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With fertility rates at an all-time low, children have become even more the 'treasures' of their families. Progress in genetic selection technology has made preimplantation genetic diagnosis an increasingly common practice in clinics. However, the practice of purposively selecting genes for future children remains controversial. In this article, the process of preimplantation genetic diagnosis is introduced and related philosophical and social perspectives are reviewed. Finally, the ethics related to this practice are discussed in the contexts of obligation theory, utility theory, and four ethical principles. The authors hope this article sheds light on the diverse perspectives used to consider and discuss the ethical issues surrounding gene selection and, importantly, helps nurses provide care grounded in ethics and humanity in ethically uncertain circumstances.
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Diagnóstico Preimplantación , Humanos , Diagnóstico Preimplantación/ética , FemeninoRESUMEN
Brain fog is a symptom that has gained increasing attention worldwide since the start of the COVID-19 pandemic, as patients affected by COVID-19 may experience cognitive dysfunction, colloquially known as brain fog, for a period of time after recovery. Brain fog affects activities of daily living and work performance and has the potential to negatively impact society and the economy. However, a clear definition and concept analysis of brain fog is lacking in the literature. In this article, a concept analysis of brain fog is conducted using Walker and Avant's concept analysis steps to verify the source and definition of brain fog, clarify related concepts similar to brain fog, and establish the defining attributes, antecedents, and consequences of this condition. Model, borderline, contrary, and related cases are listed to illustrate and provide related empirical references in the literature. The authors hope this article will provide a clearer understanding of brain fog, which then may be applied in nursing clinical practice and future research to develop strategies and care methods for improving brain fog symptoms.
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Actividades Cotidianas , Disfunción Cognitiva , Humanos , Pandemias , Formación de Concepto , Fatiga MentalRESUMEN
This paper proposes a metal artifact reduction method of using MV-CBCT images to correct metal artifacts in kV-CT images, especially for the complex metal artifacts caused by multi-metal interaction of patients with head and neck tumors. The different tissue regions are segmented in the MV-CBCT images to obtain template images and the metal region is segmented in the kV-CT images. Forward projection is performed to get sinogram of the template images, kV-CT images and metal region images. Artifact images can be reconstructed through those sonograms. Corrected images is generated by subtracting the artifact images from the original kV-CT images. After the first correction, the template images are generated again and brought into the previous step for iteration to get better correction result. CT data set of 7 patients are used in this study, compared with linear interpolation metal artifact (LIMAR) and normalized metal artifact reduction method, mean relative error of CT value is reduced by 50.5% and 63.3%, noise is reduced by 56.2% and 58.9%. The Identifiability Score of the tooth, upper/lower jaw, tongue, lips, masseter muscle and cavity in the corrected images by the proposed method have significantly improved (P < 0.05) than original images. The artifacts correction method proposed in this paper can effectively remove the metal artifacts in the images and greatly improve the CT value accuracy, especially in the case of multi-metal and complex metal implantation.
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Artefactos , Tomografía Computarizada de Haz Cónico Espiral , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Metales , Dentaduras , Fantasmas de Imagen , AlgoritmosRESUMEN
Forest carbon storage has important impacts on climate change. The previous models do not take into consideration of the inherent spatial correlation structure of residual and non-stationary of forest carbon storage which limits the prediction accuracy. Based on ETM+ remotely sensed imagery and 193 fixed plots of Maoershan Experimental Forest Farm of Northeast Forestry University, we established the geographically weighted regression kriging (GWRK) model between forest carbon storage and extracted factors from remotely sensed imagery and topographic factors. The prediction accuracy of GWRK, ordinary least square (OLS) model and geographically weighted regression (GWR) were compared. The results showed that the mean absolute error (MAE) and root mean square error (RMSE) of GWRK were lower than those of OLS and GWR models, while the mean error (ME) of GWRK model was lower than that of GWR model and was close to that of OLS model. The prediction accuracy of GWRK model was 83.2%, which was 6% and 10% higher than that of OLS model (73.7%) and GWR model (77.3%). Therefore, the GWRK model was more effective in estimating forest carbon storage than the others. The mean value of forest carbon storage predicted by GWRK model was 70.31 t·hm-2. The relatively high values presented in high altitude area, indicating that altitude had a great impact on forest carbon storage.
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Carbono/análisis , Monitoreo del Ambiente , Bosques , Regresión Espacial , China , Análisis EspacialRESUMEN
Two previously undescribed steroidal compounds, 16, 23-epoxy-22, 26-epimino-cholest-22(N), 23, 25(26)-trien-3ß-ol-3-O-ß-D-glucopyranosyl-(1â2)-ß-D-glucopyranosyl-(1â4)-ß-D-galactopyranoside (1) and 26-O-ß-D-glucopyranosyl-(25R)-5α-furost-20(22)-en-3ß, 26-diol (2), together with 7 known ones including 26-O-ß-D-glucopyranosyl-(25R)-5, 20(22)-dien-furost-3ß, 26-diol (3), (25R)-5-en-spirost-3ß-ol-O-ß-D-glucopyranosyl-(1â4)-[α-L-rhmanopyranosyl-(1â2)]-ß-D-galactopyranoside (4), funkioside D (5), aspidistrin (6), tigogenin-3-O-ß-D-lucotrioside (7), desglucolanatigonin II (8), and degalactotigonin (9), were isolated from Solanum lyratum Thunb. Their cytotoxic activities were tested in two cancer cell lines by MTT method. One of the steroidal glycosides (6) showed significant cytotoxic activity against gastric cancer SGC7901 and liver cancer BEL-7402 cells.
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Alcaloides/toxicidad , Antineoplásicos/aislamiento & purificación , Antineoplásicos/toxicidad , Glicósidos/toxicidad , Extractos Vegetales/toxicidad , Solanum/química , Esteroles/toxicidad , Alcaloides/química , Alcaloides/aislamiento & purificación , Antineoplásicos/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Glicósidos/química , Glicósidos/farmacología , Humanos , Concentración 50 Inhibidora , Estructura Molecular , Fitosteroles/química , Fitosteroles/aislamiento & purificación , Fitosteroles/toxicidad , Extractos Vegetales/química , Plantas Medicinales/química , Esteroles/química , Esteroles/farmacologíaRESUMEN
BACKGROUND: The commitment of nursing preceptors to their role is an important driving force that supports their clinical teaching and affects teaching quality. Role commitment undergoes dynamic development and thus changes over time. Existing studies have utilized only cross-sectional study designs and have not analyzed the changes in commitment trajectories with related factors. PURPOSE: This study aimed to investigate the development trajectories of the commitment of preceptors and to examine the predictors between the trajectories of role commitment among nursing preceptors. METHODS: A single-group, repeated-measures design was adopted, and 59 participants completed the Commitment to the Preceptor Role Scale and the Preceptor's Perception of Support Scale. The latent class growth analysis method was used to estimate the trajectory class patterns. The Wilcoxon rank-sum test, a nonparametric method, was used to compare the differences in demographic characteristics between the trajectories of commitment among nursing preceptors. Predictors were examined using binary logistic regression analysis. RESULTS: The two-class model was the best-fitting model to describe the trajectories of nursing preceptor commitment. The two classes in this model were "low commitment," which accounted for 90.3% of all the participants, and "high commitment," which accounted for 9.7%. A significant difference was found between the two classes in terms of motivation for being a preceptor (p = .048). Neither demographic characteristics nor organizational support had a predictive effect on the trajectories of commitment development. CONCLUSIONS/IMPLICATIONS FOR PRACTICE: This study found a low level of role commitment among new preceptors. Moreover, internal motivation was found to be a significant factor affecting the trajectories of this commitment. Therefore, institutions should foster an appropriate environment to enhance the role identity of preceptors as well as cultivate and stimulate their commitment to this role.
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Rol de la Enfermera/psicología , Lealtad del Personal , Preceptoría , Adulto , Humanos , Investigación en Educación de Enfermería , Investigación en Evaluación de Enfermería , Encuestas y Cuestionarios , Taiwán , Adulto JovenRESUMEN
Selenium (Se) is an essential micronutrient for all vertebrates, however, at environmental relevant levels, it is a potent toxin. In the San Francisco Bay-Delta, white sturgeon, an ancient Chondrostean fish of high ecological and economic value, is at risk to Se exposure. The present study is the first to examine the uptake, distribution, and excretion of various selenocompounds in white sturgeon. A combined technique of stomach intubation, dorsal aorta cannulation, and urinary catheterization was utilized, in this study, to characterize the short-term effects of Se in the forms of sodium-selenate (Selenate), sodium-selenite (Selenite), selenocystine (SeCys), l-selenomethionine (SeMet), Se-methylseleno-l-cysteine (MSeCys), and selenoyeast (SeYeast). An ecologically relevant dose of Se (â¼500 µg/kg body weight) was intubated into groups of 5 juvenile white sturgeon. Blood and urine samples were repeatedly collected over the 48 h post intubation period and fish were sacrificed for Se tissue concentration and distribution at 48 h. The tissue concentration and distribution, blood concentrations, and urinary elimination of Se significantly differ (p ≤ 0.05) among forms. In general, organic selenocompounds maintain higher blood concentrations, with SeMeCys maintaining the highest area under the curve (66.3 ± 8.7 and 9.3 ± 1.0 µg h/ml) and maximum Se concentration in blood (2.3 ± 0.2 and 0.4 ± 0.2 µg/ml) in both the protein and non-protein bound fractions, respectively. Selenate, however, did not result in significant increase of Se concentration, compared with the control, in the protein-bound blood fraction. Regardless of source, Se is preferentially distributed into metabolically active tissues, with the SeMet treated fish achieving the highest concentration in most tissues. In contrast, Selenite has very similar blood concentrations and tissue distribution profile to SeCys and SeYeast. From blood and tissue Se concentrations, Selenate is not stored in blood, but taken up rapidly by the liver and white muscle. Urinary elimination of Se is form dependent and peaks between 3 and 12 h post intubation. A basic understanding of the overall Se absorption, distribution, and elimination is provided through monitoring tissue Se concentrations, however, conclusions regarding to the dynamics and the specific processes of Se metabolism can only be inferred, in the absence of kinetic information.
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Peces/metabolismo , Compuestos de Selenio/farmacocinética , Contaminantes Químicos del Agua/farmacocinética , Animales , Área Bajo la Curva , Peces/sangre , Compuestos de Selenio/sangre , Compuestos de Selenio/orina , Factores de Tiempo , Distribución Tisular , Contaminantes Químicos del Agua/sangreRESUMEN
Sharps injuries are a common occupational hazard in the operating room. This paper presents a conceptual map of sharps injuries prevention at the intraoperative level based on the evidence-based literature. The three outcome indicators identified include safety precaution, no sharps injuries, and competence. Five preventive interventions are suggested, including using hands-free techniques, wearing double-walled gloves, using blunt-tipped needles, providing education courses and making safety devices available. Recommendations in this paper may be used as a reference in developing a standard protocol for preventing sharps injuries in the operating room.
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Accidentes de Trabajo/prevención & control , Práctica Clínica Basada en la Evidencia , Lesiones por Pinchazo de Aguja/prevención & control , Quirófanos , HumanosRESUMEN
PURPOSE: This study evaluates the difference in damage to middle ear function with CRT and IMRT techniques in the treatment of nasopharyngeal carcinoma (NPC). We explore the isthmus of the Eustachian tube (ET) as the key anatomic site for the prevention of radiation-induced otitis media with effusion. METHODS AND MATERIALS: Eighty-two patients with NPC were divided into two groups: 40 patients treated with CRT and 42 patients treated with IMRT. The difference between dosage over the middle ear cavity and the isthmus of the ET was evaluated in both CRT group and IMRT group. All patients underwent hearing tests including pure tone audiometry and impedance audiometry before and after RT. RESULTS: The dosage difference to the middle ear cavity and isthmus between these two groups was statistically significant (p<0.05). The difference in hearing test results between these two groups was also statistically significant (p<0.05). If we limited the dose to the middle ear cavity under 34 Gy and the dose to the isthmus under 53 Gy with IMRT, we may decrease radiation-induced OME even with the larger 2.25 Gy fraction size. CONCLUSIONS: IMRT may have better protected the middle ear function compared with the CRT technique, even with larger fraction sizes than for the conventional CRT technique.
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Carcinoma/radioterapia , Oído Medio/efectos de la radiación , Pérdida Auditiva/etiología , Neoplasias Nasofaríngeas/radioterapia , Radioterapia de Intensidad Modulada , Audiometría , Oído Medio/fisiopatología , Trompa Auditiva/efectos de la radiación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Otitis Media con Derrame/etiología , Dosis de Radiación , Traumatismos por Radiación , Dosificación Radioterapéutica , Radioterapia de Intensidad Modulada/efectos adversosRESUMEN
Apoptosis, which is usually accompanied by DNA degradation, is important not only for the homeostasis of metazoans but also for mammalian development. If DNA is not properly degraded in these processes, it can cause diverse diseases, such as anemia, cataracts, and some autoimmune diseases. A large effort has been made to identify these nucleases that are responsible for these effects. In contrast to Deoxyribonuclease I (DNase I), Deoxyribonuclease II (DNase II) has been less well characterized in these processes. Additionally, enzymes of DNase II family in Trichinella spiralis, which is an intracellular parasitic nematode, are also considered involved in the development of the nematode. We have compiled information from studies on DNase II from various organisms and found some nonclassic features in these enzymes of T. spiralis. Here we have reviewed the characterization and functions of DNase II in these processes and predicted the functions of these enzymes in T. spiralis during host invasion and development.
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Endodesoxirribonucleasas/fisiología , Inmunidad/fisiología , Animales , Proliferación Celular , Humanos , Trichinella spiralis/enzimología , Trichinella spiralis/patogenicidadRESUMEN
OBJECTIVE: To establish a rat model of chronic pulmonary infection by inoculating two different Pseudomonas aeruginosa embedded in minute seaweed alginate beads made by an ejection set with an acuminata hole to Sprague-Dawley rats. To evaluate the animal model with bacteriology and pathology values. METHOD: (1) 300 healthy, clean Sprague-Dawley rats were divided into 3 groups randomly: the wide-type Pseudomonas aeruginosa group (PAO(1) group), the mutant type Pseudomonas aeruginosa group (PAO-JP2 group) and the control group. (2) Two different Pseudomonas aeruginosa were embedded in minute seaweed alginate beads by an ejection set with an acuminata hole. Then the beads were inoculated into the rats' lung through tracheal intubation. The bacteria numbers in lung and pathology scores were measured 3, 7, 14, 28 days after infection. RESULTS: (1) The bacteriology values: No bacterium were detected in the control group. PAO(1) and PAO-JP2 were detected from rats of PAO1 and PAO-JP2 infected groups respectively. Bacterial number was higher than 10(5) CFU/g 3, 7 days after infection (LgCFU/g): 3 d: PAO1 group: 19 +/- 6, PAO-JP2 group: 17 +/- 7; 7 d: PAO1 group: 13 +/- 4, PAO-JP2 group: 12 +/- 4) and higher than 10(3) CFU/g 14, 28 days after infection (LgCFU/g: 14 d: PAO1 group: 11.3 +/- 2.8, PAO-JP2 group: 9.6 +/- 3.3; 28 d: PAO1 group: 9.1 +/- 1.5, PAO-JP2 group: 4.2 +/- 3.0). (2) The pathological changes showed: 3, 7 days after infection, lung abscess, edema, consolidation, haemorrhage can be seen from lungs of both groups. And at optical microscopic, alginate-Pseudomonas aeruginosa caused a pronounced inflammatory reaction with polymorphonuclear cells surrounding a bead. Small microcolonies formed at the periphery of the bead were also seen. 14, 28 days after infection, the consolidation reduced gradually and lung atelectasis, fibrinous adhesions and granulomas became the major pathological changes, which is more significant in the PAO(1) group. CONCLUSION: The animal model of chronic pulmonary infection can be established by inoculating Pseudomonas aeruginosa embedded in minute seaweed alginate beads made by an ejection set with an acuminata hole to Sprague-Dawley rats.
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Modelos Animales de Enfermedad , Neumonía Bacteriana/microbiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/crecimiento & desarrollo , Animales , Enfermedad Crónica , Femenino , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-DawleyRESUMEN
A seven-year old child was scheduled for excision of hemangioma under local anesthesia. Utilizing the concept of caring, we provided pre- and intra-operative support to both the patient and his mother. Before the operation, we effectively established the self-confidence of the patient by providing sufficient disease-related information and encouragement in a child-oriented approach, in order to enable the patient to overcome fear and pain. This caring approach proved effective during the operation since the patient was fully aware of each surgical step and the levels of pain to be experienced. The mother was also involved throughout the process. She was therefore not only emotionally pacified, but also actively involved in the psychosocial support process. Traditionally, almost all surgical procedures in pediatric patients have been performed under general anesthesia. This report indicates that under appropriate care some of the less invasive surgical procedures in school-age children can be carried out under local anesthesia to avoid the risks involved in general anesthesia.
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Procedimientos Quirúrgicos Ambulatorios/enfermería , Empatía , Hemangioma/cirugía , Madres , Adulto , Niño , Femenino , Hemangioma/enfermería , Hemangioma/psicología , Humanos , MasculinoRESUMEN
PURPOSE: To analyze the anatomical factors controlling the morbidity of radiation-induced otitis media with effusion (OME) and determine how to best preserve middle ear function when treating nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: Forty patients with nasopharyngeal carcinoma undergoing 3-D radiotherapy (RT) planning and curative RT were analyzed retrospectively. The difference in dosage over the middle ear cavity and the isthmus of the Eustachian tube (ET) was evaluated. Pure tone audiometry and impedance audiometry tests were performed before and after RT. RESULTS: Mean dosages over the isthmus of the ET for acoustic impedance and pure tone audiometry were recorded. Differences in dosage among the three classifications of unchanged, improved, and worsened ears were statistically significant. CONCLUSION: There was a correlation between the morbidity of radiation-induced OME and the radiation dosage over the middle ear cavities. Decreased OME morbidity was observed when the dosage over the isthmus of the ET was below 52 Gy and the dosage over middle ear cavity was below 46 Gy.
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Oído Medio/anatomía & histología , Trompa Auditiva/anatomía & histología , Otitis Media con Derrame/etiología , Pruebas de Impedancia Acústica , Audiometría de Tonos Puros , Oído Medio/efectos de la radiación , Trompa Auditiva/efectos de la radiación , Humanos , Persona de Mediana Edad , Neoplasias Nasofaríngeas/radioterapia , Estudios RetrospectivosRESUMEN
OBJECTIVE: To investigate the in vivo activities of ceftazidime and cefepime with susceptibility in vitro in rats with experimental pneumonia caused by extended-spectrum beta-lactamase-producing strain of Klebsiella pneumonia. METHODS: With intratracheal instillation method, 3 Klebsiella pneumonia strains isolated from this hospital were used to produce 3 groups of experimental model of pneumonia in rats. All the 3 strains showed resistant to cefotaxime and susceptible to piperacillin-tazobactam in vitro. To ceftazidime and cefepime, strain 1 was both susceptible. Strain 2 was susceptible to ceftazidime and resistant to cefepime. Strain 3 was resistant to ceftazidime and susceptible to cefepime. The three groups of rats were randomly assigned to one of the following five groups: one control group and four treatment groups. The efficacies were evaluated 96 hours later by the survival rate and the viable bacterial counts of the lungs (lg CFU/g). RESULTS: Group 1: piperacillin-tazobactam, ceftazidime and cefepime significantly improved the survival rate (75.0%, 76.9%, 80.0%) and reduced the bacterial counts [(10.8 +/- 2.8), (11.1 +/- 3.2), (11.0 +/- 3.7) lg CFU/g] compared with cefotaxime and the control group [36.0%, 32.0%; (15.7 +/- 5.6), (16.0 +/- 5.5) lg CFU/g; P < 0.05]. Group 2: piperacillin-tazobactam, ceftazidime significantly improved the survival rate (79.2%, 73.1%) and reduced the bacterial counts [(10.7 +/- 2.3), (11.0 +/- 2.7) lg CFU/g] compared with cefotaxime and the control groups [42.3%, 33.3%; (15.5 +/- 5.4), (15.8 +/- 4.6) lg CFU/g; P < 0.05]. Group 3: the survival rate in piperacillin-tazobactam and cefepime groups (80.8%, 75.0%) were significantly higher and the bacterial counts in piperacillin-tazobactam [(10.4 +/- 2.4) lg CFU/g] were significantly lower compared with the cefotaxime and the control groups [37.5%, 34.6%; (14.2 +/- 5.6), (15.3 +/- 4.9) lg CFU/g; P < 0.05]. CONCLUSION: Cefepime and ceftazidime can reduce the mortality and the number of viable bacteria in rat pneumonia caused by some ESBL-producing Klebsiella pneumonia strains susceptible to either of them and their efficacies were similar to piperacillin-tazobactam.
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Antibacterianos/uso terapéutico , Ceftazidima/uso terapéutico , Cefalosporinas/uso terapéutico , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Neumonía Bacteriana/tratamiento farmacológico , Animales , Cefepima , Femenino , Klebsiella pneumoniae/metabolismo , Ratas , Ratas Sprague-Dawley , beta-Lactamasas/biosíntesisRESUMEN
OBJECTIVE: A variety of in vitro experiments indicated that most of the extracellular virulence factors of Pseudomonas aeruginosa (PA) were controlled by the quorum sensing system. The aim of this study was to explore the role of the quorum sensing system in a rat model of PA pulmonary infection. METHODS: Rats were infected intratracheally with PA strain PAO1 or PAO1-JP2 (lasI rhlI double mutant) which was embedded in seaweed alginate bead. The difference of bacteriology and pathology between the two groups was compared. The in vitro activity of elastase was measured by the Congo Red method and the expression of exotoxin A was detected by Western blot. RESULTS: At the 14th and 28th days after challenge, the bacterial colony counts in the PAO1-JP2 group were (9.6 +/- 3.3) lgCFU/g and (4.2 +/- 3.1) lgCFU/g respectively; however, those of the PAO1 group were (11.3 +/- 2.8) lgCFU/g and (9.1 +/- 1.5) lgCFU/g respectively, which showed significant difference (P < 0.05). The lung index of macroscopic pathology (LIMP) and the score of macroscopic pathology of the PAO1-JP2 group were significantly lower than those of the PAO1 group at 7th, 14th and 28th days after challenge. The size of lung abscesses or granuloma in the lung under the microscope and the score of microscopic pathology of the PAO1-JP2 group were also significantly lower at the 7th, 14th and 28th days. The in vitro activity of elastase of the PAO1-JP2 strain was 0.02 +/- 0.00 and that of the PAO1 strain was 0.35 +/- 0.03, which showed significant difference (P < 0.05). The expression of exotoxin A could be detected by Western blot in the PAO1 strain but not in the PAO1-JP2 strain. CONCLUSION: When the quorum sensing system of PA was deficient the expression of some virulence factors, such as elastase and exotoxin A, were decreased, which resulted in milder pulmonary infection.
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Neumonía Bacteriana/microbiología , Infecciones por Pseudomonas/microbiología , Pseudomonas aeruginosa/patogenicidad , Percepción de Quorum , Factores de Virulencia/metabolismo , Animales , Neumonía Bacteriana/metabolismo , Infecciones por Pseudomonas/metabolismo , Ratas , Ratas Sprague-DawleyRESUMEN
We prepared 11C-labeled 5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole ([11C]1) and 4-[5-(4-methoxyphenyl)-3-trifluoromethyl-1H-pyrazol-1-yl]benzenesulfonamide ([11C]2) for imaging COX-1 and COX-2 isoforms, respectively, by positron emission tomography. [11C]1 and [11C]2 were synthesized in high radiochemical yields by O-[11C]methylation with [11C]methyl triflate in acetone containing an equivalent of NaOH as a base with respect to the phenolic precursors. In vivo evaluation in rats bearing AH109A hepatoma demonstrated minimal specific binding of [11C] to COX-1 in peripheral organs, such as the spleen and small intestine. Carrier-saturable uptake of [11C]2 was found in the spleen, but COX-2-specific binding of [11C]2 was not identifiable in the brain, AH109A hepatoma or other peripheral organs, although ex vivo autoradiography showed regionally different distribution in the brain and AH109A. The results suggest that neither [11C]1 nor [11C]2 is a suitable radioligand for in vivo biomarkers of COX enzymes, mainly because of marked non-specific binding.
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Carcinoma Hepatocelular/diagnóstico por imagen , Carcinoma Hepatocelular/metabolismo , Ciclooxigenasa 1/metabolismo , Ciclooxigenasa 2/metabolismo , Proteínas de la Membrana/metabolismo , Pirazoles/farmacocinética , Animales , Radioisótopos de Carbono/farmacocinética , Línea Celular Tumoral , Inhibidores de la Ciclooxigenasa/farmacocinética , Evaluación Preclínica de Medicamentos , Marcaje Isotópico/métodos , Tasa de Depuración Metabólica , Especificidad de Órganos , Cintigrafía , Radiofármacos/farmacocinética , Ratas , Distribución TisularRESUMEN
PURPOSE: To determine the changes in the visual centers of rats following monocular visual deprivation after postnatal eyelid opening (PEO). METHODS: Monocular eyelid suture was performed on rats on days 1, 3, 5, 7, 14, and 28 after PEO, and the glucose metabolism was measured 1, 2, 5, and 7 days after the eyelid suture. Ex vivo autoradiography with (14)C- or (18)F-labeled 2-deoxy-D-glucose was carried out. Effects of monocular enucleation or dark rearing were also determined. RESULTS: Monocular eyelid suture did not decrease the glucose metabolism in any contralateral visual structures on day 1 after visual deprivation in the PEO1 or PEO3 lid-sutured rats. However, there was a decrease on day 1 after the eyelid suture in PEO7 and older rats. Similarly, monocular enucleation on PEO1 did not reduce the glucose metabolism in the visual cortex (VC), but enucleation on PEO7 and thereafter did. Eyelid suture on PEO8 following dark rearing until PEO7 did not reduce the glucose metabolism 1 day after suture, but reduced it at 7 days after suture. CONCLUSIONS: Glucose metabolism was altered by visual deprivation on PEO7 and thereafter. Five days of visual experience after PEO were required for initiation of visual function in the rat visual system.
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Párpados/cirugía , Glucosa/metabolismo , Privación Sensorial , Técnicas de Sutura , Visión Monocular , Vías Visuales/metabolismo , Animales , Animales Recién Nacidos , Autorradiografía , Adaptación a la Oscuridad , Desoxiglucosa , Femenino , Fluorodesoxiglucosa F18 , Cuerpos Geniculados/metabolismo , Masculino , Ratas , Ratas Wistar , Colículos Superiores/metabolismo , Corteza Visual/metabolismoRESUMEN
To determine whether positron emission tomography (PET) can be used for imaging of neuroreceptors in eyes of rabbits. PET imaging of dopamine D(2) receptor, dopamine transporter, serotonin(1A) receptor and sigma(1) receptor in the eyes and brain was performed using corresponding positron-emitting ligands in baseline, pretreatment and displacement conditions. The 4 radioligands outlined the eyes and brain in the baseline. Pretreatment resulted in a slight reduction (26-28%) in the uptake in the anterior segments of eyes. The binding of each radioligand in the iris-ciliary body and retina was confirmed by ex vivo autoradiography. However, the PET signal in the eyes was unexpectedly higher than the autoradiography signal. The identification of radioligand-neuroreceptor binding by PET in the rabbit eyes is not specific enough.
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Ojo/diagnóstico por imagen , Glicoproteínas de Membrana/análisis , Proteínas de Transporte de Membrana/análisis , Proteínas del Tejido Nervioso/análisis , Receptor de Serotonina 5-HT1A/análisis , Receptores de Dopamina D2/análisis , Receptores sigma/análisis , Animales , Autorradiografía , Encéfalo/diagnóstico por imagen , Cuerpo Ciliar/diagnóstico por imagen , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Iris/diagnóstico por imagen , Masculino , Tomografía de Emisión de Positrones , Conejos , Ensayo de Unión Radioligante , Retina/diagnóstico por imagenRESUMEN
The specific binding of [(11)C]doxepin, which has been used as a radioligand for mapping histamine H(1) receptors in human brain by positron emission tomography, was evaluated in five animal species. In mice the [(11)C]doxepin uptake was reduced by treatment with cold doxepin and two H(1) receptor antagonists, but not with H(2)/H(3) antagonists. The specific binding evaluated with treatment with (+)-chlorpheniramine (H(1) antagonist) was in the range of 10-30% in mouse, rat, rabbit, and monkey, but was not detected in guinea pig.
Asunto(s)
Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Doxepina/farmacocinética , Receptores Histamínicos H1/metabolismo , Animales , Encéfalo/efectos de los fármacos , Radioisótopos de Carbono/farmacocinética , Cobayas , Agonistas de los Receptores Histamínicos/farmacología , Humanos , Macaca mulatta , Masculino , Tasa de Depuración Metabólica , Ratones , Unión Proteica , Conejos , Radiofármacos/farmacocinética , Ratas , Ratas Wistar , Especificidad de la Especie , Distribución Tisular , Tomografía Computarizada de Emisión/métodosRESUMEN
We investigated the potential of O-[(11)C]methyl-L-tyrosine and O-[(18) F]fluoromethyl-L-tyrosine as positron-emitting tracers for tumor imaging. The two tracers had similar distribution patterns in rats bearing AH109A hepatoma, with pancreas and, on a lesser extent, AH109A showing the highest uptake. Uptake of both tracers in the AH109A and uptake ratios of AH109A-to-tissues (with the exception of AH109A-to-bone) gradually increased for 60 min. O-[(11)C]methyl-L-tyrosine was metabolically stable, whereas a negligible low amount of metabolites was observed for O-[(18)F]fluoromethyl-L-tyrosine. Both tracers showed the potential for tumor imaging.