PubMed Health⌕ Search

Biomedical subjects

M Bigozzi

Publications and source records attributed to M Bigozzi.

7 recordsLinked to original sources
PubMed2005

Pendred syndrome: study of three families.

Although the textbook view of the Pendred syndrome is that of an autosomal recessive condition characterised by deafness and goitre, it is increasingly clear that not all patients present this classical clinical description. Malform-ations of the inner ear, specifically, enlargement of the vestibular aqueduct, are common in the Pendred syndrome. Mutations in the Pendred syndrome gene have been observed in patients with deafness and vestibular aqueduct dilatation, in the absence of other Pendred syndrome features. In our study, all patients with congenital profound or severe sensory-neural deafness were evaluated using computed tomography and magnetic resonance imaging, followed by genetic examinations and blood tests. The procedure followed was the sensory-neural child deafness protocol elaborated by the Joint Committee for Infant Hearing based on skull and petrous bone. In 3 families, the computed tomography scans (performed on 7 out of 8 of these deaf subjects) showed enlarged vestibular aqueducts. The present study evaluates whether or not enlargement of the vestibular aqueduct should be considered as the most likely presentation of the Pendred syndrome.

Connexin 26↗
PubMed2001

[2 cases of oto-spondylo-megaephyseal dysplasia].

Spondylo-epiphyseal dysplasia (SED) is a heterogeneous clinical condition covering many skeletal anomalies, particularly of the spinal column and proximal epiphysis of the long bone. It can be associated with several forms of craniofacial malformations, often with ocular pathologies and only rarely with deafness (recently described as Otospondylo-megaepiphyseal dysplasia "OSMED"). When present, hearing loss is mainly neurosensorial and this may be explained by the presence of type II collagen in the inner ear; in fact, the synthesis of this collagen is altered in "OSMED". On the other hand, antibodies vs. type II collagen have been found in patients with pathologies of both articulation and of the inner ear, including sudden hearing loss. The latter pathologies present such antibodies and provide a good prognostic index, even for immunosuppressive therapy. The present work describes two cases of SED with neurosensorial hearing loss, most likely "OSMED", diagnosed in two female patients (mother and daughter). Then there is a discussion of the clinical, anatomopathological and radiological elements that prove useful in evaluating the specific pathology, emphasizing the problems regarding genetics and differential diagnosis between this and other similar cases described in the literature since 1969. Finally, two hypotheses are advanced as to the pathogenesis of the neurosensorial hearing loss, both supported by case history, clinical and instrumental findings from these two patients.

Adult↗
PubMed1998

Hearing loss due to the mitochondrial A1555G mutation in Italian families.

Six Italian families with familial nonsyndromic hearing loss consistent with a maternal pattern of inheritance were analyzed for mitochondrial mutations. The three known mitochondrial mutations associated with nonsyndromic hearing loss were investigated by polymerase chain reaction amplification, followed by restriction fragment length analysis or DNA sequencing. The A7445G mutation and C7472 insertion were not present in either of the families, but the A1555G mutation in the 12S rRNA gene was identified in homoplasmic form in two of the families. In one of the families the onset of hearing loss is congenital, while in the other it starts later in life. The families are from different regions of Italy, and mitochondrial haplotype analysis showed that the mutation arose independently in these two families. This suggests that the A1555G mutation may not be an uncommon cause of hearing loss in Italians, and is clinically important because maternal hearing relatives of patients with the A1555G mutation are at risk for aminoglycoside induced deafness. We discuss potential reasons for the normal phenotype in some relatives with the mutation, and the different onset of hearing loss in the two families.

Adolescent↗
PubMed1986

On newborn cuddliness.

We discuss the methodological implications of research into the newborn's response to cuddling, that is cuddliness, an item on the Brazelton NBAS scale. After analyzing its dimension as an interaction cycle, we describe an investigation into cuddliness in 52 newborns aged 0 to 3 hours before they had been fed or presented to their mothers. We report on the behavioral changes that proved to be most significant both for postural sequence and for involvement of the partner. These data are correlated with the variations in level of alertness observed during the maneuvers and characterizing the course of the interaction, which started in the quiet awake state (level 3-4) and ended with the transition either to sleepiness or to tension.

Arousal↗
PubMedDate not supplied

Inherited susceptibility to aminoglycoside ototoxicity: genetic heterogeneity and clinical implications.

PURPOSE: Aminoglycoside-induced ototoxicity appears to have a genetic susceptibility in some individuals, and the A1555G mutation in the mitochondrial 12S ribosomal RNA gene has been shown to be responsible for this susceptibility in all familial cases. An Italian family with 5 family members who became deaf after aminoglycoside exposure presented to us, and molecular analysis excluded the A1555G mutation. The purpose of this study is to identify the molecular basis for the aminoglycoside susceptibility in this family. PATIENTS AND METHODS: Two sisters and three of their children developed severe to profound high-frequency hearing loss after aminoglycoside exposure. DNA was extracted from the blood of these individuals and their unaffected relatives, and analyzed for mitochondrial DNA mutations. The region around nucleotide 961 was also cloned and individual clones were sequenced. RESULTS: Sequencing of the 12S ribosomal RNA gene revealed a thymidine deletion at position 961, with a complex pattern of sequence around this mutation. Sequencing of individual clones around the 961 mutation demonstrated a varying number of inserted cytosines in different mitochondrial molecules. CONCLUSION: This family establishes the nucleotide 961 thymidine deletion associated with a varying number of inserted cytosines in the mitochondrial 12S ribosomal RNA gene as the second pathogenic mutation that can predispose to aminoglycoside ototoxicity. It demonstrates the clinical relevance of taking a family history before administering aminoglycosides to any patient. In addition, it would be desirable for sporadic patients with aminoglycoside-induced hearing loss to be screened with molecular tests for the presence of the 1555 and 961 mutations. Such screening could significantly decrease the prevalence of aminoglycoside-induced hearing loss.

Adult↗