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Biomedical subjects

G C Guazzi

Publications and source records attributed to G C Guazzi.

At least 19 recordsLinked to original sources

Cloning and sequence analysis of the human liver rhodanese: comparison with the bovine and chicken enzymes.

The cDNA for the human rhodanese (thiosulfate: cyanide sulfurtransferase, EC 2.8.1.1), a nuclearly encoded protein of the mitochondrial matrix, was isolated from a human fetal liver cDNA library. Nucleotide sequence revealed an open reading frame coding for a polypeptide of 295 amino acids, which presented a 57% and 58% identity with the bovine and avian rhodanese, respectively. The analysis of the 5'-ends of the coding region gave no evidence for the presence of a cleavable signal sequence as found in other mitochondrial proteins. A comparison with two available amino acid sequences (cow and chicken) showed that sequence similarity is not restricted to the alpha-helices and beta-structures motifs which are remarkably superimposable in the two halves of bovine rhodanese, but extends to adjacent regions.

Adrenal Glands

Schilder's diffuse sclerosis.

The natural history and the evolution of the concept of Schilder's diffuse sclerosis have been described by Poser and van Bogaert in 1956 and there is really not much to add to their analysis. The major progress made in the clinical, genetic, enzymatic and biochemical workup of many of the conditions previously grouped under the denomination of Schilder's disease confirms its heterogeneity. We will discuss (1) the myelinoclastic disorders; (2) the leukodystrophies with disorders such as adrenoleukodystrophy and the still very ill-defined sudanophilic leukodystrophies; (3) the subacute sclerosing leukoencephalitis, better known today as the subacute sclerosing panencephalitis. In conclusion, the name of Schilder is to be remembered as are all the names of the great neurologists and neuropathologists of the past but it would be better to avoid nowadays the eponym of Schilder's disease in order to prevent confusion between different disorders.

Adolescent

The clinical aspects of adult hexosaminidase deficiencies.

The authors describe the clinical phenotypes of hexosaminidase deficiencies (GM2 gangliosidosis). The symptoms, differently combined, include cerebellar ataxia, motor neuron disease, dystonia, psychosis, neurovegetative troubles with different severity. Morphological changes are evident in rectal, muscle or nerve biopsies. Minor clinical changes are described in carriers from a family. A chronic GM2 gangliosidosis has to be suspected in any atypical case with the above-mentioned symptoms with autosomal-recessive inheritance.

Adolescent

Cherry-red spot myoclonus syndrome (type I sialidosis).

The authors report the sequence of the clinical symptoms in type I sialidosis or cherry-red spot myoclonus syndrome, derived from the cases personally observed and from the literature. They also report neuropathological and neurochemical data. A serial EEG study in a case shows the tendency to a progressive deregulation of cerebral electric activity. Therapeutic attempts to reduce myoclonus, which is one of the more disabling symptoms in this syndrome, are described.

Adolescent

Giant axonal neuropathy in 2 siblings: a generalized disorder of intermediate filaments.

The authors report the clinical details and progress over 15 years of 2 siblings with giant axonal neuropathy with multisystem involvement. Changes in intermediate filaments (IF) were found in myelinated and unmyelinated fiber axons of the peripheral nerve and in Schwann cells, endothelial cells of skin vessels, skin fibrocytes and melanocytes, confirming a generalized disorder of IF organization.

Adolescent

Lymphocyte activating factor activity in the serum and cerebrospinal fluid of patients with multiple sclerosis.

Serum and cerebrospinal fluid (CSF) from patients with multiple sclerosis (MS), patients with other (non-inflammatory) neurological diseases (OND), patients with non-inflammatory non-neurological diseases, and normal controls were assayed for lymphocyte activating factor (LAF) activity by thymocyte costimulation. LAF activity was detected in normal control sera, which did not differ significantly in this respect from MS or OND patient sera. Not were there significant differences by stage of MS (chronic progressive MS, MS in relapse and MS in remission) or between MS patients and the non-inflammatory non-neurological controls. Almost all the CFSs assayed presented lower values than did the corresponding sera. Serum and CSF after fractionation showed no significant increase in LAF activity except in the 2 MS patients in remission. From these data it may be assumed that LAF activity does not necessarily correspond to the clinical phase of MS. The possible role of LAF activity as a marker of MS progression has yet to be determined.

Adult

Congenital lactic acidosis due to a defect of pyruvate dehydrogenase complex (E1). Clinical, biochemical, nerve biopsy study and effect of therapy.

We report an 8-year-old patient with clinical features suggesting Leigh's syndrome and with a decreased activity of the E1 component of the pyruvate dehydrogenase complex in cultured skin fibroblasts. A nerve biopsy showed the presence of severe peripheral neuropathy, rarely described in the literature. The partial correction of lactic acidosis with oral sodium bicarbonate chronic therapy may result in a slow evolution of the clinical symptoms.

Acidosis, Lactic

Neurocutaneous syndromes with pigmentary abnormalities and central nervous system involvement. II. Two cases with atypical incontinentia pigmenti.

Two cases are reported of a boy and a girl with similar neurocutaneous syndromes clinically characterized by hyperpigmented skin patches and severe CNS involvement. The diagnosis of atypical cases of Incontinentia Pigmenti is suggested. The different syndromes with mental and motor retardation associated with skin abnormalities (Incontinentia Pigmenti, Ito's hypomelanosis, phakomatoses, etc.) are reviewed.

Child, Preschool

Congenital oculo-facial paralysis (Moebius syndrome): evidence of dominant inheritance in two families.

Moebius syndrome is usually sporadic. The few familial cases reported in the literature have autosomal dominant inheritance, with absence of the associated congenital malformations often described in the sporadic form. Here we report two families with more than one member affected by congenital, unilateral paresis of cranial nerves, transmitted with autosomal dominant inheritance.

Adult

Frequency of blood-retina and blood-brain barrier changes in multiple sclerosis.

The frequency of blood-retina barrier (BRB) and blood-brain barrier (BBB) alterations was studied in 20 cases of Multiple Sclerosis (MS) (12 relapsing and 8 chronic-progressive). BBB impairment was found in 7 out of 20 patients (35%), 3 of whom had the chronic-progressive form of the disease. Alterations to BRB were found in 9 out 20 cases (45%): 2 out 12 (17%) of the relapsing cases and 7 out 8 of the chronic-progressive cases (87.5%). BBB impairment was found in 3 of the 9 cases (33%) with BRB alterations. Our findings indicate that BRB and BBB alterations do not occur simultaneously. We propose that the higher frequency of BRB alterations in chronic-progressive MS may be a sign of persistent antigenic stimulation.

Blood-Brain Barrier

Mitochondrial encephalo-neuro-myopathy with myoclonus epilepsy, basal nuclei calcification and hyperlactacidemia.

We report a new case of MERRF (myoclonus epilepsy with ragged red fibers) syndrome with basal nuclei calcification on the brain CT scan, without hormonal abnormalities, with high CSF protein and hyperlactacidemia, juvenile onset and death at 18 years. Biochemical study of mitochondrial muscle enzymes showed decreased NADH-cytochrome-C-reductase and Succinate-cytochrome C-reductase activity, suggesting a Complex III defect of the respiratory chain. Similar reported cases are reviewed.

Adolescent

Cerebro-ocular dysplasia and muscular dystrophy: report of two cases.

The authors report two cases with severe cerebro-ocular malformations and muscular dystrophy who died at 14 and 8 months of age. In both, muscular dystrophy was confirmed by EMG and high muscle enzyme values. In one case, autopsy showed severe cerebral malformation consisting of lissencephaly, hydrocephalus, agenesis of corpus callosum, chiasma and olfactory bulb and lobe, absence of pyramides and cerebellar vermis. In sections of cerebral cortex a clear absence of structural cellular organization and spongiosis of the white matter were evident. Similar disorganization was found in the cerebellum where numerous calcifications were present. The muscle showed signs of primitive muscular dystrophy. The clinical autonomy of the cerebro-ocular-dysplasia-muscular-dystrophy syndrome is discussed. The clinical and pathological data are compared with the two other similar syndromes (i.e. Fukuyama's and Warburg's diseases).

Abnormalities, Multiple

Type 3 (chronic) GM1 gangliosidosis presenting as infanto-choreo-athetotic dementia, without epilepsy, in three sisters.

Three sisters (ages 27, 24, and 17 years) presented with slowly progressing dystonic dementia and spastic tetraparesis with infantile onset. CSF, bone marrow, and conjunctival cells showed storage vacuoles. Biochemical analysis revealed increased urinary oligosaccharide excretion and decreased activity of acid beta-D-galactosidase and beta-D-fucosidase in serum, leukocytes, and cultured fibroblasts. The parents' enzyme values were in the heterozygous range. This is the only case in the literature of severe dementia associated with the clinical symptoms of type 3 GM1 gangliosidosis. The clinical heterogeneity of GM1 gangliosidosis and the significance of the combination of beta-D-galactosidase and beta-D-fucosidase defects in this syndrome are discussed.

Adolescent

Normal rhodanese activity in leukocytes from Leber patients: enzyme characterization and activity levels.

The thiosulfate:cyanide sulfurtransferase (rhodanese) enzyme (EC 2.8.1.1.) was studied in human leukocytes from control subjects and from nine patients with Leber's hereditary optic atrophy. Enzyme activity was proportional to protein concentration in the tested range (0.09 to 0.39 mg) as well as to incubation time. The optimal pH for reaction was 8.7 and the apparent Km for thiosulfate was 7 X 10(-3) M. No significant difference of enzyme activity was present in Leber's disease.

Female