Persea americana Glycolic Extract: In Vitro Study of Antimicrobial Activity against Candida albicans Biofilm and Cytotoxicity Evaluation.

This study evaluated the antifungal activity of Persea americana extract on Candida albicans biofilm and its cytotoxicity in macrophage culture (RAW 264.7). To determine the minimum inhibitory concentration (MIC), microdilution in broth (CLSI M27-S4 protocol) was performed. Thereafter, the concentrations of 12.5, 25, 50, 100, and 200 mg/mL (n = 10) with 5 min exposure were analyzed on mature biofilm in microplate wells for 48 h. Saline was used as control (n = 10). After treatment, biofilm cells were scraped off and dilutions were plated on Sabouraud dextrose agar. After incubation (37°C/48 h), the values of colony forming units per milliliter (CFU/mL) were converted to log10 and analyzed (ANOVA and Tukey test, 5%). The cytotoxicity of the P. americana extract was evaluated on macrophages by MTT assay. The MIC of the extract was 6.25 mg/mL and with 12.5 mg/mL there was elimination of 100% of planktonic cultures. Regarding the biofilms, a significant reduction (P < 0.001) of the biofilm at concentrations of 50 (0.580 ± 0.209 log10), 100 (0.998 ± 0.508 log10), and 200 mg/mL (1.093 ± 0.462 log10) was observed. The concentrations of 200 and 100 mg/mL were cytotoxic for macrophages, while the concentrations of 50, 25, and 12.5 mg/mL showed viability higher than 55%.

Oral microbial colonization in patients with systemic lupus erythematous: correlation with treatment and disease activity.

Treating patients with systemic lupus erythematosus (SLE) with steroids and immunosuppressive drugs may interfere in the presence of potentially opportunistic microorganisms in the oral cavity. The aim of this study was to evaluate the presence of Candida spp., Staphylococcus spp., Enterobacteria and Pseudomonas spp. in the oral cavity of SLE patients, compared with healthy controls. A group of 40 patients who had received therapy for at least 60 days was selected (19-53 years). For the control group, 40 healthy individuals matched for age, gender and use of partial prosthesis were selected. Oral rinse samples were collected and plated on specific culture media. After incubation, the number of colony forming units (CFU) was obtained and the isolates were identified at species level. Microbial counts were compared between SLE and control by analysis of variance (ANOVA) and Mann-Whitney (p < 0.05 significant). Microorganism counts in patients with and without immunosuppressive drugs, as well with active and inactive disease (according to SLEDAI score) were also compared. No significant differences in CFU/mL between SLE and control patients were observed (yeasts, p = 0.55; Staphylococci, p = 0.24; Enterobacteria/Pseudomonas spp., p = 0.26). No differences in microbial counts were observed regarding clinical parameters tested. The most frequent species isolated in the SLE group were Candida albicans, Staphylococcus epidermidis and Klebsiella oxytoca. In conclusion, no differences in frequency and microorganism levels were found between SLE patients and healthy individuals.

Posterodorsal septal lesions impair performance on both shift and stay working memory tasks.

Two groups of rats were trained preoperatively on either a shift or a stay problem in a T-maze. Training trials consisted of two runs, an "information run" in which a subject was forced to go down one of the two arms of the T-maze, followed immediately by a "choice run" in which the subject could choose either arm. In the shift condition, rats were rewarded with wet mash only for choosing the arm opposite the one they entered on the information run. In the stay condition, rats were rewarded for entering the arm that was entered on the information run. In both conditions, rats ultimately learned to perform with median accuracy of 100%, but the shift group reached this level of performance after fewer trials than the stay group. In a subsequent phase, the delay between information runs and choice runs was increased from 0 to 30, 60, 90, 210 and then decreased back to 0 s. Choice accuracy in both groups declined as the delay increased and returned to 100% at the 0-s delay. Half of the subjects in each condition then received either lesions of the posterodorsal septum-aimed at disconnecting the septum and hippocampus-or control surgery. Postoperative retention deficits resulted from posterodorsal septal lesions in both shift and stay conditions. There was some recovery of performance but no indication of "savings" during postoperative training. These results indicate that deficits in maze performance by rats with septo-hippocampal damage are not restricted to tasks that require alternation of spatial locations. This finding falsifies the notion that maze deficits reflect a spontaneous alternation deficit or changed "spatial strategy," but it supports the hypothesis of a working memory deficit in these animals.

Memory and the septo-hippocampal cholinergic system in the rat.

This study examined the effects of intrahippocampal injections of scopolamine (a muscarinic antagonist drug) on performance of a working-memory task (contingently reinforced T-maze alternation) and a reference-memory task (visual discrimination) by the same rats in the same maze. Rats in the first shipment were trained in delayed alternation, received bilateral implantation of cannulae aimed at the CA 3 field of the dorsal hippocampus, and were tested for retention with 1 microliter microinjections of scopolamine (35 micrograms) and saline on alternate days. These rats were then trained on visual discrimination and tested alternately under scopolamine or saline as described above. It was found that scopolamine impaired performance of delayed alternation to a greater extent than performance of visual discrimination. Data from rats in the second shipment replicated this finding, with the order of the tasks reversed, and, additionally, showed that delayed alternation, but not visual discrimination, was impaired at a dose of 12 micrograms/microliter. A dose of 4 micrograms/microliter had no effect on either task. It is concluded that performance of a working-memory task is significantly more sensitive to disruption of cholinergic mechanisms in the hippocampus than performance of a reference-memory task.

Operant behavior and drinking suppression in vasopressin-deficient rats (Brattleboro strain).

A group of Brattleboro rats homozygous for diabetes insipidus (DI) and a group of normal Long-Evans (LE) rats were deprived of water and tested on two tasks thought to measure reinforcement strength: a progressive-ratio schedule in an operant chamber and a quinine-induced drinking-suppression task. Since water-deprived DI rats are in more severe negative water balance than LE rats, it was hypothesized that they would sustain higher ratios than LE rats on the progressive-ratio schedule and would suppress drinking at higher quinine concentrations than LE rats. It was found that DI rats responded less than LE rats on the progressive-ratio schedule and that DI rats suppressed drinking as much as LE rats at each concentration of quinine used on the drinking-suppression test. It is suggested that the reinforcement strength of water for DI rats is not higher than that for LE rats.

T-maze alternation, response patterning, and septo-hippocampal circuitry in rats.

The effects of small electrolytic lesions in the posterodorsal septal area (aimed at the precommissural fornix) on acquisition and retention of either a spatio-temporal task (contingently reinforced T-maze alternation) or a temporal task (response patterning in a straight runway) were investigated in Long-Evans rats. Acquisition of T-maze alternation was impaired following posterodorsal septal lesions, but with extensive training there was evidence of learning. Postoperative retention of T-maze alternation was also impaired by posterodorsal septal lesions but, again, with continued practice the experimental animals relearned the task and came to perform as well as controls. Postoperative acquisition of response patterning in a runway was significantly but not greatly impaired by posterodorsal septal lesions. The experimental animals did pattern, but not as well as controls, even after substantial practice. Retention of response patterning was severely impaired following lesions in the posterodorsal septum but, as in the T-maze task, experimental animals improved significantly in performance with postoperative practice. The results were interpreted in the light of two recent formulations of the functions of the septo-hippocampal system: cognitive mapping and working memory. However, the data are not conclusive and suggest that inhibition theories of septo-hippocampal function are possibly relevant.

Septohippocampal system and the prelimbic sector of frontal cortex: a neuropsychological battery analysis in the rat.

Rats with lesions in the posterodorsal septal area (aimed at transecting the precommissural fornix) and rats with lesions in the prelimbic sector of the medial frontal cortex were tested postoperatively on a neuropsychological test battery comprised of the following tasks: time-spent-eating in two adaptation boxes, time-to-emerge and ambulation in an open field, general activity, contingently-reinforced (continuous) and schedule-specific (delayed non-matching-to-sample) T-maze alternation, visual and olfactory discrimination in a T-maze, temporal alternation (response patterning) and tactile Go/No-Go discrimination in a runway, approach-avoidance conflict in the runway, step-through inhibitory avoidance, one-way active avoidance, two-way active avoidance, and conditioned taste aversion. It was found that: (1) rats with septal (SEP) lesions spent more time eating than control (CON) rats and rats with lesions in prelimbic cortex (PRE). PRE rats did not differ from CON rats; (2) PRE rats emerged into an open field faster, and spent less time in home cage than CON and SEP rats. SEP rats stayed in home cage less than CON rats. PRE and SEP rats crossed more squares in the open field than CON rats; (3) SEP and PRE rats were more active than CON rats; (4) SEP rats performed the contigently-reinforced and schedule-specific T-maze alternation tasks worse than PRE rats, and PRE rats performed these tasks worse than CON rats. PRE, but not SEP, rats showed improvement with continued practice at brief intertrial and interrun intervals.(ABSTRACT TRUNCATED AT 400 WORDS)

Behavioral characteristics of vasopressin-deficient rats (Brattleboro strain).

A group of vasopressin-deficient rats (Brattleboro strain--DI) and a group of normal Long-Evans rats were successively evaluated on visual discrimination, olfactory discrimination, delayed alternation at short and long intertrial intervals (ITIs), approach-avoidance conflict in a straight runway, and open-field behavior. It was found that DI rats adapted more slowly than normal rats in the T-maze, in the straight runway, and they were slower to emerge into the open field. The DI rats were impaired relative to normal animals on the discrimination tasks (visual and olfactory), but they were not impaired on delayed alternation (at least for short ITIs). DI rats also showed better retention of the punishment effect in the approach-avoidance conflict test than normal animals. It is suggested that DI rats have defective reference-memory mechanisms, fairly intact working-memory processes and altered adaptability (timidity or cautiousness).

Lateral preferences in Brazilian adults: an analysis with the Edinburgh Inventory.

The lateral preferences of 959 Brazilian adults (471 males and 488 females) were assessed with the abbreviated form of the Edinburgh Inventory using the interview method. The behavioral validity of the inventory was evaluated by asking 36 subjects to perform the activities included in the inventory five months after the interview. The results showed that lateral preferences in Brazilian adults are similar to those reported from other countries. Additionally, effects of sex and age on hand preference were observed. However, area of professional occupation was not related to hand preference. Factor analysis of the Edinburgh Inventory (including items related to foot, eye and ear preference) revealed two factors. Factor I ("Motor-Related Laterality") included all handedness items and the foot-preference item, and Factor II ("Sensory-Related Laterality") included the eye and ear preference items. The Edinburgh Inventory was found to be reliable and valid in this population.

The behavior of vasopressin-deficient rats (Brattleboro strain).

Seven Brattleboro rats homozygous for diabetes insipidus (DI) and seven normal Long-Evans (LE) rats were tested on a neuropsychological test battery comprised of the following tasks: time-spent-eating in two adaptation boxes, time-to-emerge into an open field, adaptation to a T-maze, contingently reinforced T-maze alternation, olfactory and visual discrimination, runway learning, approach-avoidance conflict, step-through passive avoidance, prod burying, and stress-induced interference. It was found that DI rats adapted more slowly than LE rats to novel environments (e.g., adaptation box, T-maze, and runway), and DI rats were slower to emerge into an open field. However, DI rats performed as well as LE rats on all other tasks. These results suggest that DI rats have altered temperamental dispositions (timidity or cautiousness), normal working and reference memory, and similar susceptibility (compared to LE rats) to the interfering effects of inescapable stress.

The conners' Abbreviated Teacher Rating Scale: a factor analysis study in Brazil.

A total of 1068 school children were rated by their teachers on the Conners' Abbreviated Teacher Rating Scale (CATRS). The data were subjected to factor analysis using the principal components solution with orthogonal rotation and the varimax criterion. Three factors with eigenvalues greater than unity were extracted. The factor structure of the CATRS in Brazil was compared to reports from other countries.

Lesions in the septo-hippocampal system or prelimbic cortex of rats do not alter the performance of a T-maze visual discrimination task but disrupt the performance of a T-maze alternation task.

Rats with lesions in the posterodorsal septum (SEP), prelimbic cortex (PRE), and control operations (CON) were tested in a continuous alternation task (intertrial interval, ITI = 0 s) and a visual discrimination task (ITI ca 100 s) in a T-maze. CON rats performed the alternation task significantly better than rats with SEP or PRE lesions. PRE rats, but not SEP rats, were able to master the task with continued practice. The three groups did not differ in performance of the visual discrimination task. These data suggest that the septo-hippocampal system and, to a lesser extent, the prelimbic cortex are specifically involved in the memory processes necessary for the performance of an alternation but not a visual discrimination task in a T-maze.

Locomotor activity and one-way active avoidance after intrahippocampal injection of neurotransmitter antagonists.

Sixty-three rats with previous training in a T-maze, bilaterally implanted with cannulae directed toward the dorsal hippocampus, were used in this study. All rats received bilateral 1-microliter injections 20 min before testing for locomotor activity (day 1) and one-way active avoidance (day 3). The following drugs were injected into groups of 4 to 8 animals: scopolamine (9 or 18 micrograms/microliters), propranolol (5 or 10 micrograms/microliters), cimetidine (0.75 or 1.5 micrograms/microliters), sulpiride (5 or 10 micrograms/microliters), or vehicle (Krebs-Ringer). Locomotor activity was not changed by injection of any drug. However, intrahippocampal injections of scopolamine (9 micrograms/microliters) and sulpiride (10 micrograms/microliters) impaired avoidance behavior, particularly during the last five trials of the task. We conclude that muscarinic-cholinergic and D2-dopaminergic, but not beta-adrenergic or H2-histaminergic, mechanisms in the hippocampus are involved in the performance of one-way active avoidance behavior.

The Bender Gestalt test for 5- to 15-year old Brazilian children: norms and validity.

Norms for two modalities (normal and stress) of the Bender Gestalt test were developed for the neuropsychological assessment of children in the greater Rio de Janeiro area. For each modality, a measure of performance, a measure of speed and a measure of emotional disturbance were obtained. A total of 398 children (199 males and 199 females), 5 to 15 years old, who were attending a public school in Niterói were the subjects of this study. Analysis of the data revealed that age, but not sex, had a significant effect on performance, but not on speed, in both modalities such that older children made fewer errors than younger children. Also, the number of emotional indicators significantly decreased with age. Additionally, boys needed more time to complete the normal modality than girls, and showed a higher number of emotional indicators in both modalities. The Bender test was found to be valid in the sense that children who had failed at least one grade in school performed worse than those who had not. The number of emotional indicators was shown to be valid since it was significantly correlated with factors such as hyperactivity-conduct problem, and independent functioning, and inattention of the Composite Teacher Rating Scale (Brito GNO and Pinto RCA (1991). Journal of Clinical and Experimental Neuropsychology, 13: 417-418). We conclude that the Bender test is valid for use in schoolchildren, and the number of emotional indicators is valid as an index of psychopathology, but sex and age should be considered when using the norms in Brazil.

Developmental norms for the Gardner Steadiness Test and the Purdue Pegboard: a study with children of a metropolitan school in Brazil.

Norms for the Gardner Steadiness Test and the Purdue Pegboard were developed for the neuropsychological assessment of children in the metropolitan area of Rio de Janeiro. A computer-generated unbiased sample of 346 children with a mean age of 9.4 years (SD = 2.76), who were attending a large normal public school in this urban area, was the subject of this study. Two boys were removed from the study, one for refusing to participate and the other due to severe strabismus. Therefore, the final sample contained 344 children (173 boys and 171 girls). Sex and age of the child and hand preferred for writing, but not ethnic membership or social class, had significant effects on performance in the Gardner Steadiness Test and the Purdue Pegboard. Girls outperformed boys. Older children performed better than younger children. However, the predictive relationship between age of the child and neuropsychological performance included linear and curvilinear components. Comparison of the present results to data gathered in the United States revealed that the performance of this group of Brazilian children is equivalent to that of US children after Bonferroni's correction of the alpha level of significance. It is concluded that sex and age of the child and hand preferred for writing should be taken into account when using the normative data for the two instruments evaluated in the present study. Furthermore, the relevance of neurobehavioral antidotes for the obliteration of some of the probable neuropsychological effects of cultural deprivation in Brazilian public school children is hypothesized.

The cholinergic and dopaminergic systems of the prelimbic sector of frontal cortex and memory in the rat.

Rats were trained to perform delayed non-matching to sample (a working/representational memory task) and visual discrimination (a reference/dispositional memory task) in a T-maze, and implanted bilaterally with cannulae in the prelimbic cortex. The rats were tested postoperatively after bilateral 1-microliter injections of vehicle (Krebs-Ringer), sulpiride (10 micrograms/microliter) or scopolamine (18 micrograms/microliter). Sulpiride had no effect on the performance of either task, whereas scopolamine interfered only with the performance of delayed non-matching to sample. We conclude that dopaminergic mechanisms in the prelimbic cortex are not involved in either type of memory and that cholinergic, but not dopaminergic, mechanisms are important for working/representational memory processes.

Continuous and discrete T-maze alternation in rats: effects of intertrial and interrun intervals.

1. Recent concepts concerning animal memory have emphasized the kind of information processed in memory. Reference memory provides information relevant over several trials, i.e., it codes expectancy-based information. Working memory provides information critical for only one trial, i.e., it codes data-based information. Some investigators consider that a continuous alternation task in a T-maze depends on the reference memory of a series of left-right responses, whereas a discrete alternation task is thought to depend on working memory. 2. In the present report, we tested rats in a continuous alternation task with different intertrial intervals (ITI's). Rats were first subjected to 10 or 12 sessions at each of the following ITI's: 0, 55, 100, 200 and 600 s, and then tested at varying ITI's within each session for 12 sessions in the following sequence: 0, 55, 100, 200, 600 and 0 s. Next, the same rats were trained to perform discrete alternation with ITI's and interrun intervals (IRI's) varying across sessions but only IRI's changing within sessions, i.e., IRI = 0 or 55 with ITI = 0, 55, 100, 200 or 600 s across sessions, and IRI = 0, 55, 100, 200 and 600 s with ITI = 0 within sessions. 3. Rats performed both alternation tasks at high levels when ITI's and IRI's changed across sessions. However, when intervals changed within sessions, rats showed a better performance in the continuous task at intervals of 55, 100 and 200 s compared to their performance at these same intervals in the discrete task. In addition, for the discrete task with IRI's changing within sessions, errors probably due to proactive interference occurred more frequently with progressively increasing IRI's. 4. The hypothesis that performance of continuous alternation depends on reference memory and performance of discrete alternation depends on working memory is supported by these data.

Developmental norms for eight instruments used in the neuropsychological assessment of children: studies in Brazil.

Norms for a battery of instruments, including Denckla's and Garfield's tests of Motor Persistence, Benton's Right-Left Discrimination, two recall modalities (Immediate and Delayed) of the Bender Test, Wechsler's Digit Span, the Color Span Test and the Human Figure Drawing Test, were developed for the neuropsychological assessment of children in the greater Rio de Janeiro area. Additionally, the behavior of each child was assessed with the Composite Teacher Rating Scale (Brito GNO and Pinto RCA (1991) Journal of Clinical and Experimental Neuropsychology, 13: 417-418). A total of 398 children (199 boys and 199 girls balanced for age) with a mean age of 9.3 years (SD = 2.8), who were attending a public school in Niterói, were the subjects of this study. Gender and age had significant effects on performance which depended on the instrument. Nonachievers performed worse than achievers in most neuropsychological tests. Comparison of our data to the available counterparts in the United States revealed that American children outperformed Brazilian children on the Right-Left Discrimination, Forward Digit Span, Color Span and Human Figure Drawing Tests. Further analysis showed that the neurobehavioral data consist of different factorial dimensions, including Human Body Representation, Motor Persistence of the Legs, Orbito-Orobuccal Motor Persistence, Attention-Memory, Visuospatial Memory, Neuropsychomotor Speed, Hyperactivity-Inattention, and Anxiety-Negative Socialization. We conclude that gender and age should be taken into account when using the normative data for most of the instruments studied in the present report. Furthermore, we stress the need for major changes in the Brazilian public school system in order to foster the development of secondary cognitive abilities in our children.

The Conners Abbreviated Teacher Rating Scale: development of norms in Brazil.

Normative data for the Conners Abbreviated (10-item) Teacher Rating Scale (CATRS-10) derived from 1,068 children in Brazil are presented. Ratings of boys were higher than ratings of girls, and younger children had higher ratings than older children. Test-retest reliability data indicate that the CATRS-10 has acceptable reliability in Brazil but only when the same teacher rates the child at both test and retest (interval of 1 to 3 months). This study found that ratings at retest were significantly lower than ratings at first test whether or not the same teacher rated the child on both occasions. The CATRS-10 was shown to be a valid instrument in Brazil since children with behavioral problems requiring medical or psychological treatment were rated higher than children without such problems.

A behavioral assessment scale for attention deficit disorder in Brazilian children based on DSM-IIIR criteria.

A teacher scale based on DSM-III-R diagnostic criteria for attention deficit hyperactivity disorder (ADHD) was developed for the behavioral assessment of children in Brazil. A total of 2,082 children (782 males and 1,300 females) with a mean age of 11.2 years who were attending a public school in the greater Rio de Janeiro area were the subjects of this study. Two factors (Hyperactivity-Impulsivity and Inattention) were extracted from a principal-factor analysis conducted on the data, and the factor structure of the scale was found to be stable. Ratings of boys were higher than ratings of girls, and younger children had higher ratings than older children for both factors. Test-retest reliability for each item of the scale ranged from .56 to .70. The data are discussed in view of current controversies in the factor structure of teacher ratings of DSM-III-R ADHD symptoms.