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Biomedical subjects

Y Nevo

Publications and source records attributed to Y Nevo.

At least 19 recordsLinked to original sources
PubMed2004

Increased resting energy expenditure in subjects with Emery-Dreifuss muscular dystrophy.

We have studied changes in energy expenditure and body composition in adult males with Emery-Dreifuss muscular dystrophy, age-matched males with hyperCKemia and age-matched healthy controls. All participants were studied twice, 2-3 years apart. Resting energy expenditure was studied by indirect calorimetry, lean body mass and body fat by dual X-ray absorptiometry, and muscle mass was estimated based on 24-h urinary creatinine excretion. At baseline and 2-3 years later, body fat was significantly higher (P < 0.011 and P < 0.003, respectively) and lean body mass significantly lower (P < 0.024 and P < 0.012, respectively) in patients with Emery-Dreifuss muscular dystrophy as compared to subjects with hyperCKemia and healthy controls. Resting energy expenditure, over the study period, increased significantly in patients with Emery-Dreifuss muscular dystrophy (P < 0.031), but not in patients with hyperCKemia nor in healthy controls. Our study suggests that patients with Emery-Dreifuss muscular dystrophy may have increased energy expenditure relative to healthy subjects. If not met by increased caloric intake, this greater energy expenditure may partially contribute to a further deterioration in their muscle performance.

Absorptiometry, Photon↗
PubMed2004

Nemaline rods and complex I deficiency in three infants with hypotonia, motor delay and failure to thrive.

Three infants are described who had nemaline rods on muscle biopsy and isolated deficiency of complex I of the respiratory chain on biochemical analysis. They all manifested failure to thrive from birth, and hypotonia and muscle weakness within the first three months of life. Different genetic defects leading to isolated complex I deficiency have been described associated with a variety of morphological changes on muscle biopsy, but rods have not been described. Nemaline rods have been secondary phenomena in a number of conditions, as well as being the primary abnormality in nemaline myopathy. However, the combination of nemaline rods and complex I deficiency is an association not previously reported.

Electron Transport Complex I↗
PubMed2001

Novel mutations in the emerin gene in Israeli families.

Emery-Dreifuss Muscular Dystrophy (EMD or EDMD) is a rare X-linked recessive disorder, characterized by progressive muscle wasting and weakness, contractures, and cardiomyopathy, manifesting as heart block. Mutation analysis at the EMD gene locus was performed in 4 unrelated Israeli families with X-linked EMD and in one sporadic case. In the 4 families 4 different mutations were found, 3 of which were novel. These included two frame shift mutations in exon 2 (333delT and 412insA) and one base pair substitution at the consensus +1 donor splice in intron 5 (1429G-->A). The fourth mutation in exon 6 (1675-1678delTCCG) has been previously described. No mutations were identified in the one sporadic case. Two of the three novel mutations were found in exon 2. A summary of the previously published mutations described in the EMD Mutation Database (http://www.path.cam.ac.uk/emd/) as well as the mutations described in our study suggest that the distribution of mutations in EMD gene is not entirely random and that exon 2 is prone to mutations. Hum Mutat 17:522, 2001.

Base Sequence↗
PubMed2001

Worster-Drought and congenital perisylvian syndromes-a continuum?

A 5-year-old female was evaluated because of severe speech and expressive language delay. On examination, she could hardly speak and communicated through gestures. She manifested severe dysarthria and difficulty in protruding and moving her tongue laterally. She lacked coordination of the swallowing process, with drooling and an increased mental reflex. Her cognitive development was normal, and no associated neurologic dysfunction of the limbs was noted. On follow-up, the child experienced two episodes of seizures at 6 years of age. Magnetic resonance imaging of the brain demonstrated perisylvian and frontal polymicrogyria. Clinical and radiologic findings demonstrated a similarity and continuum between congenital suprabulbar paresis (Worster-Drought syndrome) and perisylvian syndrome.

Bulbar Palsy, Progressive↗
PubMed2001

Mutant mitochondrial thymidine kinase in mitochondrial DNA depletion myopathy.

The mitochondrial deoxyribonucleotide (dNTP) pool is separated from the cytosolic pool because the mitochondria inner membrane is impermeable to charged molecules. The mitochondrial pool is maintained by either import of cytosolic dNTPs through dedicated transporters or by salvaging deoxynucleosides within the mitochondria; apparently, enzymes of the de novo dNTP synthesis pathway are not present in the mitochondria. In non-replicating cells, where cytosolic dNTP synthesis is down-regulated, mtDNA synthesis depends solely on the mitochondrial salvage pathway enzymes, the deoxyribonucleosides kinases. Two of the four human deoxyribonucleoside kinases, deoxyguanosine kinase (dGK) and thymidine kinase-2 (TK2), are expressed in mitochondria. Human dGK efficiently phosphorylates deoxyguanosine and deoxyadenosine, whereas TK2 phosphorylates deoxythymidine, deoxycytidine and deoxyuridine. Here we identify two mutations in TK2, histidine 90 to asparagine and isoleucine 181 to asparagine, in four individuals who developed devastating myopathy and depletion of muscular mitochondrial DNA in infancy. In these individuals, the activity of TK2 in muscle mitochondria is reduced to 14-45% of the mean value in healthy control individuals. Mutations in TK2 represent a new etiology for mitochondrial DNA depletion, underscoring the importance of the mitochondrial dNTP pool in the pathogenesis of mitochondrial depletion.

Base Sequence↗
PubMed2000

Mental retardation subsequent to refractory partial seizures in infancy.

Whether seizures are the direct cause of cognitive deterioration in epileptic children is undetermined. This retrospective study aimed to delineate a subgroup of pediatric patients with cognitive deterioration and refractory seizures in the absence of recognized causes for mental retardation. Of the 80 children identified as having mental retardation and refractory seizure disorder, seven (8.7%) had normal cognitive development until at least 1 year of age. Their metabolic status was normal. Five of them suffered repeated frequent partial seizures with onset in the first year of life and two had repeated episodes of status epilepticus. All seven had similar characteristics of early onset partial seizures, six of them had partial seizures secondarily generalized and one had complex partial seizures. The time of peak cognitive deterioration correlated with increases in seizure frequency during that period. Evaluation revealed a well-defined epileptic focus in the absence of neuroimaging abnormality except for hippocampal atrophy in the two children with complex partial seizures and a small vascular malformation in one child. Uncontrolled partial seizures in the first months of life may result in cognitive deterioration.

Adolescent↗
PubMed2000

Alternating hemiplegia of childhood in half-sisters.

We present the family of two girls affected with alternating hemiplegia of childhood who were born to the same mother and different fathers. Previous reports suggested mitochondrial dysfunction as an etiologic mechanism for this disorder. Muscle biopsy, including a measurement of the respiratory chain enzymes, performed in one of the sisters showed no mitochondrial abnormalities. The mode of inheritance is not certain, but an autosomal-dominant gene is most likely.

Adolescent↗
PubMed1999

Fetal muscle biopsy as a diagnostic tool in Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a relentless progressive disorder, leading to severe disability during childhood and death in adolescence or early adulthood. In most families, prenatal diagnosis is readily achieved by molecular detection of DNA deletions using chorionic villi or amniocytes, or by linkage analysis. In some cases, however, molecular methods fail to provide a definitive diagnosis and in such cases in utero fetal muscle biopsy may serve as a diagnostic option. We describe three families in whom fetal muscle biopsy was performed, focusing on the prenatal diagnostic dilemmas, the indications and timing for in utero fetal muscle biopsy, and the difficulties encountered.

Female↗
PubMed1999

Mutation analysis in Emery-Dreifuss muscular dystrophy.

The purpose of this study was to search for STA gene defects in three families with clinically typical Emery-Dreifuss muscular dystrophy. Emery-Dreifuss is an X-linked muscular dystrophy with humeroperoneal weakness and life-threatening, but treatable, cardiac abnormalities in male patients and in female carriers. The defect is in the gene coding for emerin, a 254 amino acid protein of unknown function. Complementary and genomic DNA from T lymphocytes from the reported patients and their family members were amplified, cloned, and sequenced. A novel mutation, a 26 base-pair deletion in three brothers and a carrier mother, was detected in one family. A splicing mutation with one base pair insertion and a five base-pair deletion, which have been described previously, were found in the second and third families, respectively. The additional novel mutation detected and the findings of three different mutations in these three families support the idea of genetic heterogeneity of Emery-Dreifuss muscular dystrophy with different mutations in different families.

Adolescent↗
PubMed1999

Characterization and comparison of autistic subgroups: 10 years' experience with autistic children.

To summarize our 10-year experience with autistic children at the Tel Aviv Child Development Center, the files of all 55 children with autism treated at our center over a 10-year period were retrospectively reviewed. Particular attention was addressed to the value of the medical work-up in detecting the etiology of autism and to factors differentiating infantile autism (IA) from autistic-like behavior (ALB). Twenty-four subjects (44%) had IA and 31 (56%) had ALB. These subgroups were compared for demographic, perinatal, familial, neurological, and psychological findings, and outcome at discharge. Associated medical conditions and the yield of metabolic work-up and neuroimaging and electroencephalography studies are discussed. The two subgroups differed only in severity of autistic symptoms and cognitive function (P<0.05), but not in demographic or neurobiological findings. It was concluded that IA and ALB are similar conditions, and autism has a wide continuum of clinical expressions.

Autistic Disorder↗
PubMed1998

[Cyclic vomiting syndrome in children].

Cyclic vomiting syndrome in children is a manifestation of various etiologies, including gastroenterological and renal disorders, central and autonomic nervous system abnormalities, as well as metabolic and endocrine dysfunction. Frequently no organic cause is found. Personality profiles of children with cyclic vomiting reveal perfectionism, competitiveness, and aggressive behavior. Vomiting attacks have been induced by anxiety and excitement in patients with cyclic vomiting. We describe an 8-year-old girl with cyclic vomiting, frequently associated with occipital headaches, photophobia or dizziness. Psychiatric evaluation indicated a generalized anxiety disorder.

Anxiety Disorders↗
PubMed1998

SMA type 2 unrelated to chromosome 5q13.

We describe two brothers with clinical and histological findings of type 2 spinal muscular atrophy (SMA) associated with small head circumference (<2%) and normal cognitive development. No survival motor neuron (SMN) or neuronal apoptosis-inhibitory protein (NAIP) deletions were detected in these sibs, and they were discordant for the haplotypes determined by DNA markers flanking the 5q13 SMA locus. These findings support the presence of a distinct anterior horn disease unrelated to 5q13. This entity may have either autosomal recessive or X-linked inheritance.

Child, Preschool↗
PubMed1998

Epidemiology of epilepsy in childhood: a cohort of 440 consecutive patients.

This study analyzes the relative frequency and age of onset of the different seizure types in a 20-year cohort of a pediatric neurology outpatient clinic of an urban hospital that serves the majority of the city's population (Tel Aviv Medical Center). Only patients with two or more unprovoked seizures were included. Neonatal seizures were excluded from the analysis. The different seizure types in descending order of frequency were: partial seizures secondarily generalized (20.6%), complex partial seizures (12.5%), West syndrome (9%), simple partial seizures (8.6%), benign rolandic epilepsy of childhood (8%), absence seizures (7%), generalized tonic-clonic seizures (6.6%), generalized tonic seizures (5%), myoclonic seizures (2.2%), benign occipital epilepsy of childhood (2%), mixed type seizures (1.8%), Lennox-Gastaut syndrome (1.5%), juvenile myoclonic epilepsy (0.9%), atypical absence (0.6%), Landau-Kleffner syndrome, Ohtahara syndrome, myoclonic astatic epilepsy, electrical status epilepticus in sleep and startle epilepsy (0.2% each), and unclassified seizures (12%). The findings of this study confirm that there are more pediatric patients with partial seizures (52%) than primary generalized seizures (33%) and that partial seizures secondarily generalized is the most frequent seizure type in this age group.

Adolescent↗
PubMed1998

Neuroimaging of children with partial seizures.

The predictive value of abnormal neurological findings on neuroimaging (NI) of children with partial seizures (PS) was studied. The sample comprised 143 children and adolescents with PS from 1979 to 1996. Fifty patients had the following abnormal NI findings: diffuse atrophy and porencephalic cyst (5.6% each), hemiatrophy, tumors, neurocutaneous syndrome brain lesions, and dysgenesis (4.2% each), and arachnoid cyst and hydrocephalus (2.1% each). There were significantly more NI abnormalities among those with simple PS than among the other groups of complex PS or PS with secondary generalization. All cases of porencephalic cyst (n = 8), and hemiatrophy (n = 6) were in the hemiparetic group, all cases of tumor (n = 6) were in the normal group, while most cases of diffuse atrophy were in the mentally retarded group. Patients with abnormal NIs had a significantly earlier age of seizure onset than the others. The chance of finding a treatable abnormality in neuroimaging was 5% for tumors and 2% for arachnoid cysts in the group of patients with PS and normal neurological findings. Neither an abnormality detected in a neurological examination nor the type of seizure are predictive parameters for suggesting the presence of a resectable brain tumor. All patients with newly diagnosed PS should undergo an MRI.

Adolescent↗
PubMed1998

Childhood chronic inflammatory demyelinating polyneuropathy.

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a chronic disorder of the peripheral nervous system with sensory and motor involvement, and insidious onset over a period of months. In children and adults, both proximal and distal muscles are affected. Muscle stretch reflexes are absent or depressed. Laboratory findings include elevated cerebrospinal fluid protein with no increase of mononuclear cells. Electrophysiological and pathological studies show evidence of demyelination. No control studies of the efficacy of immunomodulating therapy in childhood CIDP are available. However, several studies have indicated clinical improvement after treatment with prednisolone, plasmapheresis and intravenous immunoglobulin, but disappointing results with other immunosuppressive agents. While some children have a monophasic course, with complete recovery, others have a protracted course, with either a slowly progressive or a relapsing-remitting course, resulting in prolonged morbidity and disability.

Adolescent↗
PubMed1998

Generalized tonic and tonic-clonic seizures of childhood.

In a retrospective analysis of all our patients with seizure onset prior to age 16 years, 25 patients with primary generalized tonic (n = 10) or tonic-clonic (n = 15) seizures were identified. These patients constituted 5.7% of the total seizure patient population in our institute between the ages of 1 month and 16 years. The natural history of generalized tonic-clonic seizures is known to be benign; however, that of isolated primary generalized tonic seizures is not clear. Therefore, an attempt was made to characterize the patients suffering from primary generalized tonic seizures and determine their outcome. Analysis of our patient population shows that both seizure types are characterized by early onset of generalized seizures that appear in normally developed children with a normal electroencephalographic background. The children usually respond quickly to antiepileptic drugs. A long-term follow-up (mean period of 7.6 years) was possible in 84% of the patients, and showed that 95% of them were seizure free at the end of the follow-up period. There was no significant difference between the two groups in regard to age of onset, family history, and seizures at follow-up. In conclusion, the natural history of patients with generalized tonic seizures is similar to the benign course of those with generalized tonic-clonic seizures.

Adolescent↗