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Biomedical subjects

J Barroso

Publications and source records attributed to J Barroso.

At least 19 recordsLinked to original sources
PubMed2005

Pattern of neuropsychological impairment in the early phase of relapsing-remitting multiple sclerosis.

To investigate the neuropsychological profile in the first few years post-onset of relapsing-remitting multiple sclerosis (MS) we carried out a comprehensive neuropsychological evaluation of 33 patients characterized by very short evolution of this disease, minimal levels of neurological disability and preserved general cognition. Thirty-three individually pair-matched controls were also evaluated. Patients performed as well as controls on many of the cognitive exploration measures. Nevertheless, the group of patients evinced a general slowness that affected motor execution and cognitive processing. Memory functions were characterized by preservation of working memory, retrieval or storage of information and a deficit at the acquisition phase in (verbal and visual) supraspan tasks. In addition, significant correlations were observed between some measures of information processing speed and memory. These results highlight the importance of studying cognitive deficits not only in the different subtypes of MS but also in different phases of the disease.

Adult↗
PubMed2002

Progression to AIDS, a clinical AIDS condition and mortality: psychosocial and physiological predictors.

BACKGROUND: The primary aim of this study is to examine prospectively the association of stressful life events, social support, depressive symptoms, anger, serum cortisol and lymphocyte subsets with changes in multiple measures of human immunodeficiency virus (HIV) disease progression. METHODS: Ninety-six HIV-infected gay men without symptoms or anti-retroviral medication use at baseline were studied every 6 months for up to 9 years. Disease progression was defined in three ways using the Centers for Disease Control (CDC) classifications (e.g. AIDS, clinical AIDS condition and mortality). Cox regression models with time-dependent covariates were used, adjusting for control variables (e.g. race, age, baseline, CD4 T cells and viral load, number of anti-retroviral medications). RESULTS: Higher cumulative average stressful life events and lower cumulative average social support predicted faster progression to both the CDC AIDS classification and a clinical AIDS condition. Higher anger scores and CD8 T cells were associated with faster progression to AIDS, and depressive symptoms were associated with faster development of an AIDS clinical condition. Higher levels of serum cortisol predicted all three measures of disease progression. CONCLUSIONS: These results suggest that stressful life events, dysphoric mood and limited social support are associated with more rapid clinical progression in HIV infection, with serum cortisol also exerting an independent effect on disease progression.

Acquired Immunodeficiency Syndrome↗
PubMed2002

(1-->6)-Beta-D-glucan as the cell wall binding site for Debaryomyces hansenii killer toxin.

AIMS: The aims of this study were to characterize the cell wall binding site of Debaryomyces hansenii killer toxin to provide a simple purification method and to determine some characteristics of this toxin. METHODS AND RESULTS: Various linear (1-->6)-beta-D-glucans of different origins were effective competitive inhibitors of the toxin action. Periodate oxidation and 1H-NMR was used to determine the receptor nature. Affinity chromatography on pustulan-Sepharose column was used to purify D. hansenii killer toxin, probably a 23-kDa protein. The killer toxin character was cureless. CONCLUSIONS: The investigation revealed that the killer toxin was mainly adsorbed by (1-->6)-beta-D-glucans. This is a low molecular weight protein, probably encoded by chromosomal genes. SIGNIFICANCE AND IMPACT OF THE STUDY: The specificity of the killer toxin for its receptor provides an effective means to purify the killer toxin. This study is the first to identify the cell wall binding site of this killer toxin, a toxin with properties of industrial relevance.

Binding Sites↗
PubMed2001

Production and characteristics of Debaryomyces hansenii killer toxin.

The optimal conditions for the production of the killer toxin of Debaryomyces hansenii CYC 1021 have been studied. The lethal activity of the killer toxin increased with the presence of NaCl in the medium used for testing the killing action. Production of the killer toxin was stimulated in the presence of proteins of complex culture media. Addition of nonionic detergents and other additives, such as dimethylsulfoxide enhanced killer toxin production significantly. Killer toxin secretion pattern followed the growth curve and reached its maximum activity at the early stationary phase. Optimal stability was observed at pH 4.5 and temperatures up to 20 degrees C. Above pH 4.5 a steep decrease of the stability was noted. The activity was hardly detectable at pH 5.1.

Cell Division↗
PubMed2001

In the field with the Beck depression inventory.

Qualitative methods are typically and formally used only in the earliest phases of instrument development to generate items. Once these items are generated, instrument development usually then moves into the testing phases, where quantitative methods prevail. The achievement of psychometric credibility is presumed to depend largely on quantitative measures of reliability and validity. Or if qualitative methods are employed, their use is masked, unfocused, and/or unplanned. The planned use of qualitative methods is critical in every phase of instrument use and in all studies that depend for their results on instruments, and their use is critical in illuminating problems with existing instruments. The authors illustrate these points by drawing on the first author's experiences in the field with the Beck Depression Inventory in her research program on managing fatigue in persons with HIV/AIDS.

Depression↗
PubMed2000

Comparison between African-American and white women in their beliefs about breast cancer and their health locus of control.

The purpose of this study was to examine the health beliefs of African-American and white women about breast cancer and locus of control, using the health belief model and the health locus of control construct. The Health Screening Questionnaire, developed by Sugarek, Deyo, and Holmes, was used to collect self-report data about health beliefs related to breast cancer and health locus of control. Participants included 197 white and 152 African-American women, between the ages of 19 and 93, recruited from various settings in central Florida. Significant differences were found between the two groups on all of the health beliefs about cancer items. The African-American women were significantly more likely to believe in chance, or to depend on powerful others for their health. Perceived susceptibility to cancer, doubts about the value of early diagnosis, and beliefs about the seriousness of breast cancer all were significantly associated with powerful other scores among African-American women. There was no relation between health beliefs and years of education for African-American women, but for white women, those with the least education were more likely to believe that death was inevitable with a cancer diagnosis. These results add to the information needed for the development of effective programs aimed at increasing breast cancer screening among African-American women.

Adult↗
PubMed2000

Metasynthesis of qualitative research on living with HIV infection.

Qualitative studies of people living with HIV infection are crucial for providing direction for practice and research because they provide the emic perspective. As more of these qualitative studies are conducted, researchers are challenged to develop ways to synthesize the findings for research and clinical practice. The purpose of the metasynthesis described in this article was to understand the experience of adults living with HIV infection as described in published research. Findings from the studies were categorized into six overarching metaphors: (a) finding meaning in HIV/AIDS, (b) shattered meaning, (c) human connectedness, (d) focusing on the self, (e) negotiating health care, and (f) dealing with stigma.

Adaptation, Psychological↗
PubMed1999

Hemispheric asymmetry in lexical decisions: the effects of grammatical class and imageability.

It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.

Adult↗
PubMed1997

Social support and long-term survivors of AIDS.

A naturalistic study design using ethnographic interviews was employed to elicit data about the phenomenon of being a long-term survivor of AIDS from 14 men and 6 women. Data were generated through multiple intensive open-ended interviews, demographic data sheets, and self-reported CD4 counts. Data were analyzed using latent and manifest content analysis techniques and the method of constant comparison. One of the dimensions that emerged from the data was "being in relation to others," the complex set of interpersonal relationships that have been renegotiated to maintain the reconstructed life. Specific ways of being in relation to others included dealing with one's family, renegotiating the friendship group, helping others with HIV, and developing a relationship with a higher power. The results of this study have implications for counseling people with HIV disease, and for nursing actions to enhance social support in this vulnerable group.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Individual and combined effects of triptoreline and gestrinone on experimental endometriosis in rats.

OBJECTIVES: To evaluate the effects of triptoreline, gestrinone, and both, on experimental endometriosis in rats. STUDY DESIGN: Experimental endometriosis was surgically induced in 225 Wistar rats. Of these, 202 rats showed at least one grown implant, 22 of which composed the control group, while 180 were treated with triptoreline, gestrinone, or both, for 28 days. The implants were evaluated again after 25 days. RESULTS: There were no changes in size in the control group. About 73% of the implants treated with triptoreline showed a high reduction (> 50%), vs. 51% with gestrinone (P < 0.0005) and 65% with both (P < 0.005). Triptoreline caused macroscopic resolution in 40% of the implants vs. 31% for gestrinone (not significant) and 26% for both substances (P < 0.05). In the triptoreline group, the mean size of the implants decreased by 65% between the 25th and 28th days, 58% between the 29th and the 35th, and 39% after the 36th day. This reduction was 51%, 36%, and 33%, respectively, in gestrinone group. CONCLUSIONS: Triptoreline was more effective than gestrinone, but perhaps not in the long run. Their association did not improve the results.

Animals↗
PubMed1995

Self-care activities of long-term survivors of acquired immunodeficiency syndrome.

The article reports the self-care activities of long-term survivors of acquired immunodeficiency syndrome (AIDS). A naturalistic, descriptive study design using ethnographic interviewing techniques was employed to interview 14 men and 6 women who had AIDS for at least 3 years. The self-care activities reported were globally labeled as taking care of oneself. Discontinuing negative health habits, undertaking health-promoting activities, being responsible for one's health, and decreasing stress were reported by participants as behaviors allowing them to survive and thrive with AIDS. This study offers nurses strategies to assist people in all stages of human immunodeficiency virus disease to find health within the context of their illness.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Hemispheric specialization for word classes with visual presentations and lexical decision task.

In the present paper we study the possible RH capabilities for the processing of adjectives and verbs of high frequency and medium imagery using a lexical decision task and a horizontal display. In the analysis of both RTs and mean errors, a RVF advantage is obtained. The interaction VF x Word Class did not reach significance. Therefore, we did not find evidence of differences in the visual-field effect for any syntactic class. These results support a LH superiority for the processing of both adjectives and verbs. For the nonword conditions (pseudoverbs and pseudoadjectives), no visual field differences were observed in either group. Methodological aspects are also discussed.

Adult↗
PubMed1991

Direct gene transfer into Actinidia deliciosa protoplasts: analysis of transient expression of the CAT gene using TLC autoradiography and a GC-MS-based method.

Chloramphenicol acetyl transferase (CAT) gene was used as a reporter gene to assess the conditions for polyethylene glycol (PEG)-mediated transfection of kiwifruit protoplasts. The effect of plasmid concentration and the presence of carrier DNA were each assessed by analysing CAT activity in transfected protoplasts using thin-layer chromatography (TLC) autoradiographic detection of acetylated chloramphenicol. A gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) non-radioactive method was developed for monitoring CAT gene activity. This method provides a high speed of analysis (30 min) and precise means of detecting acetylated products at the nanomolar level, enabling quantification at very low transfection rates. Using this method we optimized plasmid and PEG concentration and also assessed the effect of heat shock on transfection. The best CAT activity was obtained using 30% polyethylene glycol 4000 and by submitting protoplasts to heat shock (45 degrees C, 5 min) prior to transfection.

Cells, Cultured↗
PubMed1990

Semantic capabilities of the left and right cerebral hemispheres in categorization tasks: effects of verbal-pictorial presentation.

Two lateral tachistoscopic experiments were carried out to test semantic capabilities of the left and right cerebral hemispheres through categorization tasks with verbal and pictorial presentations. RVF advantages were obtained for verbal presentations in both category-membership and category-matching tasks. However, no significant visual-field differences were found for any pictorial presentation. We also found a higher degree of sensitiveness of the positive judgements for the detection of hemispheric differences and sex differences in patterns of functional asymmetries with a greater lateralization in males.

Attention↗
PubMed1989

Behavioral lateralization in rats and dopaminergic system: individual and population laterality.

Recently, we reported that practice facilitates the expression of the behavioral asymmetry in rats at individual and population levels. In the present study we investigated the side preference in the performance of four different tasks during 10 successive days. The practice increased individual laterality and internal consistency in all tasks. In addition, practice facilitated the expression of marked population laterality in two tasks (78.1% and 63.3% for right bias). The influence of dopaminergic systems on these behaviors was evaluated with apomorphine and with 6-hydroxydopamine lesions ipsi- and contralateral to the side preference. The results suggest that there is a presynaptic dominance contralateral to the side preference in the four tests. However, as influences of dopaminergic systems were different in each task and because the tests were unrelated, the results suggest that the behavioral laterality in rats, as in humans, is a phenomenon caused by different and relatively independent systems.

Animals↗
PubMed1987

Lateralization in male rats and dopaminergic system: evidence of right-side population bias.

Recent studies have reported population right-biased lateralization in rats, although with low percentages (between 54-59%). The present study investigated the spatial preference of rats in an electrified T-maze during successive days and the influence of ascending dopaminergic systems using apomorphine, a dopamine agonist, as well as ipsilateral and contralateral lesions on the side preference. Results showed a marked right-biased lateralization at both individual and population levels (85.71% of the rats presented a behavioral asymmetry, being 80% right-biased and 20% left-biased within the lateralized group). Also, the results suggest that there is a presynaptic dominance in the contralateral dopaminergic system to the spatial preference in the T-maze and postsynaptic dominance in the ipsilateral side.

Animals↗
PubMed1978

Mechanism of the pulmonary edema induced by intravenous injection of scorpion toxin in the rat.

The intravenous injection of purified scorpion toxin (tityustoxin, TsTX) into unanesthetized rats induces a severe systemic hypertension followed by a hemorrhagic edema of the lungs. The edema is focal or diffuse, whereas the hemorrhage is always focal and less prominent than the edema. Anesthesia of the rats prevents the appearance of pulmonary edema. It seems likely that this protective action of the anesthesia is due, at least in part, to an interference with the hypertension induced by TsTX. The pulmonary edema is prevented by bilateral adrenalectomy, guanethidine or phenoxybenzamine. It is suggested that the edema depends on a sympathetic-adrenal discharge and that catecholamines released by TsTX act on alpha adrenergic receptors. The mean kininogen content of the rat plasma, 1 h after TsTX injection, is not significantly different from that found in the control animals. The possible role played by kinins and other mediators in the early phases of the pulmonary edema induced by TsTX is under investigation.

Adrenalectomy↗