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J Arenas

Publications and source records attributed to J Arenas.

At least 73 records · Page 4Linked to original sources
PubMed2000

Serum levels of coenzyme Q10 in patients with Parkinson's disease.

We compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio in 33 patients with Parkinson's disease (PD) and 31 matched controls. The mean serum coenzyme Q10 levels did not differ significantly between the 2 study groups. Coenzyme Q10 levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale (UPDRS) or the Hoehn and Yahr staging in the PD group. The coenzyme Q10/cholesterol ratio had a significant correlation (although low) with duration of the disease (r = -0.46), total UPDRS score (r = -0.39), motor examination of the UPDRS (r = 0.45). These values were not influenced significantly by therapy with levodopa or dopamine agonists. The normality of serum coenzyme Q10 and coenzyme Q10/cholesterol ratio suggest that these values are not related with the risk for PD.

Age of Onset↗
PubMed2000

Serum levels of coenzyme Q10 in patients with Alzheimer's disease.

We compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio in 44 patients with Alzheimer's disease (AD), 17 patients with vascular dementia (VD), and 21 matched controls. The mean serum coenzyme Q10 and cholesterol levels and the coenzyme Q10/cholesterol ratio of patients with AD or VD did not differ significantly from those of controls. Coenzyme Q10 levels and coenzyme Q10/cholesterol ratio of AD or VD patients were not correlated with age, age at onset, duration of the disease or scores of the MiniMental State Examination. These results suggest that these values are not related with the risk for AD or VD.

Aged↗
PubMed2000

Serum levels of coenzyme Q10 in patients with amyotrophic lateral sclerosis.

To elucidate whether serum coenzyme Q10 levels are related with the risk for amyotrophic lateral sclerosis (ALS), we compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio, in 30 patients with ALS and 42 matched controls using a high performance liquid chromatography technique. The mean serum coenzyme Q10 levels and the coenzyme Q10/cholesterol ratio did not differ significantly between the 2 study groups. These values were not influenced by the clinical form (spinal vs. bulbar) of ALS, and they did not correlate with age, age at onset, and duration of the disease. These results suggest that serum coenzyme Q10 concentrations are unrelated with the risk for ALS.

Age Factors↗
PubMed2000

Normal cerebrospinal fluid levels of insulin in patients with Parkinson's disease.

We compared CSF levels insulin, measured by a Radioimmunoanalysis method, in 24 patients with Parkinson's disease (PD) and 21 matched controls. The CSF insulin levels did not differ significantly between PD patients and controls. CSF insulin levels were not correlated with age, age at onset, duration of the disease, scores of the Unified Parkinson Disease Rating Scale of the Hoehn and Yahr staging in the PD group. Antiparkinsonian therapy did not influence significantly and CSF levels of insulin. These results suggest that CSF insulin concentrations are not a biological marker of PD and its severity.

Aged↗
PubMed2000

A mitochondrial tRNA(Lys) gene mutation (T8316C) in a patient with mitochondrial myopathy, lactic acidosis, and stroke-like episodes.

We studied a patient with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes who had morphologically and biochemically abnormal muscle mitochondria. Molecular analysis revealed a T8316C transition in the mitochondrial DNA tRNA(Lys) gene. The mutation was homoplasmic in muscle from the proposita, heteroplasmic in her blood, and still less abundant in blood from her asymptomatic maternal relatives. The T8316C mutation affects a highly conserved base pair and was not found in controls, thus satisfying the accepted criteria for pathogenicity. Our data document the genetic heterogeneity in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes syndrome, underlining that the same syndrome may be associated with mutations of different genes.

Acidosis, Lactic↗
PubMed2000

Single large-scale mitochondrial DNA deletion in a patient with encephalopathy, cardiomyopathy, and prominent intestinal pseudo-obstruction.

We studied a 62 year-old woman with a clinical phenotype characterized by encephalopathy, restrictive cardiomyopathy, and prominent intestinal pseudo-obstruction. Muscle morphology showed ragged red fibres with ultrastructurally abnormal mitochondrial whereas muscle respiratory chain was normal. Molecular genetics revealed the 'common deletion' in mtDNA, which represented 40% of total mtDNA. These data expand and confirm the wide clinical spectrum of mitochondrial disorders associated with single large-scale mtDNA deletions.

Cardiomyopathies↗
PubMed2000

A homozygous missense mutation (A659D) in the myophosphorylase gene in a Spanish patient with McArdle's disease.

We identified a novel missense mutation in the myophosphorylase gene (PYGM) in a Spanish patient with McArdle's disease. This homozygous C-to-A mutation results in the replacement of a highly conserved alanine at amino acid position 659 with an aspartic acid in the C-terminal domain of the myophosphorylase gene protein, near binding sites for pyridoxal phosphate and glucose. Our data further expand the genetic heterogeneity in patients with McArdle's disease.

Adult↗
PubMed2000

Serum levels of coenzyme Q10 in patients with multiple sclerosis.

To elucidate whether serum coenzyme Q10 levels are related with the risk for multiple sclerosis (MS) or are a marker for the activity of the disease, we compared serum levels of coenzyme Q10 and the coenzyme Q10/cholesterol ratio, in 31 patients with MS (during exacerbations) and 19 matched controls using a high performance liquid chromatography technique. The mean serum coenzyme Q10 levels and the coenzyme Q10/cholesterol ratio did not differ significantly between the 2 study groups. The values did not correlate with age, age at onset, and duration of the disease. These results suggest that serum coenzyme Q10 concentrations are unrelated with the risk for MS and are not a useful marker of activity of the disease.

Adult↗
PubMed2000

Effectiveness and safety of balloon dilation of the papilla and the use of an occlusion balloon for clearance of bile duct calculi.

OBJECTIVE: The purpose of this study was to describe a technique for percutaneous bile duct stone clearance by pushing the stones into the small bowel after balloon dilation of the papilla. SUBJECTS AND METHODS: During a 2-year period, 38 patients were treated percutaneously for stones in the biliary tree. Twenty-one patients were treated through a T tube or transcystic tract. Seventeen patients were treated through a transhepatic tract. Twenty-three patients had one stone each. Eight patients had two stones, and seven patients had three or more calculi. Stone size ranged from 3 to 16 mm in diameter (mean size, 6.7 nm). Balloon diameter based on the transverse diameter of the stones ranged from 7 to 18 mm (mean, 6.7 mm). An 11.5-mm occlusion balloon was used for pushing the stones through a 7- to 9-French vascular introducer. A catheter was left in the common bile duct from 1 to 6 days for external drainage. RESULTS: The technique was successfully used for clearance of stones in 36 (94.7%) of the 38 patients. With 29 patients, the procedure was performed with only one attempt. Two attempts were necessary for five patients, and three attempts were necessary for four patients. Two major complications were cholangitis and biliary pleural effusion. No deaths were related to the procedure. CONCLUSION: Percutaneous bile duct stone clearance by dilation of the papilla and evacuation of the stones in an antegrade fashion with an occlusion balloon is a safe and effective technique. It can be an alternative to basketing stones in selected patients.

Adult↗
PubMed1999

A double mutation (A8296G and G8363A) in the mitochondrial DNA tRNA (Lys) gene associated with myoclonus epilepsy with ragged-red fibers.

OBJECTIVE: To define potential pathogenic mitochondrial DNA (mtDNA) point mutations in a patient with myoclonus epilepsy with ragged-red fibers (MERRF) syndrome. BACKGROUND: MERRF syndrome is typically associated with point mutations in the mtDNA tRNALys gene. METHODS: We performed morphologic, biochemical, and genetic analysis of muscle samples from the patient and four relatives. Molecular genetic studies included sequencing, PCR, and restriction enzyme analysis on whole muscle, blood, and single muscle fibers. RESULTS: Muscle biopsy showed cytochrome c oxidase (COX), negative ragged-red fibers (RRF), and a defect of complex I of the mitochondrial respiratory chain. We found an A8296G transition and a G8363A mutation in the mtDNA tRNALYs gene. The A8296G was almost homoplasmic in muscle and blood from the propositus and his oligosymptomatic maternal relatives. The G8363A mutation was heteroplasmic and more abundant in muscle than in blood, and its proportion correlated with clinical severity. Single muscle fiber analysis showed significantly higher levels of G8363A genomes in COX-negative than in normal fibers, and almost homoplasmic levels of mutant A8296G mtDNA in both COX-negative and normal fibers. The two mutations affect highly conserved nucleotides and were not found in controls. CONCLUSIONS: The G8363A mutation is pathogenic; the co-occurrence of the A8296G mutation is of unclear significance and is likely to be a rare polymorphism.

Adult↗
PubMed1999

Molecular analysis in Spanish patients with muscle carnitine palmitoyltransferase deficiency.

The most common mutation in muscle carnitine palmitoyltransferase II (CPT II) deficiency is a missense mutation that replaces a leucine for a serine residue at amino acid position 113 of the CPT II protein (S113L). We performed molecular analysis in a group of 14 Spanish patients with CPT II deficiency from ten unrelated families. The S113L mutation was observed in 8 of the 14 patients studied. Seven patients were homozygous for the mutation, 1 patient was heterozygous, and 6 patients did not carry the mutation on either allele. Seven healthy relatives belonging to three different families carried the mutation on one allele. One patient carried the missense mutation that replaces a tyrosine for a serine at amino acid position 628 on one allele. Our data indicate that the S113L is also the most common mutation in Spanish patients with CPT II deficiency in muscle, and that further pathogenic mutations remain to be identified.

Carnitine O-Palmitoyltransferase↗
PubMed1999

Mitochondrial diseases in children: neuroradiological and clinical features in 17 patients.

Mitochondrial diseases result from structural, biochemical or genetic defects of mitochondria, which contain the respiratory chain. They usually affect children and young adults. We report the CT and MRI findings in 17 patients under 14 years of age, the youngest reported to date, with various mitochondrial diseases. Although imaging studies may be normal negative in the early stages, follow-up usually shows many abnormalities, which depend on clinical status and the disease. We have recognised a spectrum of findings that can be divided into four patterns: nonspecific myelin lesions (8/17); grey-matter nuclei involvement (6/17); a leukodystrophic pattern; and calcification of the brain (1/17), although mixed forms, particularly myelin and grey-matter lesions are frequent.

Brain↗
PubMed1999

Doppler duplex color localization of osteoid osteomas.

We present two cases of osteoid osteoma in adolescent boys. The lesions were located in the proximal metaphysis of the right tibia and left femoral diaphysis respectively. Doppler duplex color study demonstrated clearly the highly vascular nidus and its feeding artery in one case and only the feeding artery in the second. We believe these are the first descriptions of osteoid osteomas assessed with Doppler duplex color, which was also used as guidance for the percutaneous localization and biopsy.

Adolescent↗
PubMed1999

Respiratory chain enzyme activities in spermatozoa from untreated Parkinson's disease patients.

We studied respiratory chain enzyme activities in spermatozoa homogenates from 12 untreated Parkinson's disease (PD) male patients and from 23 age matched healthy male controls. When compared with controls, PD patients showed significantly lower specific activities for complexes I+ III, II+III, and IV. However, citrate synthase corrected activities were similar in patients and controls. Values for enzyme activities in the PD group did not correlate with age at onset, duration, scores of the Unified Parkinson's Disease Rating Scales and Hoehn and Yahr staging. These results suggest that this tissue cannot be used to develop a diagnostic test for PD.

Aged↗