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Biomedical subjects

J Bello

Publications and source records attributed to J Bello.

At least 19 recordsLinked to original sources
PubMed2006

Diffuse basal ganglia or thalamus hyperechogenicity in preterm infants.

OBJECTIVE: To determine the incidence and factors associated with diffuse basal ganglia or thalamus hyperechogenicity (BGTH) in preterm infants. STUDY DESIGN: (1) Review of serial neurosonograms among neonates with gestational age (GA) <34 weeks born at Weiler Hospital during a 21-month period; (2) Color Doppler flow imaging; (3) Case-control study using GA group-matched controls; and (4) Blind reading of CT scans or MRIs in patients with BGTH. RESULTS: Among 289 infants, 24 (8.3%) had diffuse BGTH. Color Doppler flow imaging was normal in nine patients. The incidence of diffuse BGTH was inversely related to GA (P<0.01). Logistic regression (n=96) showed that diffuse BGTH was significantly associated with requirement of high-frequency oscillation (HFO) (P=0.031), severe intraventricular hemorrhage (IVH) (P=0.004), hypotension requiring vasopressors (P=0.040), hypoglycemia (P=0.031) and male gender (P=0.014). Most patients with diffuse BGTH had normal basal ganglia and thalamus on CT/MRI, one had a hemorrhage, and one had an ischemic infarction. CONCLUSIONS: In our series, diffuse BGTH occurred in 8.3%, and was associated with factors similar to those previously reported. In contrast, several series have reported almost exclusively linear or punctuate hyperechoic foci, corresponding to hyperechogenicity of the lenticulostriate vessels. Our data provide further evidence to suggest that diffuse BGTH and hyperechogenicity of the lenticulostriate vessels are two different entities. Additional studies are required to determine the long-term significance of diffuse BGTH.

Basal Ganglia↗
PubMed2002

Influence of water pressure on the final quality of arabica espresso coffee. Application of multivariate analysis.

Water pressure is one of the most important factors which influence the final quality of espresso coffee (EC). However, few studies dealing with this issue have been found. The aim of this work was to study the effect of water pressure on the final quality of Arabica ECs as well as to classify ECs prepared at different pressures (7, 9, and 11 atm) according to their physicochemical and sensory characteristics, key odorants, by means of multivariate analysis. Statistically, principal component 1 (PC1) separated ECs prepared at 7 and 9 atm from ECs prepared at 11 atm and included the main foam and taste characteristics as well as some key odorants and flavor compounds. ECs prepared at 7 and 9 atm were separated by principal component 2 (PC2). Coffees prepared at 9 atm showed consistency of foam and a high percentage of key odorants related to freshness and fruity, malty, and buttery flavors. A simple discriminate function was obtained by discriminate analysis, allowing the classification of ECs prepared at three pressures into their respective groups with a success rate of 100%.

Analysis of Variance↗
PubMed2002

Induction of micronuclei in V79 cells after combined treatments with heterocyclic aromatic amines.

Heterocyclic aromatic amines (HAs) appear in foods rich in proteins when subjected to different cooking processes. These amines have been demonstrated to be mutagenic in bacteria; in eucaryotic cells, controversial results have been referred. The objective of this study is to evaluate the clastogenic and/or aneugenic capacity of three HAs--2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3-methylimidazo[4,5-f]quinoxaline (IQx), and 2-amino-3-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)--in isolated as well as in combined treatments. The micronucleus test in vitro was used on V79 cells in the presence and absence of metabolic activation. The duration of the treatment was 2 h, and cytochalasin B was added for 21 h to stop cytokinesis; then, micronuclei (MN) were counted in binucleated cells. In the presence of metabolic activation, the three amines showed a significant increase in the number of MN with respect to the negative control. The PhIP amine presented the highest values and it also resulted slightly active in the absence of metabolic activation, although these differences have not been considered to be significant. The combined treatments of these amines have shown that the effects attributed to them when administered together are those that are expected for a possible additive effect; the effect attributed to each HA separately is not potentiated nor inhibited.

Cell Line↗
PubMed2002

Contribution to the study of ochratoxin A in Spanish wines.

With the aim of assessing ochratoxin A (OTA) contamination in wines from a Spanish northern region and the influence of harvest conditions, the following samples were analysed: 40 wines (28 red and 12 white) obtained from grapes cultivated in three different places of the northern Spanish region of Navarra, but in different years, 20 samples in 1997 and 20 in 1998. Wine samples were provided by a viticultural experimental station with very consistent and controlled cultural and enological practices. A high-performance liquid chromatography (HPLC) method with fluorescence detection and immunoaffinity columns was employed (LOD = 0.05 ng ml(-1); method recovery = 101%). Eighty five per cent of the samples from 1997 showed OTA levels >0.05 ng ml(-1) (range 0.056-0.316 ng ml(-1)) and 15% of the samples from 1998 showed OTA levels above the LOD (range 0.074-0.193 ng ml(-1)). Averages detected in 1997 positive samples were 0.185 ng OTA ml(-1) wine (SD = 0.023) in white wine samples (n = 6) and 0.160 ng ml(-1) (SD = 0.119) in the red wine samples (n = 11). These differences between contamination by OTA in the samples from the two different years were attributed to the different quality of the grapes, due to the bad climate in 1997. The possibility of the loss of the mycotoxin was excluded by the analysis of OTA in contaminated wine during 12 months. This study showed that OTA is stable in wine for at least 1 year.

Chromatography, High Pressure Liquid↗
PubMed2002

Modulation of mutagenic activity in meat samples after deep-frying in vegetable oils.

Previous studies have been carried out on the influence of frying fats on the formation of food mutagens, but most of them have been performed on model systems or under cooking conditions that are more frequent in northern countries. The objective of this work was to study the overall mutagenic activity generated in hamburgers and frankfurters deep-fried under cooking conditions that are normal practice in Spain and other Mediterranean countries, in order to determine if there was any modulation of the mutagenic activity with respect to other cooking conditions previously studied. Hamburgers were prepared from beef purchased in a butcher's shop. Frankfurters as well as the oils [olive, marc olive ('orujo'), sunflower and soya bean oil] and butter were purchased in a local supermarket. The samples were fried in a teflon-coated frying pan at 170-180 degrees C for 10, 20 or 30 min. The mutagens were extracted and the mutagenic activity evaluated using the Salmonella mammalian microsome assay with strain TA98. Two independent assays were carried out for each experimental condition. All the hamburgers showed a mutagenic activity that was more than four times higher than that of the controls. Frankfurters showed a lower mutagenic activity than hamburgers (fried under the same conditions) because they have a lower protein content and a higher fat content. Hamburgers fried in olive oil for 10 min showed a significant increase in the number of revertants with respect to the other oils, probably due to the fact that the temperature reached was approximately 10 degrees C higher. Longer frying times significantly increased the number of revertants in samples fried in oils, except in olive oil, probably due to its lower content of polyunsaturated fatty acids.

Animals↗
PubMed2001

Silent infarcts in children with sickle cell anemia and abnormal cerebral artery velocity.

BACKGROUND: A substantial minority of neurologically normal children with sickle cell disease have lesions consistent with cerebral infarction as seen on magnetic resonance imaging (MRI). OBJECTIVES: To determine if transfusion therapy affects the rate at which silent infarcts develop and to evaluate the contribution of MRI of the brain to stroke prediction by transcranial Doppler (TCD) ultrasonography. STUDY DESIGN: Children with elevated TCD ultrasonographic velocity were randomized to receive long-term transfusion therapy or standard care. Magnetic resonance imaging of the brain was obtained at randomization, annually, and with clinical neurologic events. The risk for new silent lesions and/or stroke was compared for each treatment arm. RESULTS: Among the 37% of subjects with silent infarcts, those receiving standard care were significantly more likely to develop new silent lesions or stroke than were those who received transfusion therapy. For subjects receiving standard care, those with lesions at baseline were significantly more likely to develop stroke or new silent lesions than those whose MRI studies showed no abnormality. CONCLUSIONS: Transfusion therapy lowers the risk for new silent infarct or stroke for children having both abnormal TCD ultrasonographic velocity and silent infarct. However, those with both abnormalities who are not provided transfusion therapy are at higher risk for developing a new silent infarct or stroke than are those whose initial MRI showed no abnormality. The finding of a silent infarct reinforces the need for TCD ultrasonographic screening and consideration of transfusion therapy if the abnormalities are seen. Similarly, elevated TCD ultrasonographic velocity warrants MRI of the brain because children with both abnormalities seem to be at increased risk for developing new silent infarct or stroke.

Anemia, Sickle Cell↗
PubMed2001

The effect of medial frontal and posterior parietal demyelinating lesions on stroop interference.

Functional imaging has consistently shown that attention-related areas of medial frontal and posterior parietal cortices are active during the attentional conflict induced by color naming in the presence of distracting words (Stroop task). Such studies, however, have provided few details of the correlational nature between observed regional brain activations and reaction time delay occurring in this situation. We analyzed the effect of medial frontal and posterior parietal lesions on the Stroop response in a group of patients with multiple sclerosis, a neurological disorder in which Stroop response speed is affected to varying degrees. Forty-five patients were assessed using a computer-presented verbal version of the Stroop task and specific MRI protocol. Demyelination areas were measured on five anatomical divisions of the medial frontal white matter and on white matter of the posterior parietal lobe. We found that a combination of frontal and parietal lesion measurements accounted for 45% of the Stroop interference time variance. Patients with more right frontal than left parietal demyelination showed slowed Stroop responses, whereas the predominance of lesions in the left posterior parietal region was associated with a reduced Stroop interference. These results may contribute to defining the specific participation of these attention-related brain areas in the conflict of attention represented by the Stroop paradigm. They also help to explain the variability of the Stroop effect in multiple sclerosis patients and suggest that the Stroop test does not assess just a single cognitive operation, but rather the combined effect of anatomically segregated neural processes.

Adult↗
PubMed2001

Optimizing headspace temperature and time sampling for identification of volatile compounds in ground roasted Arabica coffee.

Equilibration time and temperature were the factors studied to choose the best conditions for analyzing volatiles in roasted ground Arabica coffee by a static headspace sampling extraction method. Three temperatures of equilibration were studied: 60, 80, and 90 degrees C. A larger quantity of volatile compounds was extracted at 90 degrees C than at 80 or 60 degrees C, although the same qualitative profile was found for each. The extraction of the volatile compounds was studied at seven different equilibration times: 30, 45, 60, 80, 100, 120, and 150 min. The best time of equilibration for headspace analysis of roasted ground Arabica coffee should be selected depending on the chemical class or compound studied. One hundred and twenty-two volatile compounds were identified, including 26 furans, 20 ketones, 20 pyrazines, 9 alcohols, 9 aldehydes, 8 esters, 6 pyrroles, 6 thiophenes, 4 sulfur compounds, 3 benzenic compounds, 2 phenolic compounds, 2 pyridines, 2 thiazoles, 1 oxazole, 1 lactone, 1 alkane, 1 alkene, and 1 acid.

Alcohols↗
PubMed2001

Multivariate methods for characterization and classification of espresso coffees from different botanical varieties and types of roast by foam, taste, and mouthfeel.

Three espresso coffee (EC) samples of different botanical varieties and types of roast were prepared in standard conditions using an experimental EC prototype: Arabica coffee, Robusta Natural blend, and Robusta Torrefacto blend (a special roast by adding sugar). The ECs were characterized with regard to the physical parameters, amount of total solids, total solids on filtrate, lipids, caffeine, trigonelline, and chlorogenic acids by HPLC, and sensory descriptive analysis related to foam appearance, taste, and mouthfeel. Principal component analysis (PCA) was applied to differentiate the EC samples. Arabica and Robusta samples were separated successfully by principal component 1 (55.3% of variance) including physicochemical and sensory parameters related to foam and taste of ECs. Torrefacto and Robusta Natural EC samples were separated by principal component 2 (20.7% of total variance) including mouthfeel and other attributes of color foam. Some interesting correlations among sensory and physicochemical variables were found. A very simple discriminate function was obtained by discriminate analysis allowing the classification of each EC sample into its respective group with a success rate of 100%.

Alkaloids↗
PubMed2001

Characterization of espresso coffee aroma by static headspace GC-MS and sensory flavor profile.

The aromas of three espresso coffee (EC) samples from different botanical varieties and types of roast (Arabica coffee, Robusta natural blend, and Robusta Torrefacto blend (special roast by adding sugar)) were studied by static headspace GC-MS and sensory flavor profile analysis. Seventy-seven compounds were identified in all of the EC samples. Among them, 13 key odorants have been quantified and correlated with their flavor notes by applying multivariate statistical methods. Some correlations have been found in the EC samples: some aldehydes with fruity flavors, diones with buttery flavors, and pyrazines with earthy/musty, roasty/burnt, and woody/papery flavors. By applying principal component analysis (PCA), Arabica and Robusta samples were separated successfully by principal component 1 (60.7% of variance), and Torrefacto and Natural Robusta EC samples were separated by principal component 2 (28.1% of total variance). With PCA, the aroma characterization of each EC sample could be observed. A very simple discriminant function using some key odorants was obtained by discriminant analysis, allowing the classification of each EC sample into its respective group with a success rate of 100%.

Coffee↗
PubMed2001

Determination of ochratoxin A in pig liver-derived pâtés by high-performance liquid chromatography.

A solid phase extraction procedure followed by HPLC analysis with fluorescence detection has been developed for ochratoxin A (OTA) in pâtés derived from pig liver. After a previous extraction of OTA with 60% acetonitrile, all the samples were purified through C8 columns. The percentage recovery was 85.7% and the lower limits calculated for accurate detection and quantitation were 0.56 ng/g and 0.84 ng/g respectively. The HPLC procedure showed a good linearity in the interval of equivalent OTA concentrations of 0.84 to 3 ng/g. Values <10% were obtained for precision in HPLC determinations performed (n = 3) and (n = 9). Stability of calibration standards and samples during the analytical procedure was also demonstrated. This method was successfully applied to 38 pig-derived pâtés and three samples were found to be positive with OTA levels above the detection limit. The highest concentration (1.77 ng/g) has been found in a home-made pâté.

Animals↗
PubMed2000

Beck Depression Inventory factors related to demyelinating lesions of the left arcuate fasciculus region.

This study was conducted to further establish the significance of the previously reported association between depressive symptoms and demyelinating lesions in the region of the left arcuate fasciculus in multiple sclerosis patients. The Beck Depression Inventory (BDI) was broken down into its main symptom categories on the basis of well-established factor analyses from the literature, and the correlation pattern between the resulting BDI subscores and lesion measurements was analyzed. We found that lesions of the left arcuate fasciculus region were selectively associated with BDI items expressing patients' Affective Symptoms and Somatic Complaints. Specifically, lesion measurements from this brain location accounted for 26% of symptom score variance of the BDI part that includes only these two factors. Performance Difficulties and Cognitive Distortions were not consistently associated with the lesion measurement. Performance Difficulties, however, showed a high correlation with the neurologic deficit detected in the physical examination. These results show that lesions in the left arcuate fasciculus region are associated with the core of the depressive syndrome rather than marginal symptoms and, thus, further suggest that this left suprainsular brain region involves white matter tracts relevant to mood regulation.

Adult↗
PubMed2000

Influence of the simultaneous addition of the protease flavourzyme and the lipase novozym 677BG on dry fermented sausage compounds extracted by SDE and analyzed by GC-MS.

A dry fermented sausage (chorizo de Pamplona) was elaborated with the simultaneous addition of a lipase (Novozym 677BG) and a protease (Flavourzyme) and ripened during 21 days, in contrast to the control without enzymes and ripened during 35 days. Faster and more intense lipolytic and proteolytic activities were observed in the modified sausage, despite its shorter maturation time. At the end of the ripening, a determination of the profile of compounds extracted by simultaneous distillation-extraction with dichloromethane was carried out. The total amounts of extracted compounds (expressed in milligrams of dodecane per gram of dry matter) were 2.5 in the sausage with enzymes and 1.9 in the control. The chemical groups showing increments due to the use of enzymes were esters (103.5% increment) and acids (87% increment) in both cases due to the greater presence of long-chain fatty acid products. However, development of substances originated from further degradation process of amino acids and free fatty acids did not seem to have taken place.

Animals↗
PubMed1999

Accelerated regression of brain metastases in patients receiving whole brain radiation and the topoisomerase II inhibitor, lucanthone.

PURPOSE: To determine if lucanthone crossed the blood-brain barrier in experimental animals; and to determine accelerated tumor regression of human brain metastases treated jointly with lucanthone and whole brain radiation. METHODS AND MATERIALS: The organ distribution of 3H lucanthone in mice and 125I lucanthone in rats was determined to learn if lucanthone crossed the blood-brain barrier. Size determinations were made of patients' brain metastases from magnetic resonance images or by computed tomography before and after treatment with 30 Gy whole brain radiation alone or with lucanthone. RESULTS: The time course of lucanthone's distribution in brain was identical to that in muscle and heart after intraperitoneal or intravenous administration in experimental animals. Lucanthone, therefore, readily crossed the blood-brain barrier in experimental animals. CONCLUSION: Compared with radiation alone, the tumor regression in patients with brain metastases treated with lucanthone and radiation was accelerated, approaching significance using a permutation test at p = 0.0536.

Animals↗
PubMed1999

Calcified scleral plaques imaged on orbital computed tomography.

PURPOSE: To identify calcified scleral plaques on orbital computed tomography. METHODS: We identified all orbital computed tomographic scans at one center from January 1, 1994, through December 31, 1994. Orbital computed tomographic scans of 145 patients were reviewed to determine the presence or absence of the typical appearance of calcified scleral plaques on film. RESULTS: Of the 145 scans reviewed, nine (6.2%) demonstrated calcified scleral plaques. Seven (22.6%) of 31 scans obtained on patients older than 70 years demonstrated calcified scleral plaques. CONCLUSIONS: Calcified plaques of the sclera commonly appear on orbital computed tomographic scans, especially in elderly patients. This entity should be included in the differential diagnosis of ocular calcifications. Familiarity with the computed tomographic findings of calcified scleral plaques may help ophthalmologists and radiologists distinguish them from intrascleral metallic foreign bodies.

Adolescent↗
PubMed1999

Carbonyl reductase and NADPH cytochrome P450 reductase activities in human tumoral versus normal tissues.

The use of bioreductive agents in enzyme-directed bioreductive therapy has been proposed to take advantage not only of hypoxia in tumours, but also of the presence of reductases that metabolise such compounds. In this study, we studied the activities of NADPH cytochrome P450 reductase (P450R) and carbonyl reductase (CR) in 17 human lung tumours and 18 human breast tumours, together with the corresponding normal tissues. For lung cancer but not for breast cancer there was a significant difference in the CR activity between normal and tumour tissue. CR activity was increased with respect to the normal tissue between 2-fold and 40-fold indicating heterogeneity in tumour samples. No relationship was found between CR activity and the histological type, tumoral grade or TNM stage of the tumours. Although some variation in P450R activity in tumoral versus normal tissues was found in the majority of the samples studied, no significant differences could be demonstrated.

Alcohol Oxidoreductases↗