Serum laminin level and disease activity in primary membranous and membranoproliferative glomerulonephritis: a prospective follow-up.
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Adult↗
Biomedical subjects
R Segura
Publications and source records attributed to R Segura.
Is the post-lunch dip in sprinting performance associated with the timing of food ingestion?
To detect whether the drop in performance around lunch has any direct association with the time of food ingestion, a group of 8 sprinters were studied for 5 consecutive Saturdays. On each testing day, the times achieved during 80 meter sprints performed at eight different times of the day separated by 2 hour intervals were recorded. The 1st and 4th testing days, had identical sleep and mealtime schedules, and were therefore considered "control days", while on the 2nd and 3rd testing days the schedule was brought forward ("advanced") or backward ("delayed") by 2 hours respectively. On the 5th testing day the sleep-wake cycle was brought forward 2 hours without changing the mealtime schedule. A post-lunch dip (PLD) was detected on all testing days although at different times. No significant differences in performance were observed between days 1 and 4 while there were differences in performance during the other testing days. It is worth pointing out that PLD occurred at about 15:00 h on the control days, with significant differences between the 2nd (p < 0.05) and 3rd days (p < 0.05), and with the deterioration in performance starting at 15:00 h on the 3rd day despite the fact that lunch had been served at 16:00 h. In conclusion, PLD does not appear to be directly linked to the time of lunch, although lunch itself could potentiate its effects. It is also worth mentioning the fact that this deteriorating effect does not occur after any other meals of the day.
Adult↗
New evidence from magnetic resonance imaging of brain changes after climbs at extreme altitude.
The aim of the present study was to look for anatomical changes in climbers' brains, using magnetic resonance imaging (MRI), after extremely high-altitude climbs and to relate them to possible associated risk factors. Clinical history, neurological examinations and MRI were carried out on a group of nine climbers before and after climbing to over 7500 m without the use of supplementary oxygen. None of the subjects showed any neurological dysfunctions. In five climbers MRI abnormalities (high signal areas, cortical atrophy) were observed before the expedition. After the descent, two of them showed new high intensity signal areas recorded by MRI. Both subjects suffered severe neurological symptoms during the climb. The present study suggested that the brain changes observed by MRI could be related to the severity of clinical events at high altitude. However, we do not know the exact meaning of such MRI findings or the reason for their location, predominantly in posterior regions of the brain. The new evidence that a high percentage of climbers show MRI brain abnormalities, and especially the appearance of changes after the ascent, reinforces the possibility of a potential neurological risk in high-altitude climbing.
Adult↗
Effect of prior ingestion of glucose or fructose on the performance of exercise of intermediate duration.
The metabolic responses induced by the ingestion of a beverage containing glucose (G), fructose (F) or placebo (W) 30 min before exercise of high intensity and intermediate duration have been investigated; in these conditions the energy processes are mostly dependent on aerobic reactions. A group of 11 male recreational sportsmen ran on a treadmill, at an intensity corresponding to 82% of peak oxygen consumption, until exhaustion on three different occasions (after ingestion of a beverage containing 75 g of G, 75 g of F or W). Plasma glucose, insulin, and lactic acid concentrations were determined just prior to the ingestion of the beverages, 30 min afterwards and 10 and 30 min after completion of the exercise. The mean endurance time was 644 (SD 261) s after the ingestion of G, 611 (SD 227) s after the ingestion of F and 584 (SD 189) s after the ingestion of the W (P < 0.05 between G and W). No differences in the oxygen uptake, respiratory quotient or lactate concentrations between the three trials were observed. Both plasma glucose and insulin concentrations determined in samples obtained immediately before the onset of exercise were higher when G was ingested than when F (P < 0.05 and P < 0.05, respectively) or W (P < 0.001 and P < 0.005, respectively) were ingested. These findings would suggest that the ingestion of G prior to an effort of intermediate duration may improve physical performance.
Adult↗
Rat myocardial tissue lipids and their effect on ventricular electrical activity: influence on dietary lipids.
OBJECTIVE: The aim was to investigate the effect of diets with different lipid content on rat myocardial tissue lipid composition and their possible influence on myocardial electrical activity. METHODS: 60 male Sprague-Dawley rats were randomised in three dietary feeding groups. Half the animals were used for the myocardial lipid study and the other half for the ventricular refractory period and ventricular conduction velocity measurements. Synthetic diets of low fat, high fat (predominantly lard fat), and high fat plus marine oil, the last two with cholesterol, were supplied ad libitum for five weeks. After 2-propanol myocardial lipid extraction, lipid fractions were separated by thin layer chromatography and their esterified fatty acids by gas-liquid chromatography. Ventricular refractory period was obtained according to the extrastimulus technique and maximum conduction velocity by ventricular pacing. RESULTS: The experimental diets induced marked changes in fatty acid composition of myocardial phospholipids and in esterified cholesterol content. The high fat group showed a significant decrement in oleic and linoleic acids, with an increment in arachidonic and docosahexaenoic acids in their phospholipid composition. This dietary group had the highest esterified cholesterol content. These changes were related to lowering of maximum ventricular paced heart rate and lengthening of ventricular refractory period, and were partly corrected by marine oil supplement. CONCLUSIONS: Saturated fat diets cause profound changes in myocardial fatty acyl composition which are linked to sustained differences in myocardial electrical activity. These changes can be partly corrected by a moderate fish oil supplement.
Animals↗
Fish consumption, omega-3 fatty acids and the Mediterranean diet.
Many epidemiological, interventional and animal studies have concluded that consumption of polyunsaturated fatty acids of marine origin may confer special benefits in reducing cardiovascular heart disease (CHD) mortality rates by different physiological mechanisms. The available epidemiological data, although limited, suggest that a dietetic recommendation on the consumption of one or two servings per week (200-300 g = 2-4 g eicosapentaenoic acid) of cold water marine fish could lead to a reduction of the CHD risk. Nevertheless, there are important methodological shortcomings and contradictory findings in most published investigations on the omega-3 fatty acids. In order to assess the role of fish consumption in the Mediterranean diet, we have compared data on average fish and fatty fish consumption trends in some Mediterranean (Spain, Yugoslavia and Italy) and northern European (Norway, Denmark) countries. Fish consumption is not positively correlated with ischaemic heart disease mortality. That suggests that dietary factors other than fish, such as the lower meat consumption associated to the higher fish intake, or other differences of lifestyle have perhaps intervened, helping to explain the healthy nature of the Mediterranean diet.
Animals↗
A simplified technique for hepatic revascularization of the liver graft with inadequate recipient hepatic artery.
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Adult↗
Evaluation of duodenogastric reflux in gallstone disease before and after simple cholecystectomy.
Duodenogastric reflux (DGR) has been suggested as an etiopathogenic factor in gastric disease in patients with gallstones. We evaluated the DGR levels in 15 patients before and after simple cholecystectomy for gallstones and compared the results with those of 15 healthy subjects. Gastric juice was obtained by continuous nasogastric suction for 24 hours. The bile acids (BA) present in the samples were quantified by thin-layer chromatography and in situ spectrofluorometry. The mean BA concentration for the control subjects was 2.25 mumol reflux/hour, whereas the mean value for the 15 patients with cholelithiasis was 8.86 mumol reflux/hour before cholecystectomy and 24.55 mumol reflux/hour after cholecystectomy. Five patients did not have detectable BA in the gastric juice in both analyses; the remaining 10 patients showed a significant increase in the BA after surgery. From these data, we conclude that gallstone disease is not always accompanied by an increased DGR. However, in patients in whom DGR is present, its level is higher than in control subjects and increases significantly after cholecystectomy. This is probably due to the greater amount of bile in the duodenum that may reflux through an incompetent pyloric channel.
Adult↗
Bile reflux in postoperative alkaline reflux gastritis.
This study evaluates enterogastric reflux (EGR) levels in patients with and without symptoms of postoperative alkaline reflux gastritis (PARG) after gastric surgery. The bile acids (BA) present in the gastric juice were quantified by thin-layer chromatography and spectrofluorometry. The mean BA concentration for controls was 2.25 mumol reflux/hour, for 15 asymptomatic patients 47.94 and for 15 patients with symptoms of PARG 125.79. After biliary diversion by a Roux-en-Y anastomosis in the latter, their BA in 13 of these patients after surgery, and relapsed in only one during a 4-year follow-up. The remaining two patients had the lowest preoperative BA levels in this group. These results indicate that EGR is increased after gastric surgery more markedly indicated that EGR is increased after gastric surgery more markedly in patients with symptoms of PARG, and that patients who have high levels of EGR (more than 80 mumol BA reflux/hour) clearly benefit from biliary diversion.
Adult↗
[Sarcoidosis in Catalonia: analysis of 425 cases].
In a retrospective cooperative study carried out in three Barcelona hospitals, 425 patients in whom a diagnosis of sarcoidosis had been made during a 15-year period were evaluated. Several parameters were evaluated and compared with those from the longest series in the literature. Remarkable epidemiological and clinical features included the female predominance, explained by the high frequency of clinical presentations with erythema nodosum; the high incidence of other skin lesions, and, by contrast, the low frequency of eye involvement. It was also remarkable that in a few cases the diagnosis was made in a routine chest radiogram. In diagnostic procedures there was a good diagnostic yield from mediastinoscopy and muscle and pre-scalene fat biopsies The results of Kveim's test, functional respiratory testing and such current activity markers as 67-gallium pulmonary scintigraphy, serum levels of angiotensin converting enzyme and bronchoalveolar lavage were analyzed, and no differences with other series from the literature were found. The presence of the B8 allele and the A1 B8 haplotype was highly significant in subacute sarcoidosis. It is concluded that sarcoidosis is not an uncommonly found condition in this country if the suspicion index is high and an appropriate diagnostic workup is carried out. Its features are not different, as a rule, from those in other European series.
Adolescent↗
Correlation of plasma lipid fractions with colorimetrically determined glycated hemoglobin in a nondiabetic population.
To evaluate the incidence of protein glycation (measured as glycated hemoglobin) on plasma lipid levels in a free-living population, a colorimetric method has been used to detect 5-hydroxymethylforfural (HMF) released from glycated hemoglobin (GHb) and enzymatic methods have been used to evaluate total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting glycemia, and total plasma triacylglycerides. These results have been used to calculate low-density lipoprotein-(LDL) cholesterol levels with the Friedewald formula. Results show that a positive correlation exists in men, but not in premenopausal women, between GHb and fasting glycemia (P less than 10(-14], GHb and total plasma cholesterol (P less than .001), GHb and LDL cholesterol (P less than .0001), and GHb with the atherogenic index total/HDL cholesterol (P less than .0001), whereas a negative correlation was shown between GHb and HDL cholesterol (P less than .05). Fasting glycemia does not correlate with cholesterol lipoprotein fractions, but correlates well with total triacylglycerides. These correlations are significant when they are adjusted by age and body mass index. It has also been observed that the positive correlation between glycation of hemoglobin and total cholesterol occurs constantly at all glycohemoglobin levels, and affects all cholesterol fractions analyzed. This suggests an increased atherogenicity with increasing glycohemoglobin levels. Comparisons between groups with high and low GHb levels show variations in the order of 6.5% of total cholesterol levels and a major proportion in the different cholesterol fractions. The higher-range "glycated" populations show total cholesterol, LDL cholesterol and HDL cholesterol values significantly different from the lower-range "glycated" population.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Red blood cell fatty acids in multiple sclerosis.
The fatty acid (FA) composition of each phospholipid constituent of the red blood cells (RBC) was analyzed, by thin-layer and gas chromatography techniques, in 61 multiple sclerosis (MS) patients and 61 normal subjects, in whom the plasma lipid FA composition had previously been studied. The MS patients showed a significant decrease in the proportions of linoleic and arachidonic acids in most phospholipids, with a compensatory increase of saturated FA. Correlations between FA percentages in plasma and cell lipids demonstrated abnormalities in the MS patients, suggestive of a disturbance in the exchange between these compartments. The alterations reported in plasma and RBC in the MS patients are consistent with a relative deficiency of essential FA.
Arachidonic Acids↗
[Determination of duodenogastric reflux by quantification of bile acids in the gastric juice].
The existence of duodeno-gastric reflux was evaluated in a group of 15 healthy subjects, in fasting and for 24 hours. The assessment of duodeno-gastric reflux was made by quantitation of the bile acids (BA) present in the gastric juice. The individual free and conjugated BA were separated and quantified by means of thin-layer chromatography and in situ spectrofluorometry. In 7 of the subjects studied no BA were detected, and in the other 8 subjects the BA levels were below 6 mumol reflux/hour. There were no free BA detected in any of the subjects. The levels of BA in gastric juice increased progressively with age, but there were no differences between sex. The chromatographic technique used is highly sensitive for the analysis of BA in biological samples. The study of BA in the gastric juice provides a quantitative and reliable assessment of the degree of duodeno-gastric reflux.
Adult↗
[Liver transplant in fulminant hepatitis].
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Adult↗
Preparation of fatty acid methyl esters by direct transesterification of lipids with aluminium chloride-methanol.
A new and simple procedure has been developed that allows the direct transesterification of lipids, using aluminium chloride as a catalyst and methanol as the esterifying alcohol. The concentration of the salt and reaction conditions have been investigated for the different lipid classes. Comparative studies, performed with boron trifluoride-methanol, indicate that the same values are obtained when using either reagent. In addition, the method has been adapted for transesterification in the presence of silica gel and other adsorbents, thus allowing the preparation of fatty acid methyl or ethyl esters directly from samples previously fractionated by thin-layer chromatography. This new reagent is very stable and easy to handle, the fatty acids being generated in the same tube without further purification steps.
Aluminum↗
Separation and o-phthaldehyde fluorometric determination of 5-hydroxy- and 5-methoxyindoleamines by thin-layer chromatography: selected applications.
Individual 5-hydroxyindoles and 5-methoxyindoles were simultaneously isolated and quantified, after o-phthaldehyde condensation in different concentrations of HCl, followed by separation on silica gel plates. The 5-hydroxyindoleamines and 5-methoxyindoleamines were differentiated by intense orange and blue fluorescences, respectively. Distinct Rf values with new phase composition and optimal HCl concentrations in the condensation reaction were established for each of the nine indoleamines tested. Minimal detectable doses ranged from 0.2 ng for 5-methoxytryptophol to 4 ng for 5-hydroxyindole acetic acid. The above methodology was applied in order to determine platelet serotonin. Preliminary results suggest that this method could be adapted to other selected biological samples.
Amines↗
Effect of L-tryptophan supplementation on exercise performance.
The performance of strenuous physical exercise is associated with discomfort and pain, the tolerance for that being modulated by the activity of the endogenous opioid systems. As 5-hydroxy-tryptamine (5-HT) affects nociception through its effects on the enkephalin-endorphin system, we have analyzed the effects of a moderate supplementation with L-tryptophan, the immediate precursor of 5-HT, on endurance and sensation of effort. Twelve healthy sportsmen were subjected to a work load corresponding to 80% of their maximal oxygen uptake on two separate trials, after receiving a placebo and after receiving the same amount of L-tryptophan. The subjects ran on a treadmill until exhaustion. Total exercise time, perceived exertion rate, maximum heart rate, peak oxygen consumption, pulse recovery rate, and excess post-exercise oxygen consumption were determined during the two trials. The total exercise time was 49.4% greater after receiving L-tryptophan than after receiving the placebo. A lower rate of perceived exertion was exhibited by the group while on tryptophan although the differences from the control group were not statistically significant. No differences were observed in the other parameters between the two trials. The longer exercise time als well at the total work load performed could be due to an increased pain tolerance as a result of L-tryptophan ingestion.
Adult↗
Plasma lipids and their fatty acid composition in multiple sclerosis.
We report an extensive study of the plasma lipid profile and fatty acid composition in 61 multiple sclerosis (MS) patients compared with 61 normal subjects. The main abnormality in the MS was a reduction in the proportion of linoleic and arachidonic acids mostly evident in the HDL and in the cholesteryl esters fraction, with a compensatory increase in saturated acids. The fatty acid abnormalities correlated with the duration of the disease and the degree of disability. Thus, in the MS patients studied there was a deficiency in essential fatty acids, although this metabolic abnormality does not seem specific to MS.
Adult↗