Comment on "Metal-insulator transition of disordered interacting electrons"
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Biomedical subjects
Publications and source records attributed to C Castellani.
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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.
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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.
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.
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OBJECTIVE: To assess the practicability and monitor the results of an active carrier testing program among relatives of cystic fibrosis (CF) patients. METHODS: Parents of CF patients in the Veneto and Trentino regions of northeastern Italy were asked to help recruit relatives aged between 18 and 45 years for CF mutation testing. RESULTS: Of 409 enrolled CF parents, 59.6% agreed to send to the CF Center family composition data of relatives up to the third degree, and 28.8% recruited relatives to carrier testing, providing names and addresses of those who, being contacted, expressed a willingness to be tested. The participation of parents was higher if they were young and had a child recently diagnosed with CF. Recruiting parents indicated 333 close relatives (59%) for testing. When contacted by the CF Center, 170 of these 333 (51%) attended for testing. The percentage of close relatives who spontaneously asked for the test was 5.4% before the carrier testing program started; it rose to 25.3% following the introduction of the active strategy. CONCLUSIONS: The participation of the parents of CF patients is an important factor affecting the utilization of testing by relatives. Besides this, the influence of a favorable medical and cultural context (participation of gynecologists and family doctors in testing programs, genetic education of the general population) has to be considered.
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.
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.
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).
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.
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The preoperative serum levels of tumor necrosis factor (TNF), soluble receptors for TNF (55- and 75-kDa sTNFr), and soluble CD14 (sCD14) were retrospectively measured in 66 patients with epithelial ovarian cancer and in 59 patients with benign ovarian masses. The preoperative serum TNF and sCD14 levels were higher in patients with epithelial ovarian cancer than in those with benign ovarian disease (P = 0.001 and P < 0.0001, respectively). Among patients with advanced malignancy, preoperative serum TNF and sCD14 correlated with neither the common prognostic variables nor the clinical outcome of patients. The preoperative serum 55- and 75-kDa sTNFr levels were higher in patients with epithelial ovarian cancer than in those with benign ovarian disease (P < 0.0001 and P = 0.02, respectively). Among patients with advanced malignancy, preoperative serum 55- and 75-kDa sTNFr correlated with FIGO stage (IV vs III, P = 0.008 and P = 0.01, respectively) and with the clinical outcome of patients. Among patients followed after surgery and chemotherapy for advanced epithelial ovarian cancer, 55- and 75-kDa sTNFr levels were significantly higher in the samples drawn from patients with clinical evidence of disease when compared to those from patients without clinical evidence of disease; conversely, TNF and sCD14 levels were similar in the two groups. In conclusion, the preoperative serum levels of TNF, 55- and 75-kDa sTNFr, and sCD14 were significantly higher in patients with epithelial ovarian cancer than in those with benign ovarian disease. The measurement of serum TNF and sCD14 seemed to be of limited clinical value for the management of patients with advanced epithelial ovarian cancer. Conversely, the assay of serum 55- and 75-kDa sTNFr might have a potential clinical relevance, for both prognostic purposes and assessment of disease status.