HPLC analysis of tetrahydrobiopterin and its pteridine derivatives using sequential electrochemical and fluorimetric detection: application to tetrahydrobiopterin autoxidation and chemical oxidation.

Tetrahydrobiopterin (BH(4)) is an essential cofactor of endothelial nitric oxide (NO) synthase and when depleted, endothelial dysfunction results with decreased production of NO. BH(4) is also an anti-oxidant being a good "scavenger" of oxidative species. NADPH oxidase, xanthine oxidase, and mitochondrial enzymes producing reactive oxygen species (ROS) can induce elevated oxidant stress and cause BH(4) oxidation and subsequent decrease in NO production and bioavailability.

[Diabetic peripheral neuropathy: reflections and drug-rehabilitative treatment].

About 60 to 70 percent of people with diabetes have some neuropathy. Diabetic neuropathy can be classified as peripheral, autonomic, proximal, focal and multifocal or mixed. Peripheral neuropathy, the most common type of diabetic neuropathy, causes pain and/or loss of feeling in the toes, feet, legs, hands, and arms; extreme sensitivity to touch, loss of balance and coordination; muscle weakness and loss of reflexes, especially at the ankle, leading to changes in the way a person walks.

A pilot trial of levetiracetam in eyelid myoclonia with absences (Jeavons syndrome).

Objective: Eyelid myoclonia with absences (EMA) or Jeavons syndrome characterized by eyelid myoclonia (EM) (with or without absences), eye closure-induced EEG paroxysms, and photosensitivity. We conducted an open-label trial of levetiracetam in EMA.

Patients And Methods: Patients were recruited in different Italian Epilepsy Centres.

Epilepsy and toxocariasis: a case-control study in Italy.

Purpose: To assess the relationship between epilepsy and toxocariasis in adult subjects by means of a case-control study in Catania, Italy.

Methods: People with epilepsy (PWE) were randomly selected from the database of the center of epilepsy of our department. Epilepsy was diagnosed according to the definition proposed by the International League Against Epilepsy.

Myocardial ischemia results in tetrahydrobiopterin (BH4) oxidation with impaired endothelial function ameliorated by BH4.

Coronary vasodilation is impaired in the postischemic heart with a loss of endothelial nitric oxide synthase (eNOS) activity, but the mechanisms underlying ischemia-induced eNOS dysfunction are not understood. For nitric oxide (NO) synthesis, eNOS requires the redox-sensitive cofactor tetrahydrobiopterin (BH(4)); however, the role of BH(4) in ischemia-induced endothelial dysfunction remains unknown. Therefore, isolated rat hearts were subjected to varying durations of ischemia, and the alterations in NOS-dependent vasodilation were measured and correlated with assays of eNOS activity and cardiac BH(4) concentrations.

Hydroxylation of D-phenylalanine as a novel approach to detect hydroxyl radicals: application to cardiac pathophysiology.

Objective: Research in the pathophysiology of ischemia/reperfusion or redox signaling is hindered by lack of simple methodology to measure short-lived oxygen radicals. In the presence of hydroxyl radical ((*)OH), d-phenylalanine (d-Phe) yields para-, meta- and ortho-tyrosine. We have previously demonstrated that d-Phe can accurately detect (*)OH formation in chemical, enzymatic and cellular systems by simple HPLC methodology [Anal Biochem 290:138;2001].

Clinical and genetic findings in 26 Italian patients with Lafora disease.

Purpose: EPM2B mutations have been found in a variable proportion of patients with Lafora disease (LD). Genotype-phenotype correlations suggested that EPM2B patients show a slower course of the disease, with delayed age at death, compared with EPM2A patients. We herein report clinical and genetic findings of 26 Italian LD patients.

Metalloproteinase inhibitor counters high-energy phosphate depletion and AMP deaminase activity enhancing ventricular diastolic compliance in subacute heart failure.

Cardiac matrix metalloproteinases (MMPs) stimulated by the sympathomimetic action of angiotensin II (AII) exacerbate chamber diastolic stiffening in models of subacute heart failure. Here we tested the hypothesis that MMP inhibition prevents such stiffening by favorably modulating high-energy phosphate (HEP) stores more than by effects on matrix remodeling. Dogs were administered AII i.

Epilepsy and multiple sclerosis in Sicily: a population-based study.

Purpose: To evaluate the association between epilepsy and multiple sclerosis (MS), we analyzed the incidence of epilepsy in a population-based incidence cohort of MS in Catania, Sicily.

Methods: According to Poser's diagnostic criteria, 170 incident cases of MS have been identified from 1975 to 1994 in the city of Catania. All these subjects underwent a complete neurological examination to confirm the diagnosis of MS and to identify those patients with a history of seizures.

Autosomal dominant lateral temporal epilepsy: clinical spectrum, new epitempin mutations, and genetic heterogeneity in seven European families.

Purpose: [corrected] To describe the clinical and genetic findings of seven additional pedigrees with autosomal dominant lateral temporal epilepsy (ADLTE).

Methods: A personal and family history was obtained from each affected and unaffected member, along with a physical and neurologic examination. Routine and sleep EEGs, computed tomography (CT), or magnetic resonance imaging (MRI) were performed in almost all the patients.

Clinical heterogeneity in eyelid myoclonia, with absences, and epilepsy.

Eyelid myoclonia with absences should always be considered in the investigation of children with epilepsy.