998 resultados para mutation screening
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Vax1 and Vax2 have been implicated in eye development and the closure of the choroid fissure in mice and zebrafish. We sequenced the coding exons of VAX1 and VAX2 in 70 patients with anophthalmia/microphthalmia. In VAX1, we observed homozygosity for two successive nucleotide substitutions c.453G>A and c.454C>A, predicting p.Arg152Ser, in a proband of Egyptian origin with microphthalmia, small optic nerves, cleft lip/palate and corpus callosum agenesis. This mutation affects an invariant residue in the homeodomain of VAX1 and was absent from 96 Egyptian controls. It is likely that the mutation results in a loss of function, as the mutation results in a phenotype similar to the Vax1 homozygous null mouse. We did not identify any mutations in VAX2. This is the first description of a phenotype associated with a VAX1 mutation in humans and establishes VAX1 as a new causative gene for anophthalmia/microphthalmia. ©2011 Wiley Periodicals, Inc.
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INTRODUCTION We functionally analyzed a frameshift mutation in the SCN5A gene encoding cardiac Na(+) channels (Nav1.5) found in a proband with repeated episodes of ventricular fibrillation who presented bradycardia and paroxysmal atrial fibrillation. Seven relatives also carry the mutation and showed a Brugada syndrome with an incomplete and variable expression. The mutation (p.D1816VfsX7) resulted in a severe truncation (201 residues) of the Nav1.5 C-terminus. METHODS AND RESULTS Wild-type (WT) and mutated Nav1.5 channels together with hNavβ1 were expressed in CHO cells and currents were recorded at room temperature using the whole-cell patch-clamp. Expression of p.D1816VfsX7 alone resulted in a marked reduction (≈90%) in peak Na(+) current density compared with WT channels. Peak current density generated by p.D1816VfsX7+WT was ≈50% of that generated by WT channels. p.D1816VfsX7 positively shifted activation and inactivation curves, leading to a significant reduction of the window current. The mutation accelerated current activation and reactivation kinetics and increased the fraction of channels developing slow inactivation with prolonged depolarizations. However, late INa was not modified by the mutation. p.D1816VfsX7 produced a marked reduction of channel trafficking toward the membrane that was not restored by decreasing incubation temperature during cell culture or by incubation with 300 μM mexiletine and 5 mM 4-phenylbutirate. CONCLUSION Despite a severe truncation of the C-terminus, the resulting mutated channels generate currents, albeit with reduced amplitude and altered biophysical properties, confirming the key role of the C-terminal domain in the expression and function of the cardiac Na(+) channel.
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Participation is a key indicator of the potential effectiveness of any population-based intervention. Defining, measuring and reporting participation in cancer screening programmes has become more heterogeneous as the number and diversity of interventions have increased, and the purposes of this benchmarking parameter have broadened. This study, centred on colorectal cancer, addresses current issues that affect the increasingly complex task of comparing screening participation across settings. Reports from programmes with a defined target population and active invitation scheme, published between 2005 and 2012, were reviewed. Differences in defining and measuring participation were identified and quantified, and participation indicators were grouped by aims of measure and temporal dimensions. We found that consistent terminology, clear and complete reporting of participation definition and systematic documentation of coverage by invitation were lacking. Further, adherence to definitions proposed in the 2010 European Guidelines for Quality Assurance in Colorectal Cancer Screening was suboptimal. Ineligible individuals represented 1% to 15% of invitations, and variable criteria for ineligibility yielded differences in participation estimates that could obscure the interpretation of colorectal cancer screening participation internationally. Excluding ineligible individuals from the reference population enhances comparability of participation measures. Standardised measures of cumulative participation to compare screening protocols with different intervals and inclusion of time since invitation in definitions are urgently needed to improve international comparability of colorectal cancer screening participation. Recommendations to improve comparability of participation indicators in cancer screening interventions are made.
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AIMS: To identify the molecular basis for a low CYP1A2 metabolic status, as determined by a caffeine phenotyping test, in a 71-year-old, nonsmoking, Caucasian woman who presented with very high clozapine concentrations despite being administered a standard dose of the drug. METHODS: The nucleotide sequence of the 7 exons, exon-intron boundaries and 5'-flanking region of the CYP1A2 gene was analysed by direct sequencing. RESULTS: Only one heterozygous point mutation was identified in the donor splice site of intron 6 (3534G > A) of CYP1A2. This mutation could cause abnormal RNA splicing and therefore lead to a truncated nonfunctional enzyme. No other carrier of this mutation was identified in a population of 100 unrelated healthy Caucasians. CONCLUSIONS: This is the first report of a splice-site mutation affecting the CYP1A2 gene. This polymorphism is a likely explanation for the low CYP1A2 activity associated with high clozapine concentrations in this patient.
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Context: The debate about the balance of risks and benefits of mammography screening has prompted a comprehensive review by an independent panel in the UK. However, the panel's remit did not cover the important economic dimension of breast cancer screening. Methods: The life histories of two cohort studies of 50-year-old women, who would be eligible within the National Health Service (NHS) breast screening programme (NHSBSP), were simulated over 35 years, using a life table approach. One cohort participant was offered screening at age 50 and triennially thereafter until age 70, assuming 75% attendance, while the other received no screening. Based on the findings from the panel's report, the cost-effectiveness of the NHSBSP was assessed for various scenarios of screening effect on breast cancer incidence (base case scenario: screening advances diagnosis by 5 years; 10% incidence reduction after screening stops).
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BACKGROUND Phase-IV, open-label, single-arm study (NCT01203917) to assess efficacy and safety/tolerability of first-line gefitinib in Caucasian patients with stage IIIA/B/IV, epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). METHODS Treatment: gefitinib 250 mg day(-1) until progression. Primary endpoint: objective response rate (ORR). Secondary endpoints: disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety/tolerability. Pre-planned exploratory objective: EGFR mutation analysis in matched tumour and plasma samples. RESULTS Of 1060 screened patients with NSCLC (859 known mutation status; 118 positive, mutation frequency 14%), 106 with EGFR sensitising mutations were enrolled (female 70.8%; adenocarcinoma 97.2%; never-smoker 64.2%). At data cutoff: ORR 69.8% (95% confidence interval (CI) 60.5-77.7), DCR 90.6% (95% CI 83.5-94.8), median PFS 9.7 months (95% CI 8.5-11.0), median OS 19.2 months (95% CI 17.0-NC; 27% maturity). Most common adverse events (AEs; any grade): rash (44.9%), diarrhoea (30.8%); CTC (Common Toxicity Criteria) grade 3/4 AEs: 15%; SAEs: 19%. Baseline plasma 1 samples were available in 803 patients (784 known mutation status; 82 positive; mutation frequency 10%). Plasma 1 EGFR mutation test sensitivity: 65.7% (95% CI 55.8-74.7). CONCLUSION First-line gefitinib was effective and well tolerated in Caucasian patients with EGFR mutation-positive NSCLC. Plasma samples could be considered for mutation analysis if tumour tissue is unavailable.
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Chemotherapeutic drug resistance is one of the major causes for treatment failure in high-risk neuroblastoma (NB), the most common extra cranial solid tumor in children. Poor prognosis is typically associated with MYCN amplification. Here, we utilized a loss-of-function kinome-wide RNA interference screen to identify genes that cause cisplatin sensitization. We identified fibroblast growth factor receptor 2 (FGFR2) as an important determinant of cisplatin resistance. Pharmacological inhibition of FGFR2 confirmed the importance of this kinase in NB chemoresistance. Silencing of FGFR2 sensitized NB cells to cisplatin-induced apoptosis, which was regulated by the downregulation of the anti-apoptotic proteins BCL2 and BCLXL. Mechanistically, FGFR2 was shown to activate protein kinase C-δ to induce BCL2 expression. FGFR2, as well as the ligand fibroblast growth factor-2, were consistently expressed in primary NB and NB cell lines, indicating the presence of an autocrine loop. Expression analysis revealed that FGFR2 correlates with MYCN amplification and with advanced stage disease, demonstrating the clinical relevance of FGFR2 in NB. These findings suggest a novel role for FGFR2 in chemoresistance and provide a rational to combine pharmacological inhibitors against FGFR2 with chemotherapeutic agents for the treatment of NB.
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Many patients with Chagas disease live in remote communities that lack both equipment and trained personnel to perform a diagnosis by conventional serology (CS). Thus, reliable tests suitable for use under difficult conditions are required. In this study, we evaluated the ability of personnel with and without laboratory skills to perform immunochromatographic (IC) tests to detect Chagas disease at a primary health care centre (PHCC). We examined whole blood samples from 241 patients and serum samples from 238 patients. Then, we calculated the percentage of overall agreement (POA) between the two groups of operators for the sensitivity (S), specificity (Sp) and positive (PPV) and negative (NPV) predictive values of IC tests compared to CS tests. We also evaluated the level of agreement between ELISAs and indirect haemagglutination (IHA) tests. The readings of the IC test results showed 100% agreement (POA = 1). The IC test on whole blood showed the following values: S = 87.3%; Sp = 98.8%; PPV = 96.9% and NPV = 95.9%. Additionally, the IC test on serum displayed the following results: S = 95.7%; Sp = 100%; PPV = 100% and NPV = 98.2%. Using whole blood, the agreement with ELISA was 96.3% and the agreement with IHA was 94.1%. Using serum, the agreement with ELISA was 97.8% and the agreement with IHA was 96.6%. The IC test performance with serum samples was excellent and demonstrated its usefulness in a PHCC with minimal equipment. If the IC test S value and NPV with whole blood are improved, then this test could also be used in areas lacking laboratories or specialised personnel.
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Objectives: To compare the results of rapid PCR screening for MRSA using the GeneXpert system with those of cultures in an outbreak setting. Methods: GeneXpert was used for screening MRSA in nose, throat, groin, and other clinical samples during a 6-month period. Samples were performed using a double-swab transystem. When >1 sample was found positive in a screening set, all second swabs of the set were analysed by culture. Results: From June to October 2009, 7568 rapid tests were performed, among which 432 (5.7%) were positive (nose: 149/2090, 7.1%; throat: 98/2078, 4.7%; groin: 152/2080, 7.3%; urine: 14/1090, 1.3%; wounds: 18/150, 12%; and others:1/27, 3.7%), and 84 (1.1%) were invalid. A total of 1517 samples were analyzed by both rapid PCR and culture. Rapid tests had a sensitivity of 0.896 compared to cultures, a specificity of 0.769, a PPV of 0.763, and a NPV of 0.899. The rapid test was found to be less sensitive in throat samples (0.81) than in nose or inguinal samples (0.93 for both). In 32/192 (16%) patients a positive rapid PCR result was not confirmed by culture, despite several subsequent screening samples in some patients. Cycle threshold (Ct) for SCCmec of these PCR positive reactions were all >30. Conclusions: GeneXpert MRSA was found to be suitable for the rapid detection in nose, inguinal, and throat samples, however with a lower sensitivity in the later. Negative cultures in 16% of our PCR-positive patients raised the question of false positivity or higher sensitivity of GeneXpert. Further work is needed to investigate these cases.
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BACKGROUND: The European Guidelines specify a minimum of 5,000 screening cases to be read yearly by radiologists carrying out second reading in non-centralized programs. This professional requirement is difficult to reach and/or to implement in regional programs covering a sparse population with a high number of participating radiology units, so that alternative blind double reading strategies must be devised. OBJECTIVE: To evaluate the effect on breast cancer screening performances of two second reading strategies used in non-centralized, low-volume programs. METHODS: Reading performances in two Swiss regional breast cancer screening programs (cantons of Wallis and Vaud), covering female populations, aged 50-69, of about 31'000 and 72'000 inhabitants were computed and compared. Both programs had similar screening regimens and organizations, but differed with respect to second reading. One setting applied a selective strategy whereby only experienced radiologists performed second reading; the other elicited not to restrict second readers on the basis of their individual screening activity. Analysis included some 140,000 mammograms performed between 1999 and 2005. RESULTS: Overall, screening performances improved with increasing total volume of reading, albeit not in a linear fashion. Regardless of setting, radiologists attained a higher level of screening accuracy when performing second rather than first readings, and incident rather than prevalent screening cases. The effect of a selective, small group of second readers appeared to impact favorably on the false-positive rate and other indicators of screening quality. As the learning curve depends on the number of mammograms read, these distinct strategies may bear different outcome in the long run. Implications and practical issues for low-volume programs are discussed.
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The screening of vascular pathologies in physician offices starts with precise medical history and clinical exam. Tools like the Edinburgh Claudication Questionnaire for the peripheral artery disease or the Wells score for the probability of a thromboembolic event are useful. The measure of the ankle brachial index, the D-dimers or any other biological screening are complementary. In the presence of pathological features, it is recommended to organise a specialised consultation in order to precise diagnosis, treatment and follow-up. The screening of a vascular disease is interesting not only for the management of local symptoms, but also for the associated systemic pathologies to provide a preventive medicine of good quality.
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Prospective observational study of all HIV infected immigrants visited at the Infectious Diseases Department of the Hospital Universitari Vall d’Hebron from June 2010 to May 2011. Screening of most prevalent tropical diseases was performed according to geographical origin. 190 patients were included. Overall, 36.8% (70/190) patients had at least one positive result for any parasitic disease, including Chagas disease, schistosomiasis, strongyloidiasis, leishmaniasis, intestinal parasitosis and malaria. We propose a screening and management strategy of latent parasitic infections in immigrant HIV infected patients.
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OBJECTIVE To study the molecular genetic and clinical features of cerebral cavernous malformations (CCM) in a cohort of Spanish patients. METHODS We analyzed the CCM1, CCM2, and CCM3 genes by MLPA and direct sequencing of exons and intronic boundaries in 94 familial forms and 41 sporadic cases of CCM patients of Spanish extraction. When available, RNA studies were performed seeking for alternative or cryptic splicing. RESULTS A total of 26 pathogenic mutations, 22 of which predict truncated proteins, were identified in 29 familial forms and in three sporadic cases. The repertoire includes six novel non-sense and frameshift mutations in CCM1 and CCM3. We also found four missense mutations, one of them located at the third NPXY motif of CCM1 and another one that leads to cryptic splicing of CCM1 exon 6. We found four genomic deletions with the loss of the whole CCM2 gene in one patient and a partial loss of CCM1and CCM2 genes in three other patients. Four families had mutations in CCM3. The results include a high frequency of intronic variants, although most of them localize out of consensus splicing sequences. The main symptoms associated to clinical debut consisted of cerebral haemorrhage, migraines and epileptic seizures. The rare co-occurrence of CCM with Noonan and Chiari syndromes and delayed menarche is reported. CONCLUSIONS Analysis of CCM genes by sequencing and MLPA has detected mutations in almost 35% of a Spanish cohort (36% of familial cases and 10% of sporadic patients). The results include 13 new mutations of CCM genes and the main clinical symptoms that deserves consideration in molecular diagnosis and genetic counselling of cerebral cavernous malformations.
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INTRODUCTION Sexually transmitted infections (STI) like Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been associated with increased risk of HIV acquisition (1). It has been also described as a high prevalence of asymptomatic CT and NG infections in men who have sex with men (MSM) (2). The aim of this study was to know the prevalence of CT and/or NG infections in asymptomatic HIV-MSM and the related factors. MATERIALS AND METHODS Prospective study of a cohort of asymptomatic HIV-MSM with follow-up in Malaga (southern Spain) during October 2012-May 2014. Patients with an opportunistic event or who received active antibiotic therapy for CT and/or NG in the previous month were excluded. All of them completed a questionnaire about sexual behaviour, barrier methods and recreational drugs use. Demographical, epidemiological, clinical, analytical and therapeutic data were also collected. Pharyngeal and rectal swabs, and urine samples were collected to be tested for CT and NG by nucleic acid amplification test (c4800 CT/NG. Roche Diagnostics, Mannheim, Germany) (3). STATISTICS ANALYSIS SPSS 17.0. RESULTS 255 patients were asked to participate and 248 of them accepted. Median age was 37.7 (30.6-46.3) years, median time since HIV diagnosis was 47.7 (10.5-104.1) months, and median CD4 cells count was 607 (440-824) cell/µL. There were 195 (78.6%) patients on antiretroviral therapy; 81.5% of them had undetectable viral load. 80.5% of the patients had a past history of STI. Infection by CT and/or NG was diagnosed in 24 (9.7%) patients. Overall four urine samples, two pharyngeal, and 15 rectal ones were positive for CT, and five pharyngeal and five rectal swabs were positive for NG. Two patients were co-infected by CT and NG: one with CT in urine and both in rectum, another with CT in urine and rectum and NG in pharynx. One patient presented CT in pharynx and rectum, and two patients NG in pharynx and rectum. Positive CT and/or NG tests were only related with detectable HIV viral load (OR 3.08, 95% CI 1.2-7.4; p=0.01). It was not related with sexual behaviour, nor with alcohol or recreational drugs use. CONCLUSIONS STI screening had a great acceptance in this population. There was a high prevalence of asymptomatic CT and/or NG infections. Rectum sample was the most effective one. Viral suppression could protect from these STI. Screening should be recommended in HIV-MSM.
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BACKGROUND: Phase-IV, open-label, single-arm study (NCT01203917) to assess efficacy and safety/tolerability of first-line gefitinib in Caucasian patients with stage IIIA/B/IV, epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC). METHODS: TREATMENT: gefitinib 250 mg day(-1) until progression. Primary endpoint: objective response rate (ORR). Secondary endpoints: disease control rate (DCR), progression-free survival (PFS), overall survival (OS) and safety/tolerability. Pre-planned exploratory objective: EGFR mutation analysis in matched tumour and plasma samples. RESULTS: Of 1060 screened patients with NSCLC (859 known mutation status; 118 positive, mutation frequency 14%), 106 with EGFR sensitising mutations were enrolled (female 70.8%; adenocarcinoma 97.2%; never-smoker 64.2%). At data cutoff: ORR 69.8% (95% confidence interval (CI) 60.5-77.7), DCR 90.6% (95% CI 83.5-94.8), median PFS 9.7 months (95% CI 8.5-11.0), median OS 19.2 months (95% CI 17.0-NC; 27% maturity). Most common adverse events (AEs; any grade): rash (44.9%), diarrhoea (30.8%); CTC (Common Toxicity Criteria) grade 3/4 AEs: 15%; SAEs: 19%. Baseline plasma 1 samples were available in 803 patients (784 known mutation status; 82 positive; mutation frequency 10%). Plasma 1 EGFR mutation test sensitivity: 65.7% (95% CI 55.8-74.7). CONCLUSION: First-line gefitinib was effective and well tolerated in Caucasian patients with EGFR mutation-positive NSCLC. Plasma samples could be considered for mutation analysis if tumour tissue is unavailable.