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C Castellani

Publications and source records attributed to C Castellani.

At least 19 recordsLinked to original sources
PubMed2002

Strongly correlated superconductivity.

High-temperature superconductivity in doped Mott insulators such as the cuprates contradicts the conventional wisdom that electron repulsion is detrimental to superconductivity. Because doped fullerene conductors are also strongly correlated, the recent discovery of high-critical-temperature, presumably s-wave, superconductivity in C60 field effect devices is even more puzzling. We examine a dynamical mean-field solution of a model for electron-doped fullerenes that shows how strong correlations can indeed enhance superconductivity close to the Mott transition. We argue that the mechanism responsible for this enhancement could be common to a wider class of strongly correlated models, including those for cuprate superconductors.

Journal Article↗
PubMed2002

First-order pairing transition and single-particle spectral function in the attractive hubbard model.

A dynamical mean-field theory analysis of the attractive Hubbard model in the normal phase is carried out upon restricting to solutions where superconducting order is not allowed. A clear first-order pairing transition as a function of the coupling takes place at all the electron densities out of half filling between a Fermi liquid, stable for U U(c), and it is accompanied by phase separation. The spectral function in the metallic phase is constituted by a low-energy structure around the Fermi level, which disappears discontinuously at U = U(c), and two high-energy features (Hubbard bands), which persist in the insulating phase.

Journal Article↗
PubMed2001

Analysis of the entire coding region of the cystic fibrosis transmembrane regulator gene in idiopathic pancreatitis.

Many Cystic Fibrosis (CF) carriers have been detected testing some subjects with chronic pancreatitis for a limited number of mutations. The aim of this study was to find out if some subjects with pancreatitis and a CFTR mutation actually carry another, undetected mutation. We screened for 18 CFTR mutations plus the CFTR intron 8 poly(T) tract length a population of 67 patients suffering from idiopathic either acute, or recurrent acute, or chronic pancreatitis. Three of them were diagnosed as affected by CF. Among the others, a subset of 14 (8 CFTR mutation carriers, 4 5T carriers, and 2 sweat chloride borderliners) was selected and analyzed by denaturing gradient gel electrophoresis. Six possibly CF-related mutations were detected: L997F and 3878delG were found in two of the subjects already carrying another mutation, S1235R and L997F in one patient carrying the 5T, and L997F and D614G in the two patients with borderline sweat chloride. Among the 14 selected cases a total of 11 patients carried at least one mutation, and three of them were compound heterozygotes. Though it is debatable whether these three individuals can be considered affected by CF, their pancreatitis is possibly a clinical manifestation of some CFTR-related disease. Hum Mutat 18:166, 2001.

Acute Disease↗
PubMed2001

A pilot survey of cystic fibrosis clinical manifestations in CFTR mutation heterozygotes.

A cystic fibrosis (CF) heterozygote incidence higher than in the general population has been repeatedly reported in conditions which include clinical features found in CF, like pancreatitis, disseminated bronchiectasis, and allergic bronchopulmonary aspergillosis. Some cases may be explained by an unidentified compound heterozygosity; others could be manifesting heterozygotes. This study was aimed at detecting the incidence of CF-related clinical features in a population of carriers. A group of 261 obligate heterozygotes (mean age, 44 years) and a control group, composed of 201 individuals negative for a standard mutation panel (mean age, 36 years), were surveyed for possibly CF-related conditions (asthma, bronchiectasis, pneumothorax, allergic bronchopulmonary aspergillosis, sinusitis, nasal polyps, gallstones, liver cirrhosis, diabetes, pancreatitis, bone fractures, plus hypertension). A questionnaire was administered, and the accuracy of the statements was evaluated by phone interviews. There was no difference between heterozygotes and controls, with the exception of hypertension (carriers 28/261, controls 7/201, p = 0.004), and, in males, nasal polyps (carriers 7/126, controls 0/102, p value = 0.0178), and, again, hypertension (carriers 17/126, controls 5/102, p value = 0.0407). To avoid age bias, 126 heterozygotes matched to controls of the same gender and age were separately processed: these two groups showed no significant differences. CF-related clinical manifestations in obligate CFTR mutation heterozygotes are not more represented than in individuals with a low risk of being carriers.

Adolescent↗
PubMed2001

Neonatal screening for cystic fibrosis: long-term clinical balance.

BACKGROUND/AIMS: Very few studies have been performed on the long-term clinical advantages of neonatal screening programs for cystic fibrosis (CF) and these have been inconclusive. This is a preliminary report of two observational cohort studies on this subject. METHODS: In the first study, CF patients born between 1973 and 1981 in northeastern Italy were split into 4 groups according to the modality of diagnosis: screening by meconium test (58 patients); meconium ileus (45 patients); symptoms and pancreatic insufficiency (PI; 75 patients), or symptoms and pancreatic sufficiency (PS; 19 patients). The patients were followed for up to 26 years by three CF centers sharing common treatment protocols. In the second study, two cohorts of CF patients born between 1983 and 1992 were compared. Patients from one cohort (126 patients) were born in the Veneto region, where a neonatal screening program had been established based on immunoreactive trypsinogen. Patients from the other cohort (152 patients) were born in Sicily, where an intensive program of early diagnosis by symptoms was implemented. The cohorts were comparable for CF incidence, CFTR genotypes, gender proportion and common treatment protocols. Statistical analyses were performed by Kaplan-Meier survival curves, a Cox proportional hazard model for survival and cross-sectional comparisons by 2-year periods for weight z score, height z score and body mass index. RESULTS: In the first study, the patients detected by newborn screening (PI) showed better survival and nutritional status compared to patients diagnosed through meconium ileus or symptom presentation with PI. PS patients diagnosed by symptoms showed the best outcome, but most of them had a mild genotype. In the second study, the Veneto cohort showed better outcome with regard to survival and nutritional status over 16 years of follow-up. CONCLUSIONS: Observational cohort studies cannot give definitive evidence of the clinical benefit of neonatal CF screening; however, data have been accumulated which strongly suggest a better clinical outcome for CF patients born in an area where a screening program is performed.

Adolescent↗
PubMed2001

CFTR and cationic trypsinogen mutations in idiopathic pancreatitis and neonatal hypertrypsinemia.

BACKGROUND/AIMS: The CFTR gene has been shown to be involved in sporadic idiopathic pancreatitis (IP) and neonatal hypertrypsinemia with normal sweat chloride test (NHNST). The cationic trypsinogen gene (Try4) is responsible for hereditary pancreatitis. The aim of the present study was to find a correlation between mutations in the two genes and the two phenotypes. METHODS: Analysis of some known gene mutations and complete gene screening by denaturing gradient gel electrophoresis and DNA sequencing were undertaken. Thirty-two sporadic IP patients were investigated for the CFTR study, while 13 sporadic IP patients plus 4 hereditary pancreatitis families (24 tested individuals) were examined for the Try4 study. Fifty neonates with NHNST were investigated for the study of both genes. RESULTS: CFTR mutations were more frequently observed in sporadic IP cases with a common cystic fibrosis mutation or borderline sweat chloride than in cases with a negative sweat test. Try4 mutations were found in 1 out of the 13 sporadic IP cases tested. CONCLUSIONS: The CFTR gene may be involved in IP and NHNST, while the Try4 gene may be involved in IP, but not in NHNST, in this limited series of observations.

Cystic Fibrosis Transmembrane Conductance Regulato↗
PubMed2000

The cystic fibrosis transmembrane regulator gene and male infertility.

Congenital bilateral absence of the vas deferens (CBAVD) is a relatively frequent cause of male infertility accounting for 1-2% of cases of male sterility and at least 6% of cases of obstructive azoospermia. In the last decade a genetic basis for CBAVD has been provided by its association with cystic fibrosis (CF) and nowadays CBAVD is in most cases considered to be a mild or incomplete form of CF disease. Many individuals with CBAVD show usually mild CF-compatible clinical manifestations, but the long-term prognosis could possibly not be as innocuous as it presently looks: more data will be available through medium or long-term follow-up studies. Once a correct diagnosis of CBAVD has been formulated and if the couple is planning a pregnancy by artificial reproductive technology, it is crucial to test both the affected male and his partner for CFTR mutations. Such testing has a number of complex implications and should always be performed together with genetic counselling. Other issues are debated in this article including CF mutations in non-CBAVD forms of male infertility, and the potentially misleading role of CF genetic analysis when used to rule out other possible causes of infertility in azoospermic men.

Alleles↗
PubMed2000

Protracted neonatal hypertrypsinogenaemia, normal sweat chloride, and cystic fibrosis.

The cystic fibrosis (CF) clinical spectrum has greatly expanded in the past few years, including atypical forms with low sweat chloride concentrations. Two cases are presented which suggest that children detected by neonatal CF screening whose trypsinogen concentrations are still raised by the second month of age could, despite a negative sweat test, be affected by an atypical CF with fully expressed pulmonary involvement.

Adolescent↗
PubMed1999

Evidence of mild respiratory disease in men with congenital absence of the vas deferens.

Cystic fibrosis (CF) is a severe disorder, whose main characteristics are, in addition to congenital absence of the vas deferens (CAVD), progressive lung disease, pancreatic insufficiency and elevated sweat chloride levels; CAVD without any other manifest clinical evidence is commonly suggested to be a form of CF with primarily genital expression. We undertook this study to test the hypothesis that men with a CAVD phenotype could be more CF-like than it is usually assumed. Each subject from a population of 42 patients suffering from CAVD was screened for a panel of 16 mutations plus the intron 8 5-thymidine allele of the CF gene (5T), and underwent a thorough clinical evaluation which included a detailed anamnesis, anthropometric data, chest and paranasal sinuses X-rays, pulmonary function tests, sputum cultures, stool chymotrypsin determination, sweat test and, in a limited number of patients, Nasal Potential Difference (NPD) measurement. The genotype analysis detected one compound heterozygote, 23 heterozygotes and 15 individuals carrying the 5T allele; sweat chloride was positive in six, borderline in 11 and negative in 25 subjects; NPD was abnormal in 2/12 patients. Medical history and clinical examination were consistent with respiratory disease in 20 cases; there was radiological evidence of pulmonary hyperinflation in 37/39 and of sinus disease in 20/42 patients; Staphylococcus aureus was cultivated in the sputum of 9/36, Haemophilus influentiae in 3/36 subjects and three patients showed functional evidence of airway obstruction. These findings were equally distributed among sweat positive, borderline and negative patients. These results raise questions about the supposed benignancy of the CAVD condition. A close follow-up of men with CAVD could ascertain potential complications.

Adult↗
PubMed1998

Serum macrophage colony-stimulating factor (M-CSF) levels in patients with epithelial ovarian cancer.

The preoperative macrophage colony-stimulating factor (M-CSF) levels were measured in serum samples from 56 patients with epithelial ovarian cancer and 68 patients with benign ovarian disease who had undergone laparotomy. M-CSF values were significantly higher in the former (median, range: 2.18, 0.70-10.00 ng/ml versus 1.19, 0.17-5.54 ng/ml, P < 0.0001), and were not significantly related to stage, histology, grade of differentiation, age, and residual disease after first surgery. M-CSF concentrations were also measured in 163 serum samples drawn from patients with stage III-IV epithelial ovarian cancer at different times since the first surgery. M-CSF values were higher in the 81 samples from patients with clinically evident disease than in the 82 samples from patients with no clinical evidence of disease (median, range: 2.13, 0.60-10.00 ng/ml versus 1.05, 0.40-10.00 ng/ml, P < 0.0001). M-CSF levels before second-look laparotomy were similar in the 18 patients who showed persistent disease at surgical reevaluation and in the 11 patients who achieved pathological complete response (median, range: 1.26, 0.70-3.27 ng/ml versus 0.94, 0.46-4.23 ng/ml, P = NS). M-CSF concentrations were raised (> or = 1.70 ng/ml) only in 1 (14.3%) of the 7 samples from patients with clinically evident disease and serum CA125 < 35 U/ml, and only in 5 (38.5%) of the 13 samples from patients with positive second-look findings and serum CA125 < 35 U/ml. In conclusion, serum M-CSF levels correlated with the clinical status of disease in patients with epithelial ovarian cancer. However, the concomitant determination of serum M-CSF seems to add little to the CA125 assay alone in the monitoring of patients with this malignancy.

Adult↗
PubMed1998

Nasal potential difference in congenital bilateral absence of the vas deferens.

Congenital bilateral absence of the vas deferens (CBAVD) is supposed to be due to defective activity of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) in the genital tract. With the aim of studying CFTR activity in vivo we measured nasal potential difference (NPD) in a group of CBAVD subjects, who were then compared with normal control subjects and CF patients. Sodium transport, measured under basal conditions and after amiloride superinfusion, was normal in almost all CBAVD patients, who had NPD values similar to those of normal control subjects. Chloride transport was studied by measuring NPD during perfusion with a chloride-free solution and isoproterenol. Under these circumstances CBAVD patients as a whole showed normal chloride secretion. However, three subjects with CBAVD had abnormal NPD values. They had either elevated sweat chloride concentrations together with symptoms of mild CF, or compound heterozygosity (DeltaF508/R117H). In conclusion the group of CBAVD patients as a whole presented normal bioelectric properties of nasal epithelium, suggesting normal CFTR activity. In a small subgroup NPD was abnormal, suggesting a diagnosis of CF, later confirmed by elevated sweat chloride concentrations or positive DNA testing. We suggest that CBAVD patients with altered NPD should undergo further clinical follow-up in order to detect possible late complications of CF.

Adrenergic beta-Agonists↗
PubMed1997

Newborn screening strategy for cystic fibrosis: a field study in an area with high allelic heterogeneity.

To verify to what extent mutation analysis on blood spot could improve cystic fibrosis neonatal screening in an area with high allelic heterogeneity, we designed a special protocol. Spot trypsin estimation at birth, trypsin re-testing after 1 month, meconium lactase testing and mutation analysis of delta F508, R1162X and N1303K, were retrospectively clustered according to different patterns (trypsin/lactase/mutation; trypsin/lactase/re-testing; trypsin/mutation) and compared. The programme, which lasted 2 years (1993-94) and covered most of North-eastern Italy, included 95,553 screened newborns. Thirty-four affected babies were detected by screening and one by meconium ileus (incidence 1/2730). The combined use of trypsin, lactase and mutation analysis in cystic fibrosis neonatal screening permits a better sensitivity compared to the two other combinations (34 diagnoses vs 32 in both cases). Moreover, the higher specificity of the former method (false positives 42 vs 148) allows a reduction of recalls, which cause considerable anxiety. We confirm in trypsin-positive newborns an increased frequency of cystic fibrosis heterozygotes (1/17).

Clinical Protocols↗
PubMed1997

CFTR mutations and IVS8-5T variant in newborns with hypertrypsinaemia and normal sweat test.

Neonates positive for immunoreactive trypsinogen assay (IRT) and negative for sweat test have formerly been found to carry the major cystic fibrosis (CF) mutation, delta F508, much more frequently than the general population. Among the 716 IRT positive newborns detected by a three tier (IRT, mutation analysis plus meconium lactase assay, sweat test) CF screening programme in north eastern Italy during the period January 1993 to March 1996, we found 45 carriers, a number significantly higher than the expected 17 (p < 0.001). We speculated that some of these heterozygotes could actually be affected by a very mild form of CF, and carry on the other chromosome an undetected CFTR mutation or a DNA variant, such as the 5-thymidine allele in intron 8 of the CFTR gene (IVS8-5T). This hypothesis was tested in four samples; group A (the 45 carriers mentioned above), group B (51 non-carrier, IRT positive neonates), group C (50 IRT negative neonates), and group D (90 CF adult female carriers). Chromosomes with IVS8-5T were seven (7.78%) in group A, seven (6.86%) in group B, five (5%) in group C, and four in group D (2.22%). The 5T prevalence in group A was significantly higher (p < 0.05) compared to group D; similarly, a higher (p < 0.05) 5T frequency in group A compared to group C was detected by considering the chromosomes free from CFTR mutations. This study is consistent with previous papers in finding among neonates with high trypsin levels a CF carrier frequency significantly higher than that expected. It is also suggested that in at least some babies raised trypsin levels at birth could be a phenotypic expression of compound heterozygosity for a major CF mutation plus IVS8-5T.

Adult↗