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1.
J Dairy Sci ; 107(5): 2653-2667, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38135050

RESUMO

The purpose of this study was to investigate if consumption of a high-protein, low-carbohydrate breakfast (PRO) leads to a lower subsequent ad libitum energy intake at lunch and the rest of the day compared with ingestion of an isocaloric low-protein, high-carbohydrate breakfast (CHO) or no breakfast (CON). The study was designed as a randomized controlled 3-period crossover study. Thirty young (18-30 yr) females with overweight to obesity (body mass index >25 kg/m2) in random order completed 3 separate experimental days where they consumed either a PRO, CHO, or CON breakfast test meal followed by an ad libitum lunch meal 3 h after breakfast. Participants were allocated to a sequence group by their inclusion number. The PRO and CHO breakfasts were matched in dietary fiber and fat content. Energy intake at lunch was calculated and dietary records were obtained for the rest of the day to calculate the total daily energy intake and macronutrient intake. Ratings of appetite sensations between meals and palatability of the test meals were assessed using visual analog scale sheets in intervals ranging from 10 to 30 min. In addition, blood samples were obtained at multiple time points separated by 10 to 60 min intervals between breakfast and lunch and were analyzed for appetite-regulating gut hormones, insulin, and glucose. Finally, performance in a cognitive concentration test was tested 150 min after breakfast. Compared with CHO and CON, the area under the curves for satiety, fullness, and satisfaction in the 3 h after breakfast were significantly higher after PRO, whereas the areas under the curve for hunger, desire to eat, and prospective eating were significantly lower after PRO. The appetite-regulating gut hormones cholecystokinin, glucagon-like peptide-1, and ghrelin in the hours after breakfast, energy intake during the ad libitum lunch meal, and the total daily energy intake did not differ significantly between PRO, CHO, and CON. However, the cognitive concentration test score was 3.5 percentage points higher for PRO, but not CHO, versus CON. A dairy-based high-protein, low-carbohydrate breakfast increased satiety sensation in the hours after breakfast but did not reduce total daily energy intake compared with an isocaloric low-protein, high-carbohydrate breakfast or omitting breakfast. However, performance in a cognitive concentration test before lunch was enhanced after the high-protein, low-carbohydrate breakfast, but not the low-protein, high-carbohydrate breakfast, compared with omitting breakfast.


Assuntos
Desjejum , Sobrepeso , Feminino , Animais , Sobrepeso/veterinária , Estudos Cross-Over , Almoço , Estudos Prospectivos , Obesidade/veterinária , Ingestão de Energia , Fibras na Dieta , Insulina , Cognição , Glicemia , Período Pós-Prandial
2.
J Med Ultrasound ; 25(3): 167-172, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-30065483

RESUMO

BACKGROUND: Ultrasound has become an increasingly utilized tool for the imaging of the musculoskeletal system, especially for imaging the components of the knee. Even though MRI is touted as being the golden standard for identifying knee pathologies, the use of ultrasound has gained popularity in this field given its ability for rapid diagnosis. This study aims to investigate the efficacy of point-of-care ultrasound (POCUS) to diagnose injuries to the medial knee compartment when compared to magnetic resonance imaging (MRI). METHODS: This was a prospective, observational study conducted at an orthopedic outpatient clinic. Prospective patients with medial knee pain scheduled for an MRI of the knee were evaluated by POCUS prior to the MRI. Sonographic findings were then compared to MRI results to assess correlation. RESULTS: Nine patients were enrolled in the study. Median age was 53 years and eight were male (89%). POCUS demonstrated 100% sensitivity and 50% specificity for medial meniscus tear and 67% sensitivity and 83% specificity for medial collateral ligament (MCL) tear. CONCLUSION: Ultrasound may have a role as the initial rapid imaging modality in patients with suspected medial meniscus or MCL tears as it is highly sensitive, and it may serve as an effective screening tool for patients with both acute and chronic knee pain.

3.
Vet Rec ; 171(14): 348, 2012 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-22915682

RESUMO

Progressive infection with feline leukaemia virus (FeLV) is considered one of the major risk factors for development of feline lymphoma. The aim of this study was to compare cats with lymphoma between 1980 and 1994 (first period) and between 1995 and 2009 (second period) concerning FeLV antigenaemia and age distribution. In addition, differences between FeLV antigen-positive and antigen-negative cats with lymphoma regarding patients' characteristics, tumour location and outcome were evaluated. There was a significant decrease in the percentage of lymphoma cases associated with progressive FeLV infection from the first (59 per cent) to the second (13 per cent) observation period. FeLV antigen-positive cats were significantly younger (median 3.7 v 11.3 years), and had significantly shorter response duration (median 25 days v 472 days) with therapy. In the cats of the second period, gastrointestinal and extranodal lymphomas were the most common anatomical sites, and the majority of those cats were FeLV antigen-negative. Thus, other aetiologies than progressive FeLV infection must have a greater impact on cancerogenesis among affected cats with lymphoma to date.


Assuntos
Doenças do Gato/epidemiologia , Doenças do Gato/virologia , Vírus da Leucemia Felina , Leucemia Felina/epidemiologia , Linfoma/veterinária , Fatores Etários , Animais , Antígenos Virais/imunologia , Gatos , Feminino , Alemanha/epidemiologia , Linfoma/epidemiologia , Linfoma/virologia , Masculino , Prevalência , Fatores de Risco , Viremia/epidemiologia , Viremia/veterinária
4.
J Control Release ; 143(1): 13-22, 2010 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-20006659

RESUMO

The design of delivery vehicles that are stable in circulation but can be activated by exogenous energy sources is challenging. Our goals are to validate new imaging methods for the assessment of particle stability, to engineer stable and activatable particles and to assess accumulation of a hydrophilic model drug in an orthotopic tumor. Here, liposomes were injected into the tail vein of FVB mice containing bilateral Met-1 tumors and imaged in vivo using microPET and optical imaging techniques. Cryo-electron microscopy was applied to assess particle shape prior to injection, ex vivo fluorescence images of dissected tissues were acquired, excised tissue was further processed with a cell-digest preparation and assayed for fluorescence. We find that for a stable particle, in vivo tumor images of a hydrophilic model drug were highly correlated with PET images of the particle shell and ex vivo fluorescence images of processed tissue, R(2)=0.95 and R(2)=0.99 respectively. We demonstrate that the accumulation of a hydrophilic model drug is increased by up to 177 fold by liposomal encapsulation, as compared to accumulation of the drug at 24 hours.


Assuntos
Antineoplásicos/farmacocinética , Corantes Fluorescentes/farmacocinética , Lipídeos/farmacocinética , Neoplasias Mamárias Animais/diagnóstico por imagem , Neoplasias Mamárias Animais/metabolismo , Tomografia por Emissão de Pósitrons , Espectrometria de Fluorescência , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Química Farmacêutica , Microscopia Crioeletrônica , Composição de Medicamentos , Feminino , Fluoresceínas/metabolismo , Corantes Fluorescentes/administração & dosagem , Injeções Intravenosas , Lipídeos/administração & dosagem , Lipídeos/química , Lipossomos , Camundongos , Tamanho da Partícula , Reprodutibilidade dos Testes , Succinimidas/farmacocinética , Propriedades de Superfície , Tecnologia Farmacêutica/métodos , Temperatura
5.
Phys Med Biol ; 53(13): 3641-60, 2008 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-18562783

RESUMO

The development of transgenic reporter mice and advances in in vivo optical imaging have created unique opportunities to assess and analyze biological responses to thermal therapy directly in living tissues. Reporter mice incorporating the regulatory regions from the genes encoding the 70 kDa heat-shock proteins (Hsp70) and firefly luciferase (luc) as reporter genes can be used to non-invasively reveal gene activation in living tissues in response to thermal stress. High-intensity-focused ultrasound (HIFU) can deliver measured doses of acoustic energy to highly localized regions of tissue at intensities that are sufficient to stimulate Hsp70 expression. We report activation of Hsp70-luc expression using 1 s duration HIFU heating to stimulate gene expression in the skin of the transgenic reporter mouse. Hsp70 expression was tracked for 96 h following the application of 1.5 MHz continuous-wave ultrasound with spatial peak intensities ranging from 53 W cm(-2) up to 352 W cm(-2). The results indicated that peak Hsp70 expression is observed 6-48 h post-heating, with significant activity remaining at 96 h. Exposure durations were simulated using a finite-element model, and the predicted temperatures were found to be consistent with the observed Hsp70 expression patterns. Histological evaluation revealed that the thermal damage starts at the stratum corneum and extends deeper with increasing intensity. These results indicated that short-duration HIFU may be useful for inducing heat-shock expression, and that the period between treatments needs to be greater than 96 h due to the protective properties of Hsp70.


Assuntos
Epiderme/efeitos da radiação , Regulação da Expressão Gênica/efeitos da radiação , Genes Reporter/genética , Proteínas de Choque Térmico HSP70/efeitos da radiação , Temperatura Alta , Luciferases/efeitos da radiação , Ultrassom , Animais , Epiderme/patologia , Regulação da Expressão Gênica/genética , Proteínas de Choque Térmico HSP70/genética , Luciferases/genética , Camundongos , Camundongos Transgênicos , Fatores de Tempo , Ativação Transcricional
6.
Phys Med Biol ; 52(8): 2055-72, 2007 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-17404455

RESUMO

The goal of ultrasonic molecular imaging is the detection of targeted contrast agents bound to receptors on endothelial cells. We propose imaging methods that can distinguish adherent microbubbles from tissue and from freely circulating microbubbles, each of which would otherwise obscure signal from molecularly targeted adherent agents. The methods are based on a harmonic signal model of the returned echoes over a train of pulses. The first method utilizes an 'image-push-image' pulse sequence where adhesion of contrast agents is rapidly promoted by acoustic radiation force and the presence of adherent agents is detected by the signal change due to targeted microbubble adhesion. The second method rejects tissue echoes using a spectral high-pass filter. Free agent signal is suppressed by a pulse-to-pulse low-pass filter in both methods. An overlay of the adherent and/or flowing contrast agents on B-mode images can be readily created for anatomical reference. Contrast-to-tissue ratios from adherent microbubbles exceeding 30 dB and 20 dB were achieved for the two methods proposed, respectively. The performance of these algorithms is compared, emphasizing the significance and potential applications in ultrasonic molecular imaging.


Assuntos
Meios de Contraste/química , Sistemas de Liberação de Medicamentos/métodos , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Ultrassonografia/métodos , Microbolhas , Imagens de Fantasmas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Aderências Teciduais , Ultrassonografia/instrumentação
7.
Phys Rev Lett ; 93(8): 083601, 2004 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-15447183

RESUMO

Networks of globally coupled oscillators exhibit phase transitions from incoherent to coherent states. Atoms interacting with the counterpropagating modes of a unidirectionally pumped high-finesse ring cavity form such a globally coupled network. The coupling mechanism is provided by collective atomic recoil lasing, i.e., cooperative Bragg scattering of laser light at an atomic density grating, which is self-induced by the laser light. Under the rule of an additional friction force, the atomic ensemble is expected to undergo a phase transition to a state of synchronized atomic motion. We present the experimental investigation of this phase transition by studying the threshold behavior of this lasing process.

8.
Phys Rev Lett ; 91(18): 183601, 2003 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-14611282

RESUMO

We observe the buildup of a frequency-shifted reverse light field in a unidirectionally pumped high-Q optical ring cavity serving as a dipole trap for cold atoms. This effect is enhanced and a steady state is reached, if via an optical molasses an additional friction force is applied to the atoms. We observe the displacement of the atoms accelerated by momentum transfer in the backscattering process and interpret our observations in terms of the collective atomic recoil laser. Numerical simulations are in good agreement with the experimental results.

9.
Biotech Histochem ; 77(4): 189-200, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12503728

RESUMO

Information on ductal differentiation in the developing rat parotid gland is sparse. One of the main functions of the striated and excretory ducts in this gland is the selective exchange of electrolytes from the primary fluid secreted by the acini. These ducts are rich in a number of enzymes involved in this task, suggesting that they might be useful as markers of ductal differentiation. The objective of this investigation was to delineate the developmental changes in activity of three of these, cytochrome C oxidase (CCO), succinate dehydrogenase (SDH), nicotinamide adenine phosphate dinucleotide (reduced form)-dehydrogenase (NADPH-DH). Histochemical localization of all three enzymes in fresh frozen sections was complemented by biochemical assays of CCO and SDH and cytochemical localization of CCO. Biochemically, CCO- and SDH-specific activity in gland homogenates increased progressively after birth, reaching adult levels at 21-28 days. Histochemically, deposits of reaction products of all three enzymes increased more in the striated and excretory ducts, especially in their basal cytoplasm, than in other glandular structures between 19 days in utero and 28 days after birth. During the same age span, the mitochondria in the striated and excretory ducts increased markedly in both number and size, migrated to a mostly basal location, and increased from many to virtually all showing strong cytochemical CCO reactions. These histochemical and cytochemical patterns of changes in enzyme activity at the cellular level accounted for the overall increases in CCO and SDH seen in the biochemical assays. Only the SDH histochemical reaction was consistently weak in the acini and intercalated ducts, and thus provided the most contrast with the progressively stronger reactions in the larger ducts. We conclude that of the three enzymes evaluated in these experiments, SDH is the best marker of the functional differentiation of the striated and excretory ducts in the developing rat parotid gland.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/análise , Histocitoquímica/métodos , NADPH Desidrogenase/análise , Glândula Parótida/enzimologia , Succinato Desidrogenase/análise , Animais , Animais Recém-Nascidos , Biomarcadores , Diferenciação Celular , Citoplasma/enzimologia , Feminino , Masculino , Mitocôndrias/enzimologia , Mitocôndrias/ultraestrutura , Glândula Parótida/anatomia & histologia , Glândula Parótida/crescimento & desenvolvimento , Gravidez , Ratos , Ratos Sprague-Dawley , Ductos Salivares/enzimologia , Ductos Salivares/ultraestrutura
10.
Appl Microbiol Biotechnol ; 59(2-3): 205-10, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12111147

RESUMO

Threonine production in Escherichia coli threonine producer strains is enhanced by overexpression of the E. coli rhtB and rhtC genes or by heterologous overexpression of the gene encoding the Corynebacterium glutamicum threonine excretion carrier, thrE. Both E. coli genes give rise to a threonine-resistant phenotype when overexpressed, and they decrease the accumulation of radioactive metabolites derived from [(14)C] L-threonine. The evidence presented supports the conclusion that both RhtB and RhtC catalyze efflux of L-threonine and other structurally related neutral amino acids, but that the specificities of these two carriers differ substantially.


Assuntos
Sistemas de Transporte de Aminoácidos Neutros , Proteínas de Bactérias , Proteínas de Escherichia coli , Escherichia coli/metabolismo , Treonina/biossíntese , Transporte Biológico , Proteínas de Transporte/genética , Proteínas de Membrana/genética
11.
Histochem J ; 33(2): 71-7, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11432642

RESUMO

In examining the secretory mechanism of exocrine glands, we focused on the small GTP-binding proteins, Rab3D and Rab3B, which function in the final steps of exocytosis in non-neuronal tissues. These proteins were observed in von Ebner's glands by 32P-GTP overlay. mRNA isolated from von Ebner's glands, the pancreas, parotid glands, and liver was subjected to reverse transcription PCR and probed with primers and nested primers for Rab3D and Rab3B. Rab3D was found in all three exocrine glands and the liver, while Rab3B was found in the liver. Utilizing immunofluorescence histochemistry, Rab3D was localized to hepatocytes of the liver and to secretory granules of the exocrine glands, and Rab3B to liver and pancreatic islets. Isoproterenol evoked decreases in alpha-amylase- and Rab3D-labelled parotid secretory granules, and pilocarpine stimulated decreases in secretory granules labelled for lingual lipase and Rab3D from von Ebner's glands, and amylase and Rab3D from pancreas. Neither secretagogue affected Rab3B in pancreatic islets. These observed parallel decreases in response to beta-adrenergic (parotid) or cholinergic (von Ebner's and pancreas) secretagogues indicate that the function of Rab3D in exocytosis in these exocrine organs is similar and that the type of secretagogue does not determine the function.


Assuntos
RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas rab3 de Ligação ao GTP/genética , Proteínas rab3 de Ligação ao GTP/metabolismo , Animais , Sequência de Bases , Primers do DNA/genética , Glândulas Exócrinas/metabolismo , Imunofluorescência , Imuno-Histoquímica , Fígado/metabolismo , Pâncreas/metabolismo , Glândula Parótida/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glândulas Salivares Menores/metabolismo
12.
Artigo em Inglês | MEDLINE | ID: mdl-11370354

RESUMO

Ultrasound contrast agents are encapsulated microbubbles, filled either with air or a higher weight molecular gas, ranging in size from 1 to 10 microns in diameter. The agents are modeled as air-filled spherical elastic shells of variable thickness and material properties. The scattered acoustic field is computed from a modal series solution, and reflectivity and angular scattering are then determined from the computed fields for agents of various properties. We show that contrast agents also support shell resonance responses in addition to the monopole response, which has been the focus of previous contrast agent studies. Lamb waves appear to be the source of these additional responses. A shell or curvature Lamb wave generates dipole peaks in the 1- to 40-MHz range for 2.5 to 3.5 microns radius agents with elastic properties approximating those of albumin protein. The inclusion of damping affects the lower frequency dipole peaks but is less important for responses occurring above approximately 30 MHz. Moreover, these responses hold untapped potential for clinical ultrasound applications such as tissue perfusion studies and high frequency contrast agent imaging.


Assuntos
Ultrassonografia , Engenharia Biomédica , Velocidade do Fluxo Sanguíneo , Meios de Contraste , Gases , Humanos , Microesferas , Modelos Teóricos , Tamanho da Partícula , Espalhamento de Radiação
13.
Aust N Z J Psychiatry ; 35(1): 65-8, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11270459

RESUMO

OBJECTIVE: Our objective was to determine the outcome of novel strategies in managing a case of severe polydipsia. CLINICAL PICTURE: The patient was a 39-year-old male with a 20-year history of paranoid schizophrenia who, despite only mild residual psychotic symptoms, had been hospitalized for the previous 10 years because of severe polydipsic behaviour complicated by water intoxication. TREATMENT: Novel antipsychotic agents, risperidone and olanzapine, as well as the specific angiotensin-II receptor blocking drug, irbesartan were employed at selected intervals in a study lasting nearly 3 years. A strict behavioural management programme was ongoing, in which diurnal weight change and the number of breaches of weight limits, requiring management in a low-stimulus environment, were documented on a daily basis. Summary measures of diurnal weight change and behavioural intervention were charted against changes in treatment. OUTCOME: Polydipsic behaviour improved on risperidone up to 4 mg daily, but was not sustained. Olanzapine was similarly successful in stabilizing polydipsia, and improvement was achieved with the addition of irbesartan. CONCLUSION: We suggest that the D2-sparing profiles of receptor binding achieved with low-dose risperidone and olanzapine may account for this beneficial effect. The benefit derived with irbesartan implicates the involvement of brain angiotensin systems centrally in helping to regulate drinking behaviour.


Assuntos
Antagonistas de Receptores de Angiotensina , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Antipsicóticos/uso terapêutico , Compostos de Bifenilo/farmacologia , Compostos de Bifenilo/uso terapêutico , Pirenzepina/análogos & derivados , Pirenzepina/uso terapêutico , Risperidona/uso terapêutico , Psicologia do Esquizofrênico , Tetrazóis/farmacologia , Tetrazóis/uso terapêutico , Intoxicação por Água/tratamento farmacológico , Intoxicação por Água/etiologia , Adulto , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Antipsicóticos/administração & dosagem , Benzodiazepinas , Compostos de Bifenilo/administração & dosagem , Relação Dose-Resposta a Droga , Humanos , Irbesartana , Masculino , Olanzapina , Pirenzepina/administração & dosagem , Risperidona/administração & dosagem , Tetrazóis/administração & dosagem
14.
J Bacteriol ; 182(21): 6247-9, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11029450

RESUMO

When transport of polyamines in Escherichia coli was examined, putrescine excretion was observed under two different physiological conditions: (i) strictly correlated to growth and (ii) following a hyperosmotic shock. Spermidine was not excreted. Characterization of a deletion mutant showed that PotE is not involved in these transport processes.


Assuntos
Antiporters/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Escherichia coli , Escherichia coli/metabolismo , Poliaminas/metabolismo , Antiporters/genética , Proteínas de Bactérias/genética , Deleção de Genes , Pressão Osmótica , Putrescina/metabolismo
16.
Pediatr Pulmonol ; 29(3): 182-7, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10686038

RESUMO

Although bronchiectasis has become a rare condition in U.S. children, it is still commonly diagnosed in Alaska Native children in the Yukon Kuskokwim Delta. The prevalence of bronchiectasis has not decreased in persons born during the 1980s as compared with those born in the 1940s. We reviewed case histories of 46 children with bronchiectasis. We observed that recurrent pneumonia was the major preceding medical condition in 85% of patients. There was an association between the lobes affected by pneumonia and the lobes affected by bronchiectasis. Eight (17%) patients had surgical resection of involved lobes. We conclude that the continued high prevalence of bronchiectasis appears to be related to extremely high rates of infant and childhood pneumonia. Pediatr Pulmonol. 2000;29:182-187. Published 2000 Wiley-Liss, Inc.


Assuntos
Bronquiectasia/etiologia , Indígenas Norte-Americanos , Adolescente , Alaska/epidemiologia , Asma/complicações , Asma/fisiopatologia , Bronquiectasia/fisiopatologia , Bronquiectasia/cirurgia , Criança , Pré-Escolar , Volume Expiratório Forçado/fisiologia , Corpos Estranhos/complicações , Humanos , Lactente , Pulmão/fisiopatologia , Pneumonectomia , Pneumonia/complicações , Pneumonia/fisiopatologia , Pneumonia Aspirativa/complicações , Pneumonia Bacteriana/complicações , Prevalência , Recidiva , Tuberculose Pulmonar/complicações , Capacidade Vital/fisiologia
17.
J Infect Dis ; 180(1): 41-9, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10353859

RESUMO

Hospitalization rates for respiratory syncytial virus (RSV) infection range from 1 to 20/1000 infants. To determine the rate and severity of RSV infections requiring hospitalization for infants in the Yukon-Kuskokwim (YK) Delta of Alaska, a 3-year prospective surveillance study was conducted. The annual rate of RSV hospitalization for YK Delta infants <1 year of age was 53-249/1000. RSV infection was the most frequent cause of infant hospitalization. RSV disease severity did not differ among non-high-risk infants in the YK Delta and at Johns Hopkins Hospital (JHH). On average, 1/125 infants born in the YK Delta required mechanical ventilation for RSV infection. During the peak season, approximately $1034/child <3 years of age was spent on RSV hospitalization in the YK Delta. In YK Delta infants

Assuntos
Infecções por Vírus Respiratório Sincicial/epidemiologia , Fatores Etários , Alaska/epidemiologia , Anticorpos Antivirais/sangue , Baltimore/epidemiologia , Pré-Escolar , Sangue Fetal/imunologia , Hospitalização , Hospitais Comunitários , Humanos , Incidência , Indígenas Norte-Americanos , Lactente , Recém-Nascido , Inuíte , Vigilância da População , Estudos Prospectivos , Infecções por Vírus Respiratório Sincicial/economia , Vírus Sinciciais Respiratórios/classificação , Fatores de Risco , Estações do Ano , Índice de Gravidade de Doença
18.
Invest Ophthalmol Vis Sci ; 40(7): 1373-81, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10359319

RESUMO

PURPOSE: To develop a noninvasive technique to visualize and measure blood flow in the iris and ciliary body. METHODS: Echo data from 50-MHz ultrasound scans of the iris and ciliary body of rabbits were digitized using a new "swept scan" modality. The method makes use of spatial oversampling to identify regions with scatterers whose range changes with time. The data allowed construction of high-resolution B-mode images with embedded flow information. Pulsatility over the cardiac cycle was evaluated by sending a series of pulses along a single line of sight containing a vessel of interest. Local blood flow and changes over the cardiac cycle before and after application of atropine were quantified. RESULTS: Flow was identified in the radial vessels and major arterial circle of the iris. Vessels with lumens as small as 40 microm in diameter and flow velocities as low as 0.6 mm/sec were measured. Change in blood velocity over the cardiac cycle was determined to be approximately 27%. Peak systolic velocity after administration of topical atropine increased by 72%. CONCLUSIONS: This technique allowed visualization of flow using the same type of very-high-frequency transducer now widely used for imaging the anterior segment. The technique can also be used at lower frequencies for more posterior tissues with similar improvement of resolution over Doppler. The ability to examine flow in the anterior segment of the eye offers a new tool for study of glaucoma, hypotony, tumors, and other disorders.


Assuntos
Segmento Anterior do Olho/irrigação sanguínea , Corpo Ciliar/irrigação sanguínea , Iris/irrigação sanguínea , Artéria Oftálmica/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Animais , Velocidade do Fluxo Sanguíneo , Frequência Cardíaca , Microcirculação , Fluxo Pulsátil , Coelhos
20.
Ann N Y Acad Sci ; 842: 171-80, 1998 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-9599307

RESUMO

Recent developments in gene transfer technology have expanded the range of in vivo experimentation and provided new insights that might be applicable to the treatment of human diseases. Somatic gene transfer may complement conventional transgenic animal experiments by allowing for more restricted gene expression. Salivary glands of rats are readily transduced in vivo by adenovirus vectors. This model has been used to demonstrate the effects of transferring a water channel (aquaporin) gene to glands that have been damaged by radiation. Submandibular glands that receive the aquaporin vector increase the stimulated salivary flow close to normal levels. The possible role of E2F1 in promoting cell regeneration in vivo was also explored. A vector expressing E2F1 was capable of increasing DNA synthesis in rat salivary glands, though complete mitosis was not observed. Future generations of vectors must overcome current limitations of efficiency, immunogenicity, and transient expression.


Assuntos
Técnicas de Transferência de Genes , Glândulas Salivares , Animais , Humanos , Regeneração , Glândulas Salivares/fisiologia
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