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Biomedical subjects

R Sola

Publications and source records attributed to R Sola.

At least 19 recordsLinked to original sources
PubMed2006

MK801-induced caspase-3 in the postnatal brain: inverse relationship with calcium binding proteins.

Age-dependent, neuronal apoptosis following N-methyl-D-aspartate receptor blockade has been linked to loss of calcium. To further explore this relationship, we examined expression of activated caspase-3, as well as the calcium binding proteins, calbindin-D 28K, calretinin and parvalbumin, following injection of vehicle or the N-methyl-D-aspartate receptor blocker, MK801, in postnatal day 7 or 21 rats. At postnatal day 7, MK801-induced activated caspase-3 expression was most frequently found in mutually exclusive cell populations to those expressing any of the three calcium binding proteins. For example, in the somatosensory cortex, most immunoreactivity for activated caspase-3 was found in layers IV/V, layered between areas of high calbindin or calretinin expression. Further, in the caudate putamen, activated caspase-3 rarely invaded zones of intense calbindin immunoreactivity. Suggesting expression patterns of these proteins were inversely related, these same brain regions no longer displayed MK801-induced activated caspase-3 at postnatal day 21, but instead robustly expressed calcium binding proteins. This later surge in expression was especially true for parvalbumin in regions such as the somatosensory and retrosplenial cortex, as well as the subicular complex. Calbindin-D 28K was also found to increase in the same regions though not as impressively as parvalbumin. Thus, developmental regulation of calcium binding protein expression may be a critical factor in age-dependent sensitivity to agents that disrupt calcium homeostasis in maturing neurons, providing a possible mechanistic explanation for age-dependent MK801 toxicity.

Age Factors↗
PubMed2003

Evaluation of renal graft haemodynamia by 51Cr-EDTA and o-[131I]iodohippurate: its use in the early diagnosis of glomerular hyperfiltration.

Chronic rejection is the most important cause of renal graft dysfunction. Non-immunological mechanisms have been suggested as a probable origin of chronic graft rejection, provoking a decrease in renal mass function, followed by glomerular hyperfiltration in the remnant nephrons, which could cause progressive glomerulosclerosis and functional loss. Early, or preclinical, identification of patients with glomerular hyperfiltration, defined as an increase in glomerular filtration fraction (GFF) and in glomerular capillary pressure (GCP), could prolong graft life. The objective of this study was to evaluate, non-invasively, stable renal graft haemodynamia and early glomerular hyperfiltration. We studied 116 renal transplant patients with stable renal function and five healthy living kidney donors with normal renal function. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were determined using 51Cr-EDTA and o-[131I]iodohippurate, respectively. GFF was obtained from the relation between GFR and ERPF, and GCP from a mathematical model (Hall-Gomez' formula). A simultaneous analysis of renal function was performed. In transplant patients, the GFR and ERPF were significantly lower than in healthy, living, kidney donors (P<0.02). The same trend was observed for GCP (P<0.01), while GFF was not significantly different. Twelve patients (10.3%) had criteria of glomerular hyperfiltration. In patients without criteria of glomerular hyperfiltration, plasma level and clearance of creatinine were 128+/-33 micromol.l-1 and 56+/-15 ml.min-1, respectively; and in those patients with glomerular hyperfiltration criteria were 108+/-18 micromol.l-1 (P=NS) and 83+/-24 ml.min-1 (P=0.002) respectively. It is concluded that determinations of GFR, ERPF, GFF and GCP allow non-invasive evaluation of renal graft haemodynamia and can be useful in the early detection of glomerular hyperfiltration.

Adult↗
PubMed2001

Early ambulation after diagnostic cardiac catheterization: a 4 French study.

This study is intended to test whether the use of new 4 French (Fr) catheters can safely eliminate the need for supine bed rest and allow earlier ambulation while decreasing groin site complications and patient discomfort. Diagnostic left heart catheterization was performed using 4 Fr catheters via the femoral approach in 100 consecutive patients. After femoral sheath removal, the mean compression time with a mechanical compression device was 16.07 +/- 3.19 minutes. Mean manual compression time was 18.3 +/- 5.7 minutes. Ninety-eight patients were able to sit up 30 degrees immediately after hemostasis was achieved. The mean ambulation time was 2.18 +/- 0.71 hours. There were no major vascular complications. Four patients developed a small area (2.5-5 cm) of ecchymosis at the femoral arterial puncture site. The study demonstrated that upper body elevation and early ambulation are safe as soon as hemostasis is achieved after 4 Fr cardiac catheterization.

Adult↗
PubMed2000

19. Correlation between FDG PET data and EEG dipole modeling.

Purpose: FDG-PET images and EEG dipole modelling were used to localization of interictal epileptogenic foci. A multimodality approach with the analysis of FDG-PET images, EEG dipoles and anatomical images (MRI) were applied to patients with drug-resistant epilepsy.Methods: Source location was determined using Brain Electromagnetic Source Analysis (BESA) program. The dipole location provided by BESA was then transformed into PET co-ordinates using the patient's MRI previously registered with the PET image. As a difference with other methods, no external markers are necessary.Results: The study group includes ten drug-resistant epileptic patients. FDG hypometabolism was found in all patients. Abnormalities in glucose uptake were always ipsilateral to the EEG dipole. However, quantitative analysis of FDG-PET within hypometabolic areas showed no significant correlation between decrease glucose uptake and location of EEG-dipole source. The comparison of the results using both methods shows that the dipole location matches the FDG-PET hypometabolic area for all the patients. Combining the spatial localization on FDG-PET with the temporal accuracy of EEG dipole source aids in the exact localization of the epileptogenic focus.Conclusion: As a conclusion, the results show that projection of EEG dipole data onto FDG-PET may play a key role in the indication of surgery for the treatment of drug-resistant epileptic patients, provided it is simple and easy to perform.

Journal Article↗
PubMed1999

PCR analysis in the pathological diagnosis of Whipple's disease: emphasis on extraintestinal involvement or atypical morphological features.

PCR analysis of species-specific bacterial 16S rRNA gene of Tropheryma whippelii was performed in biopsies from 10 cases of Whipple's disease (WD). In seven patients showing the typical clinical picture of WD, PCR was performed on the diagnostic intestinal biopsy. In the remaining three cases (an autopsy case of disseminated WD and two patients showing lymphadenopathy as the initial clinical presentation), PCR was done on lymph node specimens. In one of the lymph node biopsies, an unusual sarcoidlike granulomatous reaction had led to the diagnosis of sarcoidosis. The specific bacterial DNA was detected in all cases, both in intestinal biopsies and in lymph node specimens. Follow-up biopsies after antibiotic therapy were evaluated in two patients. The two follow-up biopsies were negative, although in both of them scattered nests of PAS-positive macrophages remained. The results of this study suggest that PCR analysis of species-specific sequences of the 16S rRNA of Tropheryma whippelii is a very useful tool for the pathological diagnosis of WD. It confirms the diagnosis of WD in intestinal biopsies as well as in extraintestinal sites, even when the morphological appearance is not typical. It is also the most precise technique for monitoring therapeutic effects.

Actinobacteria↗
PubMed1995

Physicochemical changes in human high-density lipoproteins (HDL) oxidized by gamma radiolysis-generated oxyradicals. Effect on their cholesterol effluxing capacity.

This paper describes an oxidative process of human high-density lipoproteins (HDL) based upon the action of oxygenated free radicals produced by water radiolysis (OH. and OH./O2.- free radicals at pH 7), monitored by both biochemical and physical markers. Classical biochemical markers (vitamin E, thiobarbituric acid-reactive substances (TBARS), conjugated dienes and differential fluorescence) were studied as a function of the radiation dose (from 0 to 800 Gy; dose rate = 2.7 x 10(-2) Gy.s(-1)). The fluorescence polarization anisotropy (r) was measured with 1,6-diphenylhexatriene (DPH). Vitamin E decrease and formation of lipid peroxidation products (thiobarbituric acid-reactive substances and conjugated dienes) were concomitant in the case of OH. free radicals alone, whereas these products appeared after a small threshold dose when OH. and O2.- free radicals were simultaneously produced in solution. At high radiation doses, TBARS concentrations have reached plateau values (approx. 2 or 7 nmol/mg lipid with OH. or OH./O2.- free radicals, respectively) which were much lower than those obtained after copper oxidation (approx. 15 or 29 nmol/mg lipid after 12 and 24 h incubation, respectively). The free radical-induced oxidative process has led to a rigidification of the HDL and was associated with low values of cholesterol effluxing capacities when these oxidized HDL were incubated with cholesterol-loaded human fibroblasts. Similar results were obtained with copper-oxidized HDL, under our experimental conditions. Consequently, these two kinds of oxidative modification of HDL resulted both in a loss of their capacity to remove cellular cholesterol, which could be explained by the fact that this ability was under the dependence of a HDL optimum fluidity.

Cholesterol↗
PubMed1995

Effect of dexfenfluramine on energy expenditure in obese patients on a very-low-calorie-diet.

AIM: To investigate the effect of dexfenfluramine (dF) on Energy Expenditure (EE). DESIGN: 20 obese females were studied in a double-blind design. Pre-diet and at 14 and 28 days of VLCD and dF treatment (30 mg/d) or placebo, Resting Metabolic Rate (RMR), 3 h-Thermic Effect of Food (3 h-TEF) and body composition were determined. EE and body composition were measured by indirect calorimetry and bioelectrical impedance, respectively. RESULTS: No differences between groups were observed in relation to weight loss, body composition changes or RMR. At 3 h postprandial, the EE was still elevated in both groups. No changes on TEF were observed in the placebo group during VLCD. In contrast, TEF decreased in dF group during VLCD (P < 0.05). No significant differences in TEF at the end of the study were observed between groups. CONCLUSION: These results suggest that dF modifies 3 h-TEF but not RMR in obese patients during VLCD administration.

Adult↗
PubMed1994

[Estimation of energy expenditure in patients with morbid obesity].

BACKGROUND: The equations available for the prediction of basal energy expenditure (BEE) may not be applicable in morbid obese individuals since the contribution of the fat free mass (FFM) over the BEE is not constant. The aim of this study was to obtain new equations for the prediction of BEE which are specific for patients with morbid obesity. METHODS: In 26 women with morbid obesity age, weight, body composition by bioelectric impedance and BEE by open circuit indirect calorimetry were determined. The BEE observed was compared with that estimated from the previously described equations. The multiple regression method was used to obtain the BEE prediction equations. RESULTS: Upon comparison of the BEE observed with the BEE estimated by the described equations a significant relation was found between both parameters. The differences were also significant except when the Harris-Benedict equation was used. Multiple regression analysis demonstrated that when the variables of body composition were included, the FFM explained 75% of the variation in BEE and on forcing the entrance of fatty mass, the explanation increased to 79%. When only the anthropometric variables were included, weight explained 69% of the variation. CONCLUSIONS: In morbid obesity, most of the equations described for estimating basal energy expenditure are not applicable. New equations are reported for the prediction of energy expenditure.

Adult↗
PubMed1994

In vitro oxidised HDL is recognized by the scavenger receptor of macrophages: implications for its protective role in vivo.

To assess the effects of oxidative modification, human HDL was oxidised in vitro for 12 h (Ox-HDL12) and 24 h (Ox-HDL24) under similar conditions to those commonly used for LDL. The procedure resulted in: an increase in thiobarbituric acid reactive substances but with marginal change in electronegativity; protein denaturation accounting for 16% and 45% loss of immunoreactive apoprotein A-I in the Ox-HDL12 and Ox-HDL24 respectively relative to the non-oxidised, native HDL (Nat-HDL); a decrease in the polyunsaturated fatty acids of the triglyceride, cholesterol ester and phospholipid components of the lipoprotein; an increase in the proportion of short chain saturated fatty acids while the monounsaturated fatty acids remained relatively unchanged. Studies with human macrophages demonstrated: a decrease of 16% and 30% in the capacity of the Ox-HDL12 and Ox-HDL24 respectively to efflux intracellular free cholesterol; 125I-Ox-HDL24 uptake and degradation was directly comparable with that of 125I-Ac-LDL; the addition of excess unlabelled Ox-HDL24, Ac-LDL, Ox-LDL24 and Nat-HDL resulted in 74%, 67%, 69% and 19% displacement of the 125I-Ox-HDL24 respectively; fucoidin and dextran sulphate displaced 125I-Ox-HDL by 20% and 40% respectively; intracellular free and esterified cholesterol was increased 2.5-fold and 4-fold respectively relative to Nat-HDL on incubation with Ox-HDL24. These findings suggest that HDL is susceptible to oxidative modification leading to recognition by the scavenger receptor of macrophages and subsequent intracellular cholesterol accumulation. As such, the in vivo protective role of HDL in cardiovascular disease can be reversed in those circumstances in which HDL, like LDL, undergoes oxidative modification.

Cells, Cultured↗
PubMed1993

Risk factors for spontaneous bacterial peritonitis in cirrhotic patients with ascites.

BACKGROUND: This study was performed to investigate the risk factors for a first episode of spontaneous bacterial peritonitis in cirrhotic patients. METHODS: One hundred ten cirrhotics with sterile ascites, without previous spontaneous bacterial peritonitis (SBP), were included from March 1988 to October 1989 and followed up until October 1990 (follow-up, 46 +/- 3.5 weeks; range, 4-120 weeks). RESULTS: Twenty-eight patients (25.45%) suffered SBP. In multivariate analysis (Cox's regression model) including only variables commonly used in clinical practice, ascitic fluid protein concentration and serum bilirubin level independently correlated with first SBP development. Using these two variables the relative risk of a first SBP episode was calculated for each patient. According to the median relative risk coefficient (1.2), a low-risk group (relative risk, < 1.2) and a high-risk group (relative risk, > 1.2) were established. Kaplan-Meier estimates of patients free of SBP were significantly higher in the low-risk group. CONCLUSIONS: The probability of a first SBP episode is significantly influenced by the antimicrobial capacity of ascitic fluid and hepatic function.

Ascites↗
PubMed1993

Dietary monounsaturated fatty acids enhance cholesterol efflux from human fibroblasts. Relation to fluidity, phospholipid fatty acid composition, overall composition, and size of HDL3.

This study was designed to determine whether modifications induced by dietary fats on the high-density lipoprotein3 (HDL3) physicochemical characteristics could affect cholesterol efflux and intracellular cholesterol content, leading to upregulation of low-density lipoprotein (LDL) receptor activity from cultured fibroblasts. Serum HDL3S were obtained from 12 healthy women aged 26 to 49 years who adhered to four 7-week isocaloric diets containing 30% of the caloric intake as fat. Of the total calories, 15.6% of each diet was provided by (1) milk fats, rich in saturated fatty acids; (2) sunflower oil, rich in n-6 polyunsaturated fatty acids; (3) olive oil, rich in monounsaturated fatty acids; and (4) rapeseed oil, rich in n-3 polyunsaturated fatty acids. HDL3 isolated after the monounsaturated fatty acid diet induced the greatest cellular [3H]free cholesterol efflux, reduced the content of intracellular cholesterol, and enhanced 125I-LDL degradation. Univariate regression analyses suggested that the increased capacity of HDL3 to promote cellular [3H]free cholesterol efflux was in part due to its greater fluidity, higher cholesteryl ester content, elevated linoleic to linolenic acid ratio in phospholipids, and its smaller size. In conclusion dietary fats induced physicochemical changes in HDL3, which strongly modulated cellular cholesterol homeostasis in vitro. These data also suggest a novel mechanism by which dietary fats exert their effect on atherosclerosis.

Adult↗
PubMed1991

The Mediterranean-type diet: is there a need for further modification?

The effects on plasma lipoproteins of four fat-modified diets were assessed in 11 nuns in a contemplative order in the Mediterranean region of Spain. Diet 1 [high polyunsaturated fatty acid (PUFA), low monounsaturated fatty acid (MUFA), low ratio of PUFAs to saturated fatty acids (P:S)] and diet 3 (low PUFA, high MUFA, low P:S) induced significant, directly comparable reductions in total plasma (12% and 13%, respectively) and low-density-lipoprotein (LDL) cholesterol (24% and 19%, respectively). Diet 2 [high PUFA, high MUFA, low saturated fatty acid (SFA), high P:S] induced greater decrements (23% and 30% in total plasma and LDL cholesterol, respectively). Diet 4 (low PUFA, low MUFA, high SFA, low P:S) induced a significant increase in LDL cholesterol of 11%. No significant changes in high-density-lipoprotein cholesterol were observed with these diets. Because the effects of PUFAs and MUFAs are comparable, no recommendations on modifying the habitual, high-MUFA-containing Mediterranean diet need be made other than, perhaps, a reduction in the overall intake of SFAs.

Adult↗