29 research outputs found

    Development of Complex Mathematical Model of Light Naphtha Isomerization and Rectification Processes

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    The technique of developing a mathematical model of catalytic isomerization of light naphtha is stated Using experimental data from an industrial isomerization unit shows adequacy of the mathematical model to the real process. The paper presents a method for optimizing the operation of the plant together with catalytic isomerization unit and separation columns. Selection of optimal modes of separation columns allows achieving the desired flow separation between units, as well as extension of the life of the catalyst SI-2

    No Difference in Penetrance between Truncating and Missense/Aberrant Splicing Pathogenic Variants in MLH1 and MSH2:A Prospective Lynch Syndrome Database Study

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    Background. Lynch syndrome is the most common genetic predisposition for hereditary cancer. Carriers of pathogenic changes in mismatch repair (MMR) genes have an increased risk of developing colorectal (CRC), endometrial, ovarian, urinary tract, prostate, and other cancers, depending on which gene is malfunctioning. In Lynch syndrome, differences in cancer incidence (penetrance) according to the gene involved have led to the stratification of cancer surveillance. By contrast, any differences in penetrance determined by the type of pathogenic variant remain unknown. Objective. To determine cumulative incidences of cancer in carriers of truncating and missense or aberrant splicing pathogenic variants of the MLH1 and MSH2 genes. Methods. Carriers of pathogenic variants of MLH1 (path_MLH1) and MSH2 (path_MSH2) genes filed in the Prospective Lynch Syndrome Database (PLSD) were categorized as truncating or missense/aberrant splicing according to the InSiGHT criteria for pathogenicity. Results. Among 5199 carriers, 1045 had missense or aberrant splicing variants, and 3930 had truncating variants. Prospective observation years for the two groups were 8205 and 34,141 years, respectively, after which there were no significant differences in incidences for cancer overall or for colorectal cancer or endometrial cancers separately. Conclusion. Truncating and missense or aberrant splicing pathogenic variants were associated with similar average cumulative incidences of cancer in carriers of path MLH1 and path_MSH2

    Fibroblast growth factor receptor 1 (FGFR1) amplification is a potential therapeutic target in small-cell lung cancer

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    Small-cell lung cancer (SCLC) comprises about 13-15% of all lung cancers, and more than 29400 new cases have been diagnosed in the United States in the year 2012. SCLC is a biologically complex tumor typically occurring in heavy smokers. Its medical treatment has almost remained unchanged over the last decades and selected treatment options have not been established so far, mainly due to the lack of targetable genetic alterations. In this study we analyzed a cohort of 307 SCLC samples for fibroblast growth factor receptor 1 (FGFR1) amplification using a dual color FISH probe. FGFR1 status was correlated with clinical data. FGFR1 amplifications were observed in 5.6% of evaluable pulmonary SCLCs. Most of them (93%) fulfilled the criteria for high-level amplification and only one case showed low-level amplification. Amplification patterns were homogenous in the entire tumor area without occurrence of any 'hot spot' areas. FGFR1 amplification status was not associated with age, sex, stage, smoking status or overall survival. FGFR1 amplification analysis by FISH analysis in SCLC is, under respect of certain technical issues, applicable in the routine clinical setting. However, the FGFR1 amplification patterns in SCLC differs strongly from the previously described FGFR1 amplification pattern in squamous cell carcinoma of the lung, as positive SCLC harbor mostly homogeneous high-level amplifications. We provide evidence that an estimated number of 1640 newly diagnosed FGFR1-positive SCLC cases in the United States annually could benefit from targeted therapy. Therefore, we recommend including SCLC in the screening for ongoing clinical trials with FGFR1 inhibitors

    Liver transplantation in a subject with familial hypercholesterolemia carrying the homozygous p.W577R LDL-receptor gene mutation

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    Mutations within the low density lipoprotein (LDL)-receptor gene result in familial hypercholesterolemia, an autosomal dominant inherited disease. Clinical homozygous affected subjects die of premature coronary artery disease as early as in early childhood. We identified a girl at the age of five yr with clinical homozygous familial hypercholesterolemia presenting with achilles tendon xanthomas and arcus lipoides. Her total cholesterol reached up to 1050 mg/dL. Molecular characterization of the LDL-receptor gene revealed a homozygous p.W577R mutation. Despite intensive treatment interventions with the combination of diet, statins, colestipol, and LDL-apheresis, the patient developed symptomatic coronary artery disease at the age of 16 yr. Subsequently, orthotopic liver transplantation was performed to cure the defective LDL-receptor gene. Clinical follow-up for almost nine yr post-transplantation revealed excellent liver function, normal liver enzymes, normal LDL-cholesterol, and regression of both tendon xanthomas and symptomatic coronary artery disease. In conclusion, liver transplantation can effectively reduce LDL-cholesterol in a familial hypercholesterolemia recipient with subsequent regression of xanthomas and atherosclerosis. Timing is extremely important in these exceptional cases to exclude the demand for heart transplantation due to severe coronary artery disease. In addition, the identification of the LDL-receptor as etiology of clinical homozygous hypercholesterolemia is a prerequisite once liver transplantation is considered as therapeutic option

    Comparison of the genomic background of MET-altered carcinomas of the lung: biological differences and analogies

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    Although non-small-cell lung cancer is a leading cause of cancer-related deaths, the molecular characterization and classification of its genetic alterations has drastically changed treatment options and overall survival within the last few decades. In particular, tyrosine kinase inhibitors targeting specific molecular alterations, among other MET, have greatly improved the prognosis of non-small-cell lung cancer patients. Here, we compare the genomic background of a subset of non-small-cell lung cancer cases harboring either a MET high-level amplification (n = 24) or a MET exon 14 skipping mutation (n = 26), using next-generatison sequencing, fluorescence in situ hybridization, immunohistochemistry, and Nanostring nCounter (R) technology. We demonstrate that the MET-amplified cohort shows a higher genetic instability, compared with the mutant cohort (p < 0.001). Furthermore, MET mutations occur at high allele frequency and in the presence of co-occurring TP53 mutations (n = 7), as well as MDM2 (n = 7), CDK4 (n = 6), and HMGA2 (n = 5) co-amplifications. No other potential driver mutation has been detected. Conversely, in the MET-amplified group, we identify co-occurring pathogenic NRAS and KRAS mutations (n = 5) and a significantly higher number of TP53 mutations, compared with the MET-mutant cohort (p = 0.048). Of note, MET amplifications occur more frequently as subclonal events. Interestingly, despite the significantly (p = 0.00103) older age at diagnosis of stage IIIb/IV of MET-mutant patients (median 77 years), compared with MET high-level amplified patients (median 69 years), MET-mutant patients with advanced-stage tumors showed a significantly better prognosis at 12 months (p = 0.04). In conclusion, the two groups of MET genetic alterations differ, both clinically and genetically: our data strongly suggest that MET exon 14 skipping mutations represent an early driver mutation. In opposition, MET amplifications occur usually in the background of other strong genetic events and therefore MET amplifications should be interpreted in the context of each tumor's genetic background, rather than as an isolated driver event, especially when considering MET-specific treatment options

    Harmonized PD-L1 immunohistochemistry for pulmonary squamous-cell and adenocarcinomas

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    Immunohistochemistry of the PD-L1 protein may be predictive for anti-PD-1 and anti-PD-L1 immunotherapy in pulmonary adenocarcinoma and in clinically unselected cohorts of so-called non-small-cell lung cancer. Several PD-L1 immunohistochemistry assays with custom reagents and scoring-criteria are developed in parallel. Biomarker testing and clinical decision making would profit from harmonized PD-L1 diagnostics. To assess interobserver concordance and PD-L1 immunohistochemistry staining patterns, 15 pulmonary carcinoma resection specimens (adenocarcinoma: n = 11, squamous-cell carcinoma: n = 4) were centrally stained with the assays 28-8, 22C3, SP142, and SP263 according to clinical trial protocols. The slides were evaluated independently by nine pathologists. Proportions of PD-L1-positive carcinoma cells and immune cells were scored according to a 6-step system that integrates the criteria employed by the four PD-L1 immunohistochemistry assays. Proportion scoring of PD-L1-positive carcinoma cells showed moderate interobserver concordance coefficients for the 6-step Kscoring system (Light's kappa = 0.47-0.50). The integrated dichotomous proportion cut-offs (>= 1, >= 5, >= 10, >= 50%) showed good concordance coefficients (kappa = 0.6-0.8). Proportion scoring of PD-L1-positive immune cells yielded low interobserver concordance coefficients both for the 6-step-score (kappa<0.2) and the dichotomous cut-offs (kappa = 0.12-0.25). The assays 28-8 and 22C3 stained similar proportions of carcinoma cells in 12 of 15 cases. SP142 stained fewer carcinoma cells compared to 28-8, 22C3, and SP263 in four cases, whereas SP263 stained more carcinoma cells in nine cases. SP142 and SP263 stained immune cells more intensely. The data indicate that carcinoma cells can be reproducibly scored in PD-L1 immunohistochemistry for pulmonary adenocarcinoma and squamous-cell carcinoma. No differences in interobserver concordance were noticed among the tested assays. The scoring of immune cells yielded low concordance rates and might require specific standardization. The four tested PD-L1 assays did not show comparable staining patterns in all cases. Thus, studies that correlate staining patterns and response to immunotherapy are required to test the significance of the observed differences

    Ercc1 Deficiency Promotes Tumorigenesis and Increases Cisplatin Sensitivity in a Tp53 Context-Specific Manner

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    KRAS-mutant lung adenocarcinoma is among the most common cancer entities and, in advanced stages, typically displays poor prognosis due to acquired resistance against chemotherapy, which is still largely based on cisplatin-containing combination regimens. Mechanisms of cisplatin resistance have been extensively investigated, and ERCC1 has emerged as a key player due to its central role in the repair of cisplatin-induced DNA lesions. However, clinical data have not unequivocally confirmed ERCC1 status as a predictor of the response to cisplatin treatment. Therefore, we employed an autochthonous mouse model of Kras-driven lung adenocarcinoma resembling human lung adenocarcinoma to investigate the role of Ercc1 in the response to cisplatin treatment. Our data show that Ercc1 deficiency in Tp53-deficient murine lung adenocarcinoma induces a more aggressive tumor phenotype that displays enhanced sensitivity to cisplatin treatment. Furthermore, tumors that relapsed after cisplatin treatment in our model develop a robust etoposide sensitivity that is independent of the Ercc1 status and depends solely on previous cisplatin exposure. Our results provide a solid rationale for further investigation of the possibility of preselection of lung adenocarcinoma patients according to the functional ERCC1- and mutational TP53 status, where functionally ERCC1-incompetent patients might benefit from sequential cisplatin and etoposide chemotherapy. (C)2016 AACR
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