RESUMEN
INTRODUCTION: Patients with incidentally discovered small abdominal aortic aneurysms (AAA) require assessment by a vascular surgery department for possible enrollment in a surveillance programme. Our unit implemented a vascular nurse-run AAA clinic in October 2010. The aim of this study was to assess the feasibility of a specialist nurse-run small AAA clinic. METHODS: Demographic and clinical data were collected prospectively for all patients seen in the new vascular nurse clinic between October 2010 and November 2012. A validated AAA operative mortality score was used to aid decision making by the vascular nurse. RESULTS: Some 250 patients were seen in the clinic. 198 (79.2%) patients were enrolled in surveillance, 40 (16%) declined enrollment and 12 (4.8%) were referred to a consultant clinic for further assessment. The majority of patients were male and the mean age was 73.7 years. Co-morbidities included hypertension, a history of cardiovascular disease, and hyperlipidaemia. The majority of referrals were considered to be low operative risk. No aneurysms ruptured whilst under surveillance. CONCLUSIONS: A nurse-run clinic that assesses patients with incidentally discovered small AAAs for inclusion in AAA surveillance is a feasible alternative to assessment of these patients in a consultant-run clinic.
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Aneurisma de la Aorta Abdominal/cirugía , Rotura de la Aorta/cirugía , Análisis Costo-Beneficio , Enfermeras Clínicas , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma de la Aorta Abdominal/diagnóstico , Rotura de la Aorta/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermeras Clínicas/economía , Factores de Tiempo , Resultado del TratamientoRESUMEN
BACKGROUND: In a randomized controlled trial testing a home safety program designed to prevent falls in older people with severe visual impairment, it was shown that the program, delivered by an experienced occupational therapist, significantly reduced the numbers of falls both at home and away from home. OBJECTIVES: To investigate whether the success of the home safety assessment and modification intervention in reducing falls resulted directly from modification of home hazards or from behavioral modifications, or both. METHODS: Participants were 391 community living women and men aged 75 years and older with visual acuity 6/24 meters or worse; 92% (361 of 391) completed one year of follow up. Main outcome measures were type and number of hazards and risky behavior identified in the home and garden of those receiving the home safety program, compliance with home safety recommendations reported at six months, location of all falls for all study participants during the trial, and environmental hazards associated with each fall. RESULTS: The numbers of falls at home related to an environmental hazard and those with no hazard involved were both reduced by the home safety program (n = 100 participants) compared with the group receiving social visits (n = 96) (incidence rate ratios = 0.40 (95% confidence interval, 0.21 to 0.74) and 0.43 (0.21 to 0.90), respectively). CONCLUSIONS: The overall reduction in falls by the home safety program must result from some mechanism in addition to the removal or modification of hazards or provision of new equipment.
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Accidentes por Caídas/prevención & control , Accidentes Domésticos/prevención & control , Accidentes por Caídas/economía , Accidentes Domésticos/economía , Anciano , Análisis Costo-Beneficio , Suplementos Dietéticos , Terapia por Ejercicio , Femenino , Servicios de Atención de Salud a Domicilio/economía , Humanos , Masculino , Terapia Ocupacional/métodos , Cooperación del Paciente , Modalidades de Fisioterapia , Medición de Riesgo , Administración de la Seguridad , Resultado del Tratamiento , Trastornos de la Visión/rehabilitación , Vitamina D/administración & dosificaciónAsunto(s)
Enfermedades de las Glándulas Suprarrenales/etiología , Colitis Ulcerosa/cirugía , Glucocorticoides/efectos adversos , Complicaciones Posoperatorias/tratamiento farmacológico , Prednisona/efectos adversos , Síndrome de Abstinencia a Sustancias , Enfermedad Aguda , Enfermedades de las Glándulas Suprarrenales/tratamiento farmacológico , Adulto , Antiinflamatorios/uso terapéutico , Colitis Ulcerosa/tratamiento farmacológico , Enema , Glucocorticoides/uso terapéutico , Humanos , Hidrocortisona/uso terapéutico , Masculino , Prednisona/uso terapéuticoRESUMEN
BACKGROUND AND AIMS: Newly synthesised cholesterol contributes poorly to biliary lipid secretion but may assume greater importance when the rate limiting enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) is upregulated. As this occurs in the gall stone susceptible C57L/J inbred mouse, we employed two cholesterol biosynthesis inhibitors, Tu 2208 and Ro 48-8071, potent inhibitors of squalene epoxidase and oxidosqualene-lanosterol cyclase, respectively, to assess their potential in preventing cholesterol cholelithiasis in the C57L/J mouse strain. Mice were fed a lithogenic diet comprising a balanced nutrient intake with 15% dairy fat, 1% cholesterol, and 0.5% cholic acid added. METHODS: We determined gall stone phenotype, HMGR activity, biliary lipid secretion rates, and counterregulatory events in male C57L/J mice and gall stone resistant AKR treated with Tu 2208 (30-60 mg/kg/day) or Ro 48-8071 (30-100 mg/kg/day), while ingesting chow or the lithogenic diet. RESULTS: Both agents reduced the gall stone prevalence rate from 73% to 17% in C57L/J mice, inhibited HMGR activity, and decreased hepatic cholesterol concentrations without appreciably influencing biliary cholesterol secretion. In C57L as well as AKR mice, both agents increased biliary phospholipid (which is mostly phosphatidylcholine) secretion rates and at the highest doses effectively reduced the biliary cholesterol saturation index. CONCLUSIONS: Cholesterol biosynthesis inhibitors acting distally to squalene do not reduce biliary cholesterol secretion rates despite reductions in cholesterol biosynthesis and hepatocellular levels. However, they effectively prevent gall stone formation through stimulation of pathways that lead to enhanced biliary phospholipid secretion.
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Anticolesterolemiantes/uso terapéutico , Bilis/metabolismo , Colelitiasis/prevención & control , Colesterol/biosíntesis , Fosfolípidos/metabolismo , Animales , Benzofenonas/uso terapéutico , Canalículos Biliares/metabolismo , Colelitiasis/genética , Colelitiasis/metabolismo , Colesterol/sangre , Inhibidores Enzimáticos/uso terapéutico , Predisposición Genética a la Enfermedad , Transferasas Intramoleculares/antagonistas & inhibidores , Metabolismo de los Lípidos , Hígado/metabolismo , Masculino , Ratones , Ratones Endogámicos AKR , Ratones Endogámicos C57BL , Oxigenasas/antagonistas & inhibidores , Escualeno-Monooxigenasa , Tiofenos/uso terapéuticoRESUMEN
With the improved reliability and efficiency of automation, there has been an increased desire to integrate automated sample management with automated screening systems. In order to store samples "on line" for an extended period of time, an automation-compatible means for sealing and unsealing microplates is necessary. Numerous commercial solutions are available for removing loose-fitting microplate lids; however, the task of removing a tight-fitting matted lid such as the RoboLid is more challenging. This paper discusses the design of an automated workstation for the application and removal of such tight-fitting microplate lids.
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Robótica , Diseño de Equipo , Equipos y Suministros , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: In developed nations, increasing proportions of the population now reach advanced age. Physicians may be reluctant to refer such patients for non-critical diagnostic and therapeutic interventions, on the basis of perceived diminution of tolerance, safety and substantive benefits in these patients. We aimed to review the utility and safety of gastrointestinal endoscopy in an extremely elderly cohort. METHODS: The study involved 214 consecutive participants aged 85 years or more, between 1995 and 1997. They were identified using a prospective database linked to the endoscopy reporting system. Procedure type, indication, use of sedation, complications, and outcomes were evaluated. RESULTS: The median age was 87 (85-94, sigma = 2). The female:male ratio was 3:2; 185 had undergone one procedure and 29 two or more; and 65% of procedures were performed on an outpatient basis. Of the inpatient procedures, 10% of all procedures were performed emergently, predominantly for upper gastrointestinal hemorrhage. Midazolam was administered to 129 patients (60%), at a median dose of 2 mg (range 1-11); of these, 75 (35%) also received a median dose of 25 microg fentanyl (range 12.5-125). Colonoscopy (n = 95) was the most frequently performed procedure, followed by esophagogastroduodenoscopy (EGD) (n = 64) and endoscopic retrograde cholangiopancreatography (ERCP) (n = 21). There was no procedure-related mortality. The incidence of post-ERCP pancreatitis was 5%, colonic perforation 1%, and cardiopulmonary complications in sedated patients, 0.6%. The majority underwent procedures which related to active management of ongoing medical problems, and procedures were performed for palliative indications in only 15 (7%) patients. CONCLUSIONS: Gastrointestinal endoscopy is extremely safe and well tolerated in extremely elderly patients. Age alone should not influence decisions relating to its utilization.
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Endoscopía Gastrointestinal , Anciano , Anciano de 80 o más Años , Colangiopancreatografia Retrógrada Endoscópica , Colonoscopía , Endoscopía , Femenino , Gastroscopía , Humanos , MasculinoAsunto(s)
Biopsia con Aguja , Linfoma de Células B/diagnóstico , Retina/patología , Neoplasias de la Retina/diagnóstico , Femenino , Angiografía con Fluoresceína , Reordenamiento Génico de Cadena Pesada de Linfocito B/genética , Genes de Inmunoglobulinas/genética , Genes bcl-2/genética , Humanos , Cadenas Pesadas de Inmunoglobulina/genética , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Cuerpo Vítreo/patologíaRESUMEN
This study examined the frequency of lymph node micrometastases detected by expression of mutant K-ras oncogene present in the respective primary tumour. The study population consisted of consecutive patients with stage II colorectal cancer (CRC) undergoing curative resection and with disease-free survival of 60 months or longer or CRC-related death. Of 27 patients found to have K-ras mutations at codon 12, 17 had genomic DNA suitable for PCR recovered from corresponding regional lymph node tissue. The same K-ras mutation was identified in the lymph nodes of 13 patients (76%), four of whom (30%) died of CRC recurrence within 5 years. A single patient in the negative group (25%) also died. Lymph node micrometastases detected by this technique thus show no relationship to mortality in stage II CRC. Further study of this technique is necessary before it can be used in the selection of patients for adjuvant chemotherapy.
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Cromosomas Humanos Par 12 , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/mortalidad , Genes ras/genética , Ganglios Linfáticos/patología , Metástasis Linfática/genética , Mutación , Secuencia de Bases , Estudios de Cohortes , Neoplasias Colorrectales/patología , ADN de Neoplasias/análisis , Supervivencia sin Enfermedad , Femenino , Expresión Génica , Marcadores Genéticos/genética , Humanos , Irlanda , Metástasis Linfática/patología , Masculino , Datos de Secuencia Molecular , Estadificación de Neoplasias , Reacción en Cadena de la Polimerasa , Medición de Riesgo , Sensibilidad y Especificidad , Tasa de SupervivenciaRESUMEN
PURPOSE: Human T-cell lymphotrophic virus type 1 is a RNA retrovirus that primarily affects CD4+ T-cells. Human T-cell lymphotrophic virus type 1 infection is the established cause of adult T-cell leukemia/lymphoma, an aggressive malignancy of CD4+ T-cells, and two nonneoplastic conditions: human T-cell lymphotrophic virus type 1-associated myelopathy/tropical spastic paraparesis and human T-cell lymphotrophic virus type 1 uveitis. Other reported ophthalmic manifestations of human T-cell lymphotrophic virus type 1 infection include lymphomatous and leukemic infiltrates in the eye and ocular adnexa in patients with adult T-cell leukemia/lymphoma, retinal pigmentary degeneration, and neuro-ophthalmic disorders in patients with human T-cell lymphotrophic virus type 1-associated myelopathy/tropical spastic paraparesis and keratoconjunctivitis sicca, episcleritis, and sclerouveitis in asymptomatic human T-cell lymphotrophic virus type 1 carriers. This report describes the ocular findings in three Jamaican patients with human T-cell lymphotrophic virus type 1 infection and adult T-cell leukemia/lymphoma. METHODS: The clinical records of three patients with human T-cell lymphotrophic virus type 1 infection and adult T-cell leukemia/lymphoma examined at the National Eye Institute were reviewed. Each patient had one or more complete ophthalmic evaluations. RESULTS: All three patients had corneal abnormalities, including corneal haze and central opacities with thinning; bilateral immunoprotein keratopathy; and peripheral corneal thinning, scarring, and neovascularization. All three patients had elevated serum immunoglobulin levels. CONCLUSIONS: We believe that the novel corneal findings in these patients are most likely a consequence of the hypergammaglobulinemia induced by the human T-cell lymphotrophic virus type 1 infection or the T-cell malignancy.
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Enfermedades de la Córnea/virología , Infecciones Virales del Ojo , Virus Linfotrópico T Tipo 1 Humano/aislamiento & purificación , Paraparesia Espástica Tropical , Adulto , Enfermedades de la Córnea/diagnóstico , Enfermedades de la Córnea/etnología , Infecciones Virales del Ojo/diagnóstico , Infecciones Virales del Ojo/etnología , Infecciones Virales del Ojo/virología , Femenino , Anticuerpos Anti-HTLV-I/análisis , Virus Linfotrópico T Tipo 1 Humano/inmunología , Humanos , Hipergammaglobulinemia/inmunología , Hipergammaglobulinemia/virología , Inmunoglobulina G/inmunología , Jamaica/epidemiología , Masculino , Persona de Mediana Edad , Paraparesia Espástica Tropical/diagnóstico , Paraparesia Espástica Tropical/etnología , Paraparesia Espástica Tropical/virología , Agudeza VisualRESUMEN
A previously described automated thin-film deposition system based on rf-magnetron sputtering could deposit quite complex optical multilayer systems with good precision and with no one in attendance [Sullivan and Dobrowolski, Appl. Opt. 32, 2351-2360 (1993)]. However, the deposition rate was slow, and the uniform area on the substrate was limited. We describe an ac-magnetron sputtering process in which the same deposition accuracy has been combined with significantly better film uniformity and a fivefold or sevenfold increase in the deposition rate. This makes the equipment of commercial interest. Experimental results are presented for several difficult coating problems.
RESUMEN
Past research on all-dielectric nonpolarizing beam splitters is reviewed. It is shown that, for a 50-nm spectral region, it is possible to design and manufacture a two-material nonpolarizing plate beam splitter for use at an angle of 45 degrees (with a measured rms reflectance of 0.50 +/- 0.01 for both s- and p-polarized incident light).
RESUMEN
There is compelling evidence for the role of inhibitory molecules in guiding neurons to their appropriate targets. Furthermore, continued expression of these molecules in the adult could explain why there is little regeneration of neurons in the central nervous system. We have previously identified a family of glycosyl phosphatidylinositol-linked glycoproteins (GP55) from adult chicken brain that has been shown to inhibit neurite outgrowth from dorsal root ganglion and forebrain neurons. GP55 consists of two or more glycoproteins and belongs to a subgroup of the lg superfamily which contains OBCAM, LAMP, neurotrimin and CEPU-1. We now show that GP55 is anti-adhesive, blocking the adhesion of neurons to normally adhesive substrata in a concentration dependent manner. The anti-adhesive effect can be blocked using antiserum raised against GP55 and pertussis toxin (PTX) but not the beta oligomer alone. In contrast, the adhesion of fibroblasts and Schwann cells to the substrata is not affected by GP55. Indeed, non-neuronal cells spread and grow normally. These results would suggest that both the anti-adhesive effect and the inhibition of outgrowth by GP55 is specific to neurons and is mediated by a PTX sensitive, G-protein-coupled receptor.
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Proteínas de Unión al GTP/fisiología , Inmunoglobulinas , Glicoproteínas de Membrana/fisiología , Neuronas/fisiología , Receptores de Superficie Celular/fisiología , Células de Schwann/fisiología , Animales , Adhesión Celular/efectos de los fármacos , Adhesión Celular/fisiología , División Celular/efectos de los fármacos , División Celular/fisiología , Células Cultivadas , Embrión de Pollo , Fibroblastos/efectos de los fármacos , Fibroblastos/fisiología , Neuronas/efectos de los fármacos , Toxina del Pertussis , Células de Schwann/efectos de los fármacos , Factores de Virulencia de Bordetella/farmacologíaRESUMEN
We have previously identified a glycosylphosphatidylinositol-linked glycoprotein of 55 kDa (GP55) which inhibits neurite outgrowth. We now provide evidence that GP55, isolated from adult chick brain, consists of at least two bands, both of which are active, i.e., block outgrowth of neurites from chick dorsal root ganglion neurons. An antiserum raised against the adult proteins reverses the inhibition and preliminary experiments suggest that GP55 is restricted to the nervous system, increases during development from very low levels at embryonic day 10 and is most abundant after hatching. Immunofluorescence reveals that GP55 is expressed on neurons cultured from an embryonic day 14 chick brain but is barely detectable on embryonic day 10 dorsal root ganglion neurons or embryonic day 8 forebrain neurons; the neurons which respond to substrate-bound GP55. Peptide sequencing revealed considerable homology with OBCAM, a protein previously identified on the basis of binding opiates. Nested polymerase chain reaction using primers to the OBCAM sequence and internal primers to GP55 peptides produced two different polymerase chain reaction fragments with homology to OBCAM. A full length clone (E19S) corresponding to one polymerase chain reaction product and a partial length clone (E14S) corresponding to the second have been isolated from an embryonic chick brain library. Both are members of the immunoglobulin superfamily and have (or are expected to have) three C2 domains. E19S has 90% homology with LAMP at the amino acid level. This sequence only partially matches the peptides from the adult protein and hence is probably not a major component of the adult proteins. E14S (GP55-A) has 83% homology to OBCAM at the amino acid level over the region sequenced. The sequence matches several of the peptides from the adult protein and is hence likely to correspond to a major component of the adult proteins. Thus members of the GP55 family are related to OBCAM, neurotrimin, LAMP and a recently discovered chick protein CEPU-1. Our results suggest molecules within this family are capable of acting as cell adhesion molecules and inhibitors of neurite outgrowth.
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Proteínas Aviares , Proteínas Portadoras/química , Moléculas de Adhesión Celular Neuronal/química , Moléculas de Adhesión Celular/química , Glicosilfosfatidilinositoles/metabolismo , Inmunoglobulinas/química , Glicoproteínas de Membrana/química , Proteínas del Tejido Nervioso/química , Moléculas de Adhesión de Célula Nerviosa/química , Neuritas/fisiología , Neuronas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Encéfalo/metabolismo , Proteínas Portadoras/genética , Moléculas de Adhesión Celular/genética , Cerebelo/metabolismo , Embrión de Pollo , Pollos , ADN Complementario , Proteínas Ligadas a GPI , Ganglios Espinales , Inmunoglobulinas/clasificación , Inmunoglobulinas/genética , Inmunoglobulinas/metabolismo , Glicoproteínas de Membrana/clasificación , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Datos de Secuencia Molecular , Ratas , Retina/metabolismoRESUMEN
A 33-yr-old homosexual man with acquired immune deficiency syndrome (AIDS) and Mycobacterium avium intracellulare (MAI) infection presented with fever, sweats, lethargy and dyspnea. A chest radiograph showed cardiomegaly and an echocardiograph revealed a large pericardial effusion. After pericardial aspiration, which confirmed T cell non-Hodgkin's lymphoma, he remained dyspneic. Gallium-67 imaging was performed to determine whether the patient's residual dyspnea was related to pulmonary MAI infection or lymphomatous infiltration of the heart. Planar 67Ga scintigraphy revealed intense tracer uptake in two areas within the mediastinum and surrounding the entire heart shadow but no evidence of pulmonary MAI infection. SPECT 67Ga scintigraphy precisely localized the two mediastinal abnormalities and demonstrated the tracer uptake around the heart to be pericardial rather than myocardial. Gallium-67 scintigraphy suggested that pericardial lymphoma was the likely basis of the patient's dyspnea.
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Radioisótopos de Galio , Neoplasias Cardíacas/diagnóstico por imagen , Linfoma Relacionado con SIDA/diagnóstico por imagen , Pericardio/diagnóstico por imagen , Infecciones Oportunistas Relacionadas con el SIDA/complicaciones , Adulto , Humanos , Pulmón/diagnóstico por imagen , Linfoma Relacionado con SIDA/complicaciones , Linfoma Relacionado con SIDA/diagnóstico , Linfoma de Células T/complicaciones , Linfoma de Células T/diagnóstico , Linfoma de Células T/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Infección por Mycobacterium avium-intracellulare/complicaciones , Infección por Mycobacterium avium-intracellulare/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
This study reappraises the acquisition parameters defined by three current protocols for the specification of planar gamma camera performance. These are the manufacturer Standards of the National Electrical Manufacturers' Association [1] and the International Electrotechnical Commission [2], and the user-orientated protocol of the UK Department of Health (DoH, formerly DHSS) Gamma Camera Performance Assessment Group [3]. The study looks specifically at three major planar performance characteristics: intrinsic non-uniformity, intrinsic spatial resolution and intrinsic non-linearity (spatial distortion). Acquisition parameters specified for these characteristics are investigated by testing a range of values for each parameter around those figures currently advocated by the three protocols. Those acquisition parameters which may be relaxed without loss of data integrity are identified and the adoption of revised parameters for some measurements within the DoH assessment protocol is suggested. Reviewing the data obtained, observations are made regarding the accuracy of some tests performed regularly for quality control purposes. The feasibility and advantages of incorporating some suitably modified DoH performance assessment tests within a routine quality assurance protocol for the gamma camera are also discussed.
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Cámaras gamma , Cámaras gamma/normas , Guías como Asunto , Reproducibilidad de los Resultados , Reino UnidoRESUMEN
We present a technique we developed to measure specular reflectances of mirrors immersed in liquids and in air. The method works with a broad range of angles of incidence (θ = 15-75°). The wavelength range used in this research was from 250 to 800 nm, and the state of polarization of the incident rays could be continuously varied with respect to the phase of incidence. The technique used in this study is based on a low-cost variable-angle reflectometer and a commercial spectrophotometer. Here we discuss the protocol we devised to extract reflectances with this instrument. This procedure was tested with samples that were measured through the use of ellipsometric techniques. The main advantages of the method discussed here are versatility, speed, and the availability of the equipment used; these are particularly useful for controlling the quality of a large number of samples. We present the results of reflectance measurements in water for dielectric coated aluminum intended for use in light concentrators for the Sudbury Neutrino Observatory. The error in our estimate of the overall reflectance, weighted over operational distributions of wavelength and incident angle, is ±3% for one sample and ±5% for the 2000 m(2) of coated material involved in this observatory.
RESUMEN
Glycoproteins that inhibit neurite outgrowth may guide growth cones during development by acting as a barrier and closing off inappropriate routes. Their continued expression in the adult central nervous system may be a key factor in preventing regeneration of central nervous system neurons. A glycoprotein of 55 kDa has been isolated from the detergent-insoluble membrane skeleton from adult chicken brain. Initial experiments showed that dorsal root ganglion neurons would not adhere to or extend neurites on a substratum coated with GP55. Furthermore, GP55 will act as a barrier to the advance of established growth cones in the presence of poly-L-lysine, laminin or G4. Central nervous system neurons from forebrain as well as dorsal root ganglion neurons from the peripheral nervous system are inhibited by GP55. GP55 is also effective in blocking the initial adhesion of neurons to a substratum of poly-L-lysine and, particularly, laminin. In contrast to the inhibition of neurite outgrowth, neuronal adhesion is concentration independent over the range tested. A preliminary investigation of the mechanism by which GP55 inhibits outgrowth suggests that a pertussis toxin-sensitive G protein is required. Preliminary evidence suggests that GP55 is anchored in the membrane by a glycosyl phosphatidylinositol moiety. GP55 is distinct from previously identified inhibitory proteins, based on the source and molecular mass, and is thus a new member of this rapidly expanding family.
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Adhesión Celular/efectos de los fármacos , Glicosilfosfatidilinositoles/farmacología , Glicoproteínas de Membrana/farmacología , Proteínas del Tejido Nervioso/farmacología , Neuritas/efectos de los fármacos , Animales , Química Encefálica , Moléculas de Adhesión Celular Neuronal/farmacología , Células Cultivadas , Embrión de Pollo , Pollos , Ganglios Espinales/citología , Ganglios Espinales/crecimiento & desarrollo , Laminina/farmacología , Complejo de Antígeno L1 de Leucocito , Toxina del Pertussis , Polilisina/farmacología , Prosencéfalo/citología , Prosencéfalo/crecimiento & desarrollo , Factores de Virulencia de Bordetella/farmacologíaRESUMEN
The clinical experience with the Toshiba GCA-9300A single photon emission tomography (SPET) system is discussed along with typical acquisition protocols for various SPET studies. The system was used to perform SPET studies in normals and in a variety of brain and body disorders. Its three Anger-type gamma cameras forming a triangular aperture offer a substantial increase in sensitivity compared to a single rotating gamma camera. This has allowed the routine use of lead fanbeam super high-resolution collimators (SHR FB) for 99Tcm-hexamethylpropyleneamine oxime (HMPAO) brain SPET studies and high-resolution parallel-hole collimators (HR PH) for cardiac and other body studies. The resulting improvement in spatial resolution coupled with the ease of patient positioning and the greater patient throughput compared to a conventional tomographic gamma camera, will enhance the role of brain and body SPET for both routine and research purposes.
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Encefalopatías/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Dolor en el Pecho/diagnóstico por imagen , Isquemia Miocárdica/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único/instrumentación , Huesos/diagnóstico por imagen , Humanos , Riñón/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Compuestos de Organotecnecio , Oximas , Valores de Referencia , Sensibilidad y Especificidad , Exametazima de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
Nitrovasodilators, particularly the nitric oxide donor agents, are known to inhibit leukocyte functions such as chemotaxis, adherence, migration and proteolytic enzyme release. In this study, we investigated the modulatory role of nitric oxide donor agents on reactive oxygen production by canine polymorphonuclear leukocytes using luminol-enhanced chemiluminescence (LDCL). LDCL was measured before and after activation using 1 mg/ml of opsonized zymosan in the absence or presence of various agents. Unlike the nitrovasodilators, nitroglycerin and nicorandil, the nitric oxide donor agents, 3-morpholinosydnonimine (SIN-1) and sodium nitroprusside, both produced enhanced stimulation of LDCL following zymosan at low concentrations of the agonist and inhibition at high concentrations of the agonist. SIN-1 and sodium nitroprusside (but not nitroglycerin or nicorandil) also produced LDCL before activation of cells with zymosan. This increase was blocked by superoxide dismutase or catalase but not by the hydroxyl radical scavenger, mannitol. SIN-1c, the inactive product of SIN-1 produced no LDCL. Furthermore, incubation of 10 microM SIN-1 or nitroprusside with luminol in the absence of cells produced no chemiluminescence at these drug concentrations. The stimulation of LDCL in the prezymosan phase was partially inhibited by methylene blue and L-nitroarginine methyl ester. In zymosan-stimulated cells, the enhanced LDCL induced by SIN-1 was prevented with superoxide dismutase, catalase (but not mannitol) and reversed with L-nitroarginine methyl ester. Thus, nitric oxide donor agents may either stimulate or inhibit oxygen radical production by isolated neutrophils depending on the drug concentration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Neutrófilos/efectos de los fármacos , Óxido Nítrico/farmacología , Especies Reactivas de Oxígeno , Vasodilatadores/farmacología , Animales , Arginina/análogos & derivados , Arginina/farmacología , Perros , Depuradores de Radicales Libres , Mediciones Luminiscentes , Luminol , Molsidomina/análogos & derivados , Molsidomina/farmacología , NG-Nitroarginina Metil Éster , Neutrófilos/metabolismo , Óxido Nítrico/química , Nitroprusiato/farmacología , Vasodilatadores/químicaRESUMEN
The physical performance of the Toshiba GCA-9300A triple-headed SPECT system has been assessed. Using a water-filled cylinder containing 99mTc, the tomographic volume sensitivity was 33.8 and 34.8 kcps/(MBq/ml)/cm for the high-resolution, parallel-hole (HR-PH) collimator and the super high-resolution, lead fanbeam (SHR-FB) collimator, respectively, excluding the rotation time(s) during scanning when data are not acquired. The tomographic spatial resolution at the center, in air, with 132 mm radius of rotation was 10.2 and 7.8 mm FWHM with the HR-PH and SHR-FB collimators, respectively; in water it was 11.0 and 7.8 mm. Reconstructed relative activity concentrations were accurate for both collimator sets if attenuation correction was used. With the SHR-FB collimators, the average peak-to-valley ratio of five-line sources in water improved significantly when an asymmetric energy window was used. Using the three-dimensional Hoffman brain phantom which simulates a 4:1 grey matter-to-white matter ratio and the usual choice of acquisition and processing parameters for brain studies, the reconstructed grey matter-to-white matter ratio was only about 1.7 for total counts typically acquired in a 99mTc-HMPAO study (4.0 M counts) and only 2.3 for 40 M counts. There was a qualitative improvement with an asymmetric energy window.