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Biomedical subjects

A Martini

Publications and source records attributed to A Martini.

At least 37 records · Page 2Linked to original sources
PubMed2004

Occurrence of del(GIB6-D13S1830) mutation in Italian non-syndromic hearing loss patients carrying a single GJB2 mutated allele.

Molecular screening for GJB2 (connexin 26) mutations represents the standard diagnostic approach for the genotype definition of non-syndromic deafness. Nevertheless, a single GJB2 pathogenic mutation is detectable in a relevant number of cases, therefore failing to explain the phenotype. We aimed at assessing the occurrence of the recently described del(GIB6-D13S1830) mutation, occurring in the connexin 30 gene, in a group of Italian hearing-impaired patients carrying a single GJB2 mutated allele. A total of 59 non-syndromic hearing loss (NSHL) patients were screened for GJB2 mutations. Among these, nine NSHL patients were found to be heterozygous for a single GJB2 mutation. These patients, heterozygotes for different GJB2 mutated alleles (35delG, L90P, M34T, V153I), together with 11 additional 35delG/neg cases previously described, were studied for the presence of the del(GIB6-D13S1830) mutation. Two double heterozygotes del(GIB6-D13S1830)/35delG were identified. In both cases the degree of hearing loss was profound. Furthermore, GJB2 molecular screening led to the identification of a novel change (T55G) occurring in compound heterozygosity with the V37I mutation. In conclusion, our data suggest a significant frequency of del(GIB6-D13S1830) mutation in Italian hearing-impaired subjects (10% of unexplained GJB2 heterozygotes) similar to that reported in other European countries.

Connexin 26↗
PubMed2004

Assessment of discriminatory power of three different fingerprinting methods based on killer toxin sensitivity for the differentiation of Saccharomyces cerevisiae strains.

AIMS: A panel composed of 44 taxonomically certified strains of Saccharomyces cerevisiae of different origin was used to evaluate the discriminatory power of three different fingerprinting methods based on sensitivity towards 24 killer toxins. METHODS AND RESULTS: Binary data matrix (BDM), triplet data matrix (TDM) and numerical data matrix (NDM) were used as fingerprinting methods. NDM possessed the highest discriminatory power, assessed through the Simpson's, and Hunter and Gaston's indices for the measurement of diversity. The upper limits of fingerprinting ability expressed by the three above methods have been also discussed. CONCLUSIONS: NDM determined a significant increase of discriminatory power than the use of BDM or TDM, in terms of an effective amplification of their fingerprinting efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: The NDM fingerprinting method could find application in control laboratories for the discrimination of yeast strains of industrial importance or covered by patent.

DNA Fingerprinting↗
PubMed2004

Autologous stem cell transplantation in the treatment of systemic sclerosis: report from the EBMT/EULAR Registry.

OBJECTIVE: To analyse the durability of the responses after haematopoietic stem cell transplantation (HSCT) for severe systemic sclerosis (SSc) and determine whether the high transplant related mortality (TRM) improved with experience. This EBMT/EULAR report describes the longer outcome of patients originally described in addition to newly recruited cases. METHODS: Only patients with SSc, treated by HSCT in European phase I-II studies from 1996 up to 2002, with more than 6 months of follow up were included. Transplant regimens were according to the international consensus statements. Repeated evaluations analysed complete, partial, or non-response and the probability of disease progression and survival after HSCT (Kaplan-Meier). RESULTS: Given as median (range). Among 57 patients aged 40 (9.1-68.7) years the skin scores improved at 6 (n = 37 patients), 12 (n = 30), 24 (n = 19), and 36 (n = 10) months after HSCT (p<0.005). After 22.9 (4.5-81.1) months, partial (n = 32) or complete response (n = 14) was seen in 92% and non-response in 8% (n = 4) of 50 observed cases. 35% of the patients with initial partial (n = 13/32) or complete response (n = 3/14) relapsed within 10 (2.2-48.7) months after HSCT. The TRM was 8.7% (n = 5/57). Deaths related to progression accounted for 14% (n = 8/57) of the 23% (n = 13/57) total mortality rate. At 5 years, progression probability was 48% (95% CI 28 to 68) and the projected survival was 72% (95% CI 59 to 75). CONCLUSION: This EBMT/EULAR report showed that response in two thirds of the patients after HSCT was durable with an acceptable TRM. Based on these results prospective, randomised trials are proceeding.

Adolescent↗
PubMed2003

High circulating levels of biologically inactive IL-6/SIL-6 receptor complexes in systemic juvenile idiopathic arthritis: evidence for serum factors interfering with the binding to gp130.

We previously demonstrated that high levels of IL-6/sIL-6R complexes are present in sera of patients with systemic juvenile idiopathic arthritis (s-JIA) and that the amount of IL-6 estimated in the IL-6/sIL-6R complexes is markedly higher than that measured by the B9 assay. Here, we show that two additional bioassays, employing human myeloma XG-1 cells and human hepatoma Hep3B cells, detected serum IL-6 levels similar to those measured by the B9 assay and approximately 10-fold lower than the IL-6 levels estimated to be present in the IL-6/sIL-6R complex. Using an assay for the measurement of the amount of circulating IL-6 complexed with the sIL-6R and available for binding to gp130 (gp130 binding activity), we show that the IL-6/gp130 binding activity is similar to that detected by the bioassays and again significantly lower than that estimated to be present in the IL-6/sIL-6R complex. Addition of recombinant human IL-6 (rhIL-6) to sera of patients or controls results in a markedly lower increase in the gp130 binding activity in patients than in controls. Moreover, sera from s-JIA patients inhibited in a dose dependent manner the gp130 binding activity assay. These results show that sera from patients with s-JIA contain a factor, or factors, that inhibit(s) the binding of the IL-6/sIL-6R complex to gp130. This inhibitory activity does not appear to be due to soluble gp130, C-reactive protein or autoantibodies to IL-6.

Adolescent↗
PubMed2003

Fingerprinting of yeasts at the strain level by differential sensitivity responses to a panel of selected killer toxins.

We used differential sensitivities to a panel of twenty-five cell-free crude killer toxins to fingerprint forty-four Saccharomyces cerevisiae strains of different origin and all taxonomically certified by nDNA-nDNA reassociation. Cluster analysis of numerical data obtained by different growth inhibition areas observed in Petri dishes allowed the complete and reproducible discrimination of all S. cerevisiae strains.

Antibiosis↗
PubMed2003

Mapping of a new autosomal dominant non-syndromic hearing loss locus (DFNA43) to chromosome 2p12.

Hearing impairment (HI) is the most frequent sensory defect with wide genetic heterogeneity. Approximately 80% of genetic hearing loss is non-syndromic and 15-25% of exhibit autosomal dominant inheritance. We analysed an Italian three generation family in which non-syndromic hearing impairment is transmitted as an autosomal dominant trait. Onset of HI in all affected subjects occurred in the second decade of life, with subsequent gradual progression from moderate to profound loss. HI was bilateral and symmetrical, involving all frequencies. After exclusion of the known DFNA loci with markers from the Hereditary Hearing Loss Homepage (URL: http://dnalab-www.uia.ac.be/dnalab/hhh), a genome wide scan was carried out using 358 highly informative microsatellite markers. Significant linkage (Zmax=4.21, theta=0) was obtained with chromosome 2p12 markers. The results were confirmed by multipoint analysis (Zmax=4.51), using the location score method. Haplotype analysis defined a 9.6 cM disease gene interval on chromosome 2 without overlap with the other identified loci. Fine mapping and identification of candidate genes are in progress.

Chromosome Mapping↗
PubMed2003

Outcome of primary antiphospholipid syndrome in childhood.

The objective of this paper is to investigate the long-term outcome of primary antiphospholipid syndrome (APS) in the paediatric age. The features of unselected patients with primary APS who had disease onset before the age of 16 years were retrospectively analysed in three Italian referralcentres. Clinical and laboratory manifestations were assessed to establish whether, at the end of follow-up, the final diagnosis was still primary APS or whether they had developed definite SLE or lupus-like syndrome. Fourteen patients, nine boys and five girls, who had the presenting clinical manifestation of APS between three and 13 years of age (median nine years) and were followed for two to 16 years (median six years). Six patients presented with deep vein thrombosis, five with cerebral stroke, two with peripheral artery occlusion and onewith myocardial infarction. During follow-up, four patients had one or more recurrences of vascular thrombosis. At last observation, 10 patients could still be classified as having primary APS, two had developed SLE, one lupus-like syndrome and one Hodgkin's lymphoma. In conclusion; our analysis suggests that some children who present with the features of primary APS may progress to develop SLE or lupus-like syndrome.

Adolescent↗
PubMed2003

TEOAE recording protocols revised: data from adult subjects.

The objective of this study was the experimental re-evaluation of the current clinical transiently evoked otoacoustic emission (TEOAE) protocols, based on linear and non-linear protocol paradigms from a population of 42 adult subjects serving as a normative database. The linear and non-linear TEOAE responses were elicited by clicks with average intensities of 72 and 84 dB p.e. SPL respectively. An initial comparison between non-processed non-linear and linear recordings, at early recording segments from 3.2 to 5.2 ms, showed that the responses had highly similar contours and no statistically significant mean differences. The stimulus-induced artefact in the linear TEOAE responses was suppressed by post-processing the data with a window function (3.8-13.8 ms) and by a high-pass filter at 830 Hz. A repeated-measures model was used to evaluate the differences between post-processed linear and non-linear responses across clinical variables of interest (such as TEOAE response, noise, correlation, and signal-to-noise ratios (SNRs) at 1.0-5.0 kHz). The data indicated that the linear recordings demonstrate significantly lower levels of noise (and thus superior SNRs) and higher values of reproducibility. Normative adult scoring criteria were calculated from free distribution tolerance intervals for the TEOAE correlation and the SNRs at 2.0 and 3.0 kHz.

Acoustic Stimulation↗
PubMed2002

Exploring the clinical and epidemiological complexity of GJB2-linked deafness.

GJB2 mutation analysis was performed in 179 unrelated subjects with sporadic or familial hearing loss (HL). Among 57 families, 18 showed a vertical transmission of HL, the disease being present in two or three generations. Besides 155 nonsyndromic cases, 24 patients presenting with extra-auditory clinical signs were included in the molecular study. GJB2 mutation analysis was also performed in 19 subjects with an anamnestic history of perinatal risks factors for acquired HL. The 35delG mutation accounted for 22.1% of analyzed chromosomes in sporadic cases and 39.4% in familial cases; 35delG prevalence reached 41% in autosomal recessive and 44.4% in pseudodominant pedigrees. Two novel GJB2 mutations were identified in compound heterozygosity with 35delG allele (D159V, 284ins/dup[CACGT]). Two 35delG homozygous subjects were identified among HL cases classified as environmental in origin. Four patients 35delG heterozygous (35delG/V95M, 35delG/L90P, 35delG/167delT, and 35delG/?) and two homozygous presented with extra-auditory clinical signs involving different organs (skin, vascular system, hemopoietic lineages, and thyroid). In a high proportion of 35delG heterozygous HL patients (52%), no second GJB2 mutation was detected. The reported data highlight the complexity of the genetic epidemiology of GJB2-linked deafness, further enlarging the spectrum of situations in which GJB2 mutation analysis should be performed. The presence of extra-auditory signs in a significant portion of GJB2-mutated patients suggests the possibility that GJB2 loss of function could contribute to clinical phenotypes presenting in association with deafness. This hypothesis deserves further investigation. The failure to identify a presumed partnering GJB2 mutation in a high proportion of deaf patients remains a challenging problem to be clarified.

Amino Acid Sequence↗
PubMed2002

L-Dopa decreases cutaneous nociceptive inhibition of motor activity in Parkinson's disease.

OBJECTIVES: To estimate changes in motor inhibitory mechanisms at the spinal level in Parkinson's disease (PD) patients by measuring cutaneous silent responses to nociceptive stimuli in the course of L-Dopa therapy. MATERIALS AND METHODS: Fourteen patients with idiopathic PD (Group 1) and 13 patients with other forms of parkinsonism (Group 2) participated in the study. The cutaneous silent period (CSP) from the hand and clinical scores (UPDRS, part III) were measured "off" therapy (T0), after a single dose of L-Dopa (T1) and 3 months after the beginning of L-Dopa daily therapy (T2). RESULTS: At T0 the duration of the CSP was significantly prolonged in Group 1 and Group 2. At T1 and T2 the mean duration of the CSP significantly decreased in Group 1 (P < 0.05) and a significant correlation was found between the shortening of the CSP and the improvement of rigidity and bradikynesia in the upper limb. CONCLUSIONS: Our findings show that L-Dopa decreases the cutaneous nociceptive inhibition of motor activity in PD patients. CSP may be useful to assess L-Dopa responsiveness during the clinical course of PD.

Administration, Oral↗
PubMed2002

Extracellular enzymatic activity profiles in yeast and yeast-like strains isolated from tropical environments.

AIMS: The objective of this study was to investigate the extracellular enzymatic activity (EEA) profile of yeasts isolated from tropical environments of the Brazilian rain forest. This screening survey could constitute the first approach in selecting yeast strains of environmental origin potentially exploitable as enzyme producers. METHODS AND RESULTS: In this study, 348 yeast (193 ascomycetes and 155 basidiomycetes) and 46 yeast-like strains (Aureobasidium pullulans) were screened for their EEA profile. The spread occurrence of extracellular amylases, esterases, lipases, proteases, pectinases and chitinases appeared to be a strain-related character. CONCLUSIONS: Yeasts isolated from tropical environments could represent a promising source of EEA. Selected strains showed maximum levels of EEA under acidic or neutral conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrated the potential for yeasts isolated from extreme environments as sources of industrially relevant enzymes for biotechnological purposes.

Ascomycota↗
PubMed2002

Hearing loss evaluation of Sjögren's syndrome using distortion product otoacoustic emissions.

Sjögren's syndrome (SS) is a cell-mediated immune disorder primarily affecting the exocrine glands and hearing loss may be the first otological manifestation of this autoimmune disease. In order to assess the degree of sensorineural hearing loss in SS, 22 female patients were examined by means of standard audiometric tests (pure-tone audiometry, acoustic reflexes and impedance testing) and using distortion product otoacoustic emissions (DPOAEs). The results indicated that only 36.3% of the patients had mild sensorineural hearing loss. Hearing level and distortion product threshold estimates were found to be significantly correlated. No relationship was found between the duration of the disease and the DPOAE and hearing threshold variables. The data suggest that SS may not directly cause sensorineural hearing loss.

Adult↗
PubMed2002

Role of interleukin-6 in growth failure: an animal model.

Indirect evidence suggests a link between factors produced during the inflammatory response and stunted growth. The demonstration of this link was provided by the observation that mice transgenic for the inflammatory cytokine interleukin-6 (IL-6), expressing high circulating levels of IL-6 since birth, show a marked decrease in growth rate leading to adult mice 50-70% the size of wild-type littermates. The growth defect is completely abolished by neutralization of IL-6. In these mice the production of GH is normal, while circulating levels of IGF-I are markedly decreased. Administration of IL-6 to wild-type mice results in a marked decrease in IGF-I levels. These observations show that in vivo high levels of IL-6 are associated with low levels of IGF-I. However, IL-6 does not directly affect IGF-I production both in vitro and in vivo. In contrast, markedly decreased levels of IGFBP-3 are present in the IL-6 transgenic mice and administration of IL-6 to wild-type mice results in a marked decrease in IGFBP-3 levels. In these mice the decrease in IGFBP-3 levels is associated with impaired formation of the 150 kD ternary complex, even in the presence of normally functional ALS. As a consequence, IL-6 transgenic mice show increased clearance of circulating IGF-I, suggesting that IL-6 decreases IGF-I levels by increased clearance. Proteolytic degradation of IGFBP-3 occurs in the IL-6 transgenic mice, suggesting that the decrease in IGFBP-3 could be at least in part due to proteolysis. The abnormalities of the IGF-I system observed in the IL-6 transgenic mice are similar to those found in patients with systemic juvenile idiopathic arthritis, one of the chronic inflammatory diseases characterized by stunted growth and prominent production of IL-6. The IL-6 transgenic mice represent a faithful animal model of the growth impairment associated with chronic inflammation and may therefore provide information relevant to the understanding and treatment of this complication of inflammatory diseases.

Animals↗