The length‐dependent activation of contraction is equally impaired in impuberal male and female rats in monocrotaline‐induced right ventricular failure

The length‐dependent activation of contraction is attenuated in the failing myocardium of adult male rats. This pathological change is not seen in adult female rats, possibly because of a protective effect of sex hormones. The present study evaluated length‐dependent changes in isometric twitch, Ca²⁺ transient (CaT) and action potential (AP) in the right ventricular myocardium of impuberal healthy male and female rats (control) and in rats treated with a single injection of 50 mg/kg monocrotaline (MCT). Compared with sex‐matched control rats, MCT‐treated male and female rats exhibited increased right ventricular weight (134% and 142% of control, respectively), decreased left ventricular weight (72% and 79%), twitch attenuation (48.8 ± 2.7% and 57.5 ± 1.2%) and prolongation (125 ± 3% and 127 ± 2%), CaT attenuation (37.8 ± 0.4% and 39.1 ± 1.1%) and prolongation (114 ± 1% and 116 ± 1%) and AP prolongation at 90% repolarization (195 ± 2% and 203 ± 1%). The MCT‐treated male rats exhibited a 50% lower integral magnitude and an approximately 25% larger time‐to‐peak ‘bump’ compared with control male rats. These parameters in MCT‐treated female rats tended to show similar changes to those seen in the control female rats, with no significant difference between the two groups. In all groups, integral magnitude and time‐to‐peak ‘bump’ increased with length. In conclusion, the length‐dependent activation of contraction was equally blunted in the failing right ventricular myocardium of impuberal male and female rats. This was related to changes in CaT and AP, which were similar between male and female rats. Therefore, puberty is necessary for manifestation of the protective effects of sex hormones on this remodelling.     

The FNTB promoter polymorphism rs11623866 as a potential predictive biomarker for lonafarnib treatment of ovarian cancer patients

Aim

Despite promising preclinical findings regarding clinical utility of farnesyltransferase inhibitors (FTI), such as lonafarnib, success of clinical trials is limited. A multicentre AGO-OVAR-15 phase II trial reported an unfavourable effect of lonafarnib on the outcome of patients with advanced ovarian cancer. This study was performed as a genetic subgroup analysis of the AGO-OVAR-15 trial, and investigated the utility of the promoter polymorphism rs11623866 of the farnesyltransferase ß-subunit gene (FNTB) in predicting the clinical effectiveness of lonafarnib.

Methods

The influence of rs11623866 (c.-609G > C) on FNTB promoter activity was investigated by electrophoretic-mobility-shift assay, luciferase-reporter assay and RT-qPCR. A total of 57 out of 105 patients from the AGO-OVAR-15 trial, treated with carboplatin and paclitaxel ± lonafarnib, was genotyped for rs11623866 by restriction fragment length polymorphism analysis. Genotype-dependent survival analysis was performed by Kaplan–Meier analysis.

Results

The presence of the G allele was associated with increased FNTB promoter activity compared with the C allele. An unfavourable effect of lonafarnib was limited to patients carrying a GG genotype (HR_PFS 6.2, 95%CI = 2.01, 19.41, P = 0.002; HR_OS 9.6, 95%CI = 1.89, 48.54, P = 0.006). Median progression free survival (PFS) for patients with the GG genotype in the lonafarnib treated arm was 10 months, whereas median PFS without FTI-treatment was 40 months. Median overall survival (OS) in the lonafarnib-treated group was 19 months, whereas median OS was not reached in the untreated group.

Conclusions

Discrepancies between preclinical success and clinical failure may be due to the patients'' genetic variability of FNTB. Therefore, our results may encourage retrospective evaluation of FNTB polymorphisms in previous FTI studies, especially those reporting positive FTI response.     

Transdermal Diagnosis of Malaria Using Vapor Nanobubbles

A fast, precise, noninvasive, high-throughput, and simple approach for detecting malaria in humans and mosquitoes is not possible with current techniques that depend on blood sampling, reagents, facilities, tedious procedures, and trained personnel. We designed a device for rapid (20-second) noninvasive diagnosis of Plasmodium falciparum infection in a malaria patient without drawing blood or using any reagent. This method uses transdermal optical excitation and acoustic detection of vapor nanobubbles around intraparasite hemozoin. The same device also identified individual malaria parasite–infected Anopheles mosquitoes in a few seconds and can be realized as a low-cost universal tool for clinical and field diagnoses.     

Comparative Analysis of African Swine Fever Virus Genotypes and Serogroups

African swine fever virus (ASFV) causes highly lethal hemorrhagic disease among pigs, and ASFV’s extreme antigenic diversity hinders vaccine development. We show that p72 ASFV phylogenetic analysis does not accurately define ASFV hemadsorption inhibition assay serogroups. Thus, conventional ASFV genotyping cannot discriminate between viruses of different virulence or predict efficacy of a specific ASFV vaccine.