Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
1.
Eur Rev Med Pharmacol Sci ; 21(1): 199-211, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28121337

RESUMO

SGLT2 (sodium-glucose cotransporter type 2) inhibitors are a new class of drugs which reversibly block the glucose reabsorption that occurs in the kidneys. Since their mechanisms of action do not rely on insulin secretion, they constitute a complementary alternative to the classic treatment of type 2 diabetes mellitus. A glycemic level reduction in patients who used SGLT2 inhibitors due to the reversible block of their transporters could be observed. Associated with this, there was a reduction in body weight and blood pressure (BP) caused by osmotic diuresis. Few adverse effects and low drug interaction combined with antihyperglycemic effects are some of the benefits of these inhibitors widely discussed in clinical trials. Patients with history of urogenital infections or those on diuretics must be carefully evaluated before the administration of these drugs. While a promising class of drugs indicated as a treatment for patients with type 2 diabetes mellitus, SGLT2 inhibitors should not be prescribed for individuals with severe renal or hepatic impairment. Therefore, as there are only a few situations in which they should not be indicated, the efficacy, safety and tolerability of these inhibitors allow them to be used in a wide range of patients. Nevertheless, further researches are required so that the possible long-term risks can be studied and the benefits associated with their use can be more objectively elucidated.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/farmacologia , Inibidores do Transportador 2 de Sódio-Glicose , Redução de Peso/efeitos dos fármacos , Humanos , Transportador 2 de Glucose-Sódio
2.
Braz. j. med. biol. res ; 48(5): 427-432, 05/2015. tab
Artigo em Inglês | LILACS | ID: lil-744368

RESUMO

Community-acquired pneumonia (CAP) is amongst the leading causes of death worldwide. As inflammatory markers, cytokines can predict outcomes, if interpreted together with clinical data and scoring systems such as CURB-65, CRB, and Acute Physiology and Chronic Health Evaluation II (APACHE II). The aim of this study was to determine the impact of inflammatory biomarkers on the early mortality of hospitalized CAP patients. Twenty-seven CAP patients needing hospitalization were enrolled for the study and samples of interleukin-1 (IL-1) and interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), and homocystein were collected at the time of admission (day 1) as well as on the seventh day of the treatment. There was a significant reduction in the levels of IL-6 between the first and the second collections. Median IL-6 values decreased from 24 pg/mL (day 1) to 8 pg/mL (day 7) (P=0.016). The median levels of TNF-α were higher in patients: i) with acute kidney injury (AKI) (P=0.045), ii) requiring mechanical ventilation (P=0.040), iii) with short hospital stays (P=0.009), iv) admitted to the intensive care unit (ICU) (P=0.040), v) who died early (P=0.003), and vi) with worse CRB scores (P=0.013). In summary, IL-6 and TNF-α levels were associated with early mortality of CAP patients. Longer admission levels demonstrated greater likelihood of early death and overall mortality, necessity of mechanical ventilation, and AKI.


Assuntos
Adolescente , Humanos , Financiamento Governamental , Centros de Tratamento de Abuso de Substâncias/organização & administração , Transtornos Relacionados ao Uso de Substâncias/reabilitação , Bases de Dados Factuais , Garantia da Qualidade dos Cuidados de Saúde , Qualidade da Assistência à Saúde , Centros de Tratamento de Abuso de Substâncias/normas , Centros de Tratamento de Abuso de Substâncias/tendências , Estados Unidos
3.
Eur Rev Med Pharmacol Sci ; 19(4): 694-700, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25753888

RESUMO

OBJECTIVE: Vancomycin (VCM) is a tricyclic glycopeptide antibiotic produced by Streptococcus orientalis. Widely used in hospitals, it is indicated to fight severe infections caused by Gram-positive bacteria, especially with the advent of MRSA (methicillin-resistant Staphylococcus aureus), penicillin-resistant pneumococci among others. Furthermore, it is indicated for the treatment of patients allergic to penicillins and cephalosporins. Dose recommendations, dilution rates and types of infusion are controversial and also result in toxic effects. Aim of this paper was to perform a literature review showing the therapeutic and adverse effects of vancomycin. MATERIALS AND METHODS: This is a literature review of recent articles published on MEDLINE and SciELO databases in English, Portuguese and Spanish. RESULTS: The main adverse effects of vancomycin are: hypotension, phlebitis, nephrotoxicity, ototoxicity, hypersensitivity reactions, red man syndrome, neutropenia, chills, fever, interstitial nephritis. CONCLUSIONS: The use of vancomycin is still very common; however, inadequate doses and prolonged therapy pose a risk of increasing minimum inhibitory concentrations (MICs), resulting in subtherapeutic levels, treatment failures and toxicity. Therefore, further studies should be conducted to optimize the administration of vancomycin, monitoring treatments from the beginning in order to ensure a safe and effective use of the drug.


Assuntos
Antibacterianos/efeitos adversos , Antibacterianos/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Vancomicina/efeitos adversos , Vancomicina/uso terapêutico , Cefalosporinas/uso terapêutico , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Neutropenia/induzido quimicamente
4.
Braz J Med Biol Res ; 48(5): 427-32, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25714883

RESUMO

Community-acquired pneumonia (CAP) is amongst the leading causes of death worldwide. As inflammatory markers, cytokines can predict outcomes, if interpreted together with clinical data and scoring systems such as CURB-65, CRB, and Acute Physiology and Chronic Health Evaluation II (APACHE II). The aim of this study was to determine the impact of inflammatory biomarkers on the early mortality of hospitalized CAP patients. Twenty-seven CAP patients needing hospitalization were enrolled for the study and samples of interleukin-1 (IL-1) and interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), and homocystein were collected at the time of admission (day 1) as well as on the seventh day of the treatment. There was a significant reduction in the levels of IL-6 between the first and the second collections. Median IL-6 values decreased from 24 pg/mL (day 1) to 8 pg/mL (day 7) (P=0.016). The median levels of TNF-α were higher in patients: i) with acute kidney injury (AKI) (P=0.045), ii) requiring mechanical ventilation (P=0.040), iii) with short hospital stays (P=0.009), iv) admitted to the intensive care unit (ICU) (P=0.040), v) who died early (P=0.003), and vi) with worse CRB scores (P=0.013). In summary, IL-6 and TNF-α levels were associated with early mortality of CAP patients. Longer admission levels demonstrated greater likelihood of early death and overall mortality, necessity of mechanical ventilation, and AKI.


Assuntos
Interleucina-6/sangue , Pneumonia/mortalidade , Fator de Necrose Tumoral alfa/sangue , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Proteína C-Reativa/análise , Criança , Pré-Escolar , Infecções Comunitárias Adquiridas/complicações , Infecções Comunitárias Adquiridas/mortalidade , Creatinina/sangue , Feminino , Homocisteína/sangue , Humanos , Lactente , Recém-Nascido , Interleucina-1/sangue , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Pneumonia/complicações , Estudos Prospectivos , Respiração Artificial , Fatores Sexuais , Estatísticas não Paramétricas , Adulto Jovem
5.
Braz. j. med. biol. res ; 47(11): 966-971, 11/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-723904

RESUMO

Erythropoietin (EPO) has been well characterized as a renal glycoprotein hormone regulating red blood cell production by inhibiting apoptosis of erythrocyte progenitors in hematopoietic tissues. EPO exerts regulatory effects in cardiac and skeletal muscles. Duchenne muscular dystrophy is a lethal degenerative disorder of skeletal and cardiac muscle. In this study, we tested the possible therapeutic beneficial effect of recombinant EPO (rhEPO) in dystrophic muscles in mdx mice. Total strength was measured using a force transducer coupled to a computer. Gene expression for myostatin, transforming growth factor-β1 (TGF-β1), and tumor necrosis factor-α (TNF-α) was determined by quantitative real time polymerase chain reaction. Myostatin expression was significantly decreased in quadriceps from mdx mice treated with rhEPO (rhEPO=0.60±0.11, control=1.07±0.11). On the other hand, rhEPO had no significant effect on the expression of TGF-β1 (rhEPO=0.95±0.14, control=1.05±0.16) and TNF-α (rhEPO=0.73±0.20, control=1.01±0.09). These results may help to clarify some of the direct actions of EPO on skeletal muscle.


Assuntos
Animais , Masculino , Regulação para Baixo/efeitos dos fármacos , Eritropoetina/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Distrofia Muscular de Duchenne/tratamento farmacológico , Miostatina/metabolismo , Proteínas Recombinantes/uso terapêutico , Modelos Animais de Doenças , Distrofina/deficiência , Camundongos Endogâmicos mdx , Força Muscular/efeitos dos fármacos , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Miostatina/genética , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
6.
Braz J Med Biol Res ; 47(11): 966-71, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25296358

RESUMO

Erythropoietin (EPO) has been well characterized as a renal glycoprotein hormone regulating red blood cell production by inhibiting apoptosis of erythrocyte progenitors in hematopoietic tissues. EPO exerts regulatory effects in cardiac and skeletal muscles. Duchenne muscular dystrophy is a lethal degenerative disorder of skeletal and cardiac muscle. In this study, we tested the possible therapeutic beneficial effect of recombinant EPO (rhEPO) in dystrophic muscles in mdx mice. Total strength was measured using a force transducer coupled to a computer. Gene expression for myostatin, transforming growth factor-ß1 (TGF-ß1), and tumor necrosis factor-α (TNF-α) was determined by quantitative real time polymerase chain reaction. Myostatin expression was significantly decreased in quadriceps from mdx mice treated with rhEPO (rhEPO = 0.60 ± 0.11, control = 1.07 ± 0.11). On the other hand, rhEPO had no significant effect on the expression of TGF-ß1 (rhEPO = 0.95 ± 0.14, control = 1.05 ± 0.16) and TNF-α (rhEPO = 0.73 ± 0.20, control = 1.01 ± 0.09). These results may help to clarify some of the direct actions of EPO on skeletal muscle.


Assuntos
Regulação para Baixo/efeitos dos fármacos , Eritropoetina/uso terapêutico , Expressão Gênica/efeitos dos fármacos , Distrofia Muscular de Duchenne/tratamento farmacológico , Miostatina/metabolismo , Proteínas Recombinantes/uso terapêutico , Animais , Modelos Animais de Doenças , Distrofina/deficiência , Masculino , Camundongos Endogâmicos mdx , Força Muscular/efeitos dos fármacos , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/metabolismo , Miostatina/genética , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
7.
Parasitol Res ; 113(11): 4271-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25224729

RESUMO

A chemical investigation and bioassays against fifth-instar nymphae of the hematophagous insect Rhodnius prolixus, vector of Chagas disease, were conducted with the essential oil from Zanthoxylum caribaeum. The main results may be summarized as follows: (i) 54 components were identified, corresponding to 90.4% of the relative composition; sesquiterpenes (47.3%) and monoterpenes (41.2%) are the major constituents; (ii) muurola-4,5-trans-diene and isodaucene are described for the first time as chemical constituents of the essential oil from leaves of this species; (iii) topical treatment with the crude essential oil induced high levels of paralysis (from 18.88 to 33.33%) and mortality (from 80 to 98.9%) depending on the dose applied (0.5 to 5.0 µl per insect); (iv) feeding treatment with the crude essential oil also induced high levels of mortality (from 48.8 to 100%) but low levels of paralysis (from 2.22 to 7.77%) depending on the dose applied (0.5 to 5.0 µl/ml of blood); (v) in the continuous treatment, only the dose of 5.0 µl/cm(2) was able to promote statistical significant levels of mortality (63.3%) but no paralysis were detected. However in this group, occasionally, only few insects displayed malformations of legs and wings after treatment; and (vi) any treatment was able to disrupt the metamorphosis process since the low adult stage emergence observed to all groups was due the high insect mortality. These observations suggest the interference of Z. caribaeum compounds on the triatomine neuroendocrine system. The significance of these results in relation to the relevant biological events in R. prolixus as well as the possible use of insect growth regulators present in Z. caribaeum oil in integrated vector control programs against hematophagous triatomine species is herein discussed.


Assuntos
Inseticidas , Óleos Voláteis/farmacologia , Rhodnius/efeitos dos fármacos , Zanthoxylum/química , Animais , Insetos Vetores/efeitos dos fármacos , Monoterpenos/química , Monoterpenos/farmacologia , Ninfa/efeitos dos fármacos , Óleos Voláteis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Sesquiterpenos/química , Sesquiterpenos/farmacologia
8.
Clin Exp Dermatol ; 37(8): 909-12, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22924775

RESUMO

Insulin-like growth factor (IGF)-1 has shown some interesting results in studies examining its use as a hair-loss treatment. IGF-1 works by regulating cellular proliferation and migration during the development of hair follicles. Hepatotoxicity and myelotoxicity were evaluated in hamsters (Mesocricetus auratus) after topical application of the liquid gel vehicle (placebo), 1% IGF-1 or 3% IGF-1. No significant difference in the levels of aspartate aminotransferase or alanine aminotransferase was found between the control and treated groups. ELISA did not shown any increase in the plasma level of IGF-1. A haematopoietic niche was found, but it was not associated with myelotoxicity. Efficacy was determined by dermatoscopy analysis of hair density and microscopy analysis of hair diameter, with hair found to be thicker and with more rapid growth in the 3% group than in either the 1% group or the control group. These results strongly suggest that liposomal IGF-1 in a liquid gel formulation is a safe and efficient treatment for hair loss.


Assuntos
Alopecia/tratamento farmacológico , Folículo Piloso/crescimento & desenvolvimento , Cabelo/crescimento & desenvolvimento , Fator de Crescimento Insulin-Like I/farmacologia , Administração Tópica , Alanina Transaminase/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Cricetinae , Géis , Cabelo/efeitos dos fármacos , Folículo Piloso/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/efeitos adversos , Fator de Crescimento Insulin-Like I/metabolismo , Modelos Animais , Pele/efeitos dos fármacos
9.
Parasitol Res ; 105(3): 743-9, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19437041

RESUMO

Trypanosoma cruzi, the etiologic agent of Chagas' disease, is represented by a set of parasites which circulate between man, vectors, domestic and wild animals. Recently, our group isolated from Triatoma vitticeps strains of T. cruzi that were characterized as belonging to the Z3 phylogenetic lineage. Since very little is known about the biological and/or biochemical markers of sylvatic Z3 isolates, we have studied the protein and protease profiles of distinct Z3 isolates designated as SMM10, SMM53, SMM88, and SMM98. By means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, both quantitative and qualitative differences were observed in the protein profiles of these strains. All strains produced an acidic cysteine protease of 45 kDa, resembling cruzipain activity. The strain SMM10 synthesized an additional 55 kDa metalloprotease. Using Western blotting and anti-cruzipain antibody to detect cruzipain-like molecules, a 40-kDa reactive molecule was identified in all strains; in the strain SMM10, an 80-kDa protein was also reacted. Studies about cruzipain isoforms from sylvatic parasites could be valuable tools in the comprehension of the genetic variability in the pathogenesis of Chagas' disease.


Assuntos
Cisteína Endopeptidases/isolamento & purificação , Proteínas de Protozoários/isolamento & purificação , Triatoma/parasitologia , Trypanosoma cruzi/enzimologia , Animais , Western Blotting/métodos , Brasil , Cisteína Endopeptidases/química , Eletroforese em Gel de Poliacrilamida , Peso Molecular , Proteoma/análise , Proteínas de Protozoários/química , Trypanosoma cruzi/química , Trypanosoma cruzi/classificação , Trypanosoma cruzi/isolamento & purificação
10.
Mem. Inst. Oswaldo Cruz ; 103(8): 839-842, Dec. 2008. tab
Artigo em Inglês | LILACS | ID: lil-502307

RESUMO

Studies were carried out to evaluate the efficacy of the growth regulator, triflumuron (TFM) (Starycide® sc 480 Bayer), for disrupting the development of Rhodnius prolixus fifth-instar nymph by oral, topical or continuous treatment. All treatments were able to induce high levels of mortality, delay development and molt inhibition. Oral treatment induced molt inhibition in all insects that survived at doses of 0.25, 0.50 and 5.0 mg/mL of a blood meal. The highest levels of both mortality in 24 h and molt inhibition were always observed after topical treatment. The lowest doses needed to obtain considerable biological effects were always observed after continuous treatment. In this way, the highest levels of mortality within 30 days were detected after continuous treatment, which also induced an extended inter-molting period, a lower number of over-aged nymphs and the highest level of molting in nymphs that survived. Moreover, the effects of TFM on insects were often displayed in a dose response manner. These results indicate that TFM acts as a potent growth inhibitor of R. prolixus nymphs and has the potential to be used in integrated vector control programs against hematophagous triatomine species.


Assuntos
Animais , Masculino , Benzamidas/farmacologia , Inseticidas/farmacologia , Rhodnius/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Rhodnius/crescimento & desenvolvimento , Fatores de Tempo
11.
Mem Inst Oswaldo Cruz ; 103(8): 839-42, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19148427

RESUMO

Studies were carried out to evaluate the efficacy of the growth regulator, triflumuron (TFM) (Starycide sc 480 Bayer), for disrupting the development of Rhodnius prolixus fifth-instar nymph by oral, topical or continuous treatment. All treatments were able to induce high levels of mortality, delay development and molt inhibition. Oral treatment induced molt inhibition in all insects that survived at doses of 0.25, 0.50 and 5.0 mg/mL of a blood meal. The highest levels of both mortality in 24 h and molt inhibition were always observed after topical treatment. The lowest doses needed to obtain considerable biological effects were always observed after continuous treatment. In this way, the highest levels of mortality within 30 days were detected after continuous treatment, which also induced an extended inter-molting period, a lower number of over-aged nymphs and the highest level of molting in nymphs that survived. Moreover, the effects of TFM on insects were often displayed in a dose response manner. These results indicate that TFM acts as a potent growth inhibitor of R. prolixus nymphs and has the potential to be used in integrated vector control programs against hematophagous triatomine species.


Assuntos
Benzamidas/farmacologia , Inseticidas/farmacologia , Rhodnius/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Masculino , Ninfa/efeitos dos fármacos , Ninfa/crescimento & desenvolvimento , Rhodnius/crescimento & desenvolvimento , Fatores de Tempo
12.
Exp Parasitol ; 107(1-2): 89-96, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15208042

RESUMO

The effects of resident bacteria in the stomach of 5th-instar larvae of Rhodnius prolixus on the erythrocyte lysis and Trypanosoma cruzi infection were studied. The bacteria population increased approximately 10,000-fold after feeding. Hemolysis rose to approximately 28% within 24h postfeeding and then linearly grew until day 4 attaining almost 100%. The number of surviving Y strain of T. cruzi in the stomach declined drastically, while the infection with Dm28c clone was maintained stable. Five days after feeding, few different types of bacterial colonies were obtained when stomach content suspensions were spread onto BHI agar plates. The hemolytic bacteria were isolated and identified as Serratia marcescens biotype A1a (referenced as RPH), which produces the pigment prodigiosin. In vitro experiments, comparing incubations of RPH with S. marcescens SM365, a prodigiosin pigment producer, and S. marcescens DB11, a nonpigment variant, as a control, with erythrocytes and T. cruzi demonstrated that: (i) at 30 degrees C, SM365 and RPH diminished the populations of Y strain, but not DM28c clone, and DB11 was unable to lyse both T. cruzi strains; (ii) at 0 degrees C, SM263 and RPH killed the flagellates, but DB11 did not; and (iii) all three strains of S. marcescens were able to lyse erythrocytes. These results suggest that S. marcescens trypanolytic activity from the SM365 and RPH strains is distinct from the hemolytic activity and that prodigiosin is an important factor for the trypanolytic action of the bacteria.


Assuntos
Insetos Vetores/microbiologia , Insetos Vetores/parasitologia , Rhodnius/microbiologia , Rhodnius/parasitologia , Serratia marcescens/isolamento & purificação , Trypanosoma cruzi/fisiologia , Animais , Eritrócitos/microbiologia , Eritrócitos/parasitologia , Hemólise , Interações Hospedeiro-Parasita , Humanos , Larva/microbiologia , Larva/parasitologia , Prodigiosina/metabolismo , Serratia marcescens/fisiologia
13.
Phys Rev Lett ; 90(21): 210402, 2003 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-12786541

RESUMO

The microscopic properties of a single vortex in a dilute superfluid Fermi gas at zero temperature are examined within the framework of self-consistent Bogoliubov-de Gennes theory. Using only physical parameters as input, we study the pair potential, the density, the energy, and the current distribution. Comparison of the numerical results with analytical expressions clearly indicates that the energy of the vortex is governed by the zero-temperature BCS coherence length.

14.
J Insect Physiol ; 49(9): 829-37, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16256685

RESUMO

Investigations were carried out to compare aspects of the prophenoloxidase (proPO)-activating pathway in Rhodnius prolixus hemolymph in response to oral infection and inoculation of the insects with two developmental forms of Trypanosoma rangeli epimastigotes strain H14. In vivo experiments demonstrated that in control insects fed on uninfected blood, inoculation challenge with short epimastigotes resulted in high phenoloxidase (PO) activity. In contrast, previous feeding on blood containing either short or long epimastigotes was able to suppress the proPO activation induced by thoracic inoculation of the short forms. In vitro assays in the presence of short epimastigotes demonstrated that control hemolymph or hemolymph provided by insects previously fed on blood containing epimastigotes incubated with fat body homogenates from control insects significantly increased the PO activity. However, fat body homogenates from insects previously fed on blood containing epimastigotes, incubated with hemolymph taken from insects fed on control blood or blood infected with epimastigotes, drastically reduced the proPO activation. The proteolytic activity in the fat body homogenates of control insects was significantly higher than in those obtained from fat body extracts of insects previously fed on blood containing epimastigotes. These findings indicate that the reduction of the proteolytic activities in the fat body from insects fed on infected blood no longer allows a significant response of the proPO system against parasite challenge. It also provides a better understanding of T. rangeli infection in the vector and offer novel insights into basic immune processes in their invertebrate hosts.


Assuntos
Catecol Oxidase/metabolismo , Precursores Enzimáticos/metabolismo , Rhodnius/enzimologia , Rhodnius/parasitologia , Trypanosoma/fisiologia , Animais , Regulação para Baixo , Ativação Enzimática , Corpo Adiposo/enzimologia , Hemolinfa/enzimologia , Fatores de Tempo , Trypanosoma/crescimento & desenvolvimento , Tripsina/metabolismo
15.
Phys Rev Lett ; 87(19): 190401, 2001 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-11690400

RESUMO

The properties of a rotating Bose-Einstein condensate confined in a prolate cylindrically symmetric trap are explored both analytically and numerically. As the rotation frequency increases, an ever greater number of vortices are energetically favored. Though the cloud anisotropy and moment of inertia approach those of a classical fluid at high frequencies, the observed vortex density is consistently lower than the solid-body estimate. Furthermore, the vortices are found to arrange themselves in highly regular triangular arrays, with little distortion even near the condensate surface. These results are shown to be a direct consequence of the inhomogeneous confining potential.

16.
Phys Rev Lett ; 86(14): 2926-9, 2001 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-11290074

RESUMO

We have created spatial dark solitons in two-component Bose-Einstein condensates in which the soliton exists in one of the condensate components and the soliton nodal plane is filled with the second component. The filled solitons are stable for hundreds of milliseconds. The filling can be selectively removed, making the soliton more susceptible to dynamical instabilities. For a condensate in a spherically symmetric potential, these instabilities cause the dark soliton to decay into stable vortex rings. We have imaged the resulting vortex rings.

17.
Phys Rev Lett ; 86(4): 564-7, 2001 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-11177882

RESUMO

The dynamics of vortices in trapped Bose-Einstein condensates are investigated both analytically and numerically. In axially symmetric traps, the critical rotation frequency for metastability of an isolated vortex coincides with the largest vortex precession frequency (or anomalous mode) in the Bogoliubov excitation spectrum. The number of anomalous modes increases for an elongated condensate. The largest mode frequency exceeds the thermodynamic critical frequency and the nucleation frequency at which vortices are created dynamically. Thus, anomalous modes describe both vortex precession and the critical rotation frequency for creation of the first vortex in an elongated condensate.

18.
J Res Natl Inst Stand Technol ; 105(6): 875-94, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-27551642

RESUMO

The rate of scientific discovery can be accelerated through computation and visualization. This acceleration results from the synergy of expertise, computing tools, and hardware for enabling high-performance computation, information science, and visualization that is provided by a team of computation and visualization scientists collaborating in a peer-to-peer effort with the research scientists. In the context of this discussion, high performance refers to capabilities beyond the current state of the art in desktop computing. To be effective in this arena, a team comprising a critical mass of talent, parallel computing techniques, visualization algorithms, advanced visualization hardware, and a recurring investment is required to stay beyond the desktop capabilities. This article describes, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing and visualization to accelerate condensate modeling, (2) fluid flow in porous materials and in other complex geometries, (3) flows in suspensions, (4) x-ray absorption, (5) dielectric breakdown modeling, and (6) dendritic growth in alloys.

19.
Mem Inst Oswaldo Cruz ; 94(6): 771-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10585653

RESUMO

Protease activities in the haemolymph and fat body in a bloodsucking insect, Rhodnius prolixus, infected with Trypanosoma rangeli, were investigated. After SDS-polyacrylamide gel electrophoresis containing gelatin as substrate, analysis of zymograms performed on samples of different tissues of controls and insects inoculated or orally infected with short or long epimastigotes of T. rangeli, demonstrated distinct patterns of protease activities: (i) proteases were detected in the haemolymph of insects which were fed on, or inoculated with, short epimastigotes of T. rangeli (39 kDa and 33 kDa, respectively), but they were not observed in the fat body taken from these insects; (ii) protease was also presented in the fat bodies derived from naive insects or controls inoculated with sterile phosphate-saline buffer (49 kDa), but it was not detected in the haemolymph of these insects; (iii) no protease activity was observed in both haemolymph and fat bodies taken from insects inoculated with, or fed on, long epimastigotes of T. rangeli. Furthermore, in short epimastigotes of T. rangeli extracts, three bands of the protease activities with apparent molecular weights of 297, 198 and 95 kDa were detected while long epimastigotes preparation presented only two bands of protease activities with molecular weights of 297 and 198 kDa. The proteases from the insect infected with T. rangeli and controls belong to the class of either metalloproteases or metal-activated enzymes since they are inhibited by 1,10-phenanthroline. The significance of these proteases in the insects infected with short epimastigotes of T. rangeli is discussed in relation to the success of the establishment of infection of these parasites in its vector, R. prolixus.


Assuntos
Metaloendopeptidases/metabolismo , Rhodnius/enzimologia , Rhodnius/parasitologia , Tripanossomíase/enzimologia , Tecido Adiposo/enzimologia , Animais , Hemolinfa/enzimologia
20.
Mem. Inst. Oswaldo Cruz ; 94(6): 771-7, Nov.-Dec. 1999.
Artigo em Inglês | LILACS | ID: lil-251337

RESUMO

Protease activities in the haemolymph and fat body in a bloodsucking insect, Rhodnius prolixus, infected with Trypanosoma rangeli, were investigated. After SDS-polyacrylamide gel electrophoresis containing gelatin as substrate, analysis of zymograms performed on samples of different tissues of controls and insects inoculated or orally infected with short or long epimastigotes of T. rangeli, demonstrated distinct patterns of protease activities: (i) proteases were detected in the haemolymph of insects which were fed on, or inoculated with, short epimastigotes of T. rangeli (39 kDa and 33 kDa, respectively), but they were not observed in the fat body taken from these insects; (ii) protease was also presented in the fat bodies derived from naive insects or controls inoculated with sterile phosphate-saline buffer (49 kDa), but it was not detected in the haemolymph of these insects; (iii) no protease activity was observed in both haemolymph and fat bodies taken from insects inoculated with, or fed on, long epimastigotes of T. rangeli. Furthermore, in short epimastigotes of T. rangeli extracts, three bands of the protease activities with apparent molecular weights of 297, 198 and 95 kDa were detected while long epimastigotes preparation presented only two bands of protease activities with molecular weights of 297 and 198 kDa. The proteases from the insect infected with T. rangeli and controls belong to the class of either metalloproteases or metal-activated enzymes since they are inhibited by 1,10-phenanthroline. The significance of these proteases in the insects infected with short epimastigotes of T. rangeli is discussed in relation to the success of the establishment of infection of these parasites in its vector, R. prolixus


Assuntos
Animais , Vetores de Doenças , Metaloendopeptidases/metabolismo , Rhodnius/parasitologia , Trypanosoma/enzimologia , Eletroforese em Gel de Poliacrilamida , Corpo Adiposo/enzimologia , Interações Hospedeiro-Parasita , Tripanossomíase/parasitologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...