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Biomedical subjects

G Coppola

Publications and source records attributed to G Coppola.

At least 55 records · Page 3Linked to original sources
PubMed2001

Topiramate in refractory partial-onset seizures in children, adolescents and young adults: a multicentric open trial.

PURPOSE: This study was to evaluate the efficacy and safety of topiramate (TPM) in refractory partial epilepsy in children, adolescents and young adults. METHODS: We performed a prospective open label add-on study in 55 patients (age 2-30 years, mean 15 years) with refractory partial seizures. Topiramate was added to one or two other baseline drugs and the efficacy was rated according to seizure type and frequency. RESULTS: TPM was initiated at a daily dose of 0.5-1 mg/kg, followed by a 2-week titration at increments of 1-3 mg/kg/24h, up to a maximum daily dose of 12 mg/kg. After 9 months of treatment, 11 patients (20%) had 100% fewer seizures and 25 patients (45%) had a more than 50% seizure reduction. TPM appeared to be effective both in cryptogenic (76.2%) and symptomatic (58.8%) partial epilepsies. Mild to moderate adverse events were present in 25 patients (45.4%), mostly represented by drowsiness, nervousness and hyporexia with or without weight loss. CONCLUSION: TPM was an overall effective and safe add-on drug both in cryptogenic and symptomatic childhood refractory partial seizures, the adverse reactions being generally mild or moderate.

Adolescent↗
PubMed2001

A mutation (V260M) in the middle of the M2 pore-lining domain of the glycine receptor causes hereditary hyperekplexia.

We investigated the molecular basis of hyperekplexia (STHE), an inherited neurological disorder characterised by neonatal hypertonia and an exaggerated startle response, in a kindred and identified a novel missense mutation in the pore-lining M2 domain of the alpha1 subunit of the glycine receptor (GLRA1). Sequencing analysis of all exons of the GLRA1 gene revealed a G1158A base transition in affected, heterozygous patients. The base transition results in a valine to methionine substitution at codon 260 in the middle of the M2 transmembrane domain. The location within the M2 domain suggests for this substitution a likely role in altering ion channel properties.

Amino Acid Sequence↗
PubMed2000

Circulating adhesion molecules in humans: role of hyperglycemia and hyperinsulinemia.

BACKGROUND: We assessed the role of glucose and insulin in the regulation of circulating levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular adhesion molecule-1 (sVCAM-1) in normal subjects and in patients with type 2 diabetes. METHODS AND RESULTS: Plasma glucose concentrations were acutely raised in 10 normal subjects and 10 newly diagnosed, complication-free type 2 diabetic patients and maintained at 15 mmol/L for 2 hours. In normal subjects, plasma sICAM-1, but not sVCAM-1, levels rose significantly (P<0.01) at 1 hour and returned to basal values at 2 hours. In another study, octreotide was infused during the hyperglycemic clamp to block the release of endogenous insulin; this prevented the late fall of plasma sICAM-l levels observed in under control clamp conditions. The diabetic patients had plasma sICAM-1 levels significantly higher (P<0.01) than those of the control subjects; plasma sVCAM-1 levels were similar. Both sICAM-l and sVCAM-1 concentrations did not change significantly during the control hyperglycemic clamp; however, octreotide infusion increased plasma sICAM-1 levels, which remained significantly (P<0.05) above baseline during the whole clamp. In an additional 10 type 2 diabetic patients, overnight euglycemia (plasma glucose 5.5 mmol/L) obtained with the aid of an artificial pancreas or supplementation with l-arginine (10 g PO for 30 days), the natural precursor of NO, normalized the increased plasma sICAM-1 levels. CONCLUSIONS: Acute hyperglycemia increases circulating sICAM-1 levels in normal subjects, whereas the correction of hyperglycemia with insulin or l-arginine supplementation restored to normal levels the increased plasma sICAM-1 levels of type 2 diabetic patients.

Adult↗
PubMed2000

Accuracy of clinical diagnostic criteria for Friedreich's ataxia.

The accuracy of the diagnostic criteria for Friedreich's ataxia proposed by Harding and by the Quebec Cooperative Study on Friedreich's Ataxia was studied in 142 patients with progressive unremitting ataxia of autosomal recessive inheritance or sporadic occurrence. Eighty-eight patients received the molecular diagnosis of Friedreich's ataxia. Traditional diagnostic criteria are characterized by high specificity, but they yield a high number of false-negative diagnoses. We suggest three levels of diagnostic certainty: (1) possible Friedreich's ataxia, defined as sporadic or recessive progressive ataxia with (a) lower limb areflexia and dysarthria, Babinski sign, or electrocardiographic repolarization abnormalities, or (b) with lower limb retained reflexes and electrocardiographic repolarization abnormalities (95% sensitivity and 88% positive predictive value); (2) probable Friedreich's ataxia as defined by Harding's criteria (63% sensitivity and 96% positive predictive value) or by Quebec Cooperative Study on Friedreich's Ataxia criteria (63% sensitivity and 98% positive predictive value); (3) definite diagnosis, molecularly confirmed.

Adolescent↗
PubMed2000

Purification and characterization of human alpha-galactosidase A expressed in insect cells using a baculovirus vector.

Fabry disease is an X-linked inborn error of glycolipid metabolism caused by deficiency of the lysosomal enzyme alpha-galactosidase A. The enzyme is responsible for the hydrolysis of terminal alpha-galactoside linkages in various glycolipids. To perform more extensive biochemical characterization and to develop new approaches for enzyme therapy, a method of producing and purifying recombinant alpha-galactosidase A suitable for scale-up manufacture for use in humans is needed. Previously, a catalytically active recombinant human alpha-galactosidase A was expressed using a baculovirus vector and purified using conventional chromatography. However, the level of expression was too low to permit economical production and the chromatographic techniques used for enzyme purification were not suitable for enzyme to be used in humans. Therefore, the cDNA of the enzyme was cloned to an improved baculovirus vector and the enzyme was expressed in a 15-liter bioreactor using optimized growth conditions. Infection of insect cells by the baculovirus resulted in a significant fivefold increase in the level of secreted recombinant alpha-galactosidase A activity that is compatible with economic manufacturing. The recombinant alpha-galactosidase A was purified to homogeneity using ion exchange (Poros 20-CM, Poros 20-HQ) and hydrophobic chromatography (Toso-ether, Toso-butyl) using the BioCAD HPLC workstation. These chromatographic steps are readily scalable to larger volumes and are appropriate for the purification of the recombinant human alpha-galactosidase A to be used in clinical trials of enzyme replacement therapy for Fabry disease patients.

Amino Acid Sequence↗
PubMed2000

Expression and characterization of glycosylated and catalytically active recombinant human alpha-galactosidase A produced in Pichia pastoris.

Fabry disease is an X-linked inborn error of glycolipid metabolism caused by deficiency of the lysosomal enzyme alpha-galactosidase A. This enzyme is responsible for the hydrolysis of terminal alpha-galactoside linkages in various glycolipids. An improved method of production of recombinant alpha-galactosidase A for use in humans is needed in order to develop new approaches for enzyme therapy. Human alpha-galactosidase A for use in enzyme therapy has previously been obtained from human sources and from recombinant clones derived from human cells, CHO cells, and insect cells. In this report we describe the construction of clones of the methylotrophic yeast Pichia pastoris that produce recombinant human alpha-galactosidase A. Recombinant human alpha-galactosidase A is secreted by these Pichia clones and the level of production is more than 30-fold greater than that of previously used methods. Production was optimized using variations in temperature, pH, cDNA copy number, and other variables using shake flasks and a bioreactor. Expression of the human enzyme increased with increasing cDNA copy number at 25 degrees C, but not at the standard growth temperature of 30 degrees C. The recombinant alpha-galactosidase A was purified to homogeneity using ion exchange (POROS 20 CM, POROS 20 HQ) and hydrophobic (Toso-ether, Toso-butyl) chromatography with a BioCAD HPLC Workstation. Purified recombinant alpha-galactosidase A was taken up by fibroblasts derived from Fabry disease patients and normal enzyme levels could be restored under these conditions. Analysis of the carbohydrate present on the recombinant enzyme indicated the predominant presence of N-linked high-mannose structures rather than complex carbohydrates.

Bioreactors↗
PubMed2000

Pontocerebellar hypoplasia type 2 (PCH2): report of two siblings.

We describe two sisters affected by pontocerebellar hypoplasia type 2 associated with microcephaly, hypertonia, severe choreiform movements, an almost complete lack of psychomotor development, and generalized tonic-clonic seizures. Clinical and neuroradiological findings ruled out other conditions associated with pontocerebellar hypoplasia, i.e. pontocerebellar hypoplasia type 1, carbohydrate-deficient glycoprotein syndrome, and olivopontocerebellar hypoplasia/atrophy.

Agenesis of Corpus Callosum↗
PubMed2000

Influence of GAA expansion size and disease duration on central nervous system impairment in Friedreich's ataxia: contribution to the understanding of the pathophysiology of the disease.

OBJECTIVE: To verify if GAA expansion size could account for the severity of the central nervous system involvement in Friedreich's ataxia (FA). METHODS: Retrospective study of 52 FA patients (mean age 26.9+/-12.1 years; mean disease duration 10.6+/-7.6 years) homozygous for GAA expansion. Median nerve somatosensory evoked potentials (SSEPs) were available in 36 FA patients, upper limb motor evoked potentials (MEPs) to transcranial magnetic stimulation in 32, brainstem auditory evoked potentials (BAEPs) in 24, and visual evoked potentials (VEPs) in 34. N20, P100, MEP amplitude, SSEP and MEP central conduction time (CCT and CMCT), P100 latency and I-III and I-V interpeak latency, and a BAEP abnormality score were correlated with disease duration and GAA expansion size on the shorter (GAA1) and larger (GAA2) allele in each pair. RESULTS: The GAA1 size inversely correlated with the N20 amplitude (r = -0.49; P<0. 01). Disease duration directly correlated with CMCT (r = 0.57; P<0.01) and BAEP score (r = 0.61; P<0.01) and inversely with MEP (r = -0.40; P<0.05) and P100 amplitude (r = -0.39; P<0.05). CONCLUSIONS: Our data suggest that central somatosensory pathway involvement in FA is mainly determined by GAA1 expansion size. Vice versa, degeneration of pyramidal tracts, auditory and visual pathways seems to be a continuing process during the life of FA patients.

Adolescent↗
PubMed2000

Benign familial neonatal convulsions (BFNC) resulting from mutation of the KCNQ2 voltage sensor.

Benign familial neonatal convulsions (BFNC) is a rare autosomal inherited epilepsy. We studied the KCNQ2 coding region in a large, four-generation, Italian family with BFNC. A missense mutation C686T predicting the change of one of the innermost arginine (R214W) of the key functional voltage sensor (S4 helix), has been found in all affected members. This substitution probably reduces the movement of the voltage sensor that precedes channel opening during voltage-dependent activation. Several mutations affecting the trans-membrane domain and the pore region of the K+ channels belonging to the KQT-like family have been described in some human diseases associated with altered regulation of cellular excitability (ie BFNC, some LQT syndromes and DFNA2). R214W represents the first mutation involving the region of the voltage sensor.

Amino Acid Sequence↗
PubMed2000

Effect of diabetes on some primitive reflexes.

Primitive reflexes (PRs) are present in newborns; they disappear as the brain matures and increase in frequency in healthy elderly individuals. Primitive reflexes are more frequent in some neurological disorders than in age-matched controls. The aim of this study was to investigate the effect of diabetes on some PRs. We examined three PRs (glabellar tap, snout and palmomental reflexes) in 376 subjects: 111 normal age-matched controls, 60 patients with cerebrovascular disease (CVD) and 205 patients with type 2 diabetes mellitus. The latter patients were divided into three groups: (1) diabetics without neurological complications (D); (2) diabetics with cerebrovascular disease (D-CVD); and (3) diabetics with polyneuropathy (D-PN). The frequency of PRs was increased in CVD, unchanged in D-CVD (except palmomental) and greatly reduced in D and D-PN. It is possible that the vascular lesions in perforating arteries of the pons in diabetic subjects, previously studied in some pathological reports, can account for the reduced occurrence of primitive reflex responses.

Aged↗
PubMed2000

Relative frequencies of CAG expansions in spinocerebellar ataxia and dentatorubropallidoluysian atrophy in 116 Italian families.

Two hundred and forty-eight patients from 116 Italian families with dominant ataxia were studied for CAG expansion within SCA1, 2, 3, 6, 7 (spinocerebellar ataxia) and DRPLA (dentatorubropallidoluysian atrophy) genes. Fifty-six percent of the families originated from Southern, 19% from Central and 25% from Northern Italy. SCA2 was the commonest mutation, accounting for 47% of the families, followed by SCA1 (24%), SCA6 (2%), SCA7 (2%) and DRPLA (1%). No SCA3 family was found. Twenty-four percent of the families carried a still unidentified mutation. When occurrence of mutations was evaluated according to the geographic origin, SCA1 was the commonest in Northern (72%), whereas SCA2 was prevalent (63%) in Southern Italy. The number of CAG repeats in SCA1 normal alleles was higher in Northern than in Central-Southern Italy.

Alleles↗
PubMed1999

Combining serial analysis of gene expression and array technologies to identify genes differentially expressed in breast cancer.

Several methods have been used recently to determine gene expression profiles of cell populations. Here we demonstrate the strength of combining two approaches, serial analysis of gene expression (SAGE) and DNA arrays, to help elucidate pathways in breast cancer progression by finding genes consistently expressed at different levels in primary breast cancers, metastatic breast cancers, and normal mammary epithelial cells. SAGE profiles of 21PT and 21MT, two well-characterized breast tumor cell lines, were compared with SAGE profiles of normal breast epithelial cells to identify differentially expressed genes. A subset of these candidates was then placed on an array and screened with clinical breast tumor samples to find genes and expressed sequence tags that are consistently expressed at different levels in diseased and normal tissues. In addition to finding the predicted overexpression of known breast cancer markers HER-2/neu and MUC-1, the powerful coupling of SAGE and DNA arrays resulted in the identification of genes and potential pathways not implicated previously in breast cancer. Moreover, these techniques also generated information about the differences and similarities of expression profiles in primary and metastatic breast tumors. Thus, combining SAGE and custom array technology allowed for the rapid identification and validation of the clinical relevance of many genes potentially involved in breast cancer progression. These differentially expressed genes may be useful as tumor markers and prognostic indicators and may be suitable targets for various forms of therapeutic intervention.

Biomarkers, Tumor↗
PubMed1999

Why do some Friedreich's ataxia patients retain tendon reflexes? A clinical, neurophysiological and molecular study.

Among 101 patients homozygous for GAA expansion within the X25 gene, 11 from 8 families had Friedreich's ataxia with retained reflexes in the lower limbs (FARR). These patients had a lower occurrence of decreased vibration sense, pes cavus, and echocardiographic signs of left ventricular hypertrophy than the 90 FA patients with areflexia. The mean age at onset was significantly later (26.6+/-11.4 vs. 14.2+/-6.9 years), and the mean size of the smaller allele was significantly less (408+/-252 vs. 719+/-184 GAA triplets) in FARR patients. The neurophysiological findings were consistent with milder peripheral neuropathy and milder impairment of the somatosensory pathways in FARR patients.

Adult↗
PubMed1999

Spinocerebellar ataxia type 2 in southern Italy: a clinical and molecular study of 30 families.

Autosomal dominant cerebellar ataxia type I is the most common form of dominant ataxia. A genetic heterogeneity has been identified with five different loci (SCA1, 2, 3, 4, and 6). A pathological expansion of a CAG sequence has been identified in SCA1, 2, 3, and 6. We performed molecular analysis in 51 families with autosomal dominant cerebellar ataxia type I, mainly originating from southern Italy and Sicily. Thirty families carry an expanded CAG sequence within SCA2 gene. The mean number of repeats was 39.9 +/- 3.3 in 85 expanded alleles, with a range of 34-52. The number of triplets was inversely correlated with age at onset and explained 76% of the variance. The best fit was obtained with an exponential relationship between variables. Expanded alleles were unstable when transmitted from parents to offspring. Expansions were more common than contractions, accounting for 59% of the total meioses and for 80% of the father-child transmissions. The mean intergenerational variation was 1.9 repeats (range -3 to +15) with higher values for male transmissions. Bulbar and autonomic signs were related to disease duration, pyramidal signs to CAG size, cerebellar features and peripheral neuropathy to both. Among the remaining 21 families, three carried the SCA1 and one the SCA6 mutation. This study suggests that SCA2 is the prevalent mutation in southern Italy.

Adolescent↗
PubMed1997

Lamotrigine as add-on drug in children and adolescents with refractory epilepsy and mental delay: an open trial.

We report the results of an open trial with lamotrigine (LTG) as add-on drug in children and adolescents with refractory epilepsy and mental delay. Thirty-seven outpatients received LTG for a median period of 7 months at a daily dose of 5 and 15 mg/kg in valproate and non-valproate patients, respectively. The total number of seizures decreased by 100% in eight patients (21.6%) and by >50% in five patients (13.5%). However, the number of seizures remained unchanged in 20 patients (54.1%) and increased in four (10.8%). Lamotrigine was more effective in patients with typical and atypical absences, and in patients affected by atonic seizures. Six children (16.2%) developed generally mild adverse side-effects suggesting that LTG is well tolerated.

Adolescent↗
PubMed1997

Vigabatrin as add-on therapy in children and adolescents with refractory epilepsy: an open trial.

Seventy-seven children and adolescents with drug-resistant epilepsies received vigabatrin as add-on therapy for a median of 18 months (range 4-36 months) at a dose of 50 mg/kg/day divided in two doses; patients with spasms were given a maximum dose of 100 mg/kg/day. In 23 patients (29.9%), seizure frequency decreased by 50-100% and in 12 patients (15.6%) by 25-50%. The number of seizures remained unchanged in 34 patients (44.1%) and increased in seven (9.1%). Vigabatrin was most effective in cryptogenic and symptomatic partial seizures (39% and 43%, respectively), and in infantile spasms (25%). Adverse events occurred in 20 patients (26%), though they were generally mild and transient, suggesting that vigabatrin is well tolerated.

Adolescent↗
PubMed1997

Neonatal sporadic hyperekplexia: a rare and often unrecognized entity.

We report the case of a newborn infant with transient generalized stiffness, obvious from the first days of life, increased muscle tone and repeated myoclonic jerks, who was unsuccessfully treated with phenobarbital until the diagnosis of neonatal sporadic hyperekplexia. To our knowledge this is the first case successfully treated with clobazam, a 1.5 dibenzodiazepine.

Acoustic Stimulation↗