Biomedical subjects

F Mora

Publications and source records attributed to F Mora.

At least 37 records · Page 2Linked to original sources

PubMed2002

[Allergic rhinitis: evaluation of prick test positivity for German and American cockroaches (Blatella Germanica, Periplaneta Americana)].

Allergies are a widespread phenomenon and one that is in continuous expansion, especially in large cities. A heretofore underestimated allergen, at least in Italy, is the cockroach. Between April and June 2000, we administered a prick test (including the cockroach antigen in the allergen kit) to 163 patients. The prick test was executed utilizing histamine as the positive control and a normal diluent as the negative control; both indoor allergens (including dermatophagoids and dog and cat epithelium) and outdoor allergens (including trees, grasses, pollens and spores) were employed. The results obtained were evaluated by comparing the reaction provoked by these allergens to that of the histamine. About 20% of the patients who reacted to the other indoor allergens also tested positive to the cockroach antigen. Also on the basis of experiences previously carried out in other countries (United States, Korea, Japan, Turkey), the cockroach must be borne in mind as a possible significant cause of allergic reactions in Italy, too.

Adolescent↗

PubMed2002

[Behavior of serum IgE and IgA in patients with allergic rhinitis treated with iodine bromide thermal water].

The aim of this study was to test the effects of the iodine bromide water of the thermal baths of Salsomaggiore on patients suffering from specific nonseasonal rhinitis (Dermatophagoides Farinae and Dermatophagoides Pteronyssinus). The patients, 80 in all, were divided in two groups (group A and group B). All of the patients underwent rhinoscopic examination, anterior rhinomanometry, prick test, rast screening, total IgE assay together with that of the other immunoglobulins (IgA, IgM, IgG), mucociliary clearance evaluation and were asked to evaluate their degree of nasal obstruction, before and after 30 days of treatment. Group A carried out the experiment by applying endonasal Acqua Sal spray seven times a day for 30 days; group B used oily drops for the same time and with the same frequency. At the end of the trial period, the patients in group A showed a 100% improvement in their subjective perception of their symptomatology, in comparison with a 33% improvement in the control group. A characteristic decrease in the IgE and increase in the IgA was observed in the serum of the patients who had been treated with Acqua Sal spray. Iodine bromide water has a general and local anti-inflammatory effect, which is also due to the activation of the corticosurrenal system (with a relative increase in cortisol). The cleansing action of hypertonic water in the nasal cavities must also be cited, as it minimizes contact between the mucosa and allergens.

Adult↗

PubMed2002

[Computerized modification of Fukuda test].

OBJECTIVES: To study a new method to apply to Fukuda test in order to overcome the interpretational difficulty associated with a subjective evaluation of the exam. MATERIALS AND METHODS: During the exam, the patient wears a specially-designed headpiece, with a band at the back fitted with a sensor accommodating both a gyroscope and a bi-axial accelerometer. When asked to step in place, he does so in the Romberg position, eyes closed, successively rotating his head to the right and to the left. RESULTS: On analyzing the data obtained through the laterality variable (right/left oscillation) and time variable, it resulted that the difference between the averages referring to the laterality variable of right-handed and left-handed subjects was statistically significant (P = 0.001), while the difference between the averages of the time variable was not. CONCLUSIONS: To be able to propose an evaluation of the clinical validity of the test, further research must be carried out on pathological subjects, thus verifying the applicability of the method to the full.

Adolescent↗

PubMed2001

Dopamine release during stress in the prefrontal cortex of the rat decreases with age.

The effects of aging on the stress-induced increases of dopamine and the dopamine metabolites 3,4-dihydroxyphenylaectic acid (DOPAC) and homovalinic acid (HVA) in the medial prefrontal cortex of the awake rat were investigated using microdialysis. In young rats (2-3 months) handling stress produced an increase of dopamine by 205% and of the dopamine metabolites DOPAC by 120% and HVA by 155% of baseline as maximal increases. In middle-aged rats (14 months) the increase of dopamine was significantly lower than in young rats (155% of baseline), while in aged rats (30 months) stress produced no significant increases of dopamine in the prefrontal cortex. These results indicate that the effects of stress on dopamine release in the medial prefrontal cortex of the rat diminishes during the normal process of aging.

Aging↗

PubMed2001

Dopamine release in the prefrontal cortex during stress is reduced by the local activation of glutamate receptors.

Using microdialysis, we investigated the effects of the ionotropic glutamatergic agonists N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) on the stress-induced dopamine release in the prefrontal cortex of the freely moving rat. Handling-stress during 40 min increased extracellular dopamine by 195% and dopamine metabolites dihydroxyphenilacetic acid (DOPAC) by 120% and homovallinic acid (HVA) by 155% of baseline, but it did not modify extracellular glutamate, in the prefrontal cortex. Both NMDA (100 microM) and AMPA (20 microM), perfused through the microdialysis probe in the prefrontal cortex simultaneously to stress, significantly reduced the stress-induced dopamine release. These same doses or lower doses of NMDA (20 and 100 microM) and AMPA (1 and 20 microM) did not significantly modify basal dopamine release in the prefrontal cortex, but higher doses of these glutamatergic agonists significantly decreased (NMDA 500 microM) or increased (AMPA 100 microM) basal dopamine release in this area of the brain. These results show that the local activation of prefrontal glutamatergic ionotropic receptors reduces the stress-induced dopamine release in the prefrontal cortex of the rat.

3,4-Dihydroxyphenylacetic Acid↗

PubMed2001

Endogenous glutamate-taurine interaction in striatum and nucleus accumbens of the freely moving rat: studies during the normal process of aging.

Using microdialysis, the effects of endogenous glutamate on extracellular concentrations of taurine, in striatum and nucleus accumbens of the awake rat during the normal process of aging were investigated. The glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxylic acid (PDC) was perfused through the microdialysis probe to increase the endogenous concentration of glutamate. Young (2-4 months), middle aged (12-14 months), aged (27-32 months) and very aged (37 months) male Wistar rats were used. PDC (1, 2 and 4 mM) produced a dose-related increase of extracellular concentrations of glutamate and taurine in striatum and nucleus accumbens in all groups of age. Increases of glutamate, but not of taurine, decreased during aging in striatum. In nucleus accumbens there were no age-related changes in the increases of glutamate and taurine induced by PDC. In all age groups, increases of extracellular taurine were significantly correlated with increases of extracellular glutamate. However, when these taurine-glutamate correlations for all groups of age were compared, no statistical differences were found. These results show first that a decrease in the increases of glutamate produced by the glutamate reuptake inhibitor in striatum, but not in nucleus accumbens, is produced by age; second that glutamate-taurine interaction in striatum and nucleus accumbens does not change during the normal process of aging.

Aging↗

PubMed2001

Involvement of NMDA and AMPA/kainate receptors in the effects of endogenous glutamate on extracellular concentrations of dopamine and GABA in the nucleus accumbens of the awake rat.

We have investigated the effects of perfusion of the N-methyl-D-aspartate (NMDA) receptor antagonist 3-((R)-2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP) and the alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA)/kainate receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX) on the endogenous glutamate-evoked changes of extracellular dopamine and alpha-aminobutyric acid (GABA) in the nucleus accumbens of the awake rat. Local infusion of the glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxilic acid in the nucleus accumbens produced an increase in extracellular concentrations of glutamate, dopamine, and GABA. At the dose of 4 mM, the increase of extracellular glutamate, dopamine, and GABA were 3.73 +/- 0.46 microM (n = 8; p < 0.001), 4.70 +/- 0.92 nM (n = 6; p < 0.001) and 0.36 +/- 0.08 microM (n = 8; p < 0.001), respectively. Perfusion of the NMDA-receptor antagonist CPP attenuated the increases of dopamine by 90% (n = 5; p < 0.001), but enhanced the increases of GABA by 70% (n = 7; p < 0.01). Perfusion of the AMPA-receptor antagonist DNQX did not attenuate the increases of GABA. These results suggest a differential mediation of ionotropic glutamatergic receptors in the actions of endogenous glutamate on extracellular concentration of dopamine and GABA.

Animals↗

PubMed2001

Glutamatergic neurotransmission in aging: a critical perspective.

The effects of aging on glutamate neurotransmission in the brain is reviewed and evaluated. Glutamate is the neurotransmitter in most of the excitatory synapses and appears to be involved in functions such as motor behaviour, cognition and emotion, which alter with age. However, relatively few studies have been conducted to study the relationship between glutamate and aging of the brain. The studies presented here indicate the existence of a number of changes in the glutamatergic system during the normal process of aging. First, an age-related decrease of glutamate content in tissue from cerebral cortex and hippocampus has been reported, although it may be mainly a consequence of changes in metabolic activity rather than glutamatergic neurotransmission. On the other hand, studies in vitro and in vivo have shown no changes in glutamate release during aging. Since glutamate sampled in most of these studies is the result of a balance between release and uptake processes, the lack of changes in glutamate release may be due to compensatory changes in glutamate uptake. In fact, a reduced glutamate uptake capacity, as well as a loss in the number of high affinity glutamate transporters in glutamatergic terminals of aged rats, have been described. However, the most significant and consistent finding is the decrease in the density of glutamatergic NMDA receptors with age. A new perspective, in which glutamate interacts with other neurotransmitters to conform the substrates of specific circuits of the brain and its relevance to aging, is included in this review. In particular, studies from our laboratory suggest the existence of age-related changes in the interaction between glutamate and other neurotransmitters, e.g. dopamine and GABA, which are regionally specific.

Aging↗

PubMed2001

Glutamate-glutamine cycle and aging in striatum of the awake rat: effects of a glutamate transporter blocker.

This study investigated the effects of aging on the actions of a specific glutamate reuptake blocker, L-trans-pyrrolidine-2, 4-dicarboxylic acid (PDC), in extracellular glutamate and glutamine in striatum of the awake rat. Microdialysis experiments were performed on young (2-3 months), middle-aged (12-14 months), aged (27-32 months) and very aged (37 months) male Wistar rats. Local infusion of PDC (1-4 mM) in striatum increased the dialysate concentration of glutamate and decreased dialysate concentration of glutamine in all the age-groups. In young rats, decreases of dialysate glutamine were correlated with increases of dialysate glutamate. The same profile glutamine/glutamate as in young rats was found in middle-aged, aged and very aged rats, which suggests that the action of glutamate on the glutamate-glutamine cycle in striatum of the awake rat is not modified as a consequence of aging. We also found a significant correlation between the increases of glutamate produced by PDC and the basal dialysate concentration of glutamine, a relationship that did show a significant change with age. Although the significance of this latter finding remains to be elucidated, it may be important to understand the changes in glutamate-glutamine cycle during aging.

ATP-Binding Cassette Transporters↗

PubMed2001

Atrial activity enhancement by Wiener filtering using an artificial neural network.

This paper describes a novel technique for the cancellation of the ventricular activity for applications such as P-wave or atrial fibrillation detection. The procedure was thoroughly tested and compared with a previously published method, using quantitative measures of performance. The novel approach estimates, by means of a dynamic time delay neural network (TDNN), a time-varying, nonlinear transfer function between two ECG leads. Best results were obtained using an Elman TDNN with nine input samples and 20 neurons, employing a sigmoidal tangencial activation in the hidden layer and one linear neuron in the output stage. The method does not require a previous stage of QRS detection. The technique was quantitatively evaluated using the MIT-BIH arrhythmia database and compared with an adaptive cancellation scheme proposed in the literature. Results show the advantages of the proposed approach, and its robustness during noisy episodes and QRS morphology variations.

Algorithms↗

PubMed2001

Real-time ECG transmission via Internet for nonclinical applications.

Telemedicine is producing a great impact in the monitoring of patients located in remote nonclinical environments such as homes, elder communities, gymnasiums, schools, remote military bases, ships, and the like. A number of applications, ranging from data collection, to chronic patient surveillance, and even to the control of therapeutic procedures, are being implemented in many parts of the world. As part of this growing trend, this paper discusses the problems in electrocardiogram (ECG) real-time data acquisition, transmission, and visualization over the Internet. ECG signals are transmitted in real time from a patient in a remote nonclinical environment to the specialist in a hospital or clinic using the current capabilities and availability of the Internet. A prototype system is composed of a portable data acquisition and preprocessing module connected to the computer in the remote site via its RS-232 port, a Java-based client-server platform, and software modules to handle communication protocols between data acquisition module and the patient's personal computer, and to handle client-server communication. The purpose of the system is the provision of extended monitoring for patients under drug therapy after infarction, data collection in some particular cases, remote consultation, and low-cost ECG monitoring for the elderly.

Aged↗

PubMed2001

Outpatient management of upper digestive hemorrhage not associated with portal hypertension: a large prospective cohort.

OBJECTIVES: To evaluate the safety of outpatient management of upper GI hemorrhage (UGIH) not associated with portal hypertension. METHODS: A prospective cohort of 983 subjects who went to the Accident & Emergency Department (A&ED) of a University hospital in Valencia (Spain), for UGIH not associated with portal hypertension during 1994 to 1997 were evaluated. After evaluation in the A&ED, 216 patients (22%) were discharged and referred for outpatient follow-up, but 15 patients could not be located thus, reducing the follow-up to 201 subjects. The main outcome measures were rebleeding within 10 days, emergency surgery within 15 days, and mortality for any cause during the 30 days after the initial hemorrhaging episode. RESULTS: UGIH in subjects under outpatient care were less severe than those subjects in the hospitalized group. Hemorrhaging recurred in 7.3% of inpatients versus 0.5% of outpatients (p < 0.01); emergency surgery was required in 5.6% of the hospitalized patients and 0.5% of the outpatients (p < 0.01); a total of 20 deaths occurred in the hospitalized group (2.6%), while three (1.5%) occurred in outpatients (p = 0.26). After adjusting for several significant risk factors, outpatient management was not associated with outcomes that were worse. CONCLUSIONS: Treatment under an outpatient regime is a safe alternative for a large percentage of selected patients with UGIH not associated with portal hypertension.

Aged↗

PubMed2001

Presence of autoantibodies in the sera of Meniere's disease.

We examined the sera of patients with Meniere's disease for the presence of antibodies against 8 inner ear antigens by enzyme-linked immunosorbent assay (ELISA). One hundred eight patients with Meniere's disease and 28 control subjects were studied. The antibodies against chicken type II collagen, bovine type II collagen, the cyanogen bromide cleaved peptide 11 (CB11) of each, type IX and XI collagens, C-Raf, and tubulin were measured by ELISA. The sensitivity of each antigen was between 37% and 60% individually, and was 91% when all 8 inner ear antigens were combined. These results showed that 91% of Meniere's disease sera have antibody activities to 1 or more of these inner ear antigens. The results suggest that performing ELISA for these 8 inner ear antigens was useful as a diagnostic tool for Meniere's disease. Further study is required for elucidating the role of these antigens in the pathogenesis of Meniere's disease, which might eventually result in better therapy.

Autoantibodies↗

PubMed2000

Manometric comprobation of esophagogastric junction competence after Nissen fundoplication and its relation to the length of fundic wrap.

We present 98 patients operated on by two techniques of 360-degree fundoplication due to gastroesopagheal reflux disease and divided in two groups: Group I comprised those who were given a conventional valve 5 cm in length, and group II underwent a short fundoplication that did not surpass 1.5 cm. All were subjected to preoperative esophageal manometry, with determination of the pressure and length of the lower esophageal sphincter (LES) and the motor behavior of the esophageal body. The postoperative manometric results are analyzed, checking that after fundoplication there was a significant increase in tone and length of the LES (p < 0.00005); there were no differences between the two groups (p = 0.9920 and p = 0.2160, respectively). The motor function of the esophageal body did not change after surgery. We conclude that even the smallest length of the fundic wrap does not cause a reduction in the pressure and length of the manometric LES; that is, the antireflux effectiveness, measured by manometry, did not depend on the anterior length of the valvuloplasty.

Adult↗

PubMed2000

Effects of endogenous glutamate on extracellular concentrations of taurine in striatum and nucleus accumbens of the awake rat: involvement of NMDA and AMPA/kainate receptors.

Using microdialysis, the effects of endogenous glutamate on extracellular concentrations of taurine in striatum and nucleus accumbens of the awake rat were investigated. The glutamate uptake inhibitor L-transpyrrolidine-2,4-dicarboxylic acid (PDC) was used to increase the extracellular concentration of glutamate. PDC (1, 2 and 4mM) produced a dose-related increase of extracellular concentrations of glutamate and taurine in striatum and nucleus accumbens. Increases of extracellular taurine were significantly correlated with increases of extracellular glutamate, but not with PDC doses, which suggests that endogenous glutamate produced the observed increases of extracellular taurine in striatum and nucleus accumbens. The role of ionotropic glutamate receptors on the increases of taurine was also studied. In striatum, perfusion of the antagonists of NMDA and AMPA/kainate glutamate receptors attenuated the increases of extracellular taurine. AMPA/ kainate, but not NMDA receptors, also reduced the increases of extracellular taurine in nucleus accumbens. These results suggest that glutamate-taurine interactions exist in striatum and nucleus accumbens of the awake rat.

Animals↗

PubMed2000

Endogenous dopamine potentiates the effects of glutamate on extracellular GABA in the prefrontal cortex of the freely moving rat.

Using microdialysis, the effects of endogenous dopamine on basal extracellular concentrations of gamma-aminobutyric acid (GABA) and on the increases of GABA produced by glutamate were investigated in the medial prefrontal cortex of the awake rat. The dopamine uptake inhibitor nomifensine (1, 100 and 1000 microM), used to increase extracellular dopamine, produced a dose-related increase of dialysate dopamine (0.1-1 nM) but did not change dialysate concentrations of GABA or glutamate at any dose used. The glutamate uptake inhibitor L-trans-pyrrolidine-2,4-dicarboxilic acid (PDC; 0.5 and 2 mM), used to increase extracellular glutamate, produced a dose-related increase of dialysate glutamate (1.5-5.5 microM) and increased dialysate GABA by 125%. When a simultaneous increase of endogenous dopamine and glutamate was produced, the increases of dialysate GABA were significantly higher (185% of baseline) than those produced by glutamate alone. These effects on dialysate GABA were attenuated by the D2 receptor antagonist (-) sulpiride, but not by the D1 receptor antagonist SCH-23390, all of which suggests that extracellular dopamine plays an important role in modulating endogenous glutamate-GABA interactions in the prefrontal cortex of the rat.

Animals↗

PubMed2000

Overview of CARMEM: a new dynamic quantitative cardiac model for ECG monitoring and its adaptation to observed signals.

Different approaches have been proposed in order to achieve knowledge integration for coronary care monitoring applications, usually in the form of expert systems. The clinical impact of these expert systems, which are based only on "shallow" knowledge, has not been remarkable due to the difficulties associated with the construction and maintenance of a complete knowledge base. Model-based systems represent an alternative to these problems because they allow efficient integration of the "deep" knowledge on the underlying physiological phenomena being monitored. In this work, a brief review of existing model-based systems for cardiac rhythm interpretation is presented, followed by the description of a new system for Cardiac Arrhythmia Recognition by Model-Based ECG Matching (CARMEM). Fundamental characteristics of CARMEM are presented; in particular, its ability to provide online parameter adaptation to simulate complex rhythms and to match observed ECG signals. The proposed model can be useful for the explanation of the origin of cardiac arrhythmias and contribute towards their robust characterization in the context of coronary care units.

Artificial Intelligence↗

PubMed2000

Melatonin disrupts circadian rhythms of glutamate and GABA in the neostriatum of the aware rat: a microdialysis study.

The purpose of this study was to investigate possible circadian changes in extracellular concentrations of glutamate (GLU) and gamma-aminobutyric acid (GABA). and the influence of melatonin on the levels of these neurotransmitters in the neostriatum of awake rats using in vivo microdialysis. At the same time, the concentrations of the amino acids taurine (TAU), glutamine (GLN) and arginine (ARG), as well as dopamine (DA) and its metabolites 3, 4-dihydroxyphenyl acetic acid (DOPAC) and homovanillic acid (HVA), were measured in the extracellular fluid. When dialysates were collected over a 24-hr period (6 hr dark, 12 hr light, 6 hr dark), both GLU and GABA, without the infusion of melatonin, exhibited statistically significant rhythms, with higher levels of these constituents during the dark and lower levels during the day. Perfusion with melatonin (for 19 consecutive hours) prevented the daytime reductions in both GLU and GABA. Of the amino acids measured in the dialysates collected from the neostriatum of non-perfused rats, only ARG exhibited a significant change during the light:dark cycle; again, lowest concentrations were measured during the day. While melatonin perfusion did not statistically significantly influence neostriatal levels of TAU and ARG, GLN levels continued to drop during the infusion of the indoleamine. Dialysate concentrations of DA, DOPAC and HVA exhibited circadian rhythms which were not influenced by melatonin perfusion. The findings indicate there are differential effects of melatonin on extracellular neurotransmitter concentrations in the neostriatum of the awake rat. The results also suggest that the day:night variations in GLU and GABA may relate to daily changes in endogenous melatonin production, while DA and its metabolites are minimally influenced by this secretory product.

3,4-Dihydroxyphenylacetic Acid↗