Biomedical subjects
Publications and source records attributed to A Campos.
We report the joint influence of creativity factors on mental imagery among 1361 university students of Fine Arts, Mathematics, and Geography and History. Creativity accounted for 1% of the variance in imagery among Fine Arts students, 4% among Mathematics students, 2% among Geography and History students, and 3% in the whole sample.
Electron probe X-ray microanalysis was used to determine the concentrations of P, S and K (Cp, CS, CK) in the gelatinous membrane of the mouse utricle. The otolithic membranes were plunge-frozen in liquid N2, freeze-dried and carbon-coated. Quantitative analysis was carried out with an energy dispersive detector using the peak-to-background ratio method and different concentrations of KH2PO4 and K2SO4 salts dissolved in dextran solutions to calibrate the microprobe. P, S and K were measured and their concentrations plotted as bar graphs to study the frequency distributions. Regression analysis revealed a dependence between the concentrations of P and K (CK = 1454.10 - 2.83 CP, r = -0.68745, p < 0.05), and P and S (CS = 43.18 + 0.23 CP, r = 0.66949, p < 0.05); however, no correlation was found between CK and CP (r = -0.25424). The findings obtained in the present study show an inverse relationship between P and K ions, and direct relationship between P and S in the gelatinous membrane of the utricle.
An electroneurographic study was made of the accessory nerve in 15 healthy subjects by conventional peripheral electrical stimulation and transcranial magnetic stimulation at three different levels: cortical contralateral (frontoparietal), homolateral occipital and at the base of the skull. The motor evoked potential (MEP) obtained by magnetic stimulation at the skull base exhibited greater latency and amplitude than that recorded by conventional peripheral electrical stimulation. The MEP obtained by stimulating at occipital level again exhibited a greater latency than that corresponding to skull base stimulation, but the amplitude was smaller. Finally, the MEP resulting from cortical stimulation failed to appear uniformly in all of the individuals studied. Its amplitude was smaller than in the previous cases, with a mean latency of 11.76 ms and a central conduction time of 7.5 ms. The magnetic stimulation technique allowed the efficient, painless, non-invasive and easily reproducible study of the motor pathway of the spinal nerve over its entire trajectory (motor cortex-motor neuron-muscle).
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Electron probe X-ray microanalysis was used to study the phosphorus concentration in the otolithic gelatinous membrane of the saccule and the utricle with scanning electron microscopy. The otolithic membranes were plunge-frozen in liquid N2 and freeze-dried. Quantitative analysis was carried out with an energy dispersive detector using the peak-to-background ratio method and different concentrations of KH2PO4 salts dissolved in dextran solutions. The otolithic gelatinous membrane consists of a 25-30 microns-thick layer overlying the cilia of the hair cells. Elements detected in the gelatinous membrane are: Na, P, S, Cl, K and Ca. Although Student's t-test did not show significant differences between saccular and utricular concentrations of phosphorus, the distribution of this element in the two organs was different. Regression analysis established that the concentrations of phosphorus in the saccular and utricular gelatinous membrane were dependent. The regression equation was: y = 18.02x2 + 133.9 (r = 0.83, P < 0.05) where y is the concentration of phosphorus in the utricle, and x2 the concentration of phosphorus in the saccule. The findings obtained in the present study could be related to structural differences in organic phosphate residues of the phosphoproteins associated to collagen, or to different polyphosphoinositide turnover rates in the cell membrane.
We used scanning electron microscopy to study the morphological surface patterns of cells that cover the attached gingiva and intervestibular papilla of the human oral gingival epithelium. Five patterns are described on the basis of the overall appearance of morphological surface markers: microvilli, parallel, fingerprint, reticular and pitted. Statistical analyses detected significant differences in the frequency of each pattern in both regions of the oral gingival epithelium, and showed the reticular and fingerprint types to predominate. We propose that our description of the different morphological surface types may be of use as a standard for subsequent cytological studies and characterizations of morphological alterations in diseased gingiva.
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Interleukin 2 (IL-2) plays a central role in the immune response and may be involved in the derangement of cellular immunoregulation of idiopathic IgA nephropathy (IgAN). The aim of this study was to investigate the serum levels and production of IL-2 from peripheral blood mononuclear cells (PBMC) and the distribution of IL-2 receptor cells and serum-soluble IL-2 receptor cells (sIL-2R) in patients with IgAN. Twenty-four patients with IgA nephropathy and 11 healthy controls (age and sex matched) were studied during an infection-free period without signs of clinical activity at the moment of the study. Serum IL-2 concentrations did not differ between patients and controls. The supernatant levels of IL-2 taken from 24-hr cultures of PBMC stimulated with phytohemagglutinin or tumor necrosis factor increased significantly in the patients but not in the controls. The percentage of IL-2R positive cells (CD25+) was increased in patients compared with controls. Moreover, IgAN patients had increased activated CD4+ lymphocytes when compared with the controls. Serum levels of sIL-2R were significantly higher in patients than in controls. There were no correlations among renal function, serum IgA levels, and urinary findings with cellular subsets or with IL-2 levels. However, sIL-2R was higher in the subgroup of patients with episodic macrohematuria and was closely related with the presence of red blood cells in the urinary sediment. We conclude that PBMC of IgA nephropathy patients have an overproduction of IL-2 after mitogenic stimulation, an increased helper T cell activity, increased IL-2R+ cells, and elevated serum levels of sIL-2R. These alterations are present in periods of apparent clinical inactivity. Finally, sIL-2R is closely related with hematuria, providing a good marker for disease activity. Our results suggest a pivotal role of IL-2 in cellular immune responses with regard to T cell activation in patients with IgAN.
Eleven anemic children and adolescents with a median age of 14 years (range six months-20 years) on chronic hemodialysis were treated with recombinant human erythropoietin (rHuEPO) intravenously three times a week for an average of 9.2 months. After eight weeks of therapy, hematocrit rose from 20.3 +/- 1.4% to 31.7 +/- 0.7% (0.20 +/- 0.01 to 0.31 +/- 0.007, p less than 0.001, mean +/- SEM). After reaching the target hematocrit of 30% to 33% (0.30 to 0.33), doses were adjusted individually. Blood transfusions were eliminated in all but one patient. All patients experienced an increase in appetite and energy level. Serum ferritin concentrations decreased in all patients who reached target hematocrit and seven required iron supplementation. Hypertension worsened in two patients and developed in two others. One patient's vascular access clotted. Dialysis efficiency and heparin requirements during dialysis did not change significantly. We conclude that rHuEPO is safe, effective, and should be recommended as treatment for anemia in children and adolescents on hemodialysis, but close monitoring for the development of hypertension and/or iron deficiency is necessary.
We studied variables that influenced rated emotionality value of words and the contribution of each one. 218 subjects rated each word in a list of 98 pairs of words (196 words), one concrete word and one abstract word in each pair, on imagery, concreteness, meaningfulness, and emotionality. Date of entry of each word into Spanish and word length were also examined. Stepwise multiple regression procedures were performed to evaluate the contribution made by each variable to over-all emotionality values. 39.06% of the emotionality variance was explained by imagery. Concreteness and meaningfulness values contributed 3.62% and 2.82%, respectively. Word length and date of entry were rejected in the final equation, as their contributions were minimal.
In the present paper are reported alterations of the cellular immunity found in 24 patients with immunoglobulin A nephropathy (IgAN). CD4+ and CD25+ cells were increased in patients in comparison with controls. The mean of interleukin-2 (IL-2) and interleukin-4 (IL-4) levels in sera were similar in patients and controls, but the levels of IL-2 in supernatants of stimulated peripheral blood mononuclear cells from patients were higher than those of controls. There were no correlations between renal function, serum IgA levels, urinary findings, cellular subsets, and IL-2 or IL-4 sera levels. These immunological data were also unrelated to the mode of clinical presentation. The results suggest a pivotal role of IL-2 in cellular immune response with regard to T-cell activation in patients with IgAN.
To examine the relationship between psychosocial functioning and psychopathology in epilepsy, a total 37-outpatient sample was assessed by means of both the Washington Psychosocial Seizure Inventory (WPSI) and the Minnesota Multiphasic Personality Inventory (MMPI). Patients came from an epilepsy program of the Hospital psiquiátrico, Chile. Disorders in several areas pertaining to psychosocial functioning and psychopathology were observed: Their distribution was quite similar to disorders previously reported when using both instruments. The WPSI scales showed a positive correlation with the MMPI's--a relevant correlation as far as the Overall Psychosocial Functioning, and Emotional adjustment sub-scales are concerned. The relationship between psychopathology and psychosocial functioning in epilepsy is discussed as well as the usefulness of the WPSI as a screening-test for the psychosocial assessment of epileptic subjects.
The effect of tissue preparation on calcium and potassium weight percent in the otoconial layer in the utricle and saccule was studied in four groups of OF1 mice with electron probe X-ray microanalysis. Glutaraldehyde and freeze-drying, glutaraldehyde and air-drying, air-drying, and cryo-fixation and freeze-drying were compared. Ca and K changed significantly in the utricle depending on the method used (P < 0.001), and K changed significantly in the saccule (P < 0.001). We chose cryo-fixation with freeze-drying for the quantitative analysis of the otolithic membrane because this method provided the highest values of Ca and K with minimum loss of Ca and K. Microcrystalline salt standards mounted on scanning electron microscopy holders were used for the quantification of Ca and K by the peak-to-local-background (P/B) ratio method. The P/B ratio in standards with reproducible results, when plotted against weight percent, gave a straight line for Ca (r = 0.99, P < 0.001) and K (r = 0.98, P < 0.001). The Ca and K weight percent in otoconia showed similar frequency distributions in the utricle and saccule.
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We hypothesized that, contrary to prior investigations, when concrete and abstract words have similar meanings, correlations of rated emotionality with ratings of imagery, concreteness, and meaningfulness would be positive. 106 subjects rated 48 pairs of words, such as friend and friendship, that differ in only one morpheme. The words of these pairs all differed in concreteness but little in core meaning. Subjects rated the words on imagery, concreteness, emotionality, and meaningfulness. Correlations among all variables were positive and significant: .72 for imagery and emotionality, .71 imagery and meaningfulness, .87 imagery and concreteness, .41 emotionality and meaningfulness, .57 emotionality and concreteness, and .62 meaningfulness and concreteness.
The direct unmediated electrochemical response of the tetrahemic cytochrome c3 isolated from sulfate reducers Desulfovibrio baculatus (DSM 1743) and D. vulgaris (strain Hildenborough), was evaluated using different electrode systems [graphite (edge cut), gold, semiconductor (InO2) and mercury)] and different electrochemical methods (cyclic voltammetry and differential pulse voltammetry). A computer program was developed for the theoretical simulation of a complete cyclic voltammetry curve, based on the method proposed by Nicholson and Shain [Nicholson, R.S. & Shain, I. (1964) Anal. Chem. 36, 706-723], using the Gauss-Legendre method for calculation of the integral equations. The experimental data obtained for this multi-redox center protein was deconvoluted in to the four redox components using theoretically generated cyclic voltammetry curves and the four mid-point reduction potentials determined. The pH dependence of the four reduction potentials was evaluated using the deconvolution method described.
Ischemic cerebral infarcts induce hypercoagulation and microthrombosis, thus leading to vessel occlusion and reduction of local cerebral blood flow. Antiaggregant therapy can reduce the formation of microthrombi. We tested the effect of acetylsalicylic acid (ASA) and triflusal (2-acetoxy-4-tri-fluoromethylbenzonic acid) on the formation of microthrombi after middle cerebral artery (MCA) occlusion. Six groups of rats, each consisting of six animals received either ASA or triflusal at dosages of 12.5, 25 or 50 mg/1,000 g b.wt./day. One control group was sham-operated, in another control group MCA occlusion was performed; both groups received no therapy. The number of microthrombi was counted 7 days after MCA occlusion on paraffin sections. The highest number of microthrombi was found in the group with MCAO and without therapy (mean 28 microthrombi/animal). In treated groups a reduction of the number of microthrombi could be stated. The strongest reduction was achieved in the group treated with 12.5 mg triflusal (mean 5.2). No statistic significant difference in the number of microthrombi was found between the groups treated with 12.5 mg triflusal and 50 mg ASA (mean 8.7) compared to sham-operated control animals (mean 4.3, p greater than 0.05). Treatment with 12.5 mg triflusal was superior to 50 mg ASA in preventing microthrombi formation (p less than 0.05). These results indicate, that in experimental brain ischemia the number of microthrombi can be effectively reduced by application of antiaggregatory drugs.
We hypothesized that correlations among ratings on concreteness, imagery, emotionality and interest of words are high stable, independent of present ratings by the 32 boys, 80 girls, and 92 adolescents.