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Biomedical subjects

M A Pallarés

Publications and source records attributed to M A Pallarés.

6 recordsLinked to original sources
PubMed2004

Rapid diagnosis of Staphylococcus aureus bacteremia using S. aureus PNA FISH.

In the study presented here, the performance of the S. aureus PNA FISH assay was evaluated using 285 blood cultures (from 104 patients) that had gram-positive cocci resembling staphylococci on Gram stain. The new molecular test is based on a fluorescence in situ hybridization assay using peptide nucleic acid probes targeting Staphylococcus aureus 16S rRNA and is designed for the rapid identification of Staphylococcus aureus directly from positive blood cultures. The sensitivity, specificity, and positive and negative predictive values of the S. aureus PNA FISH for the rapid identification of Staphylococcus aureus directly from positive blood culture bottles were 100, 99.4, 99.2 and 100%, respectively.

Bacteremia↗
PubMed1996

Oral intake of sweetened or sweetened alcoholic beverages and open-field behavior.

The relationship between the intake of sweetened alcoholic beverages and individual differences in an open field was assessed using an oral self-administration procedure in male Wistar rats (n = 41). After four sessions in the open field, rats were gradually reduced to 80% of their ad lib body weights over a 10-day period. Rats were then allowed to drink an alcohol-containing solution (10% v/v ethanol, 3% w/v glucose) (experimental group: n = 20) or a solution of glucose (3% w/v glucose) (control group: n = 21) for 1 h/day during 9 consecutive days. Experimental rats were divided into two groups on the basis of the mean daily ethanol dose ingested (g/kg/h) in the nine sessions. The high ethanol-consuming (HEI rats), when compared with the low ethanol-consuming rats (LEI rats), only showed a tendency (p = 0.062) towards fewer global number of rearings in the open field. No relationship between open-field defecation and ethanol intake was observed. With regard to the control rats, the higher consuming also showed lower number of rearings in the open field, similarly to the experimental rats. When we divided all experimental or control rats into two subgroups on the basis of the mean daily tap-water ingested during 23 h/day, no differences in the number of rearings were found. The results suggest that rearing in a novel environment could be a predictor of susceptibility to reinforcement by sweetened or palatable beverages.

Alcoholic Beverages↗
PubMed1995

Effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in rats.

We analyzed the effects of ketamine, a noncompetitive NMDA antagonist, on the acquisition of the lever-press response in the Skinner box and on motor performance both in the open field and in the inclined screen. Ninety-six adult male Wistar rats were assigned at random to eight different groups (n = 12). The first four groups received an acute intraperitoneal (IP) injection of: (a) physiological saline, (b) 4 mg/kg ketamine, (c) 8 mg/kg ketamine, or (d) 12 mg/kg ketamine, and the subjects were tested in a free lever-press response shaping in the Skinner box. The second four groups received the same substances and doses as the first four, but the subjects were tested for locomotor activity in an open field and tested immediately afterwards for motor performance in an 80 degrees inclined screen. Results showed that ketamine impaired the acquisition of the lever-press response in a dose-dependent manner, with no effects on ambulation in the open field nor on length of stay in the inclined screen. These results suggest that ketamine effects on the acquisition of the lever-press response cannot be attributed to a motor impairment, indicating a possible specific effect of ketamine on the associative learning acquisition.

Animals↗
PubMed1992

Effects of oral ethanol self-administration on the inhibition of the lever-press response in rats.

The effects of ethanol on the inhibition of a learned response were examined in adult, male Wistar rats from two treatment groups: oral self-administration of alcoholic solution (10% ethanol and 10% glucose in distilled water) and oral self-administration of sweet solution (10% glucose in distilled water). Subjects were food deprived and alcoholic or control solutions were available 1 h per day during 15 days. After this period, rats were tested in a two-bottle paradigm during 1 h per day and placed in the operant chambers immediately afterward. This phase went on for 19 days. Subjects were trained to lever press for food and were tested in a continuous reinforcement schedule, operant extinction, successive discrimination, and two-stimuli tests. Alcohol impaired the ability to inhibit previously reinforced responses but only in situations indicated by exteroceptive stimuli. Ethanol intake did not impair the lever-press behavior neither in the acquisition of the response nor in the continuous reinforcement schedule. These data suggest that the sedative effects of alcohol at this dose were not apparent in reinforcement situations, in contrast with extinction situations.

Animals↗
PubMedDate not supplied

EtOH self-administration on shuttle box avoidance learning and extinction in rats.

The effects of ethanol on the acquisition and extinction of the two-way active avoidance response were examined in adult, male Wistar rats from two treatment groups, oral self-administration of alcohol solution (10% v/v ethanol and 3% w/v glucose in distilled water) and oral self-administration of control solution (3% w/v glucose in distilled water). Alcohol or control solutions were available 1 h per day during 15 days simultaneously with food, with free water for the rest of the day. Blood was drawn in the last day of this phase to evaluate blood ethanol levels (BEL). After this period, rats were tested in a two-bottle paradigm for 1 h per day and placed in a shuttle box immediately afterwards. This phase went lasted for 10 days. Subjects were trained to avoid an electric foot shock in the first 5 days (15 trials per day). Following this, half of the subjects were tested in an "easy extinction with punishment" (EEP) and the other half in a "difficult extinction with punishment" (DEP) of the avoidance response for the last 5 days. Alcohol accelerates the avoidance responding acquisition, and no significant effects of alcohol were seen in the extinction phase. Data are discussed in terms of the specificity of the effects of alcohol on learning.

Animals↗