Alternative splicing variant of the hypoxia marker carbonic anhydrase IX expressed independently of hypoxia and tumour phenotype

CA IX is a hypoxia-induced, cancer-associated carbonic anhydrase isoform with functional involvement in pH control and cell adhesion. Here we describe an alternative splicing variant of the CA9 mRNA, which does not contain exons 8–9 and is expressed in tumour cells independently of hypoxia. It is also detectable in normal tissues in the absence of the full-length transcript and can therefore produce false-positive data in prognostic studies based on the detection of the hypoxia- and cancer-related CA9 expression. The splicing variant encodes a truncated CA IX protein lacking the C-terminal part of the catalytic domain. It shows diminished catalytic activity and is intracellular or secreted. When overexpressed, it reduces the capacity of the full-length CA IX protein to acidify extracellular pH of hypoxic cells and to bind carbonic anhydrase inhibitor. HeLa cells transfected with the splicing variant cDNA generate spheroids that do not form compact cores, suggesting that they fail to adapt to hypoxic stress. Our data indicate that the splicing variant can functionally interfere with the full-length CA IX. This might be relevant particularly under conditions of mild hypoxia, when the cells do not suffer from severe acidosis and do not need excessive pH control

Amplification of Antimicrobial Resistance in Gut Flora of Patients Treated with Ceftriaxone

Item does not contain fulltextAlthough antibacterial therapy has an impact on human intestinal flora and the emergence of resistant bacteria, its role in the amplification of antimicrobial resistance and the quantitative exposure-effect relationship is not clear. An observational prospective study was conducted to determine whether and how ceftriaxone exposure is related to amplification of resistance in non-intensive care unit (non-ICU) patients. Serial stool samples from 122 extended-spectrum beta-lactamase-positive (ESBL(+)) hospitalized patients were analyzed by quantitative real-time PCR to quantify the resistant gene blaCTX-M Drug exposure was calculated for each patient by using a population pharmacokinetic model. Multi- and univariate regression and classification regression tree (CART) analyses were used to explore relationships between measures of exposure and amplification of blaCTX-M genes. Amplification of blaCTX-M was observed in 0% (0/11) of patients with no treatment and 33% (20/61) of patients treated with ceftriaxone. Stepwise regression analysis showed a significant association between amplification of blaCTX-M and the plasma area under the concentration-time curve from 0 to 24 h for the unbound fraction of the drug (fAUC0-24), the maximum concentration of drug in serum for the unbound fraction of the drug (fCmax), and the duration of ceftriaxone therapy. Using CART analysis, amplification of blaCTX-M was observed in 11/16 (69%) patients treated for >14 days and in 9/40 (23%) patients treated for /=222 mg . h/liter and in 4/33 (12%) patients with lower drug exposures (P = 0.0033). A similar association was found for an fCmax of >/=30 mg/liter (63% versus 13%, P = 0.0079). A significant association was found between the amplification of blaCTX-M resistance genes and exposure to ceftriaxone. Both duration of treatment and degree of ceftriaxone exposure have a significant impact on the amplification of resistance genes. (The project described in this paper has been registered at ClinicalTrials.gov under identifier NCT01208519.)

Comparative pharmacokinetics and pharmacodynamics of two formulations of agalsidase beta (agalsidase Biosidus) and Fabrazyme® by intravenous infusion in healthy male volunteers

Fabry disease is a rare X-linked lysosomal condition that leads to the accumulation of glycosphingolipids in various tissues, causing cellular dysfunction, tissue remodeling, progressive fibrosis, and organ failure. The disease results from a deficiency in the human α-galactosidase A enzyme, responsible for breaking down glycosphingolipids like globotriaosylceramide (GL-3 or Gb3) into galactose and dihexose ceramides. In individuals diagnosed with Fabry disease, treatment from 2 years of age onwards typically involves agalsidase beta, the normal recombinant form of the defective enzyme. Agalsidase beta from Biosidus has been developed as a biosimilar to Sanofi-Genzyme's Fabrazyme®. In the molecule's clinical journey, a phase I trial was designed to establish its similarity in terms of pharmacokinetics, pharmacodynamics, and immunogenicity compared to the reference medication. The study was conducted on 24 healthy male volunteers, aged between 18 and 40 years. All volunteers received a single 1 mg/kg bw dose of Fabrazyme® or Biosidus Agalsidase beta by continuous intravenous (IV) infusion over 5 h. The 90 % confidence interval (CI) of the maximum concentration (Cmax), area under the plasma concentration-time curve from time 0 to 12 h (AUC0-12 h) and area under the plasma concentration-time curve extrapolated from time 0 to infinity (AUC0-∞) ratios fell within the accepted range of 80–125 %. No differences were detected in adverse effects or antibody induction. This indicates that Biosidus agalsidase beta meets the criteria for being considered similar to the reference formulation Sanofi Genzyme's Fabrazyme®

A Predictive Model of Mortality in Patients With Bloodstream Infections due to Carbapenemase-Producing Enterobacteriaceae

Objective To develop a score to predict mortality in patients with bloodstream infections (BSIs) due to carbapenemase-producing Enterobacteriaceae (CPE). Patients and Methods A multinational retrospective cohort study (INCREMENT project) was performed from January 1, 2004, through December 31, 2013. Patients with clinically relevant monomicrobial BSIs due to CPE were included and randomly assigned to either a derivation cohort (DC) or a validation cohort (VC). The variables were assessed on the day the susceptibility results were available, and the predictive score was developed using hierarchical logistic regression. The main outcome variable was 14-day all-cause mortality. The predictive ability of the model and scores were measured by calculating the area under the receiver operating characteristic curve. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for different cutoffs of the score. Results The DC and VC included 314 and 154 patients, respectively. The final logistic regression model of the DC included the following variables: severe sepsis or shock at presentation (5 points); Pitt score of 6 or more (4 points); Charlson comorbidity index of 2 or more (3 points); source of BSI other than urinary or biliary tract (3 points); inappropriate empirical therapy and inappropriate early targeted therapy (2 points). The score exhibited an area under the receiver operating characteristic curve of 0.80 (95% CI, 0.74-0.85) in the DC and 0.80 (95% CI, 0.73-0.88) in the VC. The results for 30-day all-cause mortality were similar. Conclusion A validated score predictive of early mortality in patients with BSIs due to CPE was developed. Trial Registration clinicaltrials.gov Identifier: NCT01 764490. © 2016 Mayo Foundation for Medical Education and Researc

A Predictive Model of Mortality in Patients With Bloodstream Infections due to Carbapenemase-Producing Enterobacteriaceae

Objective To develop a score to predict mortality in patients with bloodstream infections (BSIs) due to carbapenemase-producing Enterobacteriaceae (CPE). Patients and Methods A multinational retrospective cohort study (INCREMENT project) was performed from January 1, 2004, through December 31, 2013. Patients with clinically relevant monomicrobial BSIs due to CPE were included and randomly assigned to either a derivation cohort (DC) or a validation cohort (VC). The variables were assessed on the day the susceptibility results were available, and the predictive score was developed using hierarchical logistic regression. The main outcome variable was 14-day all-cause mortality. The predictive ability of the model and scores were measured by calculating the area under the receiver operating characteristic curve. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for different cutoffs of the score. Results The DC and VC included 314 and 154 patients, respectively. The final logistic regression model of the DC included the following variables: severe sepsis or shock at presentation (5 points); Pitt score of 6 or more (4 points); Charlson comorbidity index of 2 or more (3 points); source of BSI other than urinary or biliary tract (3 points); inappropriate empirical therapy and inappropriate early targeted therapy (2 points). The score exhibited an area under the receiver operating characteristic curve of 0.80 (95% CI, 0.74-0.85) in the DC and 0.80 (95% CI, 0.73-0.88) in the VC. The results for 30-day all-cause mortality were similar. Conclusion A validated score predictive of early mortality in patients with BSIs due to CPE was developed. Trial Registration clinicaltrials.gov Identifier: NCT01 764490. © 2016 Mayo Foundation for Medical Education and Researc