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Biomedical subjects

A Luengo

Publications and source records attributed to A Luengo.

10 recordsLinked to original sources
PubMed2001

Prevalence of epilepsy in northeast Madrid.

During a period of 42 months, we studied the prevalence of epilepsy in a specific health district, composing by four towns with 98,405 inhabitants older than 10 years. This has been accomplished by a two-phase cross-sectional study. The prevalence rate observed was 4.12/1000 inhabitants for all types of epilepsy. No significant differences were found between the sexes. Sixty-three per cent of affected individuals had partial seizures, with a confirmed cause in 45%. Fifty-five patients with single unprovoked seizures, were also identified but not included in the prevalence rate.

Adolescent↗
PubMed1999

Lipoprotein(a) and other lipoproteins in hypothyroid patients before and after thyroid replacement therapy.

AIMS: To analyse the influence of thyroid hormones on serum lipoprotein(a) (Lp(a)) concentration and other lipid parameters, and hence potentially on coronary artery disease (CAD) risk. METHODS: Thirty-six patients with hypothyroidism and 165 age-matched control euthyroid subjects were evaluated in a cross- sectional study, determining thyroid function tests and fasting serum lipids and lipoproteins. In a follow-up study for those hypothyroid patients the same determinations were repeated after normalization of thyroid state by levothyroxine (L-T(4)) replacement therapy. Patients needing other treatments were excluded. At baseline, patients with hypothyroidism had significantly higher levels of Lp(a), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (apo) A-I and apo B, and a higher TC/high-density lipoprotein cholesterol (HDL-C) ratio than control subjects. RESULTS: Severity of the hypothyroid state, expressed by serum thyroid-stimulating hormone, was correlated with serum levels of Lp(a), LDL-C, and TC (r= 0.64, 0.52, 0.49, P= 0.005, P= 0.033, P= 0. 048, respectively). The pretreatment Lp(a) levels were also correlated with those of posttreatment Lp(a)(r= 0.68, P= 0.002). All patients, who presented basal Lp(a) levels higher than 30 mg/dl, showed a decrease in Lp(a) concentrations by L-T(4)therapy, and these normalized in eight cases (22.2%). Euthyroid state gave rise to a significant reduction of serum Lp(a) by 32.3%, of LDL-C by 22. 8%, of TC by 17%, of apo A-I by 9.6%, and of apo B by 9.3%. After L-T(4)therapy, CAD risk, expressed as TC/HDL-C ratio, decreased by 19.9%. CONCLUSIONS: These results show that hypothyroidism is associated not only with elevated serum levels of LDL-C but also with elevated serum Lp(a) concentrations. Lp(a) levels may be at least partially modulated by thyroid hormone-dependent mechanisms, thus increasing the risk of developing premature atherosclerosis in hypothyroid state, that might be reduced by L-T(4)therapy.

Adult↗
PubMed1998

Slow allotypic variants of the NAT2 gene and susceptibility to early-onset Parkinson's disease.

OBJECTIVE: To determine the frequency and the linkage distribution of seven mutations at the polymorphic gene coding for the arylamine N-acetyl transferase (NAT2; EC 2.3.1.5) in 121 unrelated patients with sporadic PD and in 121 unrelated healthy volunteers. METHODS: The study was performed with mutation-specific PCR using genomic DNA obtained from blood of the probands. RESULTS: Comparison of the NAT2 genotypes of the overall PD patients and control subjects did not indicate statistically significant differences. However, patients with early-onset PD (onset before the age of 50 years, n=37) showed a higher frequency of slow-acetylation genotypes (78.4% patients) compared with both healthy control subjects (55.4%) and with late-onset (onset after 51 years of age, n=84) PD patients (54.8%). Such a difference was statistically significant (p < 0.015) and was the result of a homogeneous increase in the frequency of slow-acetylation alleles. All subgroups analyzed in the study were in Hardy-Weinberg equilibrium for mutations at the NAT2 gene. CONCLUSIONS: Slow-acetylation-mutated alleles may be considered low-penetrance genes in early-onset PD pathogenesis, with a relative risk ratio for individuals with slow-acetylation genotype of 2.92 (95% CI, 1.26 to 6.78). This study provides evidence for the interaction of genetic and environmental factors in the etiology of sporadic PD.

Adult↗
PubMed1996

[Relationship between primary care and neurological care].

The problems posed by health care are related to health service structure and development. The transformation of a three level care structure into one of just two levels, primary care and specialized care, plays its part. With the aim of analyzing the importance these factors might have in present-day health care, we carried out an aleatoric study of all those patients who attended our neurological service in the years 1992 and 1993. We obtained two sample groups consisting of 921 and 849 patients respectively through interconsultatory requests from practitioners within a limited health care area. We studied the patient's background, the requesting practitioner, diagnosis obtained and complementary tests used. Patients from individual practitioners varied in number from 4 to 38, with some 20% of all patients having been referred by just six practitioners. 20% of the patients we studied showed no neurological pathology. Complementary tests used in all diagnoses sent to us amounted to less than half the number of patients studied. We analyzed the importance these factors have in the present delay in health care services.

Brain Diseases↗
PubMed1995

Association between the oxidative polymorphism and early onset of Parkinson's disease.

The frequency of five cytochrome P450IID6 allelic variants was studied in deoxyribonucleic acid from 123 patients with Parkinson's disease and 150 healthy volunteers. This was achieved by the use of mutation-specific polymerase chain reaction and restriction fragment length polymorphism. The analyses of the CYP2D6 genotype revealed no evidence for a higher prevalence of poor metabolizers among patients with Parkinson's disease. However, increased frequency of patients with Parkinson's disease with the genotype CYP2D6wt/CYP2D6B was observed. This is attributable exclusively to subjects with early onset of the disease (28 to 49 years), with a relative risk ratio of 4.16 (95% confidence limits, 2.0 to 8.3; p < 0.0005). The subjects who had late-onset Parkinson's disease (> or = 50 years) had genotypes and CYP2D6 allele frequencies similar to the healthy subjects. This indicates that the oxidative polymorphism is related to early-onset but not to late-onset Parkinson's disease. A different influence of CYP2D6 genotype on the risk of development of Parkinson's disease is observed in Spaniards, compared with previous findings in British subjects. These results suggest the combined effect of environmental toxins and CYP2D6 in the cause of Parkinson's disease.

Adult↗
PubMed1990

Aminopyrine N-demethylase activity in human liver microsomes.

Aminopyrine N-demethylase activity and the contents of cytochrome P-450, cytochrome b5, and NADPH-reductase activity in human liver microsomes from 31 different patients were studied. Our results show the existence of significant interindividual, but not sex- or age-related differences in N-demethylase activity (ranging between 0.52 and 4.42 nmol/min/mg protein), and that these differences are directly correlated with the content of cytochrome P-450 and NADPH-reductase activity, but not with that of cytochrome b5 content, in the samples. In contrast, no differences were found in the Michaelis-Menten constant values for aminopyrine (mean, 2.4 mmol/L) or NADPH (mean, 69 mumol/L), strongly suggesting that interindividual differences could be due to the occurrence of different amounts of the same enzyme, rather than the presence of different enzymes, in the population studied.

Adult↗
PubMedDate not supplied

[Acute sensory neuropathy associated with a varicella-zoster infection].

INTRODUCTION: Sensory neuropathy is a clinical entity which has been considered to be found in relation to neoplasia, Sjogren's syndrome, long-term pyridoxine treatment, or to be idiopathic. CLINICAL CASE: We present the case of a 33 year old woman who developed acute sensory neuropathy after being diagnosed as having varicella. She had no previous history of weight loss or other signs of neoplasia, no dryness of the mucous membranes or history of arthritis and had taken no toxic substances or pyridoxine, thus ruling out other causes of sensory neuropathy. The acute varicella infection was apparent from the clinical characteristics and the presence of specific IgM in serum. CONCLUSION: The clinical signs, in the absence of other circumstances which might have been related, together with the presence of acute varicella-zoster virus infection seems to indicate that the two conditions were related.

Acute Disease↗
PubMedDate not supplied

Caffeine demethylase activity in human and Dark Agouti rat liver microsomes. Comparison with aminopyrine N-demethylase activity.

Human and Dark Agouti rat liver microsomes were analyzed for caffeine metabolism focusing on demethylase activity by using a simplified isocratic HPLC method. Results showed that, despite interspecies quantitative and qualitative differences on caffeine metabolism, mainly demethylated caffeine metabolites were detected in both species. Humans showed interindividual quantitative differences in caffeine demethylase activity in contrast to rats and, in both cases, the proportion of metabolites remained constant. In addition, aminopyrine N-demethylase activity was assayed, showing a direct correlation with caffeine demethylase activity in humans (r = 0.71) that is reported here for the first time, but not in rats (r = 0.21). These results indicate that, in human liver microsomes, caffeine and aminopyrine could be demethylated by the same or by closely related enzymes; whereas in Dark Agouti rats, there is no apparent relation between caffeine and aminopyrine demethylation pathways.

Aminopyrine↗