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INTRODUCTION: Fevers following decannulation from veno-venous extracorporeal membrane oxygenation often trigger an infectious workup; however, the yield of this workup is unknown. We investigated the incidence of post-veno-venous extracorporeal membrane oxygenation decannulation fever as well as the incidence and nature of healthcare-associated infections in this population within 48 hours of decannulation. METHODS: All patients treated with veno-venous extracorporeal membrane oxygenation for acute respiratory failure who survived to decannulation between August 2014 and November 2018 were retrospectively reviewed. Trauma patients and bridge to lung transplant patients were excluded. The highest temperature and maximum white blood cell count in the 24 hours preceding and the 48 hours following decannulation were obtained. All culture data obtained in the 48 hours following decannulation were reviewed. Healthcare-associated infections included blood stream infections, ventilator-associated pneumonia, and urinary tract infections. RESULTS: A total of 143 patients survived to decannulation from veno-venous extracorporeal membrane oxygenation and were included in the study. In total, 73 patients (51%) were febrile in the 48 hours following decannulation. Among this cohort, seven healthcare-associated infections were found, including five urinary tract infections, one blood stream infection, and one ventilator-associated pneumonia. In the afebrile cohort (70 patients), four healthcare-associated infections were found, including one catheter-associated urinary tract infection, two blood stream infections, and one ventilator-associated pneumonia. In all decannulated patients, the majority of healthcare-associated infections were urinary tract infections (55%). No central line-associated blood stream infections were identified in either cohort. When comparing febrile to non-febrile cohorts, there was a significant difference between pre- and post-decannulation highest temperature (p < 0.001) but not maximum white blood cell count (p = 0.66 and p = 0.714) between the two groups. Among all positive culture data, the most commonly isolated organism was Klebsiella pneumoniae (41.7%) followed by Escherichia coli (33%). Median hospital length of stay and time on extracorporeal membrane oxygenation were shorter in the afebrile group compared to the febrile group; however, this did not reach a statistical difference. CONCLUSION: Fever is common in the 48 hours following decannulation from veno-venous extracorporeal membrane oxygenation. Differentiating infection from non-infectious fever in the post-decannulation veno-venous extracorporeal membrane oxygenation population remains challenging. In our febrile post-decannulation cohort, the incidence of healthcare-associated infections was low. The majority were diagnosed with a urinary tract infection. We believe obtaining cultures in febrile patients in the immediate decannulation period from veno-venous extracorporeal membrane oxygenation has utility, and even in the absence of other clinical suspicion, should be considered. However, based on our data, a urinalysis and urine culture may be sufficient as an initial work up to identify the source of infection.
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Oxigenação por Membrana Extracorpórea , Atenção à Saúde , Oxigenação por Membrana Extracorpórea/efeitos adversos , Febre/etiologia , Humanos , Incidência , Estudos RetrospectivosRESUMO
BACKGROUND AND PURPOSE: Treatments to facilitate recovery after traumatic brain injury (TBI) are urgently needed. We conducted a 9-month pilot, randomized placebo-controlled clinical trial to examine the safety and potential effects of the herbal supplement MLC901 (NeuroAiD II™) on cognitive functioning following TBI. METHODS: Adults aged 18-65 years at 1-12 months after mild or moderate TBI were randomized to receive MLC901 (0.8 g capsules 3 times daily) or placebo for 6 months. The primary outcome was cognitive functioning as assessed by the CNS Vital Signs online neuropsychological test. Secondary outcomes included the Cognitive Failures Questionnaire, the Rivermead Post-concussion Symptom Questionnaire (neurobehavioral sequelae), Quality of Life after Brain Injury, Hospital Anxiety and Depression Scale, Modified Fatigue Impact Scale and extended Glasgow Outcome Scale (physical disability). Assessments were completed at baseline and at 3-, 6- and 9-month follow-up. Linear mixed-effects models were conducted, with the primary outcome time-point of 6 months. RESULTS: A total of 78 participants [mean age 37.5 ± 14.8 years, 39 (50%) female] were included in the analysis. Baseline variables were similar between groups (treatment group, n = 36; control group, n = 42). Linear mixed-effects models controlling for time, group allocation, repeated measurements, adherence and baseline assessment scores revealed significant improvements in complex attention (P = 0.04, d = 0.6) and executive functioning (P = 0.04, d = 0.4) at 6 months in the MLC901 group compared with controls. There were no significant differences between the groups for neurobehavioral sequelae, mood, fatigue, physical disability or overall quality of life at 6 months. No serious adverse events were reported. CONCLUSIONS: MLC901 was safe and well tolerated post-TBI. This study provided Class I/II evidence that, for patients with mild to moderate TBI, 6 months of MLC901 improved cognitive functioning.
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Lesões Encefálicas Traumáticas/tratamento farmacológico , Lesões Encefálicas Traumáticas/psicologia , Cognição , Medicamentos de Ervas Chinesas/uso terapêutico , Fármacos Neuroprotetores/uso terapêutico , Adolescente , Adulto , Idoso , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/prevenção & controle , Avaliação da Deficiência , Método Duplo-Cego , Função Executiva , Feminino , Escala de Resultado de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Projetos Piloto , Qualidade de Vida , Resultado do Tratamento , Adulto JovemRESUMO
Wood frogs ( Rana sylvatica) are highly susceptible to infection with Frog virus 3 (FV3, Ranavirus, Iridoviridae), a cause of mass mortality in wild populations. To elucidate the pathogenesis of FV3 infection in wood frogs, 40 wild-caught adults were acclimated to captivity, inoculated orally with a fatal dose of 104.43 pfu/frog, and euthanized at 0.25, 0.5, 1, 2, 4, 9, and 14 days postinfection (dpi). Mild lesions occurred sporadically in the skin (petechiae) and bone marrow (necrosis) during the first 2 dpi. Severe lesions occurred 1 to 2 weeks postinfection and consisted of necrosis of medullary and extramedullary hematopoietic tissue, lymphoid tissue in spleen and throughout the body, and epithelium of skin, mucosae, and renal tubules. Viral DNA was first detected (polymerase chain reaction) in liver at 4 dpi; by dpi 9 and 14, all viscera tested (liver, kidney, and spleen), skin, and feces were positive. Immunohistochemistry (IHC) first detected viral antigen in small areas devoid of histologic lesions in the oral mucosa, lung, and colon at 4 dpi; by 9 and 14 dpi, IHC labeling of viral antigen associated with necrosis was found in multiple tissues. Based on IHC staining intensity and lesion severity, the skin, oral, and gastrointestinal epithelium and renal tubular epithelium were important sites of viral replication and shedding, suggesting that direct contact (skin) and fecal-oral contamination are effective routes of transmission and that skin tissue, oral, and cloacal swabs may be appropriate antemortem diagnostic samples in late stages of disease (>1 week postinfection) but poor samples to detect infection in clinically healthy frogs.
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Infecções por Vírus de DNA/veterinária , Ranavirus , Ranidae/virologia , Animais , Animais Selvagens/virologia , Infecções por Vírus de DNA/patologia , Infecções por Vírus de DNA/virologia , Masculino , Ranavirus/patogenicidade , Ranidae/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterináriaRESUMO
AIMS: To investigate whether diabetes self-care attitudes, behaviours and perceived burden, particularly related to weight management, diet and physical activity, differ between adults with Type 2 diabetes who are severely obese and matched non-severely obese control subjects. METHODS: The 1795 respondents to the Diabetes MILES--Australia national survey had Type 2 diabetes and reported height and weight data, enabling BMI calculation: 530 (30%) were severely obese (BMI ≥ 35 kg/m(2); median BMI = 41.6 kg/m(2)) and these were matched with 530 control subjects (BMI < 35 kg/m(2); median BMI = 28.2 kg/m(2)). Diabetes self-care behaviours, attitudes and burden were measured with the Diabetes Self-Care Inventory-Revised. Within-group and between-group trends were examined. RESULTS: The group with BMI ≥ 35 kg/m(2) was less likely to achieve healthy diet and exercise targets, placed less importance on diet and exercise recommendations, and found the burden of diet and exercise recommendations to be greater than the group with BMI < 35 kg/m(2). The group with BMI ≥ 35 kg/m(2) was more likely to be actively trying to lose weight, but found weight control a greater burden. These issues accentuated with increasing obesity and were greatest in those with BMI > 45 kg/m(2). There were no between-group differences in other aspects of diabetes self-care: self-monitoring of blood glucose, use of medications and smoking. Moderate-to-severe symptoms of depression were independently associated with reduced likelihood of healthy diet and physical activity, and with greater burden associated with diet, physical activity and weight management. CONCLUSIONS: Severely obese people with diabetes demonstrated self-care attitudes, behaviours and burdens that infer barriers to weight loss. However, other important diabetes self-care behaviours are supported equally by severely obese and non-severely obese individuals.
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Atitude Frente a Saúde , Diabetes Mellitus Tipo 2/psicologia , Diabetes Mellitus Tipo 2/terapia , Obesidade Mórbida/psicologia , Obesidade Mórbida/terapia , Autocuidado , Programas de Redução de Peso , Adulto , Idoso , Austrália/epidemiologia , Comportamento , Estudos de Casos e Controles , Efeitos Psicossociais da Doença , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/complicações , Obesidade Mórbida/epidemiologia , Percepção , Programas de Redução de Peso/estatística & dados numéricosRESUMO
INTRODUCTION: Global development processes have been associated with the nutritional transition, where undernutrition is replaced by overnutrition. Income transfer policies in Brazil have targeted hunger, but may not address the need for balanced nutrition. METHODS: Data was collected from government databanks that document the nutritional status of Brazilians applying for social services. This data was analyzed for descriptive statistics. RESULTS: Development and income transfer processes appear to be associated with an increase in overweight children between the years 2008 and 2012. CONCLUSIONS: Income transfer programs need to incorporate educational programs that address the need to budget for balanced nutrition.
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Peso Corporal , Estado Nutricional , Assistência Pública/estatística & dados numéricos , População Rural/estatística & dados numéricos , Brasil/epidemiologia , Humanos , Serviço Social , Fatores SocioeconômicosRESUMO
The role of cyclin-dependent kinases (CDKs) that are ubiquitously expressed in the adult nervous system remains unclear. Cdk12 is enriched in terminally differentiated neurons where its conical role in the cell cycle progression is redundant. We find that in adult neurons Cdk12 acts a negative regulator of actin formation, mitochondrial dynamics and neuronal physiology. Cdk12 maintains the size of the axon at sites proximal to the cell body through the transcription of homeostatic enzymes in the 1-carbon by folate pathway which utilize the amino acid homocysteine. Loss of Cdk12 leads to elevated homocysteine and in turn leads to uncontrolled F-actin formation and axonal swelling. Actin remodeling further induces Drp1-dependent fission of mitochondria and the breakdown of axon-soma filtration barrier allowing soma restricted cargos to enter the axon. We demonstrate that Cdk12 is also an essential gene for long-term neuronal survival and loss of this gene causes age-dependent neurodegeneration. Hyperhomocysteinemia, actin changes, and mitochondrial fragmentation are associated with several neurodegenerative conditions such as Alzheimer's disease and we provide a candidate molecular pathway to link together such pathological events.
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We implement a noiseless optical amplifier using a phase-sensitive four-wave mixing process in rubidium vapor. We observe performance near the quantum limit for this type of amplifier over a range of experimental parameters and show that the noise figure is always better than would be obtained with a phase-insensitive amplifier with the same gain. Additionally, we observe that the amplifier supports hundreds of spatial modes, making it possible to amplify complex two-dimensional spatial patterns with less than a 10% degradation of the input signal-to-noise ratio for gains up to 4.6. To confirm the multimode character of the amplifier, we study the noise figure as a function of spatially-varying losses. Additionally, we investigate the spatial resolution of the amplifier and show that it supports a range of spatial frequencies from 1.3 to more than 35 line pairs per millimeter.
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Animal biotechnology represents one subset of tools among a larger set of technologies for potential use to meet increasing world demands for food. Assisted reproductive technologies (ART) such as artificial insemination and embryo transfer continue to make positive contributions in food animal production. The US Food and Drug Administration (FDA) performed a comprehensive risk assessment to identify potential food consumption or animal health risks associated with animal cloning, an emerging ART. At that time, FDA concluded that animal cloning posed no unique risks either to animal health or to food consumption, and food from animal clones and their sexually reproduced offspring required no additional federal regulation beyond that applicable to conventionally bred animals of the species examined. At this time, no new information has arisen that would necessitate a change in FDA's conclusions on food from animal clones or their sexually reproduced offspring. Use of recombinant DNA technologies to produce genetically engineered (GE) animals represents another emerging technology with potential to impact food animal production. In its regulation of GE animals, FDA follows a cumulative, risk-based approach to address scientific questions related to the GE animals. FDA evaluates data and information on the safety, effectiveness and stability of the GE event. FDA carries out its review at several levels (e.g. molecular biology, animal safety, food safety, environmental safety and claim validation). GE animal sponsors provide data to address risk questions for each level. This manuscript discusses FDA's role in evaluation of animal cloning and GE animals.
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Clonagem de Organismos/veterinária , Inocuidade dos Alimentos , Engenharia Genética/veterinária , Técnicas de Reprodução Assistida/veterinária , United States Food and Drug Administration/legislação & jurisprudência , Animais , Engenharia Genética/métodos , Estados UnidosRESUMO
CONTEXT: People living in rural or remote Brazil, as in other sub-tropical or tropical nations, are vulnerable to infections that would not normally occur in urban areas or wealthier nations. Brazil is a geographically extensive nation, historically marked by vast socioeconomic inequalities. Approximately 16% of the population live in rural areas. ISSUE: This clinical case report demonstrates the vulnerability of rural residents who are underserved by Brazil's 'universal' public healthcare system, despite social and economic challenges that increase their risk for disease. Myiasis (especially oral myiasis) is a rare health condition in humans caused by fly larvae. Oral myiasis usually appears in periodontal pockets and open wounds, such as after dental extractions. It is associated with poverty, lack of access to health care, and very poor overall health status. While myiasis has a worldwide distribution, it is particularly associated with the tropical and sub-tropical regions of North and South America. LESSONS LEARNED: This article describes a rare case of myiasis in the upper lip of a rural male patient. The case report demonstrate that rural and remote residents can be socially excluded from the benefits of technology and biomedicine, making them vulnerable to rare infections.
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Antiparasitários/uso terapêutico , Ivermectina/uso terapêutico , Doenças Labiais/tratamento farmacológico , Mucosa Bucal , Miíase/tratamento farmacológico , Serviços de Saúde Rural , Isolamento Social , Doença de Alzheimer/diagnóstico , Anestesia Local , Brasil , Serviço Hospitalar de Emergência , Acessibilidade aos Serviços de Saúde/normas , Humanos , Doenças Labiais/parasitologia , Doenças Labiais/cirurgia , Masculino , Desnutrição/terapia , Área Carente de Assistência Médica , Pessoa de Meia-Idade , Mucosa Bucal/parasitologia , Mucosa Bucal/cirurgia , Miíase/diagnóstico , Miíase/parasitologia , Miíase/cirurgia , Guias de Prática Clínica como Assunto , Serviços de Saúde Rural/normas , Condições Sociais , Resultado do Tratamento , Populações VulneráveisRESUMO
We present experimental results showing that quantum correlated light can be produced using non-degenerate, off-resonant, four-wave mixing (4WM) on both the D1 (795 nm) and D2 (780 nm) lines of (85)Rb and (87)Rb, extending earlier work on the D1 line of (85)Rb. Using this 4WM process in a hot vapor cell to produce bright twin beams, we characterize the degree of intensity-difference noise reduction below the standard quantum limit for each of the four systems. Although each system approximates a double-lambda configuration, differences in details of the actual level structure lead to varying degrees of noise reduction. The observation of quantum correlations on light produced using all four of these systems, regardless of their substructure, suggests that it should be possible to use other systems with similar level structures in order to produce narrow frequency, non-classical beams at a particular wavelength.
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In the summer of 2007, American eels, Anguilla rostrata, from 2 localities on Cape Breton Island, were found to be infected with the swim bladder nematode Anguillicoloides crassus. This is the first documented report of this highly invasive parasite in Canadian waters. More than half of the yellow eels in Mira River (6 of 10), and 1 eel (of 5) from Sydney Harbour were infected. Parasite intensity ranged from 1 to 11 worms per eel. The occurrence of A. crassus at these 2 localities suggests the need for a more extensive survey on the distribution of this exotic parasite in eel populations throughout Cape Breton Island.
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Anguilla/parasitologia , Dracunculoidea/isolamento & purificação , Doenças dos Peixes/parasitologia , Infecções por Spirurida/veterinária , Animais , Doenças dos Peixes/epidemiologia , Nova Escócia/epidemiologia , Rios , Infecções por Spirurida/epidemiologia , Infecções por Spirurida/parasitologiaRESUMO
Earlier, we (Vijayagopal, P., et al. (1985) Biochim. Biophys. Acta 837-251) have shown that complexes of plasma low-density lipoproteins (LDL) and arterial chondroitin sulfate-dermatan sulfate proteoglycan aggregate promote LDL degradation and cholesteryl ester accumulation in mouse peritoneal macrophages. Further studies were conducted to determine whether LDL-proteoglycan complex is metabolized by a receptor-mediated process. Native proteoglycan aggregate was isolated from bovine aorta by associative CsCl isopycnic centrifugation. Complex of 125I-labeled LDL and proteoglycan aggregate formed in the presence of 30 mM Ca2+ was incubated with macrophages, and the binding at 4 degrees C and degradation at 37 degrees C of 125I-labeled LDL in the complex was monitored. Both binding and degradation of the complex were specific and saturable, suggesting that the processes are receptor mediated. The Kd for binding was 23 micrograms LDL protein per ml in the complex. Degradation of 125I-labeled LDL-proteoglycan complex was not suppressed by preincubation of macrophages with excess unlabeled complex, suggesting that the receptor for the complex is not subject to down regulation. Both binding and degradation of the complex and the resultant stimulation of cholesteryl ester synthesis were inhibited by limited treatment of cells with low doses of trypsin and pronase, indicating that the binding sites are protein or glycoprotein in nature. Binding was not inhibited by an excess of native LDL and beta-VLDL and exhibited only partial competition by excess unlabeled acetyl-LDL; however, polyinosinic acid, fucoidin and dextran sulfate, known inhibitors of acetyl-LDL binding and degradation in macrophages, did not affect LDL-proteoglycan complex binding and degradation. Similarly, excess unlabeled LDL-proteoglycan complex produced only partial inhibition of the binding and degradation of 125I-labeled acetyl-LDL by macrophages, suggesting that the binding sites for acetyl-LDL and LDL-proteoglycan complex are probably not identical. These studies provide evidence for a receptor-mediated pathway for the metabolism of LDL-proteoglycan complex in macrophages.
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Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacologia , Macrófagos/metabolismo , Proteoglicanas/metabolismo , Animais , Temperatura Baixa , Humanos , Cinética , Camundongos , Poli I/farmacologia , Polissacarídeos/farmacologia , Pronase/metabolismo , Fatores de Tempo , Tripsina/metabolismoRESUMO
We studied the effect of complexes of low-density lipoproteins (LDL) and different proteoglycan preparations from bovine aorta on LDL degradation and cholesteryl ester accumulation in mouse peritoneal macrophages. Native proteoglycan aggregate containing proteoglycan monomers, hyaluronic acid and link protein was isolated by associative extraction of aortic tissue, while proteoglycan monomer was obtained by dissociative isopycnic centrifugation of the native proteoglycan aggregate. In vitro proteoglycan aggregates were prepared by reaction of the proteoglycan monomer with exogenous hyaluronic acid. 125I-labeled LDL-proteoglycan complexes were formed in the presence of 30 mM Ca2+ and incubated with macrophages. At equivalent uronic acid levels in the proteoglycans the degradation of 125I-labeled LDL contained in the native proteoglycan aggregate complex was 3.7-7.5-fold greater than the degradation of the lipoprotein in the proteoglycan monomer complex. Degradation of 125I-LDL in the in vitro aggregate complex, while higher than that in the monomer complex, was markedly less than that in the native aggregate complex. The larger size and the greater complex-forming ability of the native proteoglycan aggregate might account for the greater capacity of the aggregate to promote LDL degradation in macrophages. The proteoglycan-stimulated degradation of LDL produced a marked increase in cholesteryl ester synthesis and content in macrophages. The LDL-proteoglycan complex was degraded with saturation kinetics, suggesting that these complexes are internalized through high-affinity receptors. Degradation was inhibited by the lysosomotropic agent, chloroquine. Acetyl-LDL, but not native LDL, competitively inhibited the degradation of the 125I-LDL component of the complex. Polyanionic compounds such as polyinosinic acid and fucoidin, while completely blocking the acetyl-LDL-stimulated cholesteryl ester formation, had no effect on the proteoglycan aggregate-stimulated cholesterol esterification. This suggests that LDL-proteoglycan complex and acetyl-LDL are not entering the cells through the same receptor pathway. These results demonstrate that the interaction of LDL with arterial wall proteoglycan aggregates results in marked cholesteryl ester accumulation in macrophages, a process likely to favor foam cell formation. A role for arterial proteoglycans in atherosclerosis is obvious.
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Ésteres do Colesterol/metabolismo , Lipoproteínas LDL/metabolismo , Macrófagos/metabolismo , Proteoglicanas/metabolismo , Animais , Feminino , Cinética , Camundongos , Poli I/farmacologia , Polissacarídeos/farmacologiaRESUMO
We describe the development of a novel plasmid-based assay for measuring the in vivo frequency of misincorporation of amino acids into polypeptide chains in the yeast Saccharomyces cerevisiae. The assay is based upon the measurement of the catalytic activity of an active site mutant of type III chloramphenicol acetyl transferase (CATIII) expressed in S. cerevisiae. A His195(CAC)-->Tyr195(UAC) mutant of CATIII is completely inactive, but catalytic activity can be restored by misincorporation of histidine at the mutant UAC codon. The average error frequency of misincorporation of histidine at this tyrosine UAC codon in wild-type yeast strains was measured as 0. 5x10(-5) and this frequency was increased some 50-fold by growth in the presence of paromomycin, a known translational-error-inducing antibiotic. A detectable frequency of misincorporation of histidine at a mutant Ala195 GCU codon was also measured as 2x10(-5), but in contrast to the Tyr195-->His195 misincorporation event, the frequency of histidine misincorporation at Ala195 GCU was not increased by paromomycin, inferring that this error did not result from miscognate codon-anticodon interaction. The His195 to Tyr195 missense error assay was used to demonstrate increased frequencies of missense error at codon 195 in SUP44 and SUP46 mutants. These two mutants have previously been shown to exhibit a translation termination error phenotype and the sup44+ and sup46+ genes encode the yeast ribosomal proteins S4 and S9, respectively. These data represent the first accurate in vivo measurement of a specific mistranslation event in a eukaryotic cell and directly confirm that the eukaryotic ribosome plays an important role in controlling missense errors arising from non-cognate codon-anticodon interactions.
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Biossíntese de Proteínas , Saccharomyces cerevisiae/genética , Alanina/genética , Sítios de Ligação/genética , Cloranfenicol O-Acetiltransferase/genética , Códon , Cicloeximida/farmacologia , Técnicas Genéticas , Histidina/genética , Mutação , Paromomicina/farmacologia , Proteína S9 Ribossômica , Proteínas Ribossômicas/genética , Tirosina/genéticaRESUMO
Phenytoin, administered by suspension into a feeding tube through which continuous enteral feedings are being given, is very poorly absorbed. There appears to be very little information regarding this potentially serious problem in the general medical literature. Commonly used doses of phenytoin (300 to 500 mg/d) may result in almost undetectable serum levels. Therapeutic phenytoin levels may be obtained if a very large dose of the drug is given. Our patient required 1800 mg daily in two divided doses to get a serum phenytoin level of 9 micrograms/mL. Commonly used enteral feedings were being delivered by way of a continuous infusion pump. We found one enteral feeding product that did not severely impair the absorption of phenytoin. The mechanism by which enteral feedings impair phenytoin absorption is unknown.
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Nutrição Enteral/efeitos adversos , Fenitoína/administração & dosagem , Hemorragia Cerebral/tratamento farmacológico , Feminino , Humanos , Absorção Intestinal , Pessoa de Meia-Idade , Fenitoína/farmacocinética , SuspensõesRESUMO
The expression of interphotoreceptor retinoid binding protein (IRBP) is limited to photoreceptor cells of the retina and pinealocytes of the pineal gland. We sought to define cis-elements of the mouse IRBP 5' flanking region that are required for this restricted activity. In vitro transient transfections of retinoblastoma and neuroblastoma cells and in vivo experiments with transgenic Xenopus laevis indicate that -1783/+101 and -156/+101 IRBP gene fragments directed expression predominantly to the retina and pineal, with minor neuronal expression elsewhere. In contrast, a -70/+101 fragment was less restrictive in controlling expression, exhibiting activity not only in retina, but also in forebrain, hindbrain, spinal cord, and motor neurons innervating gills.
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Proteínas do Olho/genética , Regiões Promotoras Genéticas , Proteínas de Ligação ao Retinol/genética , Animais , Animais Geneticamente Modificados , Linhagem Celular , Cloranfenicol O-Acetiltransferase/genética , Expressão Gênica , Humanos , Camundongos , Xenopus laevisRESUMO
Computers play an increasingly important role in radiology education and research. We surveyed all U.S. residency programs to assess computer availability, education, and use by residents. Out of 210 questionnaires sent, 132 were returned (63% response). Areas of inquiry included computer equipment and software as well as resident use of facilities. Opinions were also solicited concerning the importance of computer literacy and education. Sixty-nine percent of the respondents have computer facilities (61% within the department). Predominant uses include scientific papers, slides/audiovisual presentations and resume preparation. Popular software includes word processing, spreadsheets, databases and graphics. Of those training programs with computers, 85% provided computer education, and most (70%) felt computer training was very important. Forty-seven percent expected their residents to have at least passing acquaintance with computers. However, in 60% of programs with computers, the computers are used by less than half the residents. Of those programs without a computer, 61% provided no computer training, and only 44% felt computer education was very important. A sizable minority of radiology residency programs are still without computer facilities. Those programs that have computers tend to place a greater emphasis on computer education and literacy for radiology residents. However, even in programs that have computers, it seems they are often underutilized by residents.
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Capacitação de Usuário de Computador , Internato e Residência , Radiologia/educação , Estados UnidosRESUMO
PURPOSE: To evaluate diagnostic reliability and to establish optimal scanning techniques of a recently developed Fast Spin-echo MR pulse sequence that allows rapid proton density-weighted and T2-weighted imaging. METHODS: We compared lesion conspicuity and signal intensity measurements on Fast Spin-echo and conventional spin-echo sequences in 81 patients ranging from 1 week to 25 years in age on a 1.5-T MR unit. A total of 28 Fast Spin-echo dual-echo images (14 slice locations) were obtained in 2:08 minutes with a 256 x 128 matrix or in 3:12 minutes with a 256 x 192 matrix at a TR of 2000 msec and two excitations. RESULTS: Lesion conspicuity and characterization on Fast Spin-echo images compared favorably with conventional spin-echo images in our series when pseudo-TEs of 15 and 90 msec were employed for proton density-weighted and T2-weighted images, respectively. Fast Spin-echo images yielded diagnostic information in four nonsedated patients whose conventional spin-echo images were either degraded by motion or unobtainable. Fat signal remained bright on T2-weighted Fast Spin-echo images. Magnetic-susceptibility effects were slightly reduced with Fast Spin-echo but did not pose any diagnostic problem in our series. CONCLUSION: Diagnostically reliable rapid dual-echo brain images can be obtained with Fast Spin-echo sequences.
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Encefalopatias/diagnóstico , Neoplasias Encefálicas/diagnóstico , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Modelos Estruturais , Fatores de TempoRESUMO
PURPOSE: To examine the relative capabilities for the detection of vertebral metastases of three available fast spin-echo sequences: T1-weighted fast spin-echo, short tau inversion recovery (STIR) fast spin-echo, and T2-weighted fast spin-echo sequences with chemical shift selective saturation pulse fat suppression. METHODS: Fourteen patients were evaluated prospectively over a 2-month period with T1-weighted fast spin-echo (four echo train, four acquisitions, 1 min 59 sec-2 min 37 sec). STIR fast spin-echo (16 echo train, four acquisitions, 2 min 30 sec-3 min 19 sec), and T2-weighted fast spin-echo (16 echo train, 4 acquisitions, 2 min 27 sec-3 min 16 sec). For all three pulse sequences, measurements were obtained of the signal intensities of normal marrow, abnormal marrow, fat, and noise posterior to the spine. Contrast-to-noise ratios were calculated for metastases in each case. Lesions were evaluated by three observers and rated for size, location, and conspicuity. RESULTS: Signal intensities of fat, normal marrow, and noise were highest for T1-weighted fast spin-echo sequences. STIR fast spin-echo and fat-suppressed T2-weighted fast spin-echo had approximately similar fat-suppression capabilities. Though contrast-to-noise ratios were highest overall for STIR fast spin-echo, the finding was not statistically significant and lesion conspicuity was deemed better with fat-suppressed T2-weighted fast spin-echo and T1-weighted fast spin-echo images. Discrete lesions were well identified on all three pulse sequences. CONCLUSION: Fast spin-echo sequences appear promising for the detection of vertebral metastases. Further work should be directed toward comparison with conventional spin-echo to determine whether fast spin-echo may replace conventional spin-echo sequences for evaluation of vertebral metastases.