Magnetic resonance imaging of acute infarction of the anterior spinal cord.
Explore the source record for details and available documents.
Acute Disease↗
Biomedical subjects
A Rovira
Publications and source records attributed to A Rovira.
[Value of cranial MRI in the follow-up of dural sinus thrombosis].
INTRODUCTION: At the present time it is well established that cranial magnetic resonance (MR) is the imaging technique of choice for diagnosis of thrombosis of the dural sinuses. However, few studies have been done to evaluate its role in follow-up in this cerebrovascular disorder. OBJECTIVE: To assess the alterations in resonance signal in follow-up of patients with thrombosis of the dural sinuses and the clinical correlation of this. MATERIAL AND METHODS: We reviewed the clinical histories of 12 patients diagnosed on cranial MR as having thrombosis of the dural sinuses; 8 cases were also seen again six months later. The cranial MR study was done using a 1.5 or 1.0 T superconductive apparatus to do measured spin-echo sequences (SE) in T1 and T2 in sagittal, transverse and coronal planes. The time elapsed between diagnosis on MR and clinical diagnosis was between 24 hours and 6 months. RESULTS: All patients had stronger resonance signals in T1 and T2 indicating a subacute phase of the thrombosis (oxidative conversion of deoxyhaemoglobin to methoxyhaemoglobin) and complete absence of blood flow in the sinuses. The eight patients seen again after six months were found to be normal on neurological. On cranial MR partial recanalization was seen in 5 of these (62%). CONCLUSION: Changes in the resonance signal persist for a long time both with and without signs of recanalization. This finding does not affect the medium term clinical course.
Adult↗
[Body mass index influence in the insulin action mechanisms].
OBJECTIVE: Improve the knowledge of the "in vitro" insulin action in healthy subjects with different body mass index (BMI), in order to know the role of obesity in the diabetes mellitus. MATERIAL: In 12 healthy subjects with different BMI and normal oral glucose test we made a gluteal biopsy to obtain adipose tissue. In the isolated adipocytes we studied the interaction of insulin with its receptor and the glucose transport. RESULTS: BMI was not correlated with the maximal specific 125I-insulin binding but was negative when correlated with the glucose transport in basal situation (r = -0.63, p < 0.05) as well as when stimulated with insulin (r = -0.67, p < 0.05), when the results were expressed as number of cells. When the data were expressed as surface, BMI was negative correlated with the percentage of maximal specific 125I-insulin binding (r = -0.81, p < 0.05), and also with the basal glucose transport (r = -0.69, p < 0.05) and stimulated with insulin (r = -0.77, p < 0.01). CONCLUSION: The increase of BMI is an important diabetogenic agent, acting at receptor as well as at postreceptor level, and the data should be expressed according to the cellular diameter rather than to the number of cells in subjects with different BMI. A cutting point was established at the 30 BMI level after which the described alterations could be observed.
Adult↗
[The development of multiple sclerosis following an isolated episode of optic neuritis. Magnetic resonance study].
BACKGROUND: An important controversy on the development of multiple sclerosis (MS) after an isolated episode of optic neuritis (ON) exists. Magnetic resonance imaging (MRI) is the method of election in order to detect demyelinated lesions in MS. The current study was designed to determine the prevalence of brain abnormalities on MRI and to asses the further development of MS after an isolated idiopathic ON in our population. PATIENTS AND METHODS: From 1991 to 1995, 60 patients with decrease of visual acuity were studied, 35 (28 women, half age 31 +/- 10 years) completed criteria of idiopathic ON. A brain MRI was performed in all patients after the diagnosis of idiopathic ON and they subsequently were followed in the outpatient clinic from our center for a mean time of 29 +/- 16 months. 24 out of the 35 patients were treated with corticosteroids in different ways. RESULTS: It has been found 43% of the patients with idiopathic ON to have brain lesions by MRI. During the follow-up 14% of the patients developed a clinically definite MS; all of them had a pathological brain MRI at the basal evaluation (p = 0.009). None of the patients that were treated with high-dose of intravenously corticosteroids developed MS. CONCLUSIONS: The prevalence of silent cerebral lesions in the MRI after an idiopathic ON is elevated in our population although further development of MS is lower possibly due to the short follow-up carried out. The presence of lesions in the MRI confers a high risk for developing MS after an idiopathic ON.
Adolescent↗
Gliclazide treatment of streptozotocin diabetic rats restores GLUT4 protein content and basal glucose uptake in skeletal muscle.
This study examined whether the treatment of streptozotocin (STZ)-diabetic rats with gliclazide (5 mg/kg body weight twice daily orally) increases muscle glucose uptake. Rats were treated (group G, n = 10) or untreated (group D, n = 11) for 12 days. Normal rats served as controls (group C, n = 11). At the end of the treatment, both basal and insulin-stimulated glucose uptake by the perfused hindquarters were measured. In gastrocnemious muscles, the protein content of GLUT4 and the insulin binding and tyrosine kinase activity of partially purified solubilized insulin receptors were measured. Group G had a lower mean glycemic value during the treatment period than group D (mean +/- SEM, 17 +/- 0.6 v 19.7 +/- 0.5 mmol/L, P < .05), without differences in serum insulin levels. Basal glucose uptake by the hindquarters was significantly higher in group G versus group D (2.8 +/- 0.3 v 1.3 +/- 0.2 mumol/g/h, P < .05), and was not different versus group C (3.6 +/- 0.2 mumol/g/h). Insulin-stimulated glucose uptake was higher (P < .05) in group C compared with the two groups of diabetic rats. Glucose uptake at 10(-7) mol/L insulin was higher in group G than in group D (9.2 +/- 0.6 v 7.0 +/- 0.6 mumol/g/h, P < .05). Both insulin binding and tyrosine kinase activity were similar in muscle insulin receptors from both groups of diabetic rats. The GLUT4 protein content was higher in group G than in group D (95 +/- 10 v 57 +/- 7 arbitrary units [AU]/microgram protein, P < .05) and similar to that of group C (113 +/- 13 AU/microgram protein). In conclusion, gliclazide has a glucose-lowering effect in STZ-diabetic rats that could be attributed to an increase in muscle glucose clearance by a post-insulin receptor mechanism, probably related to a normalization of GLUT4 content.
Animals↗
Two new mutations of the glucose-6-phosphate dehydrogenase (G6PD) gene associated with haemolytic anaemia: clinical, biochemical and molecular relationships.
In two unrelated Spanish males with glucose-6-phosphate dehydrogenase (G6PD) deficiency and haemolytic anaemia, and two different novel point mutations in the G6PD gene, have been identified. A C to T transition at nucleotide 406 resulting in a (136) Arg to Cys substitution and a C to G transition at nucleotide 1155 resulting in a (385) Cys to Trp substitution. These two molecular defects have not been described before and are designated G6PD Valladolid 406 C-->T and G6PD Madrid 1155 C-->G. In vitro biochemical characterization of both mutant enzymes showed important differences in their molecular properties according to their different clinical behaviour. In G6PD Valladolid, the mutation of which is located in exon 5, the normal in vitro heat stability may explain its mild clinical expression (low-grade haemolysis interrupted by an acute haemolytic crisis at age 70). In G6PD Madrid, the mutation, located in exon 10, results in a deficient variant associated with neonatal jaundice and life-long chronic nonspherocytic haemolytic anaemia (CNSHA). This finding further emphasizes the importance of this specific region of the G6PD gene in the stabilization of the G6PD molecule. Putative relationships between these single point mutations and the molecular properties of the mutant enzymes are also discussed.
Anemia, Hemolytic↗
[Focal cortical dysplasia].
Explore the source record for details and available documents.
Adolescent↗
[Thrombosis of the superior longitudinal sinus in patients with AIDS. A review of the literature].
Cerebral dural sinus thrombosis (CSDT) is a rare disease with a high rate of mortality. Until now it has not been well-documented in patients with the acquired immunodeficiency syndrome (AIDS). Prompt diagnosis is essential for initiation of suitable treatment, especially in cases with progressive neurological involvement. The diagnostic methods include computed tomography (CT), magnetic resonance imaging (MRI) and conventional angiography. MRI and magnetic resonance angiography (MRA) have become the methods of choice because of their sensitivity and noninvasive nature. An unusual AIDS-patient, who at the time of CSDT presentation had an associated toxoplasmosis infection is described. To our knowledge, this is the first case of CSDT diagnosed by MRI and MRA in an AIDS patient. In the follow-up, MRI and MRA showed the repermeabilitation of the sinus thrombosis. Cerebral dural sinus thrombosis should be considered as a possible cause of neurological decline in a HIV-patient with central nervous system opportunistic infection.
Acquired Immunodeficiency Syndrome↗
Characterization and selection of lactobacilli isolated from Spanish fermented sausages.
The use of starter cultures to control and run the fermentative process is a usual way of manufacturing sausages in meat industries. The first stage in the starter culture designing process is to characterize the lactic acid bacteria isolated from these meat products, in order to select the best strains. The strains used for this study were isolated from different dry fermented sausages, obtained during the manufacturing process. The main tests used to identify the isolated bacteria were: microscopic-morphologic characteristics, catalase activity, production of gas, growth at 8, 15 and 45 degrees C, fermentation of carbohydrates and production of lactic acid isomers. A total of 194 strains were identified. Lactobacillus sake and Lactobacillus plantarum were the most frequent species. Other microbiological tests were also performed, and three strains of Lactobacillus sake were found which did not produce dextran from sucrose.
Carbohydrate Metabolism↗
Acute colonic pseudo-obstruction (Ogilvie's syndrome) treated with erythromycin.
Explore the source record for details and available documents.
Aged↗
[Molecular analysis of glucose-6-dehydrogenase deficiency in Spain].
PURPOSE: G6PD deficiency is the most frequent enzymopathy-producing genetic polymorphism in humans. Up to now, over 400 putative variants of G6PD have been distinguished on the basis of biochemical characterization of the deficient enzyme. Analysis of the G6PD gene has made possible a precise classification of the G6PD molecular variants by identification of about 80 different point mutations causing much of the phenotypic heterogeneity. In the Spanish population, the analysis of G6PD has led to the identification of 15 different point mutations that underlay the phenotypic heterogeneity of G6PD previously reported by biochemical analysis. The purpose of the study has been to identify the genetic mutation responsible of the G6PD deficiency and to improve the knowledge of its genetic homogeneity. PATIENTS AND METHODS: From 50 Spanish males with G6PD deficiency 34 came from out consultation and 16 from the Spanish Study Group on Red Cell Pathology (GEHBTA-Eritropatología) The methods employed included screening of prevalent mutations by ER-PCR, SSCP-PCR, genetic segmentation and biochemical characterization of the deficient enzyme. RESULTS: In 31 cases the mutations were characteristic of the four most frequent polymorphic variants found in Spain (G6PD A-376G/202A, G6PD Mediterranean 563T G6PD Union 1360T and G6PD Seattle 344C). Since these mutations either create or abolish a specific site recognized by a restriction endonuclease (RE), they can be rapidly detected by RE digestion of a PCR-amplified product (PCR-RE). In patients where none of these mutations were present (17 cases), the G6PD gene was subjected to PCR single-strand conformation polymorphism (PCR-SSCP) analysis combined with direct PCR-sequencing. By using this procedure, 9 new mutations have been identified, five of them have been also found in other geographical areas and were associated with favism (G6PD A-376G/968C, G6PD Santamaria 376G/542T, G6PD Aures 143C and G6PD Chatham 1003A) or chronic haemolytic anaemia (G6PD Tomah 1153C). The other four mutations are unique and not reported so far: Three of them are associated with favism (G6PD Málaga 542T, G6PD Murcia 209G and G6PD Valladolid 406T) and one with chronic haemolytic anaemia (G6PD Madrid 1155G). The remaining eight cases are under study. CONCLUSION: The present study confirms the marked genetic heterogeneity of G6PD deficiency in Spain and demonstrate that the PCR-RE analysis is an easy tool for rapid diagnosis of the molecular defect in subjects with the common forms of G6PD deficiency. Furthermore the fact that G6PD A-376G/202A is the most common variant within Spanish population and the finding of G6PD Aures 43C and G6PD Santamaría 76G/542T, who are polymorphic in Algeria is consistent with a significant gene flow from Africa to Europe through Spain.
Africa, Northern↗
Sulfonylureas stimulate glucose uptake through GLUT4 transporter translocation in rat skeletal muscle.
We studied the effect of gliclazide on glucose uptake and GLUT4 translocation in skeletal muscle. Rat hindquarters were perfused in the absence or presence of gliclazide (300 micrograms/ml), insulin or both drugs. The basal glucose uptake was increased 2.7-fold by gliclazide (p < 0.05). Gastrocnemius muscles perfused with gliclazide had a significant increase (2.4-fold) in the GLUT4 content in plasma membranes compared to basal conditions (p < 0.05). The stimulations produced by 1 nM insulin on muscle glucose uptake (2.8-fold) and on GLUT4 level in plasma membranes (2.5-fold) were similar to those produced by gliclazide. The effect of insulin on the glucose uptake and on the GLUT 4 translocation was significantly enhanced by gliclazide (3.4-fold and 3.7-fold vs basal, respectively). These data show that sulfonylureas stimulate glucose uptake in skeletal muscle by promoting the movement of GLUT4 to the plasma membrane.
Animals↗
[Cerebral proton spectroscopy of people infected with the human immunodeficiency virus].
BACKGROUND: This article presents a combined magnetic resonance imaging and proton spectroscopy protocol (MRI/1H-MRS) applied to study the brain of human immunodeficiency virus (HIV) infected patients. The spectroscopic results were compared with clinical and radiological parameters. PATIENTS AND METHODS: The proton spectra of 57 HIV patients and 20 control subjects were obtained from a volume of interest of 8 cm3 located in the parietooccipital region of the brain that did not include any focal lesion. The resonance areas due to N-acetyl aspartate (NAA), creatine (Cr) and choline (Cho) were obtained. The MRI exam allowed us to determine the presence of focal or diffuse lesions and the degree of atrophy. Finally, the clinical exploration included the performance of a Mini-Mental test. The NAA/Cr, NAA/Cho and Cho/Cr ratios were correlated with clinical characteristics, the result of the Mini-Mental test, the presence of lesions and the degree of atrophy. RESULTS: There were altered spectral patterns in a volume of the brain that did not contain any focal lesion. The decrease in the NAA/Cr or NAA/Cho ratios was significative when considering the presence of atrophy, the existence of signs of cognitive deficiencies or the diagnosis of AIDS-dementia complex. CONCLUSIONS: The spectral changes found in the present study suggest the existence of neuronal lesions that would be due to the HIV-infection. A combined MRI/1H-MRS study may provide a more complete information about the neurological impairment by HIV and could constitute a marker of AIDS-dementia complex.
Adult↗
A multicenter proton magnetic resonance spectroscopy study of neurological complications of AIDS.
Human immunodeficiency virus (HIV) infection as seen in Europe and the United States has predominantly been contracted through male homosexual sex or intravenous drug abuse. In infected subjects, the brain is frequently affected both clinically and neuropathologically. The aim of this multicenter study has been to evaluate the value of single-voxel proton magnetic resonance spectroscopy (MRS) in the assessment of the neurological complications of acquired immunodeficiency syndrome (AIDS). MRS (voxel size = 8 ml, TR/TE = 1600/135 msec) was performed in 137 HIV-1-seropositive patients and 64 healthy controls without risk factors at three clinical MR sites operating at 1.5 T. The first result of this multicenter trial is that good reproducibility of results among participating sites was found. This demonstrates the reliability and robustness of MRS in the study of in vivo brain metabolism. In HIV patients, there was no significant correlation between metabolite ratios of brain detected by MRS and CDC grouping of patients or CD4 count. In contrast, the variations of brain metabolite ratios (NA/Cr, NA/Cho, and Cho/Cr) were related to the occurrence of encephalopathy, brain atrophy, or diffuse white matter lesions. There was no significant difference in brain metabolites between male homosexual AIDS patients and male intravenous drug user AIDS patients, whatever their neurological status (neurosymptomatic or neuroasymptomatic). Thus, the mode of transmission of HIV infection does not appear to affect the cerebral changes observed in the proton spectra from AIDS patients. Because of its ease of implementation and high information content, single-voxel proton MRS is likely to play a significant role in the evaluation of HIV-related encephalopathies.
Acquired Immunodeficiency Syndrome↗
Congenital 6-phosphogluconate dehydrogenase (6PGD) deficiency associated with chronic hemolytic anemia in a Spanish family.
Clinical and metabolic studies were performed in four members of a Spanish family with partial (50%) 6 phosphogluconate dehydrogenase (6PGD) deficiency. In all cases the activities of 6 phosphogluconolactone (6PGL) and glutathione reductase (GR) were normal, and the molecular characterization performed in the partially purified 6PGD from the propositus showed normal kinetic and electrophoretic patterns. Two females (the propositus and her sister) suffered from a well-compensated chronic nonspherocytic hemolytic anemia (CNSHA) and exhibited decreased RBC glutathione (GSH) stability with increased oxidative susceptibility, defined by enhanced malonyldialdehyde (MDA) generation "in vitro." The other two members of the family (the propositus's mother and brother) were clinically asymptomatic. In the propositus and her sister, RBC metabolism exhibited a markedly abnormal concentration of glycolytic intermediates, mainly characterized by striking increases in fructose 1,6 bisphosphate (50-fold), dihydroxiacetone-phosphate (20-fold) and glyceraldehyde 3-phosphate (tenfold). Although the precise mechanism of the hemolysis in the two patients is unknown, the enhanced oxidative threat observed in their RBCs may interfere in some way with the glycolytic pathway function, leading to a marked increase in certain metabolic intermediates located before the glyceraldehyde 3 phosphate dehydrogenase (GA3PD) step. Since it seems that GA3PD half-life is modulated by fluctuations of the cytosolic redox status, an "in situ" approach was simulated by using permeabilized RBCs. In these conditions, GA3PD activity was significantly lower in the propositus and her sister than in the asymptomatic members of the family and the simultaneous normal control.
Adult↗
Independent origin of single and double mutations in the human glucose 6-phosphate dehydrogenase gene.
The vast majority of both polymorphic and sporadic G6PD variants are due to single missense mutations. In the four polymorphic variants that have two point mutations, one of the mutations is always 376 A-->G (126 Asn-->Asp), which on its own gives rise to the nondeficient polymorphic variant, G6PD A. In a study of G6PD deficient patients who presented with clinical favism in Spain, we have found a new polymorphic variant that we have called G6PD Malaga, whose only abnormality is a 542 A-->T (181 Asp-->Val) mutation. This is the same mutation as previously found in association with the mutation of G6PD A in the double mutant, G6PD Santamaria. G6PD Malaga is associated with enzyme deficiency (class III), and the enzymic properties of G6PD Malaga and G6PD Santamaria are quite similar, indicating that in this case the effects of the two mutations are additive rather than synergistic. G6PD Santamaria might have been produced by recombination between G6PD A and G6PD Malaga; however haplotype analysis, including the use of a new silent polymorphism, suggests that the same 542 A-->T mutation has taken place independently in a G6PD B gene to give G6PD Malaga and in a G6PD A gene to give G6PD Santamaria. These findings help to outline the relationship and evolution of mutations in the human G6PD locus.
Amino Acid Sequence↗
Sulphonylurea stimulates glucose uptake in rats through an ATP-sensitive K+ channel dependent mechanism.
We studied the effect of gliclazide, a second-generation sulphonylurea, on rat skeletal muscle glucose uptake using perfused hindquarter muscle preparations. Gliclazide at concentrations of 10 to 1000 microgram/ml increased (p < 0.05) the basal glucose uptake. The effect of gliclazide on glucose uptake was immediate and dose-dependent, reaching a plateau at a concentration of 300 micrograms/ml; the half-maximal effect was obtained between 25 and 50 micrograms/ml. The glucose uptake stimulated by gliclazide (300-1000 micrograms/ml) did not differ from that achieved by 10(-9) mol/l insulin, and was lower (p < 0.05) than that obtained with 10(-7) mol/l insulin. The combination of gliclazide (300 micrograms/ml) and 10(-9) mol/l insulin produced an increase in glucose uptake (7.7 +/- 0.6 mumol.g-1.h-1, n = 8, mean +/- SEM) which was higher (p < 0.05) than that achieved with 10(-9) mol/l insulin (5.6 +/- 0.7 mumol.g-1.h-1, n = 11) and not different from that obtained with 10(-7) mol/l insulin (9.8 +/- 1.0 mumol.g-1.h-1, n = 11). Diazoxide (100 mumol/l), an ATP-sensitive K+ channel opener, reversed the stimulatory effect of gliclazide (100 microgram/ml) on muscle glucose uptake from 3.1 +/- 0.4 to 0.5 +/- 0.2 mumol.g-1.h-1, (n = 7, p < 0.001). The addition of diazoxide prior to gliclazide into the perfusion medium blocked the gliclazide-induced glucose uptake by the hindquarter muscle preparations. In conclusion, gliclazide alone has an immediate stimulatory effect on glucose uptake by skeletal muscle and together with insulin has an additive effect on muscle glucose uptake. The effect of gliclazide on muscle glucose uptake seems to be due to the inhibition of ATP-sensitive K+ channels.
Adenosine Triphosphate↗
Colonization of a calcium phosphate/elastin-solubilized peptide-collagen composite material by human osteoblasts.
The evaluation of the suitability of a new biomaterial as a possible substitute for bone tissue is described here. This biomaterial is based on calcium phosphate particles linked to an artificial connective matrix, the elastin-solubilized peptides (ESP) associated with type I and III collagens. This work demonstrates the feasibility of shaping this composite material into discs, describes its microstructural characteristics, and evaluates its capacity as a substrate for the proliferation of human osteoblasts without loss of their phenotypic expression.
Adsorption↗