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Biomedical subjects

A Carvajal

Publications and source records attributed to A Carvajal.

At least 19 recordsLinked to original sources

Isotype-specific antibody-secreting cells in systemic and mucosal associated lymphoid tissues and antibody responses in serum of conventional pigs inoculated with PEDV.

An enzyme-linked immunospot (ELISPOT) has been developed to detect porcine epidemic diarrhea virus (PEDV)-specific antibody secreting cells (ASC) in gut associated lymphoid tissues (duodenum and ileum lamina propria and mesenteric lymph nodes) and systemic locations (spleen and blood) of conventional pigs so as to characterise the mucosal and systemic antibody response generated by the infection with PEDV. A total number of 28 eleven-day-old conventional pigs were orally inoculated with the field isolate of the PEDV strain CV-777. Diarrhea was observed in 32% of the pigs and virus shedding was demonstrated in 100% between postinoculation day (PID) 1 and 8. Serum IgG and IgA antibodies to PEDV were detected by isotype ELISA from PID 12 and 15, respectively, reaching maximum values at PID 32 (IgG) and 21 (IgA). PEDV specific IgM ASC occurred in all the tissues between PID 4 and 7, with the strongest response in the intestinal lamina propria. IgA and IgG ASC responses were evident in the intestinal lymphoid tissues from PID 21, the highest number of specific ASC corresponded to the duodenum lamina propria. In the systemic lymphoid tissues the number of IgG and IgA ASC detected were lower than in the mucosal tissues, however, in the blood, presence of IgA ASC was constantly detected from PID 14 until the end of the experiment. Memory antibody response to the PEDV was also studied by secondary in vitro stimulation of the mononuclear cells (MNC) isolated from mesenteric lymph nodes, spleen and blood. The memory B cell response was prominent at PID 21 and 25 and consisted in IgG and IgA ASC. To our knowledge, this is the first report to research into the presence and distribution of specific ASC in different locations of the systemic and the gut associated lymphoid tissues after a PEDV infection as well as the presence of memory B cells.

Animals↗

Availability of medicines in the European Union: results from the EURO-Medicines project.

OBJECTIVE: There is at present no comprehensive directory of medicines available in European countries. Such a directory would be valuable to policy analysts, clinicians, regulatory agencies, pharmaceutical companies and consumer groups. The aim of this project was to compile such a directory of all medicines marketed in each of the European Union member countries. METHODS: Lists of medicines for each country, compiled from several national sources, classified by Anatomical-Chemical-Therapeutic (ATC) code. Census date was late 1998. RESULTS: A comprehensive directory was created using data from 14 of the 15 European Union countries. Numbers of trade names and of active ingredients varied widely, from Germany with 18,554 and 1,973, respectively, to Denmark with 1,915 and 1,016, respectively. In individual therapeutic areas, there were variations in the numbers of active ingredients available: the least variation between countries was in antineoplastic medicines (ATC code L, maximum number available in any country 101, minimum 60) and wider variation in alimentary (ATC code A, maximum 256. minimum 103) or cardiovascular (ATC code C, maximum 269, minimum 112). Only 7% of all the active ingredients were available in all the countries studied. The Scandinavian countries had the greatest proportion of active ingredients (60%) available in all other countries. Each country had a number of active ingredients available only in that country Italy had the largest number of these. CONCLUSIONS: The directory illustrates the wide variations in the availability of medicines across the European Union. The range of drugs available in each country represents differences in regulatory and market policies, as well as cultural and historic differences. This directory lends itself to many further analyses.

Data Collection↗

Effect of nicorandil upon different guinea-pig and rat isolated organ preparations in vitro.

A study of the effect of nicorandil (N-2-(hydroxyethyl)nicotinamide nitrate, CAS 65141-46-0), a potassium channel and guanylatecyclase activator, upon preparations of rat was deferens and uterus, and guinea pig ileum was performed. Nicorandil does not modify rat isolated was deferens responses to noradrenaline (norepinephrine) and potassium. The drug exerts a non-competitive antagonist effect upon rat isolated uterus response to serotonin, histamine, oxytocin, and, at high concentrations, inhibits guinea-pig isolated ileum responses to acetylcholine, histamine, 4-aminopyridine and potassium.

Acetylcholine↗

Efficacy of fenfluramine and dexfenfluramine in the treatment of obesity: a meta-analysis.

A meta-analysis was conducted to estimate the difference of weight loss among patients treated with placebo and with fenfluramine or dexfenfluramine after 1, 2, 3, 6, and 12 months of treatment. Placebo-controlled, double-blind, randomized clinical trials, whose results were presented as weight loss by the placebo group and the drug-treated patient group, were selected for the analysis. For the pooled estimations, the method of the weighted means by the inverse of the variance was used. The association between the difference of means and several predictive variables was studied by means of weighted linear regression. Patients treated with fenfluramine or dexfenfluramine achieved a higher weight loss than those receiving placebo in all the periods studied. The greatest efficacy was observed after 3 months of treatment. Beyond this time, there is a decline in the effectiveness. Based on the efficacy data, treatments longer than 3 months would not be justified.

Appetite Depressants↗

Heart rate response during incremental exercise in master runners.

We analyzed the kinetics of heart rate (HR) response during incremental treadmill exercise in thirteen master runners (62 +/- 1 yr). The HR/running speed (HR/S) relationship showed the existence of a point of downward deflection (HR(d)) in only approximately 31% of the subjects. Resting echocardiographic evaluations showed similar heart dimensions in all of the subjects. In conclusion, HR does not seem to show a curvilinear response (downward deflection) in most aged athletes.

Aged↗

Polymorphisms in the presenilin 1 and presenilin 2 genes and risk for sporadic Alzheimer's disease.

We examined the possible involvement of polymorphisms of the presenilin 1 (PS1) and presenilin 2 (PS2) genes in the risk for sporadic Alzheimer's disease (AD), either through an independent effect or through interaction with the existing apolipoprotein E (ApoE) risk, in 211 AD cases and 188 age-matched control subjects. No significant differences were obtained in any of the comparisons relating the effect of the PS1 and PS2 polymorphisms; thus, these polymorphisms do not appear to be sufficient risk factors by themselves for sporadic AD. Although the ApoE varepsilon4 genotype is the only definite predictor of risk, homozygosity for either the 1 allele of the PS1 or the C allele of the PS2 genes may increase the risk conferred by the presence of an ApoE epsilon4 allele. Additionally, combination of PS1/11 and PS2/CC genotypes might have a small synergistic effect on the risk for AD.

Adult↗

[Anti-ulcer drug consumption in Spain].

OBJECTIVE: To check whether therapy to eradicate Helicobacter pylori has succeeded in reducing the consumption of traditional ulcer medication. DESIGN: A longitudinal, retrospective study of the use of medication. SETTING: Spain in the decade from 1988 to 1997. PARTICIPANTS: Pharmaceutical products belonging to the anatomical therapeutic group AO2B (for ulcers) and dispensed at the Social Security's expense. MEASUREMENTS AND MAIN RESULTS: Despite the widespread use of treatments to eradicate H. pylori, it was found that consumption of ulcer medication continued to increase markedly, from 5 daily doses per 1000 inhabitants in 1988 to 19 in 1997. In 1997 the two most frequently taken active principles in the group were omeprazole and ranitidine. Drugs indicated for gastric protection were also used much more. However, in absolute values, they stayed well below anti-H2 drugs and proton pump inhibitors. CONCLUSION: The introduction into Spain of therapy to eradicate H. pylori has failed to reduce the use of ulcer medication. The use of anti-H2 drugs and proton pump inhibitors for gastric protection may explain a part of the increase in consumption experienced by these two pharmacological groups.

Anti-Ulcer Agents↗

Opioid consumption in Spain--the significance of a regulatory measure.

OBJECTIVE: To investigate the impact of new regulatory measures on opioid consumption in Spain during the period 1985-1998. METHODS: A search in the ECOM (Especialidades Consumo de Medicamentos) database of the Ministry of Health was made for the 1985-1998 period. This database contains information about drug preparations prescribed in primary care in the National Health System in Spain. RESULTS: Since 1985-1998, the overall opioid consumption has increased tenfold, from 94.7 DDD (defined daily dose) per million inhabitants per day to more than 1000 DDD. For the five drugs that require a special prescription form (morphine, methadone, pethidine, tilidine and fentanyl), the consumption has increased 13.5-fold. CONCLUSION: A huge increase in opioid consumption has occurred. In this increase, changes in supply and, to a lesser extent, regulatory measures have played an important role.

Analgesics, Opioid↗

Breathing pattern in highly competitive cyclists during incremental exercise.

The purpose of our investigation was to analyse the breathing patterns of professional cyclists during incremental exercise from submaximal to maximal intensities. A group of 11 elite amateur male road cyclists [E, mean age 23 (SD 2) years, peak oxygen uptake (VO2peak) 73.8 (SD 5.0) ml kg(-1) min(-1)] and 14 professional male road cyclists [P, mean age 26 (SD 2) years, (VO2peak) 73.2 (SD 6.6) ml kg(-1) min(-1)] participated in this study. Each of the subjects performed an exercise test on a cycle ergometer following a ramp protocol (exercise intensity increases of 25 W x min(-1)) until the subject was exhausted. For each subject, the following parameters were recorded during the tests: oxygen consumption (VO2), carbon dioxide output (VCO2), pulmonary ventilation (VE), tidal volume (VT), breathing frequency (fb), ventilatory equivalents for oxygen (VE x VO2(-1)) and carbon dioxide (VE x VCO2(-1)), end-tidal partial pressure of oxygen and partial pressure of carbon dioxide, inspiratory (tI) and expiratory (tE) times, inspiratory duty cycle (tI/tTOT, where tTOT is the time for one respiratory cycle), and mean inspiratory flow rate (VT/tI). Mean values of VE were significantly higher in E at 300, 350 and 400 W (P < 0.05, P < 0.05 and P < 0.01, respectively); fb was also higher in E in most moderate-to-maximal intensities. On the other hand, VT showed a different pattern in both groups at near-to maximal intensities, since no plateau was observed in P. The response of tI and tE was also different. Finally, VT/tI and tI/tTOT showed a similar response in both P and E. It was concluded that the breathing pattern of the two groups differed mainly in two aspects: in the professional cyclists, VE increased at any exercise intensity as a result of increases in both VT and fb, with no evidence of tachypnoeic shift, and tE was prolonged in this group at high exercise intensities. In contrast, neither the central drive nor the timing component of respiration seem to have been significantly altered by the training demands of professional cycling.

Adult↗

Effect of venlafaxine hydrochloride in different preparations of isolated guinea-pig and rat organ tissues.

A study was undertaken to know better the effects of venlafaxine hydrochloride on the responses of isolated rat vas deferens to noradrenaline and dopamine, those of isolated rat uterus to serotonin and histamine, and those of isolated guinea-pig ileum to acetylcholine and histamine. Venlafaxine hydrochloride increased the response of rat vas deferens to noradrenaline but not to dopamine. Venlafaxine did not alter the response of rat isolated uterus to serotonin. In rat uterus, venlafaxine did not modify the response to histamine but was able to increase it in guinea-pig ileum. An anticholinergic effect was observed with the lowest concentration tested. Although venlafaxine is a selective serotonine reuptake inhibitor in the central nervous system, serotonin uptake was not seen in the rat uterus. The anticholinergic effects observed in the present study might be consistent with some of the side-effects associated with venlafaxine.

Acetylcholine↗

Heart rate response to professional road cycling: the Tour de France.

The aim of the present investigation was to evaluate the heart rate response of 8 professional cyclists (26+/-3 yr; 68.9+/-5.2 kg; V02max: 74.0+/-5.8 ml x kg(-1) x min(-1)) during the 3-week Tour de France as an indicator of exercise intensity. Subjects wore a heart rate telemeter during 22 competition stages and recorded data were analysed using computer software. Two reference heart rates (corresponding to the first and second ventilatory thresholds or VT1 and VT2) were used to establish three levels of exercise intensity defined as phases I ( VT2) is substantially lower than that of light, aerobic exercise (<VT1), a clear distinction must be made between the different type of stages (i.e. easy, flat parcours vs mountain stages or time trials) and the role of each cyclist in the team must be also considered.

Adult↗

Analysis of the aerobic-anaerobic transition in elite cyclists during incremental exercise with the use of electromyography.

OBJECTIVES: To investigate the validity and reliability of surface electromyography (EMG) as a new non-invasive determinant of the metabolic response to incremental exercise in elite cyclists. The relation between EMG activity and other more conventional methods for analysing the aerobic-anaerobic transition such as blood lactate measurements (lactate threshold (LT) and onset of blood lactate accumulation (OBLA)) and ventilatory parameters (ventilatory thresholds 1 and 2 (VT1 and VT2)) was studied. METHODS: Twenty eight elite road cyclists (age 24 (4) years; VO2MAX 69.9 (6.4) ml/kg/min; values mean (SD)) were selected as subjects. Each of them performed a ramp protocol (starting at 0 W, with increases of 5 W every 12 seconds) on a cycle ergometer (validity study). In addition, 15 of them performed the same test twice (reliability study). During the tests, data on gas exchange and blood lactate levels were collected to determine VT1, VT2, LT, and OBLA. The root mean squares of EMG signals (rms-EMG) were recorded from both the vastus lateralis and the rectus femoris at each intensity using surface electrodes. RESULTS: A two threshold response was detected in the rms-EMG recordings from both muscles in 90% of subjects, with two breakpoints, EMGT1 and EMGT2, at around 60-70% and 80-90% of VO2MAX respectively. The results of the reliability study showed no significant differences (p > 0.05) between mean values of EMGT1 and EMGT2 obtained in both tests. Furthermore, no significant differences (p > 0.05) existed between mean values of EMGT1, in the vastus lateralis and rectus femoris, and VT1 and LT (62.8 (14.5) and 69.0 (6.2) and 64.6 (6.4) and 68.7 (8.2)% of VO2MAX respectively), or between mean values of EMGT2, in the vastus lateralis and rectus femoris, and VT2 and OBLA (86.9 (9.0) and 88.0 (6.2) and 84.6 (6.5) and 87.7 (6.4)% of VO2MAX respectively). CONCLUSION: rms-EMG may be a useful complementary non-invasive method for analysing the aerobic-anaerobic transition (ventilatory and lactate thresholds) in elite cyclists.

Adult↗

Trace elements and electrolytes in human resting mixed saliva after exercise.

OBJECTIVES: Exercise is known to cause changes in the concentration of salivary components such as amylase, Na, and Cl. The aim of this investigation was to evaluate the effect of physical exercise on the levels of trace elements and electrolytes in whole (mixed) saliva. METHODS: Forty subjects performed a maximal exercise test on a cycle ergometer. Samples of saliva were obtained before and immediately after the exercise test. Sample concentrations of Fe, Mg, Sc, Cr, Mn, Co, Cu, Zn, Se, Sr, Ag, Sb, Cs, and Hg were determined by inductively coupled plasma mass spectrometry and concentrations of Ca and Na by atomic absorption spectrometry. RESULTS: After exercise, Mg and Na levels showed a significant increase (p < 0.05) while Mn levels fell (p < 0.05). Zn/Cu molar ratios were unaffected by exercise. CONCLUSIONS: Intense physical exercise induced changes in the concentrations of only three (Na, Mg, and Mn) of the 16 elements analysed in the saliva samples. Further research is needed to assess the clinical implications of these findings.

Adult↗

Heart dimensions may influence the occurrence of the heart rate deflection point in highly trained cyclists.

OBJECTIVES: To determine whether the heart rate (HR) response to exercise in 21 highly trained cyclists (mean (SD) age 25 (3) years) was related to their heart dimensions. METHODS: Before performing an incremental exercise test involving a ramp protocol with workload increases of 25 W/min, each subject underwent echocardiographic evaluation of the following variables: left ventricular end diastolic internal diameter (LVIDd), left ventricular posterior wall thickness at end diastole (LVPWTd), interventricular septal wall thickness at end diastole (IVSTd), left ventricular mass index (LVMI), left atrial dimension (LAD), longitudinal left atrial (LLAD) and right atrial (LRAD) dimensions, and the ratio of early to late (E/A) diastolic flow velocity. RESULTS: The HR response showed a deflection point (HRd) at about 85% VO2MAX in 66.7% of subjects (D group; n = 14) and was linear in 33.3% (NoD group; n = 7). Several echocardiographic variables (LVMI, LAD, LLAD, LRAD) indicative of heart dimensions were similar in each group. However, mean LPWTd (p<0.01) and IVSTd (p<0.05) values were significantly higher in the D group. Finally, no significant difference between groups was found with respect to the E/A. CONCLUSIONS: The HR response is curvilinear during incremental exercise in a considerable number of highly trained endurance athletes-that is, top level cyclists. The departure of HR increase from linearity may predominantly occur in athletes with thicker heart walls.

Adult↗