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Biomedical subjects

A Serra

Publications and source records attributed to A Serra.

At least 19 recordsLinked to original sources
PubMed2005

Sensorineural hearing loss in sickle cell disease patients in Sicily.

AIM: Sickle cell disease has been frequently associated with sensorineuronal hearing loss. Several studies have demonstrated a significant prevalence rate of sensorineuronal hearing loss in black patients reporting a range of 11-41%, while few data are reported for white people with Hb S/beta thalassemia. In this paper we evaluated the prevalence of sensorineuronal hearing loss in a Sicilian population affected by sickle cell disease. METHODS: Otologic and audiologic examinations were performed in 50 patients with S-beta thalassemia (37 with the beta(s)beta(0th) and 13 with the beta(s)beta(+th)) and 23 patients with sickle cell anemia (beta(s)beta(s)) observed at the Department of Pediatric Hematology and Oncology, University of Catania. RESULTS: A sensorial hearing loss of more than 25 dB was recorded in 24% of subjects with Hb S/beta0-thalassemia, in 23% of subjects with Hb S/beta+-thalassemia and in 30% of subjects with sickle cell anemia. We found an increase in the frequency of hearing loss with increasing age. CONCLUSIONS: Our data showed that sensorineuronal hearing loss is a common complication in white patients with sickle cell anemia, and in patients with severe forms of Hb S/beta-thalassemias.

Adolescent↗
PubMed2004

Brain perfusion abnormalities in patients with euthyroid autoimmune thyroiditis.

PURPOSE: Brain perfusion abnormalities have recently been demonstrated by single-photon emission computed tomography (SPECT) in rare cases of severe Hashimoto's thyroiditis (HT) encephalopathy; moreover, some degree of subtle central nervous system (CNS) involvement has been hypothesised in HT, but no direct evidence has been provided so far. The aim of this study was to assess cortical brain perfusion in patients with euthyroid HT without any clinical evidence of CNS involvement by means of 99mTc-ECD brain SPECT. Sixteen adult patients with HT entered this study following informed consent. METHODS: The diagnosis was based on the coexistence of high titres of anti-thyroid auto-antibodies and diffuse hypoechogenicity of the thyroid on ultrasound in association with normal circulating thyroid hormone and TSH concentrations. Nine consecutive adult patients with non-toxic nodular goitre (NTNG) and ten healthy subjects matched for age and sex were included as control groups. All patients underwent 99mTc-ECD brain SPECT. Image assessment was both qualitative and semiquantitative. Semiquantitative analysis was performed by generation of four regions of interest (ROI) for each cerebral hemisphere--frontal, temporal, parietal and occipital--and one for each cerebellar hemisphere in order to evaluate cortical perfusion asymmetry. The Asymmetry Index (AI) was calculated to provide a measurement of both magnitude and direction of perfusion asymmetry. RESULTS: As assessed by visual examination, 99mTc-ECD cerebral distribution was irregular and patchy in HT patients, hypoperfusion being more frequently found in frontal lobes. AI revealed abnormalities in 12/16 HT patients, in three of the nine NTNG patients and in none of the normal controls. A significant difference in the mean AI was found between patients with HT and both patients with NTNG (p<0.003) and normal controls (p<0.001), when only frontal lobes were considered. CONCLUSION: These results show the high prevalence of brain perfusion abnormalities in euthyroid HT. These abnormalities are similar to those observed in cases of severe Hashimoto's encephalopathy and may suggest a higher than expected involvement of CNS in thyroid autoimmune disease.

Adult↗
PubMed2004

Frontal cortical perfusion abnormalities related to gluten intake and associated autoimmune disease in adult coeliac disease: 99mTc-ECD brain SPECT study.

OBJECTIVE: Since brain perfusion abnormalities have been described by single-photon emission computed tomography in some autoimmune diseases, the aim of the present study was to evaluate the incidence of perfusion abnormalities by brain single-photon emission computed tomography in a group of coeliac disease patients, and to investigate whether gluten intake and associated autoimmune diseases may be considered risk factors in causing cerebral impairment. METHODS: Thirty-four adult coeliac patients (16 on a gluten-free diet and 18 on a gluten-containing diet, 18 (53%) with autoimmune diseases) underwent 99mTc-ethyl cysteinate dimer brain single-photon emission computed tomography and qualitative evaluation of brain perfusion was performed together with a semiquantitative estimation using the asymmetry index. Ten subjects on our database, matched for sex, age and ethnic group, who were proved normal by histology ofjejunal mucosa (four males and six females; median age 39 years, range 27-55 years), were included as control group. RESULTS: Twenty-four out of 34 patients (71%) showed brain single-photon emission computed tomography abnormalities confirmed by abnormal regional asymmetry index (>5%; range 5.8-18.5%). Topographic comparison of the brain areas showed that the more significant abnormalities were localised in frontal regions, and were significantly different from controls only in coeliac disease patients on unrestricted diet. The prevalence of single-photon emission computed tomography abnormalities was similar in coeliac disease patients with (74%) and without (69%) associated autoimmune disease. CONCLUSIONS: Abnormalities of brain perfusion seem common in coeliac disease. This phenomenon is similar to that previously described in other autoimmune diseases, but does not appear to be related to associated autoimmunity and, at least in the frontal region, may be improved by a gluten-free diet.

Adult↗
PubMed2004

Brief exposure to -2 Gz reduces cerebral blood flow velocity during subsequent +2 Gz acceleration.

In order to determine the implication of the cerebral vasoconstriction occurring under -Gz acceleration in the mechanism of the push-pull effect, four healthy male non-pilots were submitted to a control centrifugation at +2 Gz, and then to an experimental run with identical +2 Gz plateau, but preceded by -2 Gz exposure. Cerebral blood flow velocity (CBFV), pulsatility index, and resistance index (RI) were continually measured with a transcranial Doppler instrument. The decrease in blood pressure and in CBFV was more important during the experimental run, when the change in RI was not different. We concluded that the cerebral vasoconstriction occurring under -2 Gz exposure seems not to be a major contributor in the mechanism of the push-pull effect appearing during subsequent +2 Gz acceleration.

Blood Pressure↗
PubMed2003

Internalization-associated proteins among Streptococcus pyogenes isolated from asymptomatic carriers and children with pharyngitis.

Sixty-two strains of Streptococcus pyogenes isolated from 30 asymptomatic school children and 32 children with pharyngitis were characterized to analyze the involvement of 2 fibronectin-binding proteins (F/SfbI and PrtF2/PfbpI) in S. pyogenes colonizing asymptomatic carriers and to determine the possible association between these proteins and the genes associated with macrolide resistance. In this study, we demonstrated that the proportion of S. pyogenes strains carrying the pfbpI gene was significantly higher among asymptomatic carriers (80%) than among children with pharyngitis (53%; P<.05). With regard to the proportion of prtF1-positive strains, no significant differences were found between the 2 groups (70% vs. 69%, for asymptomatic carriers and children with pharyngitis, respectively). Another important finding is the significant association between macrolide resistance and protein F/SfbI (P<.001) in both groups. These results suggest that the presence of the pfbpI gene can be linked to the ability of S. pyogenes to persist in the throat of asymptomatic carriers.

Adhesins, Bacterial↗
PubMed2003

Characterization of the metabolic shift of Saccharomyces bayanus var. uvarum by continuous aerobic culture.

Saccharomyces bayanus, being of interest for wine-making, is not as well known as S. cerevisiae and, due to many changes in the yeast classification, accurate data concerning its metabolic activity are difficult to find. In order to produce this yeast as an active dry yeast to be used as a starter in wine-making, its sensitivity to glucose was determined as the objective of our work. Using the pulse technique in continuous culture, it was found that growth in a synthetic medium was not limited by vitamins or mineral salts. We determined the critical dilution rate of a continuous culture and performed an aerobic continuous culture, measuring the respiratory quotient on-line in order to observe the metabolic shift from respiratory to fermentative metabolism. The S. bayanus var. uvarum strain studied was Crabtree-positive (glucose-sensitive) but had a weaker respiratory capacity than S. cerevisiae since the dilution rate of the metabolic shift was only 0.15 h(-1). These new data provide essential information for the biomass production of this yeast strain for wine-making.

Aerobiosis↗
PubMed2003

Audiological range in Turner's syndrome.

Turner's syndrome is generally characterised by bilateral gonadal disgenesis, short stature and inadequate sexual development secondary to anomalous karyotype. The purely otorhinolaryngoiatric pathology considerably influences the symptomatological features in Turner's subject and this is based on possible morphologically structured anomalies in the external, middle and inner ear, but also on the oral cavity and pharynx. From this there is evidence of otological emergence on a phlogistic infectious basis with remarkable long-term repercussion on the hearing process. Otofunctional evaluation in 21 Turner's syndrome patients shows predominance of conductive hearing loss (42.8%), proven through evidence of otitis media (33.3%) and chronic otitis media (9.5%). This, therefore, demands an attentive audiologic monitoring related to the possible development of chronic forms or cholesteatoma and the possible rehabilitative-prothesis procedure.

Acoustic Impedance Tests↗
PubMed2003

Within-gene interaction between c.135 G/A genotypes and RET proto-oncogene germline mutations in HSCR families.

Hirschsprung disease (HSCR) is considered a model for a complex inheritance disorder. Several genes, including the major HSCR-susceptibility RET proto-oncogene, play an aetiological role in the development of HSCR. Genetic linkage analysis in familial HSCR with both long- and short-segment phenotypes has demonstrated a tight linkage to the RET locus, while the phenotype within a HSCR family is characterised by an incomplete penetrance or a variable extension of the aganglionosis. Therefore, additional genetic alterations of RET are postulated in the aetiology or modification of the HSCR phenotype. In this study, the coding region of all 21 exons of the RET proto-oncogene, including the flanking intronic sequences, were investigated by direct DNA sequencing in a HSCR population. We genotyped the c.135 G/A polymorphism and resolved haplotypes comprising the mutation locus and the c.135 G/A polymorphism. Twenty different mutations were detected in 18 of 76 HSCR patients. In ten families the mutations were inherited from the parents, while only four patients had a positive family history for the disease. Moreover, in all ten families an incomplete penetrance of the HSCR phenotype was observed. We have investigated the effect of the non-mutated wild-type allele as well as the c.135 G/A polymorphism on the phenotype within the HSCR families. Our findings support the notion that both RET alleles are involved in the pathogenesis of a subgroup of HSCR patients in a dose-dependent fashion. Additionally, we have shown a modifying effect of the c.135 G/A polymorphism on the HSCR phenotype within HSCR families.

Alleles↗
PubMed2003

The usefulness of 99mTc-SestaMIBI scan in the diagnostic evaluation of thyroid nodules with oncocytic cytology.

OBJECTIVE: To assess the relevance of (99m)Tc-SestaMIBI (MIBI) scan in the diagnostic evaluation of thyroid nodules with oncocytic cytology. SUBJECTS AND METHODS: Twenty-four patients with a single (or prevalent) 'cold' solid nodule with Hurthle cells (HC) at fine needle aspiration cytology (FNAC) were studied. Cytological diagnosis of oncocytic metaplasia (OM) or HC tumor (HCT) was made when HC on the smear were comprised 10-75%, or >75%. Nodules concentrating MIBI at early and late (2 h after washout) stages were considered MIBI-positive. In all cases histological findings were obtained after total thyroidectomy. RESULTS: FNAC was malignant or suspect for malignancy in 16 cases (six HCT and 10 OM) and not suspect in eight (two HCT and six OM). Histological examination revealed 14 malignant tumors (11 HCT and three OM), and 10 benign thyroid lesions (three HCT and seven OM). Sensitivity of FNAC for malignancy was 92.8% and specificity was 70.0%; HCT were identified by FNAC in only 35.7% and OM in 70.0% of cases. No significant difference in MIBI positivity was found between malignant and benign thyroid nodules. The highest percentage of MIBI positivity was found in HCT (78.5%), but MIBI-positive nodules were also observed in thyroid lesions with HC metaplasia (40.0%). CONCLUSIONS: MIBI scintiscan has no value in differentiating malignant from benign HC thyroid neoplasias. Most HCT are MIBI-positive, but this scan is not sufficiently specific to differentiate true HC neoplasias from other thyroid lesions showing HC at FNAC, although an MIBI-negative scan strongly supports the absence of true HCT.

Adenoma, Oxyphilic↗
PubMed2003

p53 overexpression on the resection margins as a marker of local recurrence in glottic T1a carcinoma.

Glottic carcinoma, in the early stage, may benefit, with excellent results "quoad vitam atque quoad valitudinem", from various modes of treatment--radiotherapy, laser microsurgery and cordectomy being the most common--in definitive cure of the disease. Nevertheless, recurrence, in relation to treatment, oscillates between 4.3-24.1% with laser CO2 surgery, 5.5-32.4% for cordectomy and 5.3-34% for radiotherapy. Prognostic biological markers of recurrence remain to be elucidated, mainly due to the clinical differences in the subjects examined. The present study focused on patients with glottic T1a carcinoma treated with CO2 laser surgery in which correlation between histo-pathological aspects and expression of p53 protein on resection borders were confirmed by onset of local recurrence. Study population comprised 39 patients treated with CO2 laser surgery (January 1985-December 1991) in Clinical Division of Otorhinolarygology, University of Catania. Survival rate, free from recurrence, at 3 and 5 years for this patient group was 87.1% (34/39) and 82% (32/39), respectively. Disease-free survival at 3 and 5 years, was 86.6% in patients with positive resection margins for carcinoma and 87.5% and 79.1%, respectively, for patients with negative resection margins. Survival rate, free from local recurrence, in p53 positive patients, at 3 and 5 years was 78.9% and 68.4%, respectively. In p53 negative patients, survival, free from local recurrence, at 3 and 5 years, was 94.7%. Presence of overexpression of oncoprotein p53 on borders of resection with aspects of dysplasia of various degrees seems, therefore, a marker of high risk of tumour progression and recurrence.

Adult↗
PubMed2002

Serotonin and serotonin receptor expression in the aorta of carotid intact and denervated newborns.

Pharmacological blocking of serotonin (5-HT) 5A receptors abolishes aortic ventilatory chemosensitivity of carotid body denervated (CBD) piglets [J. Appl. Physiol. 92 (2002) 893]. Accordingly, the purpose of the present study was to determine whether 5-HT and 5-HT receptors exist at aortic sites that are chemosensitive after CBD. Aortas from CBD and sham CBD rats and piglets and from aortic denervated (AOD) and combined AOD+CBD piglets were harvested, sectioned and then studied using immunohistochemistry and western blot techniques. 5-HT immunoreactivity in piglets and rats was concentrated in the endothelium and sub-endothelial areas in several aortic regions studied, and in some areas also in the adventitia. At the aortic chemosensitive site (descending aorta in CBD piglets and the ascending aorta in CBD rats), the immunoreactivity was greater (P < 0.05) than in other aortic regions and greater than in other groups studied. The 5-HT(5a) receptor was expressed only at the chemosensitive sites and only in aortic innervated piglets. We conclude that the data from this and a previous study [J. Appl. Physiol. 92 (2002) 893] suggest that a serotonergic mechanism contributes to the aortic ventilatory chemoreflex after CBD.

Analysis of Variance↗
PubMed2002

Vasculitides with predominantly renal involvement: influence of age on the mode of presentation.

Vasculitis with predominant renal involvement are increasingly observed in elderly patients. It predominantly involves patients with microscopic polyangiitis, Wegener's granulomatosis, renal limited vasculitis and, in a smaller proportion, Churg Strauss syndrome. The elderly patients present very few obvious symptoms or signs of vasculitis such as hemoptysis and pulmonary infiltrates, and they are often submitted to: 1/renal biopsy when renal failure is already advanced; 2/ have more severe renal disease than do young and middle-aged patients (81% of acute and/or rapidly progressive renal failure versus 62%, and 30% of oliguria versus 6%); and 3/ a worse prognosis compared with younger individuals (probability of survival at 3 months, 1 year and 5 years of 93%, 93% and 92% in patients under 65, versus 67%, 62% and 46% in the elderly). Management of all patients with vasculitis and predominant renal involvement requires a quick diagnosis and immunosuppressive treatment aimed at controlling the disease. Treatment is mantained for 18 to 24 months. Nevertheless, relapses do occur (between 20% to 52%) of all patients with microscopic polyangiitis and Wegener's granulomatosis.

Age Factors↗
PubMed2002

Assessment of minimal residual disease (MRD) in CBFbeta/MYH11-positive acute myeloid leukemias by qualitative and quantitative RT-PCR amplification of fusion transcripts.

The inv(16)(p13q22) chromosomal rearrangement associated with FAB M4Eo acute myeloid leukemia (AML) subtype is characterized by the presence of the CBFbeta/MYH11 fusion transcript that can be used to detect minimal residual disease (MRD). However, qualitative RT-PCR studies of MRD have so far produced conflicting results and seem of limited prognostic value. We have evaluated retrospectively MRD in a large series of CBFbeta/MYH11-positive patients employing both qualitative and quantitative (real-time PCR) approaches. 186 bone marrow samples from 36 patients were examined with a median follow-up of 27.5 months; 15 patients relapsed during follow-up. In qualitative studies, carried out by 'nested' RT-PCR assay, all patients in complete remission (CR) immediately after induction/consolidation therapy were found to be PCR positive. However, follow-up samples at later time points were persistently negative (except one case) in patients remaining in continuous CR (CCR) for more than 12 months. 16 patients were evaluated by quantitative real-time PCR assay: CBFbeta/MYH11 transcript copy number was normalized for expression of the housekeeping gene ABL, expressed as fusion gene copy number per 10(4) copies of ABL. A 2-3 log decline in leukemic transcript copy number was observed after induction/consolidation therapy. After achieving CR, the mean copy number was significantly higher in patients destined to relapse compared to patients remaining in CCR (151 vs 9, P < 0.0001 by Mann-Whitney test). Moreover, in CCR patients, the copy number dropped below the detection threshold after the treatment protocol was completed and remained undetectable in subsequent MRD analysis in accordance with results obtained by qualitative RT-PCR. On the contrary, in the seven patients who relapsed, the copy number in CR never declined below the detection threshold; thus a cut-off value discriminating these two groups of patients could be established. The findings of our study, if confirmed, might confer an important predictive value to quantitative real-time PCR determinations of MRD in patients with inv(16) leukemia.

Adolescent↗
PubMed2002

Quantitative assessment of WT1 expression by real time quantitative PCR may be a useful tool for monitoring minimal residual disease in acute leukemia patients.

In order to verify if quantitative assessment of the WT1 transcript amount by the real time quantitative PCR (RQ-PCR) can be used as a marker for minimal residual disease detection, the WT1 transcript amount was determined in BM and PB samples of patients with myeloid and lymphoid acute leukemia, in normal controls, in regenerating bone marrow samples and in purified CD34-positive cells from normal subjects. In 10 patients bearing a fusion gene transcript suitable for minimal residual disease quantitative assessment, we performed a simultaneous analysis of the WT1 and of the fusion-gene transcript at sequential time intervals during follow-up. Sequential WT1 analysis was also performed in five AML patients lacking additional molecular markers. The data obtained show that normal and regenerating BM samples and purified CD34-positive cells consistently express minimal amounts of WT1 transcript and that this is extremely low and frequently undetectable in normal PB. By contrast, high levels of WT1 expression are present in the BM and PB samples of all acute leukemia (AL) cases at diagnosis. The WT1 levels during follow-up were found to follow the pattern of the other molecular markers (fusion gene transcripts) used for MRD monitoring and increased WT1expression in the BM and/or PB during follow-up of AL patients was always found to be predictive of an impending hematological relapse.

Base Sequence↗