment with closed reduction and percutaneous nailing continues to provide good results, but physical therapy and appropriate early rehabilitation are needed. MATERIAL AND METHODS: We assessed patients with distal radius fractures treated with reduction with percutaneous maneuvers and nailing; we used clinical functional scales, like the DASH, the Mayo Clinic wrist scale, and the Visual Analog Scale (VAS) to assess pain. Patient results were compared at 12 and 24 weeks. We also compared patients with and without rehabilitation. RESULTS: A total of 60 patients were assessed using the DASH scale; patients with rehabilitation had a score of 4.3, while those without rehabilitation had a score of 10.5 (p = 0.00001). In the Mayo Clinic scale, patients with rehabilitation had a score of 86.7, while those without rehabilitation had a score of 77.8 (p = 0.00001). The VAS was not significant. CONCLUSION: All patients showed improvement in their clinical assessment scales. However, when patients with and without rehabilitation are compared, the difference was greater in the Mayo Clinic scale and in the DASH scale.


Assuntos
Fixação de Fratura , Fraturas do Rádio/diagnóstico por imagem , Fraturas do Rádio/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Feminino , Fixação de Fratura/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Adulto Jovem
13.
Ann Oncol ; 18(9): 1529-38, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17761710

RESUMO

BACKGROUND: Epigenetic aberrations lead to chemotherapy resistance; hence, their reversal by inhibitors of DNA methylation and histone deacetylases may overcome it. PATIENTS AND METHODS: Phase II, single-arm study of hydralazine and magnesium valproate added to the same schedule of chemotherapy on which patients were progressing. Schedules comprised cisplatin, carboplatin, paclitaxel, vinorelbine, gemcitabine, pemetrexed, topotecan, doxorubicin, cyclophosphamide, and anastrozole. Patients received hydralazine at 182 mg for rapid, or 83 mg for slow, acetylators, and magnesium valproate at 40 mg/kg, beginning a week before chemotherapy. Response, toxicity, DNA methylation, histone deacetylase activity, plasma valproic acid, and hydralazine levels were evaluated. RESULTS: Seventeen patients were evaluable for toxicity and 15 for response. Primary sites included cervix (3), breast (3), lung (1), testis (1), and ovarian (7) carcinomas. A clinical benefit was observed in 12 (80%) patients: four PR, and eight SD. The most significant toxicity was hematologic. Reduction in global DNA methylation, histone deacetylase activity, and promoter demethylation were observed. CONCLUSIONS: The clinical benefit noted with the epigenetic agents hydralazine and valproate in this selected patient population progressing to chemotherapy' and re-challenged with the same chemotherapy schedule after initiating hydralazine and valproate' lends support to the epigenetic-driven tumor-cell chemoresistance hypothesis (ClinicalTrials.gov Identifier: NCT00404508).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Hidralazina/administração & dosagem , Neoplasias/tratamento farmacológico , Ácido Valproico/administração & dosagem , Adolescente , Metilação de DNA , Epigênese Genética , Feminino , Histona Desacetilases/metabolismo , Humanos , Hidralazina/efeitos adversos , Hidralazina/sangue , Masculino , Neoplasias/genética , Ácido Valproico/efeitos adversos , Ácido Valproico/sangue
14.
J Exp Clin Cancer Res ; 25(1): 73-8, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16761621

RESUMO

The ras gene family (H, K and N-ras) encodes the Ras protein, a GTPase-activating protein that regulates several signal transduction pathways including cellular proliferation and differentiation. Mutations in codons 12, 13 and 61 of the ras genes constitute one of the most frequent alterations in human cancer. In the Western Hemisphere, a low frequency of mutations in these genes has been observed in head and neck carcinomas; a higher frequency has been found in countries such as India and Taiwan. Increased protein expression is a relatively frequent event in larynx carcinomas. This study was aimed to evaluate the participation of the k-ras gene and Ras expression in 20 Mexican patients with larynx squamous carcinoma, 2 with dysplasia and 4 with normal mucosa. Samples (of 26 patients) were embedded in paraffin and immunohistochemical analysis was performed for the Ras protein, as well as amplification of the k-ras gene exon 1 (108 bp) by laser capture microdissection. Then, DNA extraction, PCR and sequencing were performed looking for possible mutation in codons 12 and 13. All patients with larynx carcinoma were men, median age 62 years. Eighty-five percent of the patients had risk factors such as smoking and/or alcohol consumption, 25% were in clinical stages I and II, and 75% in stages III and IV; 45% of the patients presented tumor recurrence or persistence. In this study, no mutations were found in codons 12 or 13 of the k-ras gene; however, protein expression was observed in 95% of the samples and a higher expression of the protein was associated with tumor recurrence or persistence, although this was not statistically significant. Unexpectedly, well-differentiated carcinomas and dysplasias presented an increase in protein expression. These results suggest that ras may be involved in early stages of larynx carcinogenesis and may be activated by other mechanisms different from mutations, such as epigenetic events.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Análise Mutacional de DNA , Genes ras , Neoplasias Laríngeas/metabolismo , Proteína Oncogênica p21(ras)/metabolismo , Proteínas ras/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/genética , Epigênese Genética , Feminino , Humanos , Neoplasias Laríngeas/genética , Masculino , Pessoa de Meia-Idade , Proteína Oncogênica p21(ras)/genética , Transdução de Sinais
15.
Mem Inst Oswaldo Cruz ; 96(3): 379-80, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11313647

RESUMO

The brain cell karyotype of New World sand fly Lutzomyia shannoni was described. This species has four pairs of chromosomes, 2N=8, with one pair of heteromorphic chromosomes.


Assuntos
Encéfalo/citologia , Bandeamento Cromossômico , Psychodidae/genética , Animais , Feminino , Cariotipagem , Masculino , Metáfase
16.
Mem Inst Oswaldo Cruz ; 96(1): 127-31, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11285484

RESUMO

The life cycle of Clerada apicicornis was determined under laboratory conditions. Mean development times in days were: egg 27.2, nymph I 12.5, nymph II 12, nymph III 13.4, nymph IV 16.4, nymph V 26. The life expectancy of adults ranged from 117 to 317 days (mean 196 days). Based on a cohort of 29 females of C. apicicornis, a horizontal life table was constructed. The following predictive parameters were obtained: net rate of reproduction (Ro = 48.31), intrinsic rate of population increase (r(m) = 0.153), generation time (Tc = 28.20 weeks), and finite rate of population increment (lambda = 1.16). The reproductive value (Vx) for each age class of the cohort females was calculated. The following observed parameters were calculated after mortality in each stage: net rate of reproduction (R'o=13.4), intrinsic rate of population increase (r c' =0.09 ), and finite rate of population increment (lambda' =1.1). The generation time (Tc' =27.4) was estimated using the methods of Laughlin and Bengstron. A vertical life table was elaborated and mortality was described for one generation of the cohort.


Assuntos
Hemípteros/crescimento & desenvolvimento , Estágios do Ciclo de Vida , Animais , Feminino , Masculino , Dinâmica Populacional
17.
Mem Inst Oswaldo Cruz ; 96(2): 189-96, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11285496

RESUMO

Polyacrylamide gel electrophoresis was used to elucidate genetic variation at 13 isozyme loci among forest populations of Lutzomyia shannoni from three widely separated locations in Colombia: Palambí (Nariño Department), Cimitarra (Santander Department) and Chinácota (Norte de Santander Department). These samples were compared with a laboratory colony originating from the Magdalena Valley in Central Colombia. The mean heterozygosity ranged from 16 to 22%, with 2.1 to 2.6 alleles detected per locus. Nei's genetic distances among populations were low, ranging from 0.011 to 0.049. The estimated number of migrants (Nm=3.8) based on Wright's F-Statistic, F ST, indicated low levels of gene flow among Lu. shannoni forest populations. This low level of migration indicates that the spread of stomatitis virus occurs via infected host, not by infected insect. In the colony sample of 79 individuals, the Gpi locus was homozygotic (0.62/0.62) in all females and heterozygotic (0.62/0.72) in all males. Although this phenomenon is probably a consequence of colonization, it indicates that Gpi is linked to a sex determining locus.


Assuntos
Variação Genética , Psychodidae/genética , Animais , Colômbia , Eletroforese em Gel de Poliacrilamida/métodos , Feminino , Frequência do Gene , Masculino , Psychodidae/enzimologia
18.
Rev. biol. trop ; Rev. biol. trop;48(Supl.1): 77-86, dic. 2000.
Artigo em Espanhol | LILACS | ID: lil-503276

RESUMO

Melongena corona bispinosa was studied in Yucatán, México (21 degrees 16' N, 89 degrees 49' W) for a year. Males have reproductive peaks in February and December, and a post-copulation peak in June. Female peaks are in March and May, plus oviposition peaks in April and January. Males and females differ in the mean gonadosom ic index (F=13.79, p<0.05) but not in the dry tissue/shell weight (F=0.0902, p<0.05), dry tissue and total weight (F=0.2466, p<0.05) and dry tissue weight/internal shell volume (F=1.0565, p<0.05).


Assuntos
Animais , Masculino , Feminino , Moluscos/fisiologia , Americanos Mexicanos , Reprodução/fisiologia , Estações do Ano , Fatores Sexuais
19.
Med. U.P.B ; 19(2): 169-178, oct. 2000.
Artigo em Espanhol | LILACS | ID: lil-612369

RESUMO

Este trabajo recopila, en un lenguaje sencillo y útil, la fisiopatología de la Diabetes Tipo 2, los mecanismos por los cuales la insulina controla la homeostasis de la glucosa, su relación con el síndrome metabólico y la forma de aparición de resistencia a la insulina. Del entendimiento de éstos se comprenderán más fácilmente las alteraciones moleculares que explican la enfermedad.


Assuntos
Humanos , Insulina
20.
Mem Inst Oswaldo Cruz ; 95(1): 131-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10656719

RESUMO

Because of its ability to prey on Triatominae in rural houses, Clerada apicicornis has been suggested as a potential biological control agent of Rhodnius prolixus. It has also been suggested as a potential vector of mammalian trypanosomes such as Trypanosoma cruzi, because of its ability to take blood directly from mammals. To help resolve these conflicting ideas, we assessed the haematophagic behaviour of C. apicicornis by carrying out feeding trials on laboratory animals. Cleptohaematophagic behaviour was also assessed by allowing C. apicicornis to feed on R. prolixus previously engorged with avian blood. The low proportion of blood meals taken directly from laboratory animals indicates a facultative haematophagy in this species, whereas a greater proportion of nymphs and adults were able to obtain vertebrate blood by predation on engorged R. prolixus. The results suggest that C. apicicornis is unlikely to be effective as a biological control agent, but is also unlikely to have a significant role in the transmission of vertebrate pathogens.


Assuntos
Comportamento Alimentar , Hemípteros/fisiologia , Insetos Vetores , Controle Biológico de Vetores/métodos , Rhodnius , Animais , Heterópteros , Comportamento Predatório , Reduviidae
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