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Objective: To compare the accuracy of 6 intraocular lens power calculation formulas based on the new swept-source optical coherence tomography biometry and to analyze the prediction error. Methods: Retrospective case series study. Clinical data were collected from 599 patients (599 eyes) who had underwent uncomplicated phacoemulsification and the IOLMaster 700 examination at the Eye Hospital of Wenzhou Medical University between November 2018 and November 2019. Among the patients, there were 208 males and 391 females with an age of (69±10) years. According to the axial length (AL), eyes were divided into the short AL group (≤22.5 mm, n=100), the normal AL group (>22.5 mm and<25.5 mm, n=375); and the long AL group (≥25.5 mm, n=124). Eyes were also grouped based on the mean keratometry (Km) as flat (≤42.00 D, n=47), normal (>42.00 D to<46.00 D, n=461), and steep (≥46.00 D, n=91), and by anterior chamber depth (ACD) as shallow (≤2.5 mm, n=71), normal (>2.5 mm to<3.5 mm, n=436), and deep (≥3.5 mm, n=92). The median absolute errors (MedAEs) of the Barrett Universal â ¡, Haigis, Hoffer Q, Holladay â , Holladay â ¡, and SRK/T formulas in different AL, Km, and ACD groups were compared using the Friedman test. Results: The differences in MedAE among the 6 formulas of 599 patients (599 eyes) were statistically significant (χ²=120.549, P<0.001). The MedAE of the Barrett Universal â ¡ formula was smallest (0.35 D), followed by the SRK/T formula (0.36 D). There was no significant difference between the MedAEs of the Barrett universal â ¡ and Haigis, SRK/T formula (all P=1.000), but there were statistically significant differences among the other formulas (all P<0.01). In different AL groups, the MedAE of each formula was statistically different (χ²=38.307, 38.779, 112.997; all P<0.01).The Barrett Universal â ¡ formula resulted in the lowest MedAE in the short AL group (0.40 D) and the long AL group (0.31 D). The MedAE of the SRK/T in the normal AL group was lowest (0.35 D). The 6 formulas showed significant differences in MedAE values in different Km groups (χ²=12.284, 90.924, 39.387; all P<0.05).The Haigis formula achieved the lowest MedAE in the flat Km group (0.26 D) and the steep Km group (0.34 D). The Barrett Universalâ ¡ formula achieved the lowest MedAE in the normal Km group (0.33 D). The differences in MedAE values of the 6 formulas in different ACD groups were statistically significant (χ²=37.389, 57.643, 52.845; all P<0.01), and the MedAE values of the Barrett Universal â ¡ in different ACD groups were smallest (0.46, 0.33, 0.31 D). Conclusions: The Barrett Universal â ¡ formula perform the best over the entire AL range, followed by the Haigis and SRK/T formulas. The Barrett Universal â ¡ formula result in the lowest prediction error in the short AL group, the long AL group, and all ACD groups. The Haigis formula may be more accurate when the Km was ≤42.00 D or ≥46.00 D. (Chin J Ophthalmol, 2021, 57: 502-511).
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Lentes Intraoculares , Facoemulsificación , Anciano , Biometría , Femenino , Humanos , Implantación de Lentes Intraoculares , Masculino , Persona de Mediana Edad , Óptica y Fotónica , Refracción Ocular , Estudios Retrospectivos , Tomografía de Coherencia ÓpticaRESUMEN
BACKGROUND: Accumulating quantitative outcome parameters may contribute to constructing a healthcare organization in which outcomes of clinical procedures are reproducible and predictable. In imaging studies, measurements are the principal category of quantitative para meters. OBJECTIVES: The purpose of this work is to develop and evaluate two natural language processing engines that extract finding and organ measurements from narrative radiology reports and to categorize extracted measurements by their "temporality". METHODS: The measurement extraction engine is developed as a set of regular expressions. The engine was evaluated against a manually created ground truth. Automated categorization of measurement temporality is defined as a machine learning problem. A ground truth was manually developed based on a corpus of radiology reports. A maximum entropy model was created using features that characterize the measurement itself and its narrative context. The model was evaluated in a ten-fold cross validation protocol. RESULTS: The measurement extraction engine has precision 0.994 and recall 0.991. Accuracy of the measurement classification engine is 0.960. CONCLUSIONS: The work contributes to machine understanding of radiology reports and may find application in software applications that process medical data.
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Minería de Datos/métodos , Procesamiento de Lenguaje Natural , Radiología , Informe de Investigación , Programas InformáticosRESUMEN
The Double Chooz experiment presents an indication of reactor electron antineutrino disappearance consistent with neutrino oscillations. An observed-to-predicted ratio of events of 0.944±0.016(stat)±0.040(syst) was obtained in 101 days of running at the Chooz nuclear power plant in France, with two 4.25 GW(th) reactors. The results were obtained from a single 10 m(3) fiducial volume detector located 1050 m from the two reactor cores. The reactor antineutrino flux prediction used the Bugey4 flux measurement after correction for differences in core composition. The deficit can be interpreted as an indication of a nonzero value of the still unmeasured neutrino mixing parameter sin(2)2θ(13). Analyzing both the rate of the prompt positrons and their energy spectrum, we find sin(2)2θ(13)=0.086±0.041(stat)±0.030(syst), or, at 90% C.L., 0.017
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There is a growing body of evidence to support the direct link between obstructive bladder dysfunction and erectile dysfunction (ED). However, there have been few pathophysiological studies to determine the relationship between lower urinary tract syndrome (LUTS) and ED. As the transforming growth factor-ß1 (TGF-ß1) that induces the synthesis of collagen in the penile tissues is critical for the development of ED, the first aim of this study was to investigate the expression of TGF-ß1 in the penis from male rabbits with chronic partial bladder outlet obstruction (PBOO). Besides, it has been suggested that oxidative stress plays a significant role in the pathophysiological mechanism of ED. Thus, the second aim of this study was to further investigate whether the urinary or serum oxidative stress markers are involved in chronic PBOO-induced penile dysfunction. A total of 16 male New Zealand White rabbits were separated equally into four groups: a control group and PBOO groups obstructed for 2, 4 and 8 weeks respectively. Using the RT-PCR and Western blot analysis, a progressive increase of TGF-ß1 in penis was found at 2, 4 and 8 weeks after obstruction. Moreover, the biomarkers for oxidative stress or oxidative damage were significantly detected in the penis of rabbits after PBOO, which include the enhancement of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in urine and plasma, plasma malondialdehyde (MDA) and total antioxidant capacity (TAC), as well as reduction of glutathione (GSH). On the basis of our results, the increase of TGF-ß1 and elevated systemic oxidative stress may play key roles to contribute to penile dysfunction after chronic PBOO.
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Estrés Oxidativo , Pene/metabolismo , Factores de Crecimiento Transformadores/metabolismo , Obstrucción del Cuello de la Vejiga Urinaria/metabolismo , Animales , Western Blotting , Masculino , Reacción en Cadena de la Polimerasa , ConejosRESUMEN
In this study of 41 patients, we used proteomic, Western blot and immunohistochemical analyses to show that several reactive oxygen species scavenging enzymes are expressed differentially in patients with primary osteoarthritis and those with non-loosening and aseptic loosening after total hip replacement (THR). The patients were grouped as A (n = 16, primary THR), B (n = 10, fixed THR but requiring revision for polyethylene wear) and C (n = 15, requiring revision due to aseptic loosening) to verify the involvement of the identified targets in aseptic loosening. When compared with Groups A and B, Group C patients exhibited significant up-regulation of transthyretin and superoxide dismutase 3, but down-regulation of glutathione peroxidase 2 in their hip synovial fluids. Also, higher levels of superoxide dismutase 2 and peroxiredoxin 2, but not superoxide dismutase 1, catalase and glutathione perioxidase 1, were consistently detected in the hip capsules of Group C patients. We propose that dysregulated reactive oxygen species-related enzymes may play an important role in the pathogenesis and progression of aseptic loosening after THR.
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Artroplastia de Reemplazo de Cadera/efectos adversos , Depuradores de Radicales Libres/metabolismo , Osteoartritis de la Cadera/enzimología , Falla de Prótesis/efectos adversos , Especies Reactivas de Oxígeno/metabolismo , Líquido Sinovial/química , Anciano , Western Blotting , Regulación hacia Abajo , Enzimas/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoartritis de la Cadera/cirugía , Proteómica , Regulación hacia ArribaRESUMEN
PURPOSE: Previous studies showed that cranberries and related products may play a role in the prevention of urinary tract infection. The objective of this study is to investigate composite UmayC, a cranberry composite with the herbal extract Acrobio TS and Acrobio GL, in its effectiveness for catheter-associated lower urinary tract infection in an animal model. MATERIALS AND METHODS: A catheter was inserted into the bladder of rats with or without bacterial suspension. The rats were randomly assigned to the treated or the control group, which, respectively, received or did not receive UmayC in chowder diet. The voiding pattern was recorded using a metabolic cage. Spleen lysate cytokines were measured in both groups with Western blot analysis. RESULTS: The voiding pattern remained nearly the same in UmayC-treated rats, even when they had a bacterial suspension-filled catheter inserted. The most significant cytokine changes in these rats were decreased spleen interleukin-10 and interleukin-6, which may indicate a diminished host response to infection under UmayC herbal composite treatment. CONCLUSIONS: UmayC herbal composite can reduce bladder irritation caused by catheter-related infection. The host immune response to infection may also be altered and improved by the preventive effectiveness of Acrobio TS- and Acrobio GL-composited cranberry.
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Antiinfecciosos/farmacología , Infecciones Relacionadas con Catéteres/prevención & control , Extractos Vegetales/farmacología , Preparaciones de Plantas/farmacología , Cateterismo Urinario/efectos adversos , Animales , Infecciones Relacionadas con Catéteres/inmunología , Infecciones Relacionadas con Catéteres/microbiología , Infecciones Relacionadas con Catéteres/fisiopatología , Citocinas/metabolismo , Modelos Animales de Enfermedad , Combinación de Medicamentos , Femenino , Humanos , Proyectos Piloto , Ratas , Ratas Sprague-Dawley , Bazo/efectos de los fármacos , Bazo/inmunología , Urodinámica/efectos de los fármacosRESUMEN
OBJECTIVE: To evaluate change in regional cerebral perfusion (rCBF) after median nerve stimulation (MNS) therapy in brain-damaged patients. METHODS: Twelve brain-damaged patients received 12 courses of MNS. Technetium-99m-ethyl cysteinate diethylester (99mTc-ECD) SPECT was performed before and 4 weeks after MNS initiation. Clinical response was assessed by Glasglow coma scale or clinical improvement. 12 MNS patients were grouped as good responder (GR) (n = 6) and poor responder (PR) (n = 6) according to therapy response. Scan images were analyzed by Statistical Parametric Mapping 2 (SPM2). RESULTS: In the GR group, paired Student t test between the pre- and post-MNS images showed 2 activation clusters over the left frontal and parietal lobes, including regions of the precentral gyrus, middle frontal gyrus, superior frontal gyrus, subgyral, inferior parietal lobule, and postcentral gyms (corresponding to Brodmann areas 4, 6, and 40). In the PR group, paired Student t test did not show any activation clusters. Clusters with significant differences between the GR and PR groups shared no mutual voxels with those clusters having significant regional effects after MNS in the GR group. CONCLUSIONS: Median nerve stimulation enhanced the rCBF of the contralateral motor and somatosensory cortex, which is compatible with the few previous studies using other modalities.
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Daño Encefálico Crónico/terapia , Circulación Cerebrovascular/efectos de la radiación , Terapia por Estimulación Eléctrica/métodos , Lateralidad Funcional/fisiología , Nervio Mediano/efectos de la radiación , Corteza Motora/irrigación sanguínea , Corteza Somatosensorial/irrigación sanguínea , Adolescente , Adulto , Anciano , Daño Encefálico Crónico/diagnóstico por imagen , Daño Encefálico Crónico/patología , Mapeo Encefálico , Circulación Cerebrovascular/fisiología , Femenino , Humanos , Masculino , Nervio Mediano/fisiología , Persona de Mediana Edad , Corteza Motora/diagnóstico por imagen , Radiofármacos , Corteza Somatosensorial/diagnóstico por imagen , Exametazima de Tecnecio Tc 99m , Tomografía Computarizada de Emisión de Fotón ÚnicoRESUMEN
OBJECTIVE: To explore the emerging tobacco epidemic in female workers in the growing micro-electronics industry of Taiwan. METHODS: Workers were surveyed regarding their smoking status, sociodemographics and work characteristics. In total, 1950 female employees in two large micro-electronics companies in Taiwan completed the survey. RESULTS: Approximately 9.3% of the female employees were occasional or daily smokers at the time of the survey. The prevalence of smoking was higher in those aged 16-19 years (20.9%), those not married (12.9%), those with a high school education or less (11.7%), those employed by Company A (11.7%), shift workers (14.3%), and those who had been in their present employment for 1 year or less (13.6%). Results of multivariate adjusted logistic regression indicated that younger age, lower level of education, shorter periods of employment with the company and shift working were the important factors in determining cigarette smoking among the study participants. The odds ratio of being a daily smoker was similar to that of being a current smoker. Marital status was the only significant variable when comparing former smokers with current smokers. CONCLUSIONS: Smoking prevalence in female workers in the two micro-electronics companies studied was much higher than previous reports have suggested about female smoking prevalence in Taiwan and China. We suggest that smoking is no longer a 'male problem' in Taiwan. Future smoking cessation and prevention programmes should target young working women as well as men.
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Electrónica , Industrias , Fumar/epidemiología , Salud de la Mujer , Adolescente , Adulto , Estudios Transversales , Femenino , Estado de Salud , Encuestas Epidemiológicas , Humanos , Persona de Mediana Edad , Encuestas y Cuestionarios , Taiwán/epidemiología , Recursos HumanosAsunto(s)
Economía Médica , Innovación Organizacional , Radiología/economía , Radiología/tendencias , HumanosRESUMEN
We sought to determine the possible neural conduction blockade of tramadol and whether there is evidence of localized neural toxicity with spinal somatosensory evoked potential (SSEP) measurements. Male Wistar rats were used. SSEP, elicited by supramaximally stimulating the hind paw and recorded from the thoracolumbar and the first and second lumbar interspinous ligaments, was monitored. SSEPs were obtained before drug application as the pretreatment baseline and measured every 15 min after treatment for 2 h and at 60-min intervals thereafter until SSEP returned to baseline or for another 4 h. Two small strips of Gelfoam (0.6 x 1.0 cm(2)) soaked with the drug were placed under and over the left sciatic nerve for a 30-min period. Gelfoam was prepared with tramadol hydrochloride (Tramal; the US trade name is Ultram) 5, 2.5, and 1.25 mg, diluted if needed with saline to a total volume of 100 microL (5%, 2.5%, and 1.25%, respectively). The control data were obtained from the right side limb with normal saline by following the same method. Spinal SSEPs were measured after 48 h to detect the late neural damage. The results showed that direct tramadol application on sciatic nerves dose-dependently reduced both the amplitude and conduction velocity of SSEPs when compared with the pretreatment baseline. All SSEPs returned to pretreatment baseline, and no significant changes of SSEP between bilateral limbs were noted at the 48-h measurements. No evidence of irreversible conduction blockade indicative of local neural toxicity was seen. Pretreatment with naloxone 1 mg/kg failed to block the changes of SSEP produced by 2.5% tramadol 100 microL. We conclude that tramadol exerts a local anesthetic-type effect on peripheral nerves.
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Analgésicos Opioides/farmacología , Potenciales Evocados Somatosensoriales/efectos de los fármacos , Nervio Ciático/efectos de los fármacos , Tramadol/farmacología , Analgésicos Opioides/administración & dosificación , Animales , Relación Dosis-Respuesta a Droga , Masculino , Ratas , Ratas Wistar , Tramadol/administración & dosificaciónRESUMEN
BACKGROUND AND OBJECTIVES: Brachial plexus block (BPB) has been cited as a treatment modality for complex regional pain syndrome type I (CRPS I) of the upper limb. However, there are no reports using axillary BPB with patient controlled analgesia (PCA) for the treatment of CRPS I. This report is based on the retrospective observations of the outcome and effects of axillary BPB with PCA in a patient with CRPS I. CASE REPORT: A 32-year-old man suffered from CRPS I of the right upper limb after surgical release of carpal tunnel syndrome of the right hand. Symptoms and signs over the right hand were alleviated under rehabilitation and conventional pharmacological management, but severe painful swelling of the right wrist persisted. Axillary BPB with PCA was performed on the 32nd postoperative day, which soon resulted in significant reduction of pain with gradual improvement of function of the right wrist. CONCLUSIONS: Axillary BPB with PCA may provide patients with CRPS I of the upper limb a feasible and effective treatment. .
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Analgesia Controlada por el Paciente , Plexo Braquial , Bloqueo Nervioso , Distrofia Simpática Refleja/terapia , Adulto , Anestésicos Locales/administración & dosificación , Bupivacaína/administración & dosificación , Humanos , Lidocaína/administración & dosificación , MasculinoRESUMEN
Zta, a transcription factor encoded by Epstein-Barr virus, is efficiently translated from a BRLF1-BZLF1 bicistronic mRNA. In this study, we demonstrate that inserting a stem-loop structure, which is known to block ribosome scanning, in the 5' region of the intercistronic region does not prevent the translation of a luciferase reporter protein from the bicistronic mRNA fused with the firefly luciferase gene, suggesting that the translation does not involve translation reinitiation. Mutational analyses reveal that the region between nucleotides 86 and 125 (region I) of the intercistronic region is essential for the translation. Meanwhile, the region between nucleotides 126 and 165 (region II) is also important since, without this region, the translation is inefficient. The region I sequence is partially complementary to the sequence between nucleotides 1489 and 1524 of 18S rRNA. This homology is significant, since disrupting the homology reduces the translation efficiency. Furthermore, luciferase is efficiently translated if the entire intercistronic region is replaced with a sequence complementary to the region between nucleotides 1401 and 1560 of the 18S rRNA. We hypothesize that Rta may assist 40S ribosome in recognizing the region I sequence to start a scanning process for Zta translation.
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Proteínas de Unión al ADN/biosíntesis , Proteínas de Unión al ADN/genética , Herpesvirus Humano 4/genética , Proteínas Inmediatas-Precoces/genética , Biosíntesis de Proteínas , ARN Mensajero/fisiología , Transactivadores/biosíntesis , Transactivadores/genética , Proteínas Virales , Secuencia de Bases , Humanos , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Regiones Promotoras Genéticas , ARN Mensajero/química , ARN Ribosómico 18S/química , Ribosomas/metabolismo , TATA Box , Células Tumorales CultivadasRESUMEN
OBJECTIVE: The objective of our study was to identify relevant and reliable CT signs of bowel injury, to determine the overall performance of CT in detection of bowel injuries, and to establish the effect of the training level of radiologists on this performance. MATERIALS AND METHODS: Abdominal CT scans of 112 patients with blunt abdominal trauma were prospectively and retrospectively reviewed. Fifty patients had proven bowel injuries (with or without other visceral injuries), whereas 62 patients had no bowel injury and comprised the comparison or control group. Thirty-one of the 62 patients in the comparison group had surgical proof of abdominal but not bowel or mesenteric injuries. The retrospective review of the 112 CT scans was performed randomly and individually by nine radiologists unaware of the diagnosis, including three faculty abdominal radiologists, three senior residents in training, and three junior residents in training. Individual performance and group performance were evaluated by receiver operating characteristic analysis, and interobserver agreement was tested. Individual CT signs as relevant predictors of bowel injury were identified by logistic regression. RESULTS: Relevant predictors of bowel injury included mesenteric infiltration, bowel wall thickening, extravasation of vascular or enteric contrast agent, and the presence free air. In the retrospective blinded review, CT showed good to excellent interobserver reliability for individual CT signs as well as for diagnosis of bowel and visceral injuries. Faculty radiologists tended to diagnose injuries with greater accuracy and confidence, but they showed significantly better performance than residents only in diagnosing duodenal perforation. For the prospective CT diagnosis of bowel injury, CT had a sensitivity of 64%, an accuracy of 82%, and a specificity of 97%. CONCLUSION: Bowel injuries are challenging to diagnose on CT. Radiologists with various levels of experience and expertise can achieve accurate and reproducible results using a variety of CT criteria.
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Intestinos/lesiones , Tomografía Computarizada por Rayos X , Traumatismos Abdominales/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Intestinos/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Estudios Prospectivos , Curva ROC , Estudios Retrospectivos , Heridas no Penetrantes/diagnóstico por imagenRESUMEN
OBJECTIVE: The purpose of this study was to use hepatic arterial phase helical CT to assess tumor vascularity and predict the likelihood of response to transcatheter arterial chemoembolization in patients with hepatocellular carcinoma. MATERIALS AND METHODS: Helical CT findings for 57 patients with hepatocellular carcinoma were classified into one of three patterns of vascularity on the basis of the degree of tumor or liver enhancement during the hepatic arterial phase. Cases in which hypervascular lesions predominated were classified as a type 1 pattern. Cases in which hypovascular lesions predominated were classified as a type 2 pattern. Patients were classified as responders or nonresponders on the basis of the changes of tumor size revealed on CT after three transcatheter arterial chemoembolization treatments. RESULTS: We classified the 57 patients as 37 responders (65%) and 20 nonresponders (35%). A statistically significant correlation between the type 1 hypervascular pattern and response to transcatheter arterial chemoembolization was seen; conversely, the type 2 hypovascular pattern correlated with nonresponse to transcatheter arterial chemoembolization (chi-square = 7.85, p = 0.02). Patients classified as responders lived significantly longer than those classified as nonresponders with 12-, 24-, and 36-month survival rates of 90%, 67%, and 36%, respectively, for responders and 70%, 17%, and 10%, respectively, for nonresponders. CONCLUSION: We found that patients who responded to transcatheter arterial chemoembolization had prolonged survival (p < 0.01). Response correlated closely with tumor vascularity as shown on hepatic arterial phase helical CT.
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Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica , Neoplasias Hepáticas/terapia , Tomografía Computarizada por Rayos X , Antineoplásicos/administración & dosificación , Carcinoma Hepatocelular/irrigación sanguínea , Carcinoma Hepatocelular/mortalidad , Estudios de Casos y Controles , Cisplatino/administración & dosificación , Medios de Contraste , Femenino , Esponja de Gelatina Absorbible , Humanos , Neoplasias Hepáticas/irrigación sanguínea , Neoplasias Hepáticas/mortalidad , Masculino , Microesferas , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Almidón , Tasa de Supervivencia , Tomografía Computarizada por Rayos X/métodosRESUMEN
The present study was designed to test whether tramadol is effective in the control of neuropathic pain in rats. Chronic constriction injury (CCI) of the sciatic nerve was induced over the left hind limb in male Sprague-Dawley rats. Identical surgery was performed on the opposite side except that the sciatic nerve was not ligated (sham surgery). Paw withdrawal latency (PWL) to heat was tested for each hind paw 1 day before surgery and on the 4th day after surgery to ensure the development of thermal hyperalgesia. In the acute treatment groups, saline or tramadol was administered subcutaneously at doses of 10, 20 or 30 mg/kg, and PWLs were measured 30, 60, 90, 120, 150 and 180 min after treatment. In the semi-chronic treatment groups, continuous systemic administration of tramadol 40 mg/kg/day or saline for 7 days was provided at a uniform rate via osmotic mini pumps. Tramadol reversed PWL in a dose-dependent manner in the acute treatment groups. PWLs were significantly reversed at 2 days after tramadol infusion, and this effect was sustained throughout the remainder of the treatment period in comparison with the saline group. Tramadol also resulted in a decreased sensitivity to thermal stimulus on the sham limb both in acute and semi-chronic administration. We conclude that both acute and semi-chronic tramadol treatment relieves thermal hyperalgesia effectively in rats with CCI of the sciatic nerve. This indicates that tramadol shows promise as a potential treatment for relief of neuropathic pain in humans.
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Analgésicos Opioides/uso terapéutico , Hiperalgesia/tratamiento farmacológico , Enfermedades del Sistema Nervioso Periférico/tratamiento farmacológico , Nervio Ciático , Tramadol/uso terapéutico , Analgésicos Opioides/administración & dosificación , Animales , Constricción Patológica , Calor/efectos adversos , Hiperalgesia/etiología , Masculino , Enfermedades del Sistema Nervioso Periférico/complicaciones , Ratas , Ratas Sprague-Dawley , Tramadol/administración & dosificaciónRESUMEN
BACKGROUND: Propofol has several properties beneficial to intracranial operation such as reduction in cerebral metabolic rate and cerebral blood flow (CBF) in a dose-dependent manner while leaving autoregulation intact. Several studies have demonstrated that the responsiveness of CBF to changes in arterial carbon dioxide tension (PaCO2) is maintained during propofol anesthesia in both humans and animals. These studies showed a significant difference in the CBF-CO2 reactivity slope between awake and propofol anaesthetized groups, but no comparison with different doses of propofol was made. To determine the dose effect of propofol on cerebrovascular CO2 reactivity, we used laser Doppler flowmetry (LDF) to detect the changes of CBF during propofol anesthesia. METHODS: Ten rabbits were studied using LDF on the parietal cortex. After surgical preparation, anesthesia was maintained with 66% N2O in O2, morphine 10 mg/kg and pancuronium. Three experimental conditions were studied sequentially with intravenous administration of the following drugs: (1) normal saline (control), (2) propofol 20 mg/kg/h i.v., (3) propofol 40 mg/kg/h i.v. Mean arterial pressure, rectal temperature and hematocrit were kept constant. The arterial carbon dioxide tension (PaCO2) was adjusted to three levels during each condition: 20-25 mmHg (hypocapnia), 35-40 mmHg (normocapnia) and 45-50 mmHg (hypercapnia). CBF was measured continuously and recorded after the target PaCO2 had been reached. RESULTS: There were no differences among all conditions in mean arterial pressure and heart rate. The changes of CBF as PaCO2 increased at the three different CO2 levels during each of the conditions were significantly different. The slope of CBF-CO2 reactivity among three different propofol doses was not significantly different. CONCLUSIONS: These data indicate that cerebral vasomotor responsiveness to CO2 during propofol anesthesia is preserved and that the slope of CBF-CO2 reactivity is independent of propofol doses as mean arterial blood pressure is maintained.
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Anestésicos Intravenosos/farmacología , Dióxido de Carbono/farmacología , Circulación Cerebrovascular/efectos de los fármacos , Propofol/farmacología , Animales , Presión Sanguínea/efectos de los fármacos , Relación Dosis-Respuesta a Droga , ConejosRESUMEN
OBJECTIVE: The purpose of this study was to evaluate a recently developed hardware and software system for CT scanning that generates images in real time and switches to helical CT scanning by either a visual cue or a region of interest (ROI) amplitude threshold. SUBJECTS AND METHODS: We randomly and prospectively divided 120 abdominal CT examinations into three groups. Two groups received 75 ml of contrast agent at 1.5 ml/sec. Helical CT scanning began after visualization of the contrast bolus arrival in the hepatic veins (visual cue triggering) (39 patients) or after reaching an ROI threshold (automated ROI threshold triggering) (39 patients). A third group served as a control group (42 patients) and received 150 ml of contrast agent at 1 ml/sec. Quality of hepatic enhancement was assessed objectively and subjectively. Comparisons were made after stratifying each group into three weight classes. RESULTS: Errors occurred in 12 (31%) of 39 examinations in the group with automated ROI threshold triggering. In that group, we found a significantly (p < .04) lower mean hepatic enhancement in two of three weight categories, and a significantly (p < .04) lower mean subjective scan quality in one of three weight categories, than we found in the group with visual cue triggering. CONCLUSION: Optimizing portal venous phase helical CT of the liver after a low-volume bolus of contrast agent and an injection rate of 1.5 ml/sec is best achieved by initiating helical CT scanning after visualizing the contrast bolus arrival within the liver rather than after reaching a preset attenuation threshold.
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Hígado/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste/administración & dosificación , Femenino , Humanos , Yohexol , Yotalamato de Meglumina , Neoplasias Hepáticas/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
The location of the BcLF1 promoter of Epstein-Barr virus (EBV) has been identified by primer extension, which indicates that the +1 site of the BcLF1 mRNA is located at nucleotide 137676 of the EBV genome. According to deletion analysis, the region upstream from nucleotide -38 is not essential for transcription of BcLF1. A 23 bp region in the promoter, from nucleotide -38 to -16, was identified as necessary for regulating the expression of BcLF1, i.e. the promoter activity is activated by 12-O-tetradecanoylphorbol 13-acetate but is repressed by phosphonoacetic acid. The results presented also demonstrate that the oriLyt sequence in cis is essential for enhancing the expression of BcLF1.