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1.
Clin Radiol ; 75(12): 962.e1-962.e8, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32888654

RESUMEN

AIM: To investigate the best cut-off percentage volume of delayed kinetics using magnetic resonance imaging (MRI) with computer-aided diagnosis (CAD) to reduce unnecessary biopsies in patients with newly diagnosed breast cancer. MATERIALS AND METHODS: Between January 2017 and December 2018, 94 malignant and 56 benign masses were analysed using MRI CAD. All malignant and benign masses measured <2 cm and were confirmed histopathologically. The optimal cut-off values for washout, plateau, and persistent components were determined using the maximum Youden Index. The positive predictive value (PPV) was analysed using morphological descriptors and combining the percentage volume of delayed kinetics. RESULTS: The area under the curve (AUC) was highest at ≤73% persistent component (AUC=0.759). In the subgroup analyses of masses <1 cm, the AUC was highest a plateau of >26% (AUC=0.697). When the persistent ≤73% criterion was applied to the lesions of C4a, the positive predictive value (PPV) increased from 61.9% to 72.44% with reduced false-negative cases and when applied to the lesions of C4a and C4b, the PPV increased from 61.9% to 78.1% with slightly increased false-negative cases. For subcentimetre lesions, the PPV increased from 46.77% to 54.72% with the same number of false-negative cases, when a plateau of >26% was applied to C4a, and the PPV increased from 46.77% to 61.36% with five false-negative cases when applied to C4a and C4b. CONCLUSION: The percentage volume of delayed kinetics has the potential to improve the PPV of breast MRI. When suspicious masses <2 cm do not show ≤73% persistence, follow-up rather than biopsy could be considered; however, to avoid increasing false-negative cases, delayed kinetic information should be used with caution and accurate margin assessment is essential.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Diagnóstico por Computador , Imagen por Resonancia Magnética/métodos , Adulto , Anciano , Biopsia/estadística & datos numéricos , Neoplasias de la Mama/patología , Reacciones Falso Positivas , Femenino , Humanos , Cinética , Persona de Mediana Edad , Estudios Retrospectivos , Carga Tumoral , Procedimientos Innecesarios/estadística & datos numéricos
2.
Clin Radiol ; 74(10): 817.e15-817.e21, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31362885

RESUMEN

AIM: To compare the diagnostic performance of abbreviated magnetic resonance imaging (MRI) and full diagnostic MRI with computer-aided diagnosis (CAD) system in patients with a personal history of breast cancer and to evaluate how the kinetic features affect the performance of two radiologists. MATERIALS AND METHODS: Between 1 January 2014 and 31 December 2017, 3,834 breast MRI examinations in 2,310 patients with a history of breast cancer comprised the study population. MRI images were reviewed retrospectively by two radiologists. First, two radiologists independently reviewed T1-weighted images scanned at 90 seconds after the contrast medium injection and T2-weighted images. After 6 months, the two readers reviewed contrast-enhanced T1-weighted images with five consecutive delayed images using CAD. The diagnostic performance of the abbreviated-sequence and full-sequence MRI were compared. RESULTS: Fifty-one intramammary recurrences were detected with breast MRI in 47 patients. Of the 51 tumour recurrences, 36 (70.6%) lesions occurred >3 years after initial cancer surgery and seven (13.7%) lesions at <2 years after initial surgery. The sensitivity and specificity were 92.2-94.1% and 97.6-98.6% on the abbreviated sequence and 94.1-96.1% and 97.9-98.3% on the full diagnostic MRI. Of 51 malignant lesions, six showed delayed persistent pattern, of which three lesions were non-mass enhancement and three lesions were small enhancing masses <1 cm. CONCLUSION: Overall diagnostic performances of abbreviated MRI and full diagnostic MRI were similar in both readers. The CAD-generated kinetic features could affect reader performance and the sensitivity could be improved or the specificity improved according to the reader.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Diagnóstico por Computador , Imagen por Resonancia Magnética/métodos , Recurrencia Local de Neoplasia/diagnóstico por imagen , Neoplasias de la Mama/terapia , Carcinoma in Situ/diagnóstico por imagen , Carcinoma Ductal de Mama/diagnóstico por imagen , Carcinoma Lobular/diagnóstico por imagen , Medios de Contraste , Femenino , Humanos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Sensibilidad y Especificidad
3.
Clin Radiol ; 72(9): 796.e1-796.e8, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28454640

RESUMEN

AIM: To investigate the advantage of digital tomosynthesis (DTS) over chest radiography (CXR) and dual-energy subtraction radiography (DES) for pulmonary nodule detection according to the location and size of solid simulated pulmonary nodules (SPNs). MATERIALS AND METHODS: Ninety-six SPNs of variable sizes were inserted into eight different regions of a lung phantom. These regions were further classified into two groups of danger and non-danger zones based on anatomical location influencing the detection of pulmonary nodules. The 96 cases with inserted SPNs and an additional nodule-free 96 control cases all underwent CXR, DES, and DTS examinations. Three observers independently reviewed all the images. The jackknife alternative free-response receiver operating characteristic was used to analyse diagnostic performance for each technique. RESULTS: DTS was superior to CXR and DES for detection of smaller SPNs, except in the retrodiaphragmatic and apical regions. DTS outperformed CXR and DES for detection of larger SPNs in the paramediastinal region. For 5- and 8-mm SPNs, DTS was superior to CXR and DES in the apical, paramediastinal and lateral pulmonary regions. In the retrodiaphragmatic region, the three techniques showed similar diagnostic performance regardless of the SPN size. DES was similar to DTS for detection of 8-mm SPN in the apical region. For 10- and 12-mm SPNs, CXR and DES showed similar diagnostic performance to DTS in the apical and lateral pulmonary regions; however, DTS was superior to CXR and DES in the paramediastinal region. CONCLUSIONS: DTS significantly improved the capability to detect synthetic pulmonary nodules compared with CXR and DES, for detection of smaller nodules in the apical, paramediastinal, and lateral pulmonary regions, and larger nodules located in the paramediastinal region in a thoracic phantom.


Asunto(s)
Intensificación de Imagen Radiográfica/métodos , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Radiografía Torácica/métodos , Nódulo Pulmonar Solitario/diagnóstico por imagen , Humanos , Fantasmas de Imagen , Sensibilidad y Especificidad
4.
J Appl Microbiol ; 122(3): 554-567, 2017 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-27914202

RESUMEN

The use of lactobacilli as probiotics in swine has been gaining attention due to their ability to improve growth performance and carcass quality, prevent gastrointestinal infection and most importantly, their 'generally recognized as safe' status. Previous studies support the potential of lactobacilli to regulate host immune systems, enhance gut metabolic capacities and maintain balance in the gut microbiota. Research on swine gut microbiota has revealed complex gut microbial community structure and showed the importance of Lactobacillus to the host's health. However, the species- and strain-specific characteristics of lactobacilli that confer probiotic benefits are still not well understood. The diversity of probiotic traits in a complex gut ecosystem makes it challenging to infer the relationships between specific functions of Lactobacillus sp. and host health. In this review, we provide an overview of how lactobacilli play a pivotal role in the swine gut ecosystem and identify key characteristics that influence gut microbial community structure and the health of pigs. In addition, based on recent and ongoing meta-omics and omics research on the gut microbiota of pigs, we suggest a workflow combining culture-dependent and culture-independent approaches for more effective selection of probiotic lactobacilli.


Asunto(s)
Microbioma Gastrointestinal , Lactobacillus , Probióticos/uso terapéutico , Porcinos/microbiología , Animales
5.
Br J Radiol ; 88(1052): 20150143, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26110204

RESUMEN

OBJECTIVE: To evaluate the diagnostic performance of ultrasound, MRI and fluorine-18 fludeoxyglucose positron emission tomography (¹8F-FDG PET)/CT for the diagnosis of metastatic axillary lymph node (ALN) after neoadjuvant chemotherapy (NAC) and to find out histopathological factors affecting the diagnostic performance of these imaging modalities. METHODS: From January 2012 to November 2014, 191 consecutive patients with breast cancer who underwent NAC before surgery were retrospectively reviewed. We included 139 patients with ALN metastasis that was confirmed on fine needle aspiration or core needle biopsy at initial diagnosis. RESULTS: After NAC, 39 (28%) patients showed negative conversion of ALN on surgical specimens of sentinel lymph node (LN) or ALN. The sensitivity of ultrasound, MRI and PET/CT was 50% (48/96), 72% (70/97) and 22% (16/73), respectively. The specificity of ultrasound, MRI and PET/CT was 77% (30/39), 54% (21/39) and 85% (22/26), respectively. The Az value of combination of ultrasound and PET/CT was the highest (0.634) followed by ultrasound (0.626) and combination of ultrasound, MRI and PET/CT (0.617). The size of tumour deposit in LN and oestrogen receptor was significantly associated with the diagnostic performance of ultrasound (p < 0.001 and p = 0.009, respectively) and MRI (p = 0.045 and p = 0.036, respectively). The percentage diameter decrease, size of tumour deposit in LN, progesterone receptor, HER2 and histological grade were significantly associated with the diagnostic performance of PET/CT (p = 0.023, p = 0.002, p = 0.036, p = 0.044 and p = 0.008, respectively). On multivariate logistic regression analysis, size of tumour deposit within LN was identified as being independently associated with diagnostic performance of ultrasound [odds ratio, 13.07; 95% confidence interval (CI), 2.95-57.96] and PET/CT (odds ratio, 6.47; 95% CI, 1.407-29.737). CONCLUSION: Combination of three imaging modalities showed the highest sensitivity, and PET/CT showed the highest specificity for the evaluation of ALN metastasis after NAC. Ultrasound alone or combination of ultrasound and PET/CT showed the highest positive-predictive value. The size of tumour deposit within ALN was significantly associated with diagnostic performance of ultrasound and PET/CT. ADVANCES IN KNOWLEDGE: This study is about the diagnostic performance of ultrasound, MRI, PET/CT and combination of each imaging modality for the evaluation of metastatic ALN after NAC. Of many histopathological factors, only the size of tumour deposit within ALN was an independent factor associated with the diagnostic performance of ultrasound and PET/CT.


Asunto(s)
Neoplasias de la Mama/patología , Imagen Multimodal/normas , Neoplasias de la Mama/tratamiento farmacológico , Quimioterapia Adyuvante , Femenino , Fluorodesoxiglucosa F18 , Humanos , Metástasis Linfática , Imagen por Resonancia Magnética/normas , Persona de Mediana Edad , Imagen Multimodal/métodos , Tomografía de Emisión de Positrones/normas , Curva ROC , Estudios Retrospectivos , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos X/normas , Ultrasonografía Mamaria/normas
6.
Br J Radiol ; 88(1046): 20140638, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25429418

RESUMEN

OBJECTIVE: The purpose of our study was to evaluate whether strong background parenchymal enhancement (BPE) would be a significant independent factor associated with positive resection margin in patients treated initially with breast-conserving surgery (BCS). METHODS: Retrospective evaluation of breast MRI examinations of 314 patients with breast cancer was carried out. Breast cancer was histologically confirmed in all patients who underwent BCS from January 2008 to December 2010. BPE was dichotomized into weak (minimal or mild) and strong (moderate or marked) enhancement for statistical analysis. Histopathological features of attained specimens were evaluated by an experienced pathologist and were also dichotomized for statistical analysis. RESULTS: On univariate analysis, positive extensive intraductal component (p < 0.001), strong BPE (p = 0.001) and human epidermal growth factor receptor 2 (HER2) positivity (p = 0.08) had significant association with positive surgical margin. Tumour size, axillary lymph node metastasis, nuclear grade, histological grade, lymphovascular invasion, oestrogen receptor and progesterone receptor did not show significant correlation with positive surgical margin. On multivariate analysis, the significant independent predictors were extensive intraductal component [odds ratio, 5.68; 95% confidence interval (CI), 2.72-11.82] and strong BPE (odds ratio, 2.39; 95% CI, 1.20-4.78). CONCLUSION: Strong BPE is a significant independent factor for positive resection margin along with positive extensive intraductal component, and performing MRI during the period of lower parenchymal enhancement is needed in patients with strong BPE. ADVANCES IN KNOWLEDGE: As far as we know, this is the first study to reveal that BPE is a significant independent factor associated with positive resection margin.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Mama/patología , Imagen por Resonancia Magnética/métodos , Mastectomía Segmentaria , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/cirugía , Femenino , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , Estudios Retrospectivos
7.
J Appl Microbiol ; 117(2): 485-97, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24807045

RESUMEN

AIMS: In this report, we characterized the probiotic potential of Lactobacillus mucosae LM1, focusing on its in vitro mucin-adhesion abilities. METHODS AND RESULTS: Screening assays were used to evaluate LM1. Previous studies on Lact. mucosae species have been performed, but few have examined the ability of this species to adhere to and colonize the intestinal mucosa. Thus, adhesion, aggregation and pathogen inhibition assays of LM1 along with microbial adhesion to solvents (MATS) assay were carried out in comparison with another putative probiotic, Lactobacillus johnsonii PF01, and the commercial strain, Lactobacillus rhamnosus GG. Based on MATS assay, the cell surfaces of the lactobacilli strains were found to be hydrophobic and highly electron-donating, but the average hydropathy (GRAVY) index of predicted surface-exposed proteins in the LM1 genome indicated that most were hydrophilic. LM1 showed the highest adhesion, aggregation and hydrophobicity among the strains tested and significantly inhibited the adhesion of Escherichia coli K88 and Salmonella enterica serovar Typhimurium KCCM 40253. Correlations among adhesion, aggregation and hydrophobicity, as well as between coaggregation and displacement of E. coli, were observed. CONCLUSIONS: Increased adhesion may not always correlate with increased pathogen inhibition due to various strain-specific mechanisms. Nevertheless, LM1 has promising probiotic properties that can be explored further using a genomics approach. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data on adhesion of LM1 strain showed a significant correlation between adhesion, hydrophobicity of cell surface and autoaggregation. This study gives basic knowledge for the elucidation of the adhesion mechanism of Lactobacillus sp. and prediction of its adherence in specific host models.


Asunto(s)
Adhesión Bacteriana , Lactobacillus/fisiología , Probióticos , Adhesinas Bacterianas/análisis , Metabolismo de los Hidratos de Carbono , Escherichia coli/fisiología , Interacciones Hidrofóbicas e Hidrofílicas , Mucosa Intestinal/microbiología , Lactobacillus/metabolismo , Mucinas/metabolismo
8.
Nuklearmedizin ; 53(3): 89-94, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24220324

RESUMEN

UNLABELLED: The aim of this study was to evaluate the diagnostic abilities of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography(PET/CT) compared with those of ultrasonography and magnetic resonance imaging (MRI) for axillary lymph node staging in breast cancer patients. PATIENTS, METHODS: Preoperative 18F-FDG PET/non-contrast CT, ultrasonography and MRI were performed in 215 women with breast cancer. Axillary lymph node dissection was performed in all patients and the diagnostic performance of each modality was evaluated using histopathologic assessments as the reference standard. ROC curves were compared to evaluate the diagnostic ability of several imaging modalities (i. e., ultrasonography, MRI and 18F-FDG PET/CT). RESULTS: In total, 132 patients (61.4%) had axillary lymph node metastasis. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for the detection of axillary lymph node metastasis were 72.3%, 77.3%, 66.7%, 81.6%, 75.3% for ultrasonography, 67.5%, 78.0%, 65.9%, 79.2%, 74.0% for MRI, and 62.7%, 88.6%, 77.6%, 79.1%, 78.6% for 18F-FDG PET/CT, respectively. There was no significant difference in diagnostic ability among the imaging modalities (i.e., ultrasonography, MRI and 18F-FDG PET/CT). The diagnostic ability of 18F-FDG PET/CT was significantly improved by combination with MRI (p = 0.0002) or ultrasonography (p < 0.0001). The combination of 18F-FDG PET/CT with ultrasonography had a similar diagnostic ability to that of all three modalities combined (18F-FDG PET/CT+ultrasonography+MRI, p = 0.05). CONCLUSION: The diagnostic performance of 18F-FDG PET/CT for detection of axillary node metastasis was not significantly different from that of ultrasonography or MRI in breast cancer patients. Combining 18F-FDG PET/CT with ultrasonography or MRI could improve the diagnostic performance compared to 18F-FDG PET/CT alone.


Asunto(s)
Neoplasias de la Mama/diagnóstico , Carcinoma/diagnóstico , Carcinoma/secundario , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía Mamaria/métodos , Adulto , Anciano , Anciano de 80 o más Años , Axila , Femenino , Fluorodesoxiglucosa F18 , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Estadificación de Neoplasias , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
9.
J Appl Microbiol ; 114(1): 121-33, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23035872

RESUMEN

AIMS: To clone, characterize and compare the bile salt hydrolase (BSH) genes of Lactobacillus johnsonii PF01. METHODS AND RESULTS: The BSH genes were amplified by polymerase chain reaction (PCR) using specific oligonucleotide primers, and the products were inserted into the pET21b expression vector. Escherichia coli BLR (DE3) cells were transformed with pET21b vectors containing the BSH genes and induced using 0·1 mmol l(-1) isopropylthiolgalactopyranoside. The overexpressed BSH enzymes were purified using a nickel-nitrilotriacetic acid (Ni(2+) -NTA) agarose column and their activities characterized. BSH A hydrolysed tauro-conjugated bile salts optimally at pH 5·0 and 55°C, whereas BSH C hydrolysed glyco-conjugated bile salts optimally at pH 5·0 and 70°C. The enzymes had no preferential activities towards a specific cholyl moiety. CONCLUSIONS: BSH enzymes vary in their substrate specificities and characteristics to broaden its activity. Despite the lack of conservation in their putative substrate-binding sites, these remain functional through motif conservation. SIGNIFICANCE AND IMPACT OF THE STUDY: This is to our knowledge the first report of isolation of BSH enzymes from a single strain, showing hydrolase activity towards either glyco-conjugated or tauro-conjugated bile salts. Future structural homology studies and site-directed mutagenesis of sites associated with substrate specificity may elucidate specificities of BSH enzymes.


Asunto(s)
Amidohidrolasas/metabolismo , Ácidos y Sales Biliares/metabolismo , Lactobacillus/enzimología , Amidohidrolasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Escherichia coli/genética , Escherichia coli/metabolismo , Genes Bacterianos , Concentración de Iones de Hidrógeno , Lactobacillus/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Especificidad por Sustrato , Temperatura
10.
Clin Radiol ; 67(8): 754-65, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22749383

RESUMEN

AIM: To assess the prognostic value of 64-section multidetector computed tomography (MDCT) to predict follow-up myocardial dysfunction and functional recovery after reperfusion therapy in patients with acute myocardial infarction (MI) as defined by echocardiography. MATERIALS AND METHODS: After reperfusion therapy for acute MI, 71 patients underwent two-phase contrast-enhanced MDCT and follow-up echocardiography. MDCT findings were compared with echocardiographic findings using kappa statistics. The areas under the receiver operating characteristic curves (AUCs) and the odds ratios (ORs) of early perfusion defects (EPD), delayed enhancement (DE), and residual perfusion defects (RPD) for predicting follow-up myocardial dysfunction and functional recovery were calculated on a segmental basis. RESULTS: The presence of transmural EPD (EPD(TM)) or RPD showed good agreement (k = 0.611 and 0.658, respectively) with follow-up myocardial dysfunction, while subendocardial EPD (EPD(sub)) or subendocardial DE (DE(sub)) showed fair agreement with follow-up myocardial dysfunction (k = 0.235 and 0.234, respectively). The AUC of RPD (0.796) was superior (p < 0.001 and 0.031, respectively) to those of EPD(TM) (0.761) and DE(TM) (0.771). The presence of EPD(TM), DE(TM), and RPD were significant, independent positive predictors of follow-up myocardial dysfunction (OR = 6.4, 1.9, and 9.8, respectively). EPD(TM) was a significant, independent negative predictor of myocardial functional recovery (OR = 0.13). CONCLUSION: Abnormal myocardial attenuation on two-phase MDCT after reperfusion therapy may provide promising information regarding myocardial viability in patients with acute MI.


Asunto(s)
Tomografía Computarizada Multidetector/métodos , Infarto del Miocardio/diagnóstico por imagen , Anciano , Medios de Contraste , Femenino , Estudios de Seguimiento , Humanos , Yohexol , Masculino , Persona de Mediana Edad , Infarto del Miocardio/terapia , Reperfusión Miocárdica/efectos adversos , Pronóstico , Ultrasonografía
11.
J Microsc ; 239(2): 87-91, 2010 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-20629914

RESUMEN

Spectrally encoded confocal microscopy and optical frequency domain imaging are two non-contact optical imaging technologies that provide images of tissue cellular and architectural morphology, which are both used for histopathological diagnosis. Although spectrally encoded confocal microscopy has better transverse resolution than optical frequency domain imaging, optical frequency domain imaging can penetrate deeper into tissues, which potentially enables the visualization of different morphologic features. We have developed a co-registered spectrally encoded confocal microscopy and optical frequency domain imaging system and have obtained preliminary images from human oesophageal biopsy samples to compare the capabilities of these imaging techniques for diagnosing oesophageal pathology.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Microscopía Confocal/métodos , Patología/métodos , Tomografía de Coherencia Óptica/métodos , Enfermedades del Esófago/diagnóstico , Esófago/patología , Humanos
12.
Radiologia ; 52(5): 469-72, 2010.
Artículo en Español | MEDLINE | ID: mdl-20483440

RESUMEN

Technological advances in multidetector computed tomography (MDCT) like second-generation dual source scanners have made it possible to evaluate myocardial perfusion as well as the anatomy of the coronary arteries in patients with suspected coronary disease; until recently, this application was confined to other imaging modalities. In this brief communication, we report a cardiac CT imaging protocol that combines CT coronary angiography with the analysis of ventricular function, perfusion, and myocardial viability in a single examination, thereby enabling a comprehensive assessment of coronary disease.


Asunto(s)
Enfermedad de la Arteria Coronaria/diagnóstico , Tomografía Computarizada por Rayos X , Adenosina , Angiografía Coronaria/métodos , Prueba de Esfuerzo/métodos , Humanos , Masculino , Persona de Mediana Edad
13.
J Anim Sci ; 87(11): 3589-95, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19648502

RESUMEN

This study was conducted to evaluate the effect of dietary administered delta-aminolevulinic acid (ALA) and vitamin C on the hematological profiles and performance of sows and sucking pigs and to determine if iron status could be improved by dietary administration of ALA. Seven days before parturition, 120 sows (Landrace x Yorkshire) were randomly assigned within parities to 1 of 4 dietary treatments. The lactation treatments were arranged as a 2 x 2 factorial with 2 ALA concentrations (0 or 10 mg/kg of feed, as fed) and 2 vitamin C concentrations (0 or 500 mg/kg of feed, as fed). After farrowing, daily feed allowance increased gradually, and sows had ad libitum access to feed by wk 2. Sows provided diets with ALA tended to consume more feed (P < 0.10) than sows fed diets that did not contain ALA. Conversely, backfat losses were less in sows that received the diets with ALA compared with those received the nonsupplemented diets (P < 0.05). Supplementation with ALA and vitamin C resulted in improved hematological profiles (total protein, albumin, and IgG) in sows (P < 0.05). The iron status in the blood and milk were also improved by ALA supplementation (P < 0.05). Moreover, the BW at weaning and the ADG during the sucking period increased in response to supplementation of ALA and vitamin C (P < 0.05). The blood iron status of piglets was also improved by ALA supplementation (P < 0.05). In conclusion, dietary supplementation of ALA can increase the blood iron status of sows and sucking pigs, as well as the iron transfer efficiency from sows to piglets through elevated milk iron concentrations.


Asunto(s)
Ácido Aminolevulínico/farmacología , Ácido Ascórbico/farmacología , Ingestión de Alimentos/efectos de los fármacos , Hierro/sangre , Sus scrofa/fisiología , Tejido Adiposo/efectos de los fármacos , Tejido Adiposo/crecimiento & desarrollo , Alimentación Animal , Animales , Animales Lactantes/sangre , Animales Lactantes/fisiología , Femenino , Hemoglobinas/análisis , Lactancia/efectos de los fármacos , Embarazo , Sus scrofa/sangre , Sus scrofa/crecimiento & desarrollo
14.
Knowl Inf Syst ; 9(2): 157-179, 2006 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-20351793

RESUMEN

In many application domains, there is a need for learning algorithms that can effectively exploit attribute value taxonomies (AVT)-hierarchical groupings of attribute values-to learn compact, comprehensible and accurate classifiers from data-including data that are partially specified. This paper describes AVT-NBL, a natural generalization of the naïve Bayes learner (NBL), for learning classifiers from AVT and data. Our experimental results show that AVT-NBL is able to generate classifiers that are substantially more compact and more accurate than those produced by NBL on a broad range of data sets with different percentages of partially specified values. We also show that AVT-NBL is more efficient in its use of training data: AVT-NBL produces classifiers that outperform those produced by NBL using substantially fewer training examples.

15.
J Ind Microbiol Biotechnol ; 27(3): 177-82, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11780789

RESUMEN

In the A-factor regulatory cascade leading to the onset of streptomycin biosynthesis and aerial mycelium formation in Streptomyces griseus, the A-factor receptor protein (ArpA) serves as a DNA-binding repressor and A-factor releases the repression by binding to ArpA and dissociating it from the DNA. Mutants defective in arpA therefore produce streptomycin and aerial hyphae in the absence of A-factor. A gene that inhibits streptomycin production and aerial hyphae formation in an arpA mutant was cloned on a high-copy-number plasmid and found to encode a eukaryotic-type adenylate cyclase (CyaA). Consistent with this, an exogenous supply of cAMP at high concentration almost abolished streptomycin production and aerial hyphae formation. On the other hand, cAMP at lower concentrations stimulated or accelerated these developmental processes. The effects of cAMP were detectable only in arpA mutants, and not in the wild -type strain; an exogenous supply of cAMP or cyaA disruption in the wild-type strain caused almost no effect on these phenotypes. Thus the effects of cAMP became apparent only in the arpA-defective background. cAMP at high concentrations inhibited stringent response factor ppGpp production, which is important for the onset of antibiotic biosynthesis. cAMP also influenced the timing of tyrosine phosphorylation of more than nine proteins. These findings show that a cAMP regulatory relay for physiological and morphological development functions in a concerted and interdependent way with other signal transduction pathways.


Asunto(s)
4-Butirolactona/análogos & derivados , 4-Butirolactona/metabolismo , Proteínas Bacterianas , AMP Cíclico/metabolismo , Regulación Bacteriana de la Expresión Génica , Streptomyces griseus/crecimiento & desarrollo , Streptomyces griseus/fisiología , Proteínas de Unión al ADN/metabolismo , Proteínas Represoras/metabolismo , Streptomyces griseus/genética , Estreptomicina/biosíntesis
16.
Mol Cells ; 10(5): 546-51, 2000 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-11101146

RESUMEN

While dopamine is likely to modulate hippocampal synaptic plasticity, there has been little information about how dopamine affects synaptic transmission in the hippocampus. The expression of IEGs including c-fos has been associated with late phase LTP in the CA1 region of the hippocampus. The induction of c-fos by dopaminergic receptor activation in the rat hippocampus was investigated by using semiquantitative RT-PCR and immunocytochemistry. The hippocampal slices which were not treated with dopamine showed little expression of c-fos mRNA. However, the induction of c-fos mRNA was detected as early as 5 min after dopamine treatment, peaked at 60 min, and remained elevated 5 h after treatment. Temporal profiles of increases in c-fos mRNA by R(+)-SKF-38393 (50 microM) and forskolin (50 microM) were similar to that of dopamine. An increase in [cAMP] was observed in dopamine-, SKF-, or forskolin-treated hippocampal slices. By immunocytochemical studies, control hippocampal cells showed little expression of c-Fos immunoreactivity. However, when cells were treated with dopamine, an increase in the expression of c-Fos immunoreactivity was observed after treatment for 2 h. The treatment of hippocampal neurons with R(+)-SKF38393 (50 microM) or forskolin (50 microM) also induced a significant increase in c-Fos expression. These results indicate that the dopamine D1 receptor-mediated cAMP dependent pathway is associated with the expression of c-Fos in the hippocampal neurons. These data are consistent with the possible role of endogenous dopamine on synaptic plasticity via the regulation of gene expression. Furthermore, these results imply that dopamine might control the process of memory storage in the hippocampus through gene expression.


Asunto(s)
2,3,4,5-Tetrahidro-7,8-dihidroxi-1-fenil-1H-3-benzazepina/farmacología , Dopamina/farmacología , Regulación de la Expresión Génica , Genes fos , Hipocampo/fisiología , Neuronas/fisiología , Proteínas Proto-Oncogénicas c-fos/genética , Receptores Dopaminérgicos/fisiología , Transcripción Genética/efectos de los fármacos , Animales , Células Cultivadas , Colforsina/farmacología , AMP Cíclico/metabolismo , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Hipocampo/citología , Inmunohistoquímica , Técnicas In Vitro , Cinética , Masculino , Neuronas/citología , Embarazo , Proteínas Proto-Oncogénicas c-fos/análisis , Ratas , Ratas Sprague-Dawley , Receptores Dopaminérgicos/efectos de los fármacos , Receptores de Dopamina D1/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa
17.
Mol Cells ; 9(6): 609-16, 1999 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-10672927

RESUMEN

To develop an orally delivered subunit vaccine for rotavirus infection, a trypsin cleavage product of VP4, recombinant VP8*, was expressed in Escherichia coli. The recombinant VP8* (rVP8*), purified by affinity chromatography, was reactive against human rotavirus positive serum in Western-blot analysis. To further evaluate the immunogenicity of the oral-delivered rVP8*, it was encapsulated with alginate-microsphere and administered in combination with cholera toxin (CT) as a mucosal adjuvant perorally into mice. The ELISPOT assay showed that the number of rVP8*-specific IgG1 antibody secreting cells increased about 3-fold and about 2-fold in spleen and Peyer's patch, respectively as compared to non-immune mice. In addition, the number of rVP8*-specific IgA antibody secreting cells increased about 2-fold in Peyer's patch. Finally, rVP8*-specific IgA antibody response was significantly enhanced in the intestinal fluids from the mice immunized perorally with encapsulated rVP8* and CT. Taken together, these results indicate that rVP8* possessed proper immunogenicity and it would be potentially useful as a subunit vaccine against rotavirus-associated disease through peroral immunization.


Asunto(s)
Proteínas de la Cápside , Cápside/inmunología , Inmunoglobulina A/inmunología , Intestinos/inmunología , Infecciones por Rotavirus/prevención & control , Vacunas Virales/administración & dosificación , Adyuvantes Inmunológicos , Administración Oral , Alginatos , Animales , Western Blotting , Cápside/química , Toxina del Cólera/inmunología , Composición de Medicamentos , Ensayo de Inmunoadsorción Enzimática , Escherichia coli , Humanos , Inmunización , Mucosa Intestinal/inmunología , Ratones , Microscopía Electrónica de Rastreo , Microesferas , Proteínas Recombinantes/inmunología , Tripsina
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