Search PubMed⌕ Search

Biomedical subjects

M T Medina

Publications and source records attributed to M T Medina.

31 records · Page 2Linked to original sources
PubMed1994

Progress in mapping human epilepsy genes.

The chromosomal loci for seven epilepsy genes have been identified in chromosomes 1q, 6p, 8q, 16p, 20q, 21q, and 22q. In 1987, the first epilepsy locus was mapped in a common benign idiopathic generalized epilepsy syndrome, juvenile myoclonic epilepsy (JME). Properdin factor or Bf, human leukocyte antigen (HLA), and DNA markers in the HLA-DQ region were genetically linked to JME and the locus, named EJM1, was assigned to the short arm of chromosome 6. Our latest studies, as well as those by Whitehouse et al., show that not all families with JME have their genetic locus in chromosome 6p, and that childhood absence epilepsy does not map to the same EJM1 locus. Recent results, therefore, favor genetic heterogeneity for JME and for the common idiopathic generalized epilepsies. Heterogeneity also exists in benign familial neonatal convulsions, a rare form of idiopathic generalized epilepsy. Two loci are now recognized; one in chromosome 20q (EBN1) and another in chromosome 8q. Heterogeneity also exists for the broad group of debilitating and often fatal progressive myoclonus epilepsies (PME). The gene locus (EPM1) for both the Baltic and Mediterranean types of PME or Unverricht-Lundborg disease is the same and is located in the long arm of chromosome 21. Lafora type of PME does not map to the same EPM1 locus in chromosome 21. PME can be caused by the juvenile type of Gaucher's disease, which maps to chromosome 1q, by the juvenile type of neuronal ceroid lipofuscinoses (CLN3), which maps to chromosome 16p, and by the "cherry-red-spot-myoclonus" syndrome of Guazzi or sialidosis type I, which has been localized to chromosome 10. A point mutation in the mitochondrial tRNA(Lys) coding gene can also cause PME in children and adults (MERFF).

Chromosome Mapping↗
PubMed1992

Clinical pharmacokinetics of albendazole in patients with brain cysticercosis.

Albendazole pharmacokinetics were studied in eight patients who were receiving albendazole in doses of 15 mg/kg per day for 8 days as treatment of brain cysticercosis. Albendazole was not detected in plasma, but its main metabolite albendazole sulphoxide could be measured. Maximum plasma levels for albendazole sulphoxide ranged from 0.45 to 2.96 micrograms/mL. The half-life of albendazole sulphoxide was between 10 and 15 hours. A double peak was found in three patients. Mean residence time values were from 14 to 20 hours. Plasma levels of albendazole sulphoxide at the steady state showed great intraindividual variability. The results suggest that albendazole can be administered twice daily rather than three times as is currently done.

Administration, Oral↗
PubMed1992

Continuous focal spikes during REM sleep in a case of acquired aphasia (Landau-Kleffner syndrome).

We report a girl 3 years and 6 months old with onset of aphasia at age 3 years and 3 months. There was no evidence of brain damage and there were no seizures. The neuropsychological evaluation showed that the girl tended to be right-handed, that aphasia was global and that other higher cortical functions seemed to be preserved. Isolated spikes and spikes-and-wave were recorded during wake over the right temporal region with rare independent contralateral abnormalities. During polysomnography (PSG), the physiological patterns of sleep were preserved and right temporal epileptiform discharges were significantly increased in all sleep stages. Maximal activation was obtained at sleep onset and during rapid eye movement (REM) sleep periods, when focal abnormalities became continuous and spread contralaterally. Repeat PSGs showed that the activation profile retained this particular trait, although subclinical discharges tended to increase during slow wave sleep (SWS). This pattern of subclinical temporal status epilepticus during REM sleep differs from the characteristic activation profile found in the syndrome of continuous spikes-and-waves during SWS. However, this profile was transient and all epileptiform changes disappeared during clinical recovery at 18 months of follow-up.

Anticonvulsants↗
PubMed1992

Fatty change in the endometrium.

Fatty change of the endometrial stroma is reported for the first time in the literature. This incidental finding further exemplifies the capacity of the endometrial stroma to undergo benign mesenchymal metaplasia.

Adipose Tissue↗
PubMed1990

Dexamethasone increases plasma levels of albendazole.

Therapy of neurocysticercosis with cysticidal drugs is frequently complicated by the exacerbation of symptoms that follows the inflammation triggered by the acute destruction of cysticerci. Treatment of such adverse reactions with dexamethasone is highly effective. However, it has been shown that dexamethasone lowers the plasma levels of praziquantel, thus reducing its cysticidal efficacy. We measured plasma levels of albendazole, another strong cysticidal drug, when dexamethasone was given simultaneously. We found that dexamethasone increased the plasma levels of albendazole by about 50% (P less than 0.002); hence, it seems that cysticercosis and the ensuing inflammation can be treated simultaneously with albendazole and dexamethasone without diminishing the efficacy of the cysticidal drug.

Adult↗
PubMed1990

Plasma and CSF levels of albendazole and praziquantel in patients with neurocysticercosis.

Albendazole or praziquantel were measured in plasma and cerebrospinal fluid (CSF) in 29 patients with neurocysticercosis. Mean levels of albendazole in plasma were 0.918 microgram/ml and in CSF were 0.392 microgram/ml and levels of praziquantel were 1.640 micrograms/ml in plasma and 0.398 microgram/ml in CSF, after doses of 15 and 50 mg/kg, respectively. Drug concentrations in CSF were 43% for albendazole and 24% for praziquantel. The drug levels obtained for both drugs showed ample individual variations that were not related to age, sex, presence of inflammation in the subarachnoid space, or therapeutic effectiveness; such variations seem to be due to individual differences in pharmacokinetics. Both drugs were effective and the doses currently used of each drug seem to be optimal for therapy of neurocysticercosis.

Adolescent↗
PubMed1990

Neurocysticercosis as the main cause of late-onset epilepsy in Mexico.

We studied 100 consecutive Mexican patients with epilepsy that started after the age of 25 years. All patients underwent clinical evaluation, computed tomography, and electroencephalography; additionally, cerebrospinal fluid analysis was performed in 82 of them. Neurocysticercosis or its sequelae were diagnosed in 50 patients (50%); 36 of these patients had partial seizures, 41 had parenchymal calcifications, and 15 had two or more lesions. Our results are in contrast with those of most studies from countries with a low incidence of neurocysticercosis, where brain tumors, cerebrovascular disease, trauma, and alcoholism are the main causes of tardive epilepsy.

Adult↗
PubMedDate not supplied

Effect of anticysticercal treatment on the prognosis of epilepsy in neurocysticercosis: a pilot trial.

Epilepsy secondary to active or inactive neurocysticercosis (NCC) is a major public health problem in Latin American countries. In an open-label pilot trial, we evaluated and followed (mean = 13 months) 16 patients with epilepsy resulting from active NCC which was treated with anticisticercal (ACC) drugs. These patients were aged 12-68 years with confirmed active NCC and seizures not controlled by adequate antiepileptic drug (AED) therapy. Patients were treated with albendazole or praziquantel (ALB and PZQ, ACC drugs) and AED monotherapy. The number of NCC cysts was markedly reduced by ACC therapy. Thirteen patients remained seizure-free and 2 had only one seizure during follow-up. Our data suggest a positive effect of ACC treatment on the prognosis of epilepsy caused by active NCC, but a prospective, double-blind, controlled study with long-term follow-up must be performed to determine whether ACC therapy improves long-term seizure control.

Adolescent↗
PubMedDate not supplied

[Juvenile myoclonic epilepsy in chromosome 6p12: clinical and genetic advances].

Amongst idiopathic generalized epilepsies, juvenile myoclonic epilepsy (JME) is the most common, accounting for 12% to 30% of all epilepsies in the Western world. Classic JME consists of awakening myoclonias, grand mal convulsions and EEG 4 to 6 Hz polyspike waves that appear in adolescence. Probands and affected family members do not have pyknoleptic 3Hz spike and wave absences. However, in 10 to 30% of patients, rare or spanioleptic polyspike wave absences appear. In 1988,1995,1996,we mapped classic JME to a 7 cM locus in chromosome 6p12 11, called EJM1, using families from Los Angeles and Belize. In 2001,we studied one large family from Belize and 21 new families from Los Angeles and Mexico Cities, aided by a BAC/PAC based physical map and 6 new dinucleotide repeats, to narrow EJM1 to an interval between D6S272 and D6S1573. In 2002, we found myoclonin, the putative gene for typical JME in 6p12. At the congress, we will reveal the identity of the myoclonin gene, its putative function and discuss the significance of this discovery in the JME population at large.

Belize↗