Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
Development ; 149(8)2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35452096

RESUMO

Previously, we have demonstrated that a subpopulation of microglia, known as Hoxb8 microglia, is derived from the Hoxb8 lineage during the second wave (E8.5) of yolk sac hematopoiesis, whereas canonical non-Hoxb8 microglia arise from the first wave (E7.5). Hoxb8 microglia have an ontogeny distinct from non-Hoxb8 microglia. Dysfunctional Hoxb8 microglia cause the acquisition of chronic anxiety and an obsessive-compulsive spectrum-like behavior, trichotillomania, in mice. The nature and fate of the progenitors generated during E8.5 yolk sac hematopoiesis have been controversial. Herein, we use the Hoxb8 cell lineage reporter to define the ontogeny of hematopoietic cells arising during the definitive waves of hematopoiesis initiated in the E8.5 yolk sac and aorta-gonad-mesonephros (AGM) region. Our murine cell lineage analysis shows that the Hoxb8 cell lineage reporter robustly marks erythromyeloid progenitors, hematopoietic stem cells and their progeny, particularly monocytes. Hoxb8 progenitors and microglia require Myb function, a hallmark transcription factor for definitive hematopoiesis, for propagation and maturation. During adulthood, all immune lineages and, interestingly, resident macrophages in only hematopoietic/lymphoid tissues are derived from Hoxb8 precursors. These results illustrate that the Hoxb8 lineage exclusively mirrors murine definitive hematopoiesis.


Assuntos
Hematopoese , Saco Vitelino , Animais , Linhagem da Célula , Células-Tronco Hematopoéticas , Proteínas de Homeodomínio/genética , Mesonefro , Camundongos
2.
J Prim Care Community Health ; 12: 21501327211014084, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34009054

RESUMO

"Why treat insomnia?" This question grows out of the perspective that insomnia is a symptom that should only receive targeted treatment when temporary relief is needed or until more comprehensive gains may be achieved with therapy for the parent or precipitating medical or psychiatric disorders. This perspective, however, is untenable given recent data regarding the prevalence, course, consequences, and costs of insomnia. Further, the emerging data that the treatment of insomnia may promote better medical and mental health (alone or in combination with other therapies) strongly suggests that the question is no longer "why treat insomnia," but rather "when isn't insomnia treatment indicated?" This perspective was recently catalyzed with the American College of Physicians' recommendation that chronic insomnia should be treated and that the first line treatment should be cognitive-behavioral therapy for insomnia (CBT-I).


Assuntos
Terapia Cognitivo-Comportamental , Distúrbios do Início e da Manutenção do Sono , Humanos , Distúrbios do Início e da Manutenção do Sono/terapia , Resultado do Tratamento
3.
J Sleep Res ; 30(5): e13342, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33853197

RESUMO

According to the "3P model" of insomnia, the variable that mediates the transition from acute insomnia (AI) to chronic insomnia is "sleep extension" (the behavioural tendency to expand sleep opportunity to compensate for sleep loss). In the present analysis, we sought to evaluate how time in bed (TIB) varies relative to the new onset of AI and chronic insomnia. A total of 1,248 subjects were recruited as good sleepers (GS). Subjects were monitored over 1 year with sleep diaries. State transitions were defined, a priori, for AI, recovered from AI (AI-REC), and for chronic insomnia (AI-CI). Two additional groupings were added based on profiles that were unanticipated: subjects that exhibited persistent poor sleep following AI (AI-PPS [those that neither recovered or developed chronic insomnia]) and subjects that recovered from chronic insomnia (CI-REC). All the groups (GS, AI-REC, AI-CI, AI-PPS and CI-REC) were evaluated for TIB differences with longitudinal mixed effects models. Post hoc analyses for the percentage of the groups that were typed as TIB "restrictors, maintainers, and expanders" were conducted using longitudinal mixed effects models and contingency analyses. Significant differences for pre-post AI TIB were not detected for the insomnia groups. Trends were apparent for the AI-CI group, which suggested that minor increases in TIB occurred weeks before the declared onset of AI. Additionally, it was found that a significantly larger percentage of AI-CI subjects engaged in sleep extension (as compared to GS). The present data suggest that transition from AI to chronic insomnia does not appear to be initiated by sleep extension and the transition may occur before the elapse of 3 months of ≥3 nights of sleep continuity disturbance. Given these findings, it may be that the mismatch between sleep ability and sleep opportunity is perpetuated over time given the failure to "naturally" engage in sleep restriction (as opposed to sleep extension).


Assuntos
Distúrbios do Início e da Manutenção do Sono , Humanos , Sono , Distúrbios do Início e da Manutenção do Sono/diagnóstico
4.
J Cardiothorac Vasc Anesth ; 35(5): 1404-1409, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33067088

RESUMO

OBJECTIVE: Assess the efficacy of adding liposomal bupivacaine (LB) to bupivacaine-containing intercostal nerve blocks (ICNBs) to improve analgesia and decrease opioid consumption and hospital length of stay compared with bupivacaine-only ICNBs. DESIGN: This retrospective, observational investigation compared pain intensity scores and cumulative opioid consumption within the first 72 postoperative hours in patients who received ICNBs with bupivacaine plus LB (LB group) versus bupivacaine only (control group) after minimally invasive anatomic pulmonary resection. LB was tested for noninferiority on pain scores and opioid consumption. If LB was noninferior, superiority of LB was tested on both outcomes. SETTING: Academic tertiary care medical center. PARTICIPANTS: Adult patients undergoing minimally invasive anatomic pulmonary resection. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: For the secondary analysis, hospital length of stay was compared through the Cox regression model. Of 396 patients, 178 (45%) received LB and 218 (55%) did not. The mean (standard deviation) pain score was three (one) in the LB group and three (one) in the control group, with a difference of -0.10 (97.5% confidence interval [-0.39 to 0.18]; p = 0.41). The mean (standard deviation) cumulative opioid consumption (intravenous morphine equivalents) was 198 (208) mg in the LB group and 195 (162) mg in the control group. Treatment effect in opioid consumption was estimated at a ratio of geometric mean of 0.94 (97.5% confidence interval [0.74-1.20]; p = 0.56). Pain control and opioid consumption were noninferior with LB but not superior. Hospital discharge was not different between groups. CONCLUSIONS: LB with bupivacaine in ICNBs did not demonstrate superior postoperative analgesia or affect the rate of hospital discharge.


Assuntos
Cirurgia Torácica , Adulto , Analgésicos Opioides , Anestésicos Locais , Bupivacaína , Humanos , Dor Pós-Operatória/diagnóstico , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Estudos Retrospectivos
5.
Ann Thorac Surg ; 108(1): e19-e20, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30597141

RESUMO

Use of continuous erector spinae plane (ESP) blocks for pectus excavatum repair may be a valuable alternative to thoracic epidural placement. This report describes the successful use of bilateral ESP blocks in 2 patients with complex medical histories in which thoracic epidural placement was either contraindicated or unsuccessful. The benefits of continuous ESP blocks in this subset of patients include pain control with a focus on opioid sparing, early extubation, decreased atelectasis, improved mobilization and physical therapy, and decreased length of hospital stay.


Assuntos
Tórax em Funil/cirurgia , Bloqueio Nervoso/métodos , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Manejo da Dor
6.
PLoS One ; 13(4): e0193405, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29694353

RESUMO

We conducted a series of experiments to examine short-term (2-5 days) effects of abrupt increases in the partial pressure of carbon dioxide (pCO2) in seawater on rates of primary and bacterial production at Station ALOHA (22°45' N, 158° W) in the North Pacific Subtropical Gyre (NPSG). The majority of experiments (8 of 10 total) displayed no response in rates of primary production (measured by 14C-bicarbonate assimilation; 14C-PP) under elevated pCO2 (~1100 µatm) compared to ambient pCO2 (~387 µatm). In 2 of 10 experiments, rates of 14C-PP decreased significantly (~43%) under elevated pCO2 treatments relative to controls. Similarly, no significant differences between treatments were observed in 6 of 7 experiments where bacterial production was measured via incorporation of 3H-leucine (3H-Leu), while in 1 experiment, rates of 3H-Leu incorporation measured in the dark (3H-LeuDark) increased more than 2-fold under high pCO2 conditions. We also examined photoperiod-length, depth-dependent (0-125 m) responses in rates of 14C-PP and 3H-Leu incorporation to abrupt pCO2 increases (to ~750 µatm). In the majority of these depth-resolved experiments (4 of 5 total), rates of 14C-PP demonstrated no consistent response to elevated pCO2. In 2 of 5 depth-resolved experiments, rates of 3H-LeuDark incorporation were lower (10% to 15%) under elevated pCO2 compared to controls. Our results revealed that rates of 14C-PP and bacterial production in this persistently oligotrophic habitat generally demonstrated no or weak responses to abrupt changes in pCO2. We postulate that any effects caused by changes in pCO2 may be masked or outweighed by the role that nutrient availability and temperature play in controlling metabolism in this ecosystem.


Assuntos
Dióxido de Carbono/análise , Ecossistema , Plâncton/crescimento & desenvolvimento , Água do Mar/química , Oceano Pacífico , Temperatura
7.
mSystems ; 1(3)2016.
Artigo em Inglês | MEDLINE | ID: mdl-27822538

RESUMO

Marine plastic debris has become a significant concern in ocean ecosystems worldwide. Little is known, however, about its influence on microbial community structure and function. In 2008, we surveyed microbial communities and metabolic activities in seawater and on plastic on an oceanographic expedition through the "great Pacific garbage patch." The concentration of plastic particles in surface seawater within different size classes (2 to 5 mm and >5 mm) ranged from 0.35 to 3.7 particles m-3 across sampling stations. These densities and the particle size distribution were consistent with previous values reported in the North Pacific Ocean. Net community oxygen production (NCP = gross primary production - community respiration) on plastic debris was positive and so net autotrophic, whereas NCP in bulk seawater was close to zero. Scanning electron microscopy and metagenomic sequencing of plastic-attached communities revealed the dominance of a few metazoan taxa and a diverse assemblage of photoautotrophic and heterotrophic protists and bacteria. Bryozoa, Cyanobacteria, Alphaproteobacteria, and Bacteroidetes dominated all plastic particles, regardless of particle size. Bacteria inhabiting plastic were taxonomically distinct from the surrounding picoplankton and appeared well adapted to a surface-associated lifestyle. Genes with significantly higher abundances among plastic-attached bacteria included che genes, secretion system genes, and nifH genes, suggesting enrichment for chemotaxis, frequent cell-to-cell interactions, and nitrogen fixation. In aggregate, our findings suggest that plastic debris forms a habitat for complex microbial assemblages that have lifestyles, metabolic pathways, and biogeochemical activities that are distinct from those of free-living planktonic microbial communities. IMPORTANCE Marine plastic debris is a growing concern that has captured the general public's attention. While the negative impacts of plastic debris on oceanic macrobiota, including mammals and birds, are well documented, little is known about its influence on smaller marine residents, including microbes that have key roles in ocean biogeochemistry. Our work provides a new perspective on microbial communities inhabiting microplastics that includes its effect on microbial biogeochemical activities and a description of the cross-domain communities inhabiting plastic particles. This study is among the first molecular ecology, plastic debris biota surveys in the North Pacific Subtropical Gyre. It has identified fundamental differences in the functional potential and taxonomic composition of plastic-associated microbes versus planktonic microbes found in the surrounding open-ocean habitat. Author Video: An author video summary of this article is available.

8.
Sleep ; 37(2): 327-41, 2014 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-24497661

RESUMO

STUDY OBJECTIVES: Examine whether cognitive behavioral therapy for insomnia (CBT-I) improves sleep in posttraumatic stress disorder (PTSD) as well as nightmares, nonsleep PTSD symptoms, depression symptoms, and psychosocial functioning. DESIGN: RANDOMIZED CONTROLLED TRIAL WITH TWO ARMS: CBT-I and monitor-only waitlist control. SETTING: Department of Veterans Affairs (VA) Medical Center. PARTICIPANTS: Forty-five adults (31 females: [mean age 37 y (22-59 y)] with PTSD meeting research diagnostic criteria for insomnia, randomly assigned to CBT-I (n = 29; 22 females) or monitor-only waitlist control (n = 16; nine females). INTERVENTIONS: Eight-session weekly individual CBT-I delivered by a licensed clinical psychologist or a board-certified psychiatrist. MEASUREMENTS AND RESULTS: Measures included continuous monitoring of sleep with diary and actigraphy; prepolysomnography and postpolysomnography and Clinician-Administered PTSD Scale (CAPS); and pre, mid, and post self-report questionnaires, with follow-up of CBT-I participants 6 mo later. CBT-I was superior to the waitlist control condition in all sleep diary outcomes and in polysomnography-measured total sleep time. Compared to waitlist participants, CBT-I participants reported improved subjective sleep (41% full remission versus 0%), disruptive nocturnal behaviors (based on the Pittsburgh Sleep Quality Index-Addendum), and overall work and interpersonal functioning. These effects were maintained at 6-mo follow-up. Both CBT-I and waitlist control participants reported reductions in PTSD symptoms and CAPS-measured nightmares. CONCLUSIONS: Cognitive behavioral therapy for insomnia (CBT-I) improved sleep in individuals with posttraumatic stress disorder, with durable gains at 6 mo. Overall psychosocial functioning improved following CBT-I. The initial evidence regarding CBT-I and nightmares is promising but further research is needed. Results suggest that a comprehensive approach to treatment of posttraumatic stress disorder should include behavioral sleep medicine. CLINICAL TRIAL INFORMATION: TRIAL NAME: Cognitive Behavioral Treatment Of Insomnia In Posttraumatic Stress Disorder. URL: http://clinicaltrials.gov/ct2/show/NCT00881647. REGISTRATION NUMBER: NCT00881647.


Assuntos
Terapia Cognitivo-Comportamental , Depressão/terapia , Sonhos/psicologia , Distúrbios do Início e da Manutenção do Sono/psicologia , Distúrbios do Início e da Manutenção do Sono/terapia , Comportamento Social , Transtornos de Estresse Pós-Traumáticos/complicações , Actigrafia , Adulto , Depressão/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Pacientes Desistentes do Tratamento , Polissonografia , São Francisco , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Fases do Sono/fisiologia , Transtornos de Estresse Pós-Traumáticos/fisiopatologia , Transtornos de Estresse Pós-Traumáticos/psicologia , Inquéritos e Questionários , Adulto Jovem
9.
Am J Pathol ; 180(3): 1107-1120, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22214838

RESUMO

Coxsackieviruses are significant human pathogens causing myocarditis, meningitis, and encephalitis. We previously demonstrated the ability of coxsackievirus B3 (CVB3) to persist within the neonatal central nervous system (CNS) and to target neural stem cells. Given that CVB3 is a cytolytic virus and may therefore damage target cells, we characterized the potential reduction in neurogenesis within the developing brain and the subsequent developmental defects that occurred after the loss of these essential neural stem cells. Neonatal mice were inoculated with a recombinant CVB3 expressing eGFP (eGFP-CVB3), and alterations in neurogenesis and brain development were evaluated over time. We observed a reduction in proliferating cells in CNS neurogenic regions simultaneously with the presence of nestin(+) cells undergoing apoptosis. The size of the brain appeared smaller by histology, and a permanent decrease in brain wet weight was observed after eGFP-CVB3 infection. We also observed an inverse relationship between the amount of virus material and brain wet weight up to day 30 postinfection. In addition, signs of astrogliosis and a compaction of the cortical layers were observed at 90 days postinfection. Intriguingly, partial brain wet weight recovery was observed in mice treated with the antiviral drug ribavirin during the persistent stage of infection. Hence, long-term neurological sequelae might be expected after neonatal enteroviral infections, yet antiviral treatment initiated long after the end of acute infection might limit virus-mediated neuropathology.


Assuntos
Sistema Nervoso Central/virologia , Infecções por Coxsackievirus/complicações , Enterovirus Humano B , Células-Tronco Neurais/virologia , Neurogênese/fisiologia , Animais , Animais Recém-Nascidos , Antivirais/farmacologia , Apoptose/fisiologia , Astrócitos/virologia , Encéfalo/crescimento & desenvolvimento , Encéfalo/virologia , Divisão Celular , Proliferação de Células , Sistema Nervoso Central/crescimento & desenvolvimento , Proteínas de Fluorescência Verde/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Tamanho do Órgão , Proteínas Recombinantes , Carga Viral
10.
Behav Brain Res ; 181(1): 110-7, 2007 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-17507102

RESUMO

Although recent work on amygdalar function has concentrated on a role in fear and anxiety, a possible role in reward processes continues to be considered. This function may occur via anatomical connections between the basolateral amygdala (BLA) and the mesoaccumbens dopamine (DA) system (i.e., ventral tegmental area [VTA] to nucleus accumbens septi [NAS]), particularly at the level of the NAS. The current experiments investigated a possible role of the BLA in the reward of intracranial self-stimulation (ICSS) of the VTA. Rats were trained in either an autotitration ICSS task or a rate-frequency ICSS task. We examined the effect of intra-BLA injections of muscimol, a GABA(A) agonist which inhibits the firing of most neurons, on VTA ICSS in both behavioral procedures. The injections produced a pattern of behavioral change which, across the two tasks, was more consistent with a change in behavioral processes other than primary reward. Possible processes include cost/benefit analysis and incentive motivation.


Assuntos
Tonsila do Cerebelo/fisiologia , Comportamento Animal/fisiologia , Recompensa , Área Tegmentar Ventral/fisiologia , Ácido gama-Aminobutírico/metabolismo , Tonsila do Cerebelo/efeitos dos fármacos , Animais , Comportamento Animal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Estimulação Elétrica/métodos , Agonistas GABAérgicos/farmacologia , Masculino , Muscimol/farmacologia , Ratos , Ratos Sprague-Dawley , Autoadministração/métodos , Área Tegmentar Ventral/efeitos dos fármacos
11.
Proc Inst Mech Eng H ; 220(2): 311-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16669397

RESUMO

The deformation of metallic acetabular cups employed for metal-on-metal hip resurfacing procedures was considered theoretically using the finite element method in the present study, following on the experimental investigation reported in Part 1. Three representative cups, characterized by the cup wall thickness as thin, intermediate, and thick, were considered. For the intermediate cup, the effects of both the size and the diametral interference on the cup deformation were investigated. Both two-dimensional axisymmetric and three-dimensional finite element models were developed to examine the important parameters during and after the press-fit procedure, and in particular the deformation of the metallic cup. The theoretical prediction of the cup deformation was in reasonable agreement with the corresponding experimental measurement reported in Part 1. The most significant factor influencing the cup deformation was the cup wall thickness. Both the size and the diametral interference were also shown to influence the cup deformation. It is important to ensure that the cup deformation does not significantly affect the clearance designed and optimized for tribological performances of metal-on-metal hip resurfacing prostheses. Furthermore the contact parameters at the cup and bone interface associated with the press fit were also discussed.


Assuntos
Acetábulo/fisiopatologia , Materiais Biocompatíveis/química , Desenho Assistido por Computador , Testes de Dureza/métodos , Prótese de Quadril , Metais/química , Modelos Biológicos , Acetábulo/cirurgia , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Simulação por Computador , Elasticidade , Desenho de Equipamento , Análise de Falha de Equipamento/métodos , Análise de Elementos Finitos , Dureza , Humanos , Teste de Materiais , Pressão , Desenho de Prótese , Falha de Prótese , Propriedades de Superfície
12.
Artigo em Inglês | MEDLINE | ID: mdl-15923072

RESUMO

By influencing the central nervous system, cytokines, which regulate immune function innately and adaptively, may play a key role in mediating depression-like neuro-behavioral changes. However, the similarity between cytokine and stressor-effects in animal models raises a question about the degree to which behavioral and neurochemical outcomes of cytokine challenge represent depressive disorder per se. The present review attempts to illustrate the degree of overlap between cytokines and stressors with respect to their effects on neurochemistry and behavior in animal models. The review also shows how short-term effects of cytokine exposure in typical animals may be discerned from characteristics that might otherwise be described as depression-like. By comparing outcomes of immune challenge in typical rodent strains (e.g., Sprague-Dawley [SD], Wistar) and an accepted animal model of depression (e.g., Fawn Hooded [FH] rodent strain), differences between short-term effects of cytokines and depression-like characteristics in rodents are demonstrated. Additionally, because it is known that preexisting vulnerability to depression may affect outcomes of immune challenge, we further compare immunological, biochemical and behavioral effects of cytokines between SD and FH rodent strains. Interestingly, the acute neurochemical and behavioral effects of the cytokine interleukin 1alpha (IL-1alpha) reveal stressor-like responses during behavioral habituation in both strains, though this appears to a stronger degree in FH animals. Further, the subacute response to IL-1alpha vastly differed between strains, indicating differences in adaptive mechanisms. Thus, stressor-like effects of immune challenge, particularly in FH animals, provide validation for recent "cross-sensitization" models of depression pathogenesis that incorporate immune factors.


Assuntos
Adaptação Psicológica/fisiologia , Citocinas/fisiologia , Transtorno Depressivo/psicologia , Estresse Psicológico/psicologia , Animais , Citocinas/farmacologia , Transtorno Depressivo/genética , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Estresse Psicológico/genética
14.
Pharmacol Res ; 39(4): 297-304, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10208760

RESUMO

Receptor concentrations for adrenaline, steroid hormones, PGF2alpha, LH and FSH were measured in the hypophysis and ovary of dairy cows with ovarian cysts and the results were compared with those of healthy animals. Significant modifications were found in all receptor concentrations, either between follicular and luteal structures or between the hypophyseal and ovarian receptorial status. The correlations between catecholaminergic and steroidal systems have already been demonstrated, particularly those existing between beta-adrenoceptors and steroid hormone receptors. Particular attention has been given to the possibility that a derangement in neurogenic inputs may be at the basis of some ovarian pathologies. The results of the present study suggest that the modifications of the ovarian and hypophyseal receptorial status of healthy and affected cows could play an important role in the pathogenesis of ovarian cysts.


Assuntos
Cistos Ovarianos/metabolismo , Ovário/metabolismo , Hipófise/metabolismo , Receptores de Superfície Celular/metabolismo , Animais , Bovinos , Estradiol/sangue , Feminino , Cistos Ovarianos/patologia , Ovário/citologia , Hipófise/citologia , Progesterona/sangue , Receptores Adrenérgicos beta/metabolismo , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/metabolismo , Receptores do FSH/metabolismo , Receptores do LH/metabolismo , Receptores de Progesterona/metabolismo , Receptores de Prostaglandina/metabolismo
15.
Int J Artif Organs ; 20(8): 436-9, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9323506

RESUMO

Laser profiling techniques have been used to examine the 2-dimensional and 3-dimensional patterns of leaflet motion in functioning bovine pericardial heart valves (1 normal valve and 1 fatigued/calcified). In the normal valve the general patterns of opening and closing were similar for all leaflets; however, localised variations such as areas of high curvature, retarded motion and high speed motion were identified. In the fatigued/calcified valve significant differences from the normal leaflet motion were observed e.g. increased crimping, gross leaflet lag and irregular deformation. The laser profiling technique was able to reveal changes in the functional dynamics of pericardial valve leaflets not otherwise detectable by conventional hydrodynamic measurements of valve performance.


Assuntos
Calcinose , Doenças das Valvas Cardíacas/diagnóstico , Lasers , Animais , Bovinos , Modelos Anatômicos , Pericárdio/fisiologia
16.
Int J Artif Organs ; 20(6): 327-31, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9259209

RESUMO

A flexible trileaflet polyurethane valve has been made by dip-moulding leaflets directly onto an injection-moulded frame. The durability of this value is, in part, determined by the thickness of its leaflets. Leaflet thickness is also a major determinant of hydrodynamic function. This study examines valves (n = 31) with leaflets made of a polyetherurethane (PEU, n = 22) or a polyetherurethaneurea (PEUE, n = 9), of varying thickness distributions. The valves were subjected to accelerated fatigue test at 37 degrees C and failure monitored. Leaflet thicknesses ranged from 60 to 200 microns. PEU leaflet thickness bore no relationship to durability, which was less than 400 million cycles. PEUE valves, in contrast, exceeded 800 million cycles. Durability in PEUE valves was directly related to leaflet thickness (r = 0.93, p < 0.001), with good durability achieved with median leaflet thicknesses of approximately 150 microns. Thus polyurethane valves can be made with good hydrodynamic properties and with sufficient durability to consider potential clinical use.


Assuntos
Materiais Biocompatíveis/normas , Próteses Valvulares Cardíacas/normas , Poliuretanos/normas , Fenômenos Biomecânicos , Equipamentos Médicos Duráveis , Polímeros , Poliuretanos/química , Análise de Regressão
17.
Vet Microbiol ; 59(1): 27-36, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9460194

RESUMO

A new ELISA for antibodies against chlamydial abortion of ewes which uses detergent solubilised proteins (dsp) of Chlamydia psittaci as antigen (Anderson, I.E., Herring, A.J., Jones, G.E., Low, J.C., Greig, A., 1995. Development and evaluation of an indirect ELISA to detect antibodies to abortion strains of Chlamydia psittaci in sheep sera. Vet. Microbiol., 43, pp. 1-12] was compared with the complement fixation test (CFT) in screening 1000 ovine and caprine sera obtained from selected flocks/herds ('flocks') and submitted to a veterinary diagnostic laboratory. Fifteen of the 17 'flocks' had a history of abortion while the remaining two did not and were classified as 'negative flocks'. Infection with Chlamydia was confirmed during the study period in five 'flocks' using direct immunofluorescence and the modified Ziehl Neelsen stain on pathological material. The dspELISA and CFT identified 37 and 45 positive sera on 158 samples tested from these 'flocks'. Chlamydia antibodies were not detected in one of the two negative flocks, in two other flocks where the cause of abortion was undetermined and in three flocks in which the causes of abortion were diagnosed as Listeriosis and/or Salmonellosis. One of the 'negative flocks' yielded two positive reactors by CFT and five by dspELISA, suggesting infection with a cross-reactive subtype of C. pecorum. Of the five 'flocks' in which a definitive diagnosis from pathological material was not possible, four were positive by both serological tests, suggesting that the abortions were due to Chlamydia. The fifth flock, though negative by dspELISA and marginally positive in two samples by CFT, had experienced confirmed chlamydial abortions in previous lambing seasons, but culling and tetracycline treatment have prevented further abortions in the study period. Overall, the proportions of samples positive by CFT and dspELISA were similar (9.1% and 8.8%). These studies confirmed the value of the dspELISA as a screening test for chlamydial abortion. Furthermore, the dspELISA compared to the CFT is easier to perform, does not require reagent titration at each testing and uses automated assessment of results.


Assuntos
Aborto Animal/microbiologia , Anticorpos Antibacterianos/sangue , Doenças das Cabras , Psitacose/veterinária , Doenças dos Ovinos , Animais , Chlamydophila psittaci/imunologia , Chlamydophila psittaci/isolamento & purificação , Diagnóstico Diferencial , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Cabras , Listeriose/diagnóstico , Listeriose/veterinária , Gravidez , Psitacose/diagnóstico , Reprodutibilidade dos Testes , Salmonelose Animal/diagnóstico , Testes Sorológicos/métodos , Testes Sorológicos/veterinária , Ovinos
18.
J Clin Microbiol ; 33(1): 79-84, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7699071

RESUMO

The detection of foot-and-mouth disease virus (FMDV)-persistent carriers among convalescent ruminants is of paramount importance in the aftermath of a field outbreak. To this purpose, FMDV-specific antibody should be investigated first, since virus isolation procedures from such carriers are seriously constrained. The complexity of the overall picture may be compounded by possible emergency vaccinations in the affected areas at the beginning of the outbreak. In this case, it is suggested that mucosal rather than serum antibody be investigated. In fact, we showed that FMDV-infected cattle regularly mount an antibody response in oropharyngeal fluids, in contrast to vaccinated cattle. Antibody could be revealed by neutralization assays and/or an immunoglobulin A (IgA)-specific kinetic enzyme-linked immunosorbent assay (ELISA). Cattle vaccinated once seldom showed a mucosal antibody response, which could be only detected by a total immunoglobulin-specific kinetic ELISA. Very few, if any, cattle showed a mucosal IgA response after repeated vaccinations. Our kinetic, IgA-specific ELISA generally allowed an early detection of FMDV-infected cattle; in particular, it proved to be more sensitive than the usual indirect, antigen-trapping ELISA in experiments on saliva samples.


Assuntos
Anticorpos Antivirais/isolamento & purificação , Portador Sadio/veterinária , Ensaio de Imunoadsorção Enzimática/métodos , Febre Aftosa/diagnóstico , Orofaringe/imunologia , Animais , Portador Sadio/diagnóstico , Portador Sadio/imunologia , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/prevenção & controle , Convalescença , Febre Aftosa/imunologia , Febre Aftosa/prevenção & controle , Imunoglobulina A/isolamento & purificação , Mucosa Bucal/imunologia , Saliva/imunologia , Vacinação
19.
Arch Virol ; 140(1): 13-25, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7646338

RESUMO

Persistent foot-and-mouth disease (FMD) virus infection in vitro has been studied in a chronically infected cloned BHK-21 cell line. Virus growth during serial cell passages was followed by infectivity assay and immunocytochemical staining. Only a small percentage of cells (0.006-6%) was found to harbour virus during persistence. Light and electron microscopy showed the presence of cytoplasmic protuberances ("blebs") at the surface of persistently infected cells. The curing of cell cultures was achieved by passaging them in the presence of polyvalent immune serum. The absence of virus in cured cells was confirmed by infectivity assay and immunocytochemistry. This finding, together with the low percentage of infected cells in cultures confirms that persistently infected BHK-21 cells satisfy the definitions of a carrier culture. The characteristics of the in vitro system and its relevance to the study of FMD carrier state in vivo are discussed.


Assuntos
Aphthovirus/fisiologia , Replicação Viral , Animais , Complexo Antígeno-Anticorpo , Aphthovirus/imunologia , Aphthovirus/ultraestrutura , Linhagem Celular , Clorofluorcarbonetos de Metano , Células Clonais , Cricetinae , Soros Imunes , Rim/citologia , Rim/virologia , Testes de Neutralização
20.
J Virol Methods ; 49(2): 179-86, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7822459

RESUMO

Persistent foot-and-mouth disease (FMD) infection of cattle was established by exposure to infected pigs. Oesophageal-pharyngeal fluid samples collected ante-mortem and tissue samples obtained post-mortem were tested for virus by conventional means and for viral RNA by the polymerase chain reaction (PCR). The results showed that the PCR was superior for detecting the carrier state in tissue samples. A high neutralising activity in tissues probably influenced the yields of virus obtained by infectivity assay.


Assuntos
Aphthovirus/isolamento & purificação , Febre Aftosa/diagnóstico , Reação em Cadeia da Polimerase/métodos , RNA Viral/análise , Animais , Aphthovirus/genética , Sequência de Bases , Bovinos , Primers do DNA , Eletroforese em Gel de Ágar , Esôfago/virologia , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Palato Mole/virologia , Tonsila Palatina/virologia , Faringe/virologia , Sensibilidade e Especificidade , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...