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Biomedical subjects

E Fernández-Alvarez

Publications and source records attributed to E Fernández-Alvarez.

At least 19 recordsLinked to original sources
PubMed2006

Palatal tremor in childhood: clinical and therapeutic considerations.

Palatal tremor (PT) is a rhythmic movement of the soft palate that often causes an ear click. PT can be symptomatic (SPT) or essential (EPT). The symptomatic form usually occurs in adults and the essential form mainly occurs in children. Several different treatments for EPT in children appear in the literature with variable reported efficacy. This report details four paediatric patients with EPT (three males, one female; mean age 6y 4mo [SD 6mo]; age at onset 6-7y) treated with piracetam (2-oxo-1-pyrrolidine acetamide). Piracetam was used to treat EPT because of its antimyoclonic properties. All children showed a good response to doses of 100 to 300mg/kg/day. EPT relapsed on withdrawal of piracetam and remitted on reintroduction. Piracetam's effect on EPT was sustained. It is concluded that piracetam is an effective drug for the treatment of EPT in children.

Child↗
PubMed2005

[Movement disorders of functional origin (psychogenic) in children].

PATIENTS AND METHODS: Sixteen cases of functional (psychogenic) pediatric movement disorders (PMD) have been analyzed. They represents 2.4% of a PMD personal series (age of onset less than 18). RESULTS: Apart from a case, age of onset was older than 10 years. 81% (13/16 cases) were females. Tremor (68%) was the predominant abnormal movement followed by mioclonus. These facts are according with the scarce studies reported of functional PMD. We emphasize the diagnostic difficulties of this kind of conditions. CONCLUSIONS: Diagnostic clues are age of onset older than 10 years, female gender, clinical inconsistency of the movement, increasing or decreasing of the movements with attention to the movements or distraction, normality of the exams including neurophysiological studies. However in some cases a follow-up is necessary to confirm the diagnosis.

Humans↗
PubMed2003

Electrophysiological approach to the study of essential tremor in children and adolescents.

Surface electromyography and accelerometry provide essential information on the neurophysiological characteristics of essential tremor. There are many reports on neurophysiological features in adult-onset essential tremor, but to our knowledge there have been no similar investigations of essential tremor in children. We conducted a neurophysiological study of nine children, six males and three females, with definite essential tremor. They were subdivided into two groups according to age: a 'children's group', consisting of four patients aged from 7 to 12 years, and an 'adolescent group', consisting of five patients aged from 14 to 16 years. Finger tremor as opposed to hand tremor was studied. In children the mean tremor frequency was 5.3 Hz (SD 0.5) with arms extended, which increased to 8.2 Hz (SD 1.5) when we added a mass of 300 g. In adolescents the mean tremor frequency was 9.0 Hz (SD 1.4) with arms extended, and 7.2 Hz (SD 1.8) with added mass. We discuss several hypotheses to find an explanation for these results.

Adolescent↗
PubMed2003

[Stereotypic movements].

Stereotypic movements are repetitive patterns of movement with certain peculiar features that make them especially interesting. Their physiopathology and their relationship with the neurobehavioural disorders they are frequently associated with are unknown. In this paper our aim is to offer a simple analysis of their dominant characteristics, their differentiation from other processes and a hypothesis of the properties of stereotypic movements, which could all set the foundations for research work into their physiopathology.

Child↗
PubMed2002

Autosomal dominant Emery-Dreifuss muscular dystrophy: a new family with late diagnosis.

Emery-Dreifuss muscular dystrophy is characterized by the clinical triad of early onset contractures of elbows, Achilles tendons and spine, wasting and weakness with a predominantly humero-peroneal distribution and life-threatening cardiac conduction defects and/or cardiomyopathy. Two main types of inheritance have been described: the X-linked form is caused by mutations in the STA gene on locus Xq28 and the gene for the autosomal dominant form (LMNA gene) has been localized on chromosome 1q11-q23. Recently, mutations in this LMNA gene have been also found to be responsible for the less frequent autosomal recessive form of the disease. Although all forms share a similar clinical presentation, some differences appear to exist between them as has been described recently in a large number of patients. We present the first documented Spanish family genetically confirmed to have autosomal dominant Emery-Dreifuss muscular dystrophy. Clinical, pathological and genetic data are described. We emphasize the difficulties in diagnosis, especially in sporadic cases or young patients in whom the clinical picture is not completely established.

Achilles Tendon↗
PubMed2002

[Comorbid disorders associated with tics].

INTRODUCTION: Tics are the most frequent abnormal movements in children. This is one reason for their importance. Another reason is their relationship to fascinating disturbances of human behaviour such as compulsion and obsessions. Several 'behavioural disorders', mainly attention-deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD), are more frequent in patients with tics than in the general population. These associated disorders (named 'comorbid') are probably of more consequence than the tics. Relationship between tics and comorbid disorders is not well known. This review considers data, consequences, hypothesis and management of comorbid disorders associated to tics. DEVELOPMENT: From the personal series of children with tics, data of comorbid disorders associated to tics was analysed. Of 340 cases of tics, 132 (39%) cases have ADHD, 135 (40%) cases have OCD, obsessive compulsive symptoms (OCS) or obsessive-compulsive behaviour (OCB). 68 (20%) cases have both ADHD and OCD. Considering only Tourette cases (219) the figures are only slight higher: ADHD (42%), OCD (45%) and ADHD plus OCD (24%) suggesting that all the spectrum of tics has a common basis. CONCLUSIONS: Familial studies shows that 44 percent of the patients with tics have a positive familial history of tics and 30 percent positive familial history of obsessive compulsive signs. The data of the literature on the tics and comorbid disorders relationship is also revised.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

Glutaryl-CoA dehydrogenase deficiency in Spain: evidence of two groups of patients, genetically, and biochemically distinct.

Glutaryl-CoA dehydrogenase (GCDH) deficiency causes glutaric aciduria type I (GA I), an inborn error of metabolism that is characterized clinically by dystonia and dyskinesia and pathologically by neural degeneration of the caudate and putamen. Studies of metabolite excretion allowed us to categorize 43 GA I Spanish patients into two groups: group 1 (26 patients), those presenting with high excretion of both glutarate and 3-hydroxyglutarate, and group 2 (17 patients), those who might not be detected by routine urine organic acid analysis because glutarate might be normal and 3-hydroxyglutarate only slightly higher than controls. Single-strand conformation polymorphism (SSCP) screening and sequence analysis of the 11 exons and the corresponding intron boundaries of the GCDH gene allowed us to identify 13 novel and 10 previously described mutations. The most frequent mutations in group 1 were A293T and R402W with an allele frequency of 30% and 28%, respectively. These two mutations were also found in group 2, but always in heterozygosity, in particular in combination with mutations V400M or R227P. Interestingly, mutations V400M and R227P were only found in group 2, and at least one of these mutations was found in 11 of 15 unrelated alleles, accounting together for 53% of the mutant alleles in group 2. Therefore, it seems clear that two genetically and biochemically distinct groups of patients exist. The severity of the clinical phenotype seems to be closely linked to the development of encephalopathic crises rather than to residual enzyme activity or genotype. Comparison of GCDH protein with other acyl-CoA dehydrogenases (whose x-ray crystal structure has been determined) reveals that most of the mutations identified in GCDH protein seem to affect folding and tetramerization, as has been described for a number of mutations affecting mitochondrial beta-oxidation acyl-CoA dehydrogenases.

Alleles↗
PubMed1999

Inhibition of human immunodeficiency virus type (HIV-1) replication by some diversely functionalized spirocyclopropyl derivatives.

Inhibition of HIV-1 replication by differently substituted spirocyclopropyl compounds has been evaluated. Compound 21 showed a moderate activity (EC50 ranging from 2.3 to 5.8 micrograms/ml) against different HIV-1 strains (IIIB, RF, NDK, and an AZT-resistant strain) in different cell lines (MT-4 and C-8166 cells), while it was cytotoxic at 77.7 micrograms/ml, resulting in a selectivity index of 34. This compound was inactive against HIV-2 (ROD) and SIV (MAC251). From "time-of-addition" experiments compound 21, like AZT, appeared to inhibit HIV-1 at the reverse transcriptase step.

Anti-HIV Agents↗
PubMed1999

Relevance of benzyloxy group in 2-indolyl methylamines in the selective MAO-B inhibition.

1. Previous studies with indolyl derivatives as monoamine oxidase (MAO) inhibitors have shown the relevance of the indole structure for recognition by the active site of this enzyme. We now report a new series of molecules with structural features which determine the selectivity of MAO inhibition. 2. A benzyloxy group attached at position 5 of the indole ring is critical for this selective behaviour. Amongst all of these benzyloxy-indolyl methylamines, N-(2-propynyl)-2-(5-benzyloxyindol)methylamine FA-73 was the most potent MAO-B 'suicide' inhibitor studied. 3. The Ki values for MAO-A and MAO-B were 800+/-60 and 0.75+/-0.15 nM, respectively. These data represent a selectivity value of 1066 for MAO-B, being 48 times more selective than L-deprenyl (Ki values of 376+/-0.032 and 16.8+/-0.1 nM for MAO A and MAO-B, respectively). The IC50 values for dopamine uptake in striatal synaptosomal fractions from rats were 150+/-8 microM for FA-73 and 68 +/- 10 microM for L-deprenyl whereas in human caudate tissue the IC50 values were 0.36+/-0.015 microM for FA-73 and 0.10+/-0.007 microM for L-deprenyl. Moreover, mouse brain MAO-B activity was 90% ex vivo inhibited by both compounds 1 h after 4 mg kg(-1) administration, MAO-A activity was not affected. 4. These novel molecules should provide a better understanding of the active site of monoamine oxidase and could be the starting point for the design of further selective, non-amphetamine-like MAO-B inhibitors with therapeutic potential for the treatment of neurological disorders.

Animals↗
PubMed1999

[Moyamoya disease. A cause of vascular occlusion in childhood].

OBJECTIVE: The objective of this study was to review the cases of Moya-Moya diagnosed in our center. PATIENTS AND METHODS: We reviewed the Moya-Moya cases diagnosed from 1979 to 1997. We evaluated the following elements: age of clinical onset, sex, clinical features, complementary examinations, neuroimage, treatment and follow-up. RESULTS: Six patients were diagnosed. The first case appeared in 1979 and the last in 1997. These included four boys and 2 girls, with ages between 5 months and 14 years. The initial clinical feature in all six cases was acute hemiparesis, noting that in one case this was preceded by homolateral seizures. Neuroimaging revealed ischaemic infarction areas in brain CT or MNR. The diagnosis was based on angiography, where in four cases there appeared bilateral occlusion of the internal carotid, or of the anterior or middle cerebral arteries and in the other two there was a unilateral occlusion of the interior carotid and middle cerebral arteries. Regarding etiology, in four patients the dysfunction was due to either fibromuscular dysplasia of the carotid, neurofibromatosis, cranial trauma or to Down's syndrome. In the other two cases no other primary cause was found. CONCLUSIONS: Acute stroke is an infrequent disease of pediatric age patients, however it is necessary to do a thorough angiography study to rule out the Moya-Moya like vascular anomalies.

Adolescent↗
PubMed1998

"In vitro" effect of some 5-hydroxy-indolalkylamine derivatives on monoamine uptake system.

Three different indolalkylamine derivatives (FA 102, FA 69, FA 70) having in common an -OH group at 5 position of the indole ring and differing in the presence of a methyl group at the N or the acetylenic group of the side chain, have been synthesized and assayed as monoamine oxidase-A (MAO-A) [E.C.1.4.3.4] inhibitors. They were effective inhibitors with, in some cases, similar potencies to clorgyline. "In vitro" experiments were performed on rat brain synaptosomes to investigate whether these MAO-A inhibitors had any effect on noradrenaline (NA), dopamine (DA) and 5-hydroxytryptamine (5-HT) transport systems in different rat brain regions. The effect of these drugs were compared with those of clorgyline and 1-deprenyl. FA 102, FA 69, FA 70 behaved as inhibitors of 3H-monoamine uptake with similar rank of order of potency for amine uptake inhibition: 5-HT > DA > NA. The IC50 values for FA 102, FA 69, FA 70, respectively, were: 17 microM, 60 microM, 18 microM for 5HT uptake in cortex and 37 microM, 55 microM and 20 microM in hippocampus; 70 microM, 385 microM for NA uptake in cortex and 315 microM, 255 microM and 600 microM in hypothalamus; 270 microM, 160 microM, 40 microM for DA uptake in striatum. 1-Deprenyl was a very poor inhibitor of monoamine uptake, whereas clorgyline behaved similarly to these indolalkylamine derivatives. Comparing these results with the IC50 values of citalopram, nisoxetine and GBR12909, specific and selective inhibitors of 5-HT, NA and DA transport systems respectively, indicated that these indolalkylamine derivatives interact more strongly with the 5HT uptake system.

Animals↗
PubMed1997

[The Ohtahara's syndrome: a special form of age-dependent epilepsy].

The aim of this report is to review the clinical and the outcome data in four patients with Ohtahara syndrome at Sant Joan de Déu Hospital, Barcelona, following the same clinical and electroencephalografic criteria reported by the author. The etiology of this syndrome is unknown and plurifactorial. Investigation studies were negative except for the EEG and neuroimaging. MRI was performed in two children, and pachigyria was observed in one and mycropoligyria in the other. There were no response to cofactors, phenobarbital, vigabatrine and valproate. Therefore two patients underwent treatment with ACTH with no response in one and good response in the other. Two patients died at 2 and 6 months; other one was transferred to another center at 6 months-old and was lost at follow-up. The fourth patient, fourteen-month-old, is free of seizures with improvement of EEG register with important development retardation. We conclude that Ohtahara syndrome is a severe neonatal epilepsy with poor neurologic outcome; MRI detects often brain malformations as cortical dysplasia and a therapeutic trial of ACTH is indicated because the possibility of control of the seizures.

Adrenocorticotropic Hormone↗
PubMed1996

[Ataxia telangiectasia: review of 13 new cases].

We report the review of 13 patients who were diagnosed of ataxia telangiectasia before 6 years of age. All of them manifested cerebelous ataxia, oculocutaneus telangiectasias (11), sinopulmonary infections (9), dystonia (9), oculomotor apraxia (9) and Burkitt linfoma (1). We analyse the most common presentation of the disease in early stages and the complementary studies performed. The prompt diagnosis allow us a better control of infections, malignant process and finally the possibility of genetic counseling.

Adolescent↗
PubMed1994

Kinetic behaviour of some acetylenic indolalkylamine derivatives and their corresponding parent amines.

Different methoxy indolalkylamines based on a common structure, and differing in the side chain attached at the 2 position of the indole ring were studied as MAO A inhibitors. Some are acetylenic derivatives and consequently might behave as "suicide" MAO inhibitors (FA 42, FA 43, FA 45). The rest of compounds are the corresponding parent amines and they might behave as MAO substrates (FA 51, FA 52, FA 53, FA 54). The kinetic behaviour of the parent amines as MAO A and MAO B inhibitors and substrates was determined. In case of acetylenic derivatives, kinetic constants defining the non-covalent adduct formation and the covalent adduct formation were also calculated for the mechanism-based inhibition. These parameters will allow us to establish the correlation with structural features that predetermine one compound to be a good MAO substrate or a good MAO A and MAO B inhibitor.

Acetylene↗
PubMed1994

Kinetics of the reversible tight-binding inhibition of pig liver catechol-O-methyltransferase by [2-(3,4-dihydroxy-2- nitrophenyl)vinyl]phenyl ketone.

The inactivation of partially purified pig liver catechol-O-methyltransferase (COMT) by [2-(3,4-dihydroxy-2-nitrophenyl)vinyl]phenylketone has been studied. The results demonstrated that COMT is inhibited in a reversible tight-binding fashion with an apparent Ki of 0.2 microM. IC50 values were determined at different concentrations of both substrates of the enzymatic reaction, pyrocatechol and S-adenosyl-L-methionine (AdoMet). The plot of IC50 versus pyrocatechol concentration gave a straight line, suggesting competitive inhibition. However the nitrocatechol derivative showed an uncompetitive inhibition pattern when measured as a function of AdoMet concentration.

Animals↗
PubMed1993

Inhibition of catechol-O-methyltransferase by 1-vinyl derivatives of nitrocatechols and nitroguaiacols. Kinetics of the irreversible inhibition by 3-(3-hydroxy-4-methoxy-5-nitro benzylidene)-2,4-pentanedione.

It is well known that activated alkene derivatives react with thiol groups according to a Michael's addition reaction. On the basis of the presence of at least one thiol group essential for the activity of catechol-O-methyltransferase (COMT), several 1-vinyl derivatives of nitrocatechol and nitroguaiacol were synthesized and tested as potential irreversible active site-directed inhibitors of COMT. All the synthesized products were potent inhibitors of partially purified pig liver COMT. However, the inhibition was reversible in most cases, with the exception of 3-(3-hydroxy-4-methoxy-5-nitrobenzylidene)-2,4-pentanedione (compound 2) which inhibited COMT in an irreversible manner. When the inhibition of COMT was measured as a function of the length of time of pre-incubation with 2, biphasic kinetics were observed, suggesting the modification of at least two thiol groups which are essential for COMT activity. The analysis of the two parts of the inhibition curve as a function of the inhibitor concentration showed that compound 2 modified the more reactive group in a non-specific manner, while it behaved as an active site-directed inhibitor on the second slow-reacting thiol group. Importantly, a saturating concentration of S-adenosyl-L-methionine (AdoMet) in the pre-incubation mixture gave pseudo-first order kinetics, suggesting total protection of one thiol group. Magnesium ions had no effect on the protection of COMT by AdoMet. In the presence of 3,5-dinitrocatechol (DNC) slight protection of COMT was observed; when the inactivation of both groups was analysed independently, protection of the specifically modified group was detected, while the reaction with the other group was faster in the presence of DNC. When both AdoMet and DNC were present, inactivation of COMT by 2 was not observed, suggesting that both reacting groups are located at or near the active site.

Animals↗