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1.
J Hum Nutr Diet ; 28(6): 593-603, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25231461

RESUMEN

BACKGROUND: The present study aimed to explore facilitators and barriers to weight loss (WL) and weight loss maintenance (WLM) in women who participated in a primary, 18-week comparative trial that promoted WL with an energy-restricted diet. METHODS: Twenty-three women participated in seven focus groups conducted by a moderator and co-facilitator using open-ended questions and probes. Focus groups were held in a private room and audio tape-recorded. Tapes were transcribed verbatim and thematic analysis was used to evaluate transcripts for common themes. RESULTS: Accountability to others, social support, planning ahead, awareness and mindfulness of food choices, basic nutrition education, portion control, exercise, and self-motivation were perceived as key facilitators for WL and WLM by women. Identified barriers included life transitions, health status changes, internal factors, environmental pressures, lack of accountability and an absence of social support. CONCLUSIONS: Future interventions should address these salient facilitators and barriers to promote sustainable changes in women across their WL and WLM journeys.


Asunto(s)
Restricción Calórica/psicología , Ejercicio Físico/psicología , Preferencias Alimentarias/psicología , Motivación/fisiología , Investigación Cualitativa , Pérdida de Peso/fisiología , Adulto , Conducta de Elección , Ejercicio Físico/fisiología , Femenino , Grupos Focales , Preferencias Alimentarias/fisiología , Estado de Salud , Humanos , Apoyo Social
2.
Biol Lett ; 8(4): 481-3, 2012 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-22048891

RESUMEN

Emerging infectious diseases are a significant threat to global biodiversity. While historically overlooked, a group of iridoviruses in the genus Ranavirus has been responsible for die-offs in captive and wild amphibian, reptile and fish populations around the globe over the past two decades. In order to share contemporary information on ranaviruses and identify critical research directions, the First International Symposium on Ranaviruses was held in July 2011 in Minneapolis, MN, USA. Twenty-three scientists and veterinarians from nine countries examined the ecology and evolution of ranavirus-host interactions, potential reservoirs, transmission dynamics, as well as immunological and histopathological responses to infection. In addition, speakers discussed possible mechanisms for die-offs, and conservation strategies to control outbreaks.


Asunto(s)
Infecciones por Virus ADN/transmisión , Infecciones por Virus ADN/veterinaria , Interacciones Huésped-Patógeno , Ranavirus/patogenicidad , Anfibios/virología , Animales , Enfermedades Transmisibles Emergentes/transmisión , Congresos como Asunto , Infecciones por Virus ADN/virología , Vectores de Enfermedades , Ecosistema , Enfermedades de los Peces/transmisión , Enfermedades de los Peces/virología , Minnesota , Reptiles/virología
3.
Parasitol Int ; 84: 102380, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33984514

RESUMEN

A wild adult male giant panda that was rescued from a nature reserve in Sichuan Province, China, has died. The panda had been in poor physical condition: it was wheezing and had increased serum amylase. A pathological examination was performed in order to determine the cause of death. Gross examination revealed 1380 mL of yellowish fluid in the abdominal cavity, 356 nematodes in the digestive tract and one filling the pancreatic duct, contractions and variably-sized dark purple areas in the spleen, a collapsed right lung and consolidation of the left lung. Acute pancreatitis was confirmed histopathologically via edema, focal necrosis and hemorrhage with inflammatory cell infiltration. Other major histopathological changes included serous-hemorrhagic pneumonia, lymphocytic necrosis and depletion in the spleen, and degeneration and necrosis of renal tubular epithelial cells. The nematodes were identified as Baylisascaris schroederi via molecular assays. In conclusion, the cause of death of the giant panda was determined to be multiple organ dysfunction syndrome caused by baylisascariasis-induced acute pancreatitis. To our knowledge, this is the first report of fatal baylisascariasis-induced acute pancreatitis in the giant panda.


Asunto(s)
Infecciones por Ascaridida/veterinaria , Ascaridoidea/aislamiento & purificación , Pancreatitis/veterinaria , Ursidae , Enfermedad Aguda , Animales , Animales de Zoológico , Infecciones por Ascaridida/parasitología , Infecciones por Ascaridida/patología , Análisis Químico de la Sangre/veterinaria , China , ADN de Helmintos/análisis , Resultado Fatal , Pruebas Hematológicas/veterinaria , Masculino , Pancreatitis/parasitología , Pancreatitis/patología , Análisis de Secuencia de ADN/veterinaria
4.
Hum Reprod ; 25(2): 406-11, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19910324

RESUMEN

BACKGROUND: Endometriosis is a common cause of infertility and pelvic pain. Lectin histochemistry has shown that glycan expression is a sensitive marker of differentiation in the normal endometrium. Endometrial biopsies were taken during the implantation window from women with subfertility and advanced (stage III and IV) endometriosis to evaluate specific glycans bound by lectins from Dolichos biflorus agglutinin (DBA) and Vicia villosa agglutinin (VVA), which detect related but distinct glycan sequences regulated by progesterone action. METHODS: Endometrial tissue from 12 women with subfertility and advanced endometriosis and 11 healthy controls were taken on days 19-24 of the menstrual cycle and processed into either epoxy resin or paraffin wax. Lectin histochemistry was analysed using light microscopy to quantify the amount of glandular reaction product. RESULTS: There was a significant (P = 0.011) reduction in DBA binding to endometrium from patients with endometriosis compared with controls, which was not seen with VVA (P = 0.135). Three stage IV biopsies and one stage III biopsy completely failed to bind DBA and, of these, three showed moderate glandular binding of VVA. DBA and VVA binding differed significantly (P= 0.0039) in the endometriosis specimens whereas in controls no significant difference was detected (P = 0.812). CONCLUSION: Secretory phase glycosylation in women with advanced endometriosis differs from that in healthy women with a reduction in fucosylated N-acetylgalactosamine sequences bound by DBA. Shorter VVA-binding glycans are not significantly affected. In addition to indicating abnormalities of epithelial differentiation, these findings may be directly relevant to implantation failure, as blastocyst attachment requires a critical interaction with the epithelial glycocalyx.


Asunto(s)
Implantación del Embrión/fisiología , Endometriosis/patología , Endometriosis/fisiopatología , Infertilidad Femenina/fisiopatología , Lectinas de Plantas/metabolismo , Acetilgalactosamina/metabolismo , Adulto , Femenino , Glicosilación , Humanos , Infertilidad Femenina/patología
5.
Vet Pathol ; 47(5): 991-3, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20574071

RESUMEN

An approximately one-and-a-half-year-old, neutered male, mixed-breed dog was presented for a chronic history of vomiting. Profuse diarrhea was also noted during examination. An exploratory laparotomy was performed, bone chips were removed from the stomach, and a raised, circular area of gastric mucosa was biopsied. Histologically, there was severe gastric cryptosporidiosis as well as numerous spiral bacteria, consistent with Helicobacter spp. Polymerase chain reaction revealed visible bands for the 18S ribosomal RNA gene for Cryptosporidium spp. The polymerase chain reaction product was sequenced and was found to be most similar to Cryptosporidium muris. Both the gastric location and the species of Cryptosporidium are unusual in a dog.


Asunto(s)
Criptosporidiosis/veterinaria , Cryptosporidium/aislamiento & purificación , Enfermedades de los Perros/parasitología , Gastropatías/veterinaria , Vómitos/veterinaria , Animales , Antiprotozoarios/uso terapéutico , Biopsia/veterinaria , Criptosporidiosis/diagnóstico , Criptosporidiosis/tratamiento farmacológico , Criptosporidiosis/parasitología , Cryptosporidium/genética , ADN Protozoario/química , ADN Protozoario/genética , Diagnóstico Diferencial , Enfermedades de los Perros/diagnóstico , Enfermedades de los Perros/tratamiento farmacológico , Perros , Cuerpos Extraños/patología , Cuerpos Extraños/cirugía , Inmunohistoquímica/veterinaria , Masculino , Metronidazol/administración & dosificación , Metronidazol/uso terapéutico , Omeprazol/administración & dosificación , Omeprazol/uso terapéutico , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico 18S/química , ARN Ribosómico 18S/genética , Gastropatías/diagnóstico , Gastropatías/tratamiento farmacológico , Gastropatías/parasitología , Vómitos/diagnóstico , Vómitos/tratamiento farmacológico , Vómitos/parasitología
6.
J Fish Biol ; 76(7): 1825-40, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20557634

RESUMEN

This study investigated immediate effects of intense sound exposure associated with low-frequency (170-320 Hz) or with mid-frequency (2.8-3.8 kHz) sonars on caged rainbow trout Oncorhynchus mykiss, channel catfish Ictalurus punctatus and hybrid sunfish Lepomis sp. in Seneca Lake, New York, U.S.A. This study focused on potential effects on inner ear tissues using scanning electron microscopy and on non-auditory tissues using gross and histopathology. Fishes were exposed to low-frequency sounds for 324 or 628 s with a received peak signal level of 193 dB re 1 microPa (root mean square, rms) or to mid-frequency sounds for 15 s with a received peak signal level of 210 dB re 1 microPa (rms). Although a variety of clinical observations from various tissues and organ systems were described, no exposure-related pathologies were observed. This study represents the first investigation of the effects of high-intensity sonar on fish tissues in vivo. Data from this study indicate that exposure to low and midfrequency sonars, as described in this report, might not have acute effects on fish tissues.


Asunto(s)
Oído Interno/patología , Ictaluridae/anatomía & histología , Ruido/efectos adversos , Oncorhynchus mykiss/anatomía & histología , Perciformes/anatomía & histología , Animales , Oído Interno/ultraestructura , Microscopía Electrónica de Rastreo
7.
Health Phys ; 118(2): 136-148, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31634260

RESUMEN

The purpose of this study is to support retrospective dose estimation for epidemiological studies by providing estimates of historical absorbed organ doses to the brain, lens of the eye, salivary glands, and thyroid from intraoral dental radiographic examinations performed from 1940 to 2009. We simulated organ doses to an adult over 10 y time periods from 1940 to 2009, based on commonly used sets of x-ray machine settings collected from the literature. Simulations to estimate organ dose were performed using personal computer x-ray Monte Carlo software. Overall, organ doses were less than 1 mGy for a single intraoral radiograph for all decades. From 1940 to 2009, doses to the brain, eye lens, salivary glands, and thyroid decreased by 86, 96, 95, and 89%, respectively. Of these four organs, the salivary glands received the highest doses, with values decreasing from about 0.23 mGy in the 1940s to 0.025 mGy in the 2000s for a single intraoral radiograph. Based on simulations using collected historical data on x-ray technical parameters, improvements in technology and optimization of the technical settings used to perform intraoral dental radiography have resulted in a decrease in absorbed dose to the brain, eye lens, salivary glands, and thyroid over the period from 1940 to 2009.


Asunto(s)
Encéfalo/efectos de la radiación , Cristalino/efectos de la radiación , Radiografía Dental , Glándulas Salivales/efectos de la radiación , Glándula Tiroides/efectos de la radiación , Adulto , Humanos , Método de Montecarlo , Dosis de Radiación , Estudios Retrospectivos
8.
J Clin Microbiol ; 47(4): 1264-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19109465

RESUMEN

Isolation and characterization of the new species Chrysosporium ophiodiicola from a mycotic granuloma of a black rat snake (Elaphe obsoleta obsoleta) are reported. Analysis of the sequences of different fragments of the ribosomal genes demonstrated that this species belongs to the Onygenales and that this species is genetically different from other morphologically similar species of Chrysosporium. This new species is unique in having both narrow and cylindrical-to-slightly clavate conidia and a strong, pungent odor.


Asunto(s)
Chrysosporium/clasificación , Chrysosporium/aislamiento & purificación , Colubridae/microbiología , Granuloma/veterinaria , Micosis/veterinaria , Animales , Chrysosporium/citología , Chrysosporium/genética , ADN de Hongos/química , ADN de Hongos/genética , ADN Ribosómico/química , ADN Ribosómico/genética , ADN Espaciador Ribosómico/química , ADN Espaciador Ribosómico/genética , Genes de ARNr , Granuloma/microbiología , Datos de Secuencia Molecular , Micosis/diagnóstico , Micosis/microbiología , Filogenia , ARN de Hongos/genética , ARN Ribosómico/genética , Análisis de Secuencia de ADN
9.
J Cell Biol ; 72(1): 11-25, 1977 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12183

RESUMEN

A system of preparation of rat hepatocytes with extended viability has been developed to study the role of hormones and other plasma components upon secretory protein synthesis. Hepatocytes maintained in minimal essential medium reduced the levels of all amino acids in the medium except the slowly catabolized amino acids leucine, isoleucine, and valine, which steadily increase as the result of catabolism of liver protein. Although the liver cells catabolize 10-15% of their own protein during a 20-h incubation, the cells continue to secrete protein in a linear fashion throughout the period. The effects of insulin, cortisol, and epinephrine on general protein synthesis, and specifically on fibrinogen and albumin synthesis, have been tested on cells from both normal rats and adrenalectomized rats. Cells from normal animals show preinduction of tyrosine amino transferase (TAT), having at the time of isolation a high level of enzyme which shows only an increase of approximately 60% upon incubation with cortisol. In contrast, cells from adrenalectomized animals initially have a low level of enzyme which increases fourfold over a period of 9 h. The effects of both epinephrine and cortisol on protein synthesis are also much larger in cells from adrenalectomized animals. After a delay of several hours, cortisol increases fibrinogen synthesis sharply, so that at the end of the 20-h incubation, cells treated with hormone have secreted nearly 2.5 times as much fibrinogen as control cells. The effect is specific; cortisol stimulates neither albumin secretion nor intracellular protein synthesis. The combination of cortisol and epinephrine strongly depresses albumin synthesis in both types of cells. Insulin enhances albumin and general protein synthesis but has little effect on fibrinogen synthesis.


Asunto(s)
Fibrinógeno/biosíntesis , Hígado/citología , Albúmina Sérica/biosíntesis , Adrenalectomía , Aminoácidos/metabolismo , Animales , Supervivencia Celular , Inducción Enzimática , Epinefrina/farmacología , Hidrocortisona/farmacología , Insulina/farmacología , Hígado/metabolismo , Masculino , Colagenasa Microbiana , Biosíntesis de Proteínas , Ratas , Tirosina Transaminasa/biosíntesis
10.
J Cell Biol ; 147(2): 335-50, 1999 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-10525539

RESUMEN

The single cytoplasmic dynein and five of the six kinesin-related proteins encoded by Saccharomyces cerevisiae participate in mitotic spindle function. Some of the motors operate within the nucleus to assemble and elongate the bipolar spindle. Others operate on the cytoplasmic microtubules to effect spindle and nuclear positioning within the cell. This study reveals that kinesin-related Kar3p and Kip3p are unique in that they perform roles both inside and outside the nucleus. Kar3p, like Kip3p, was found to be required for spindle positioning in the absence of dynein. The spindle positioning role of Kar3p is performed in concert with the Cik1p accessory factor, but not the homologous Vik1p. Kar3p and Kip3p were also found to overlap for a function essential for the structural integrity of the bipolar spindle. The cytoplasmic and nuclear roles of both these motors could be partially substituted for by the microtubule-destabilizing agent benomyl, suggesting that these motors perform an essential microtubule-destabilizing function. In addition, we found that yeast cell viability could be supported by as few as two microtubule-based motors: the BimC-type kinesin Cin8p, required for spindle structure, paired with either Kar3p or Kip3p, required for both spindle structure and positioning.


Asunto(s)
Proteínas Asociadas a Microtúbulos/fisiología , Mitosis/fisiología , Proteínas Motoras Moleculares , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/citología , Saccharomyces cerevisiae/fisiología , Dineínas/fisiología , Proteínas Fúngicas/fisiología , Cinesinas/fisiología
11.
Science ; 251(4995): 754-61, 1991 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-17775454

RESUMEN

The traveling salesman problem is one of a class of difficult problems in combinatorial optimization that is representative of a large number of important scientific and engineering problems. A survey is given of recent applications and methods for solving large problems. In addition, an algorithm for the exact solution of the asymmetric traveling salesman problem is presented along with computational results for several classes of problems. The results show that the algorithm performs remarkably well for some classes of problems, determining an optimal solution even for problems with large numbers of cities, yet for other classes, even small problems thwart determination of a provably optimal solution.

12.
Science ; 205(4405): 505-7, 1979 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-451616

RESUMEN

Human platelets were induced by 2.1-megahertz ultrasound to form aggregates around gas-filled pores in membranes immersed in platelet-rich plasma. The spatial peak intensities required were only about 16 to 32 milliwatts per square centimeter. Ultrasound generated by a medical Doppler device, whose intensity exceeded this, induced aggregate formation under the same conditions.


Asunto(s)
Plaquetas/ultraestructura , Agregación Plaquetaria/efectos de la radiación , Ultrasonido , Plaquetas/efectos de la radiación , Humanos , Masculino , Microscopía Electrónica de Rastreo
13.
Science ; 257(5078): 1906-12, 1992 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-1329199

RESUMEN

A silicon-based device, dubbed a microphysiometer, can be used to detect and monitor the response of cells to a variety of chemical substances, especially ligands for specific plasma membrane receptors. The microphysiometer measures the rate of proton excretion from 10(4) to 10(6) cells. This article gives an overview of experiments currently being carried out with this instrument with emphasis on receptors with seven transmembrane helices and tyrosine kinase receptors. As a scientific instrument, the microphysiometer can be thought of as serving two distinct functions. In terms of detecting specific molecules, selected biological cells in this instrument serve as detectors and amplifiers. The microphysiometer can also investigate cell function and biochemistry. A major application of this instrument may prove to be screening for new receptor ligands. In this respect, the microphysiometer appears to offer significant advantages over other techniques.


Asunto(s)
Fenómenos Fisiológicos Celulares , Concentración de Iones de Hidrógeno , Potenciometría/instrumentación , Animales , Biotecnología , Células Cultivadas , Medios de Cultivo , Infecciones por VIH/fisiopatología , Humanos , Técnicas In Vitro , Receptores de Superficie Celular/fisiología , Silicio
14.
Radiat Res ; 170(5): 553-65, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18959462

RESUMEN

Radiation dose to the brain and subsequent lifetime risk of diagnosis of radiation-related brain tumors were estimated for pediatric patients undergoing intracranial embolization. Average dose to the whole brain was calculated using dosimetric data from the Radiation Doses in Interventional Radiology Study for 49 pediatric patients who underwent neuroradiological procedures, and lifetime risk of developing radiation-related brain tumors was estimated using published algorithms based on A-bomb survivor data. The distribution of absorbed dose within the brain can vary significantly depending on field size and movement during procedures. Depending on the exposure conditions and age of the patient, organ-averaged brain dose was estimated to vary from 6 to 1600 mGy. The lifetime risk of brain tumor diagnosis was estimated to be increased over the normal background rates (57 cases per 10,000) by 3 to 40% depending on the dose received, age at exposure, and gender. While significant uncertainties are associated with these estimates, we have quantified the range of possible dose and propagated the uncertainty to derive a credible range of estimated lifetime risk for each subject. Collimation and limiting fluoroscopy time and dose rate are the most effective means to minimize dose and risk of future induction of radiation-related tumors.


Asunto(s)
Neoplasias Encefálicas/etiología , Encéfalo/efectos de la radiación , Neoplasias Inducidas por Radiación/etiología , Dosis de Radiación , Radiografía Intervencional/efectos adversos , Adolescente , Niño , Preescolar , Irradiación Craneana , Femenino , Fluoroscopía , Humanos , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Piel/efectos de la radiación
15.
Med Phys ; 35(2): 673-80, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18383689

RESUMEN

This article summarizes the dosimetric results of an International Atomic Energy Agency coordinated research program to investigate the feasibility of adopting guidance levels for invasive coronary artery procedures. The main study collected clinical data from hospitals located in five countries. A total of 2265 coronary angiograms (CA) and 1844 percutaneous coronary interventions (PCI) were analyzed. Substudies evaluated the dosimetric performance of 14 fluoroscopes, skin dose maps obtained using film, the quality of CA procedures, and the complexity of PCI procedures. Kerma-area product (PKA) guidance levels of 50 and 125 Gy cm2 are suggested for CA and PCI procedures. These levels should be adjusted for the complexity of the procedures performed in a given institution.


Asunto(s)
Guías de Práctica Clínica como Asunto , Protección Radiológica/métodos , Protección Radiológica/normas , Radiografía Intervencional/métodos , Radiografía Intervencional/normas , Radiometría/métodos , Radiometría/normas , Carga Corporal (Radioterapia) , Estudios de Factibilidad , Humanos , Proyectos Piloto , Dosis de Radiación , Efectividad Biológica Relativa
16.
Ann ICRP ; 47(3-4): 142-151, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29714065

RESUMEN

The mandate of Committee 3 of the International Commission on Radiological Protection (ICRP) is concerned with the protection of persons and unborn children when ionising radiation is used in medical diagnosis, therapy, and biomedical research. Protection in veterinary medicine has been newly added to the mandate. Committee 3 develops recommendations and guidance in these areas. The most recent documents published by ICRP that relate to radiological protection in medicine are 'Radiological protection in cone beam computed tomography' (ICRP Publication 129) and 'Radiological protection in ion beam radiotherapy' (ICRP Publication 127). A report in cooperation with ICRP Committee 2 entitled 'Radiation dose to patients from radiopharmaceuticals: a compendium of current information related to frequently used substances' (ICRP Publication 128) has also been published. 'Diagnostic reference levels in medical imaging' (ICRP Publication 135), published in 2017, provides specific advice on the setting and use of diagnostic reference levels for diagnostic and interventional radiology, digital imaging, computed tomography, nuclear medicine, paediatrics, and multi-modality procedures. 'Occupational radiological protection in interventional procedures' was published in March 2018 as ICRP Publication 139. A document on radiological protection in therapy with radiopharmaceuticals is likely to be published in 2018. Work is in progress on several other topics, including appropriate use of effective dose in collaboration with the other ICRP committees, guidance for occupational radiological protection in brachytherapy, justification in medical imaging, and radiation doses to patients from radiopharmaceuticals (an update to ICRP Publication 128). Committee 3 is also considering the development of guidance on radiological protection in medicine related to individual radiosusceptibility, in collaboration with ICRP Committee 1.


Asunto(s)
Exposición a la Radiación/prevención & control , Protección Radiológica/normas , Radiación Ionizante , Humanos , Agencias Internacionales , Medicina Nuclear/normas , Radiología Intervencionista/normas , Radiofármacos/normas
17.
Phys Med ; 52: 56-64, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30139610

RESUMEN

INTRODUCTION: The International Atomic Energy Agency (IAEA) organized the 3rd international conference on radiation protection (RP) of patients in December 2017. This paper presents the conclusions on the interventional procedures (IP) session. MATERIAL AND METHODS: The IAEA conference was conducted as a series of plenary sessions followed by various thematic sessions. "Radiation protection of patients and staff in interventional procedures" session keynote speakers presented information on: 1) Risk management of skin injuries, 2) Occupational radiation risks and 3) RP for paediatric patients. Then, a summary of the session-related papers was presented by a rapporteur, followed by an open question-and-answer discussion. RESULTS: Sixty-seven percent (67%) of papers came from Europe. Forty-four percent (44%) were patient studies, 44% were occupational and 12% were combined studies. Occupational studies were mostly on eye lens dosimetry. The rest were on scattered radiation measurements and dose tracking. The majority of patient studies related to patient exposure with only one study on paediatric patients. Automatic patient dose reporting is considered as a first step for dose optimization. Despite efforts, paediatric IP radiation dose data are still scarce. The keynote speakers outlined recent achievements but also challenges in the field. Forecasting technology, task-specific targeted education from educators familiar with the clinical situation, more accurate estimation of lens doses and improved identification of high-risk professional groups are some of the areas they focused on. CONCLUSIONS: Manufacturers play an important role in making patients safer. Low dose technologies are still expensive and manufacturers should make these affordable in less resourced countries. Automatic patient dose reporting and real-time skin dose map are important for dose optimization. Clinical audit and better QA processes together with more studies on the impact of lens opacities in clinical practice and on paediatric patients are needed.


Asunto(s)
Protección Radiológica , Humanos , Exposición Profesional/prevención & control , Seguridad del Paciente , Protección Radiológica/instrumentación , Protección Radiológica/métodos
18.
Ann ICRP ; 47(3-4): 196-213, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29741403

RESUMEN

Radiation therapy of cancer patients involves a trade-off between a sufficient tumour dose for a high probability of local control and dose to organs at risk that is low enough to lead to a clinically acceptable probability of toxicity. The International Commission on Radiological Protection (ICRP) reviewed epidemiological evidence and provided updated estimates of 'practical' threshold doses for tissue injury, as defined at the level of 1% incidence, in ICRP Publication 118. Particular attention was paid to cataracts and circulatory diseases. ICRP recommended nominal absorbed dose threshold for these outcomes as low as 0.5 Gy. Threshold doses for tissue reactions can be reached in some patients during radiation therapy. Modern treatment planning systems do not account for such low doses accurately, and doses to therapy patients from associated imaging procedures are not generally accounted for. While local control is paramount, the observations of ICRP Publication 118 suggest that radiation therapy plans and processes should be examined with particular care. The research needs are discussed in this paper.


Asunto(s)
Enfermedades Cardiovasculares/radioterapia , Catarata/radioterapia , Protección Radiológica/normas , Radioterapia/normas , Incidencia , Agencias Internacionales , Medición de Riesgo/normas
19.
Ann ICRP ; 47(2): 1-118, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29532669

RESUMEN

Abstract: In recent publications, such as Publications 117 and 120, the Commission provided practical advice for physicians and other healthcare personnel on measures to protect their patients and themselves during interventional procedures. These measures can only be effective if they are encompassed by a framework of radiological protection elements, and by the availability of professionals with responsibilities in radiological protection. This framework includes a radiological protection programme with a strategy for exposure monitoring, protective garments, education and training, and quality assurance of the programme implementation. Professionals with responsibilities in occupational radiological protection for interventional procedures include: medical physicists; radiological protection specialists; personnel working in dosimetry services; clinical applications support personnel from the suppliers and maintenance companies; staff engaged in training, standardisation of equipment, and procedures; staff responsible for occupational health; hospital administrators responsible for providing financial support; and professional bodies and regulators. This publication addresses these elements and these audiences, and provides advice on specific issues, such as assessment of effective dose from dosimeter readings when an apron is worn, estimation of exposure of the lens of the eye (with and without protective eyewear), extremity monitoring, selection and testing of protective garments, and auditing the interventional procedures when occupational doses are unusually high or low (the latter meaning that the dosimeter may not have been worn).


Asunto(s)
Exposición Profesional/normas , Exposición a la Radiación/normas , Protección Radiológica/normas , Radiometría/normas , Humanos , Exposición Profesional/prevención & control , Exposición a la Radiación/prevención & control
20.
J Clin Invest ; 73(4): 980-6, 1984 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-6707214

RESUMEN

Serum ionized calcium levels are lower and immunoreactive parathyroid hormone levels are higher in the spontaneously hypertensive (SH) rat than in the normotensive Wistar-Kyoto (WKy) control. We postulated that there is either a defect in the regulation of vitamin D metabolism by parathyroid hormone or that the gut target organ for vitamin D in the SH rat is unresponsive. To test these hypotheses we measured serum concentrations of vitamin D metabolites and intestinal transport of calcium and sodium. Compared with that of WKy controls, in vitro calcium transport by duodenal sacs of the SH rat was decreased (P less than 0.001) at 5 wk, before the development of hypertension, and at 12 wk, after hypertension was well established. When measured in vivo in the most proximal 20 cm of small intestine, maximum velocity (Vmax) for calcium transport was decreased (P less than 0.05) and net absorption of sodium and water was increased (P less than 0.05) in SH rats as compared with WKy rats. Vmax for calcium transport was also decreased (P less than 0.05) in the most distal 20 cm of small intestine of SH rats, but net sodium and water transport were the same in SH and WKy rats. At 12 wk, serum concentration of 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] was the same in both SH and WKy groups, but its precursor, 25-hydroxycholecalciferol, was increased (P less than 0.05) in the SH rat. We conclude that in the SH rat: (a) the concentration of 1,25-(OH)2D3 is inappropriately low in relation to the elevated immunoreactive parathyroid hormone and the depressed calcium absorption, suggesting a defect in the regulation of vitamin D metabolism; and (b) the depressed calcium absorption, in the setting of normal concentrations of [1,25-(OH)2D3], demonstrates unresponsiveness of the gut to vitamin D and may explain in part the low serum ionized calcium found in earlier studies. The presence of these abnormalities before we found a significant difference in blood pressure suggests that they may be causal, not secondary, to the hypertension.


Asunto(s)
Calcio/metabolismo , Hipertensión/metabolismo , Sodio/metabolismo , Vitamina D/metabolismo , Animales , Transporte Biológico , Peso Corporal , Dieta , Dihidroxicolecalciferoles/sangre , Duodeno/anatomía & histología , Hipertensión/fisiopatología , Absorción Intestinal , Masculino , Tamaño de los Órganos , Ratas , Ratas Endogámicas , Ratas Mutantes
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