Characteristics and outcomes of advanced melanoma patients with complete response and elective discontinuation of first-line anti-programmed death-1 monotherapy: A real-world multicentre observational cohort study

Anti-programmed death-1 (anti-PD1) treatment has significantly improved outcomes of advanced melanoma with a considerable percentage of patients achieving complete response (CR). This real-world study analyzed the feasibility of elective anti-PD1 discontinuation in advanced melanoma patients with CR and evaluated factors related to sustained response. Thirty-five patients with advanced cutaneous or primary unknown melanoma with CR to nivolumab or pembrolizumab from 11 centers were included. Mean age was 66.5 years, and 97.1% had ECOG PS 0–1. 28.6% had ≥3 metastatic sites with 58.8% having M1a-M1b disease; 8.6% had liver and 5.7% had brain metastases. At baseline, 80% had normal LDH, and 85.7% had a neutrophil-to-lymphocyte ratio ≤3. 74.3% of patients had CR confirmed in PET-CT. Median duration of anti-PD1 was 23.4 months (range 1.3–50.5). 24 months after therapy discontinuation, 91.9% of patients were progression-free. Estimated PFS and OS at 36, 48, and 60 months from the start of anti-PD1 were 94.2%, 89.9%, 84.3%, and 97.1%, 93.3%, 93.3%, respectively. Antibiotics use after anti-PD1 discontinuation increased the odds of progression (OR 16.53 [95% CI 1.7, 226.03]). The study confirms the feasibility of elective anti-PD1 discontinuation in advanced melanoma patients with CR and favorable prognostic factors at baseline.     

Electrophoretic mobility of N- and C-terminal monoferric fragments of bovine transferrin phenotypes AA,D1D1, D2D2, and EE,and N-terminal amino acid sequences

Iron-saturated bovine transferrins A, D1, D2, and E were cleaved by trypsin yielding monoferric fragments. The N-terminal fragments (F) of transferrins A and D2 had identical mobility in cellulose acetate electrophoresis, that of transferrin D1 a slower mobility, and that of E a still slower mobility. The C-terminal fragments (S) gave multiple bands which were essentially identical in the case of transferrins A, D1, and E, but of slower mobility in the case of transferrin D2. All four variants had identical N-terminal amino acid sequences. The electrophoretic mobility of the C-terminal fragments was reduced by neuraminidase treatment, but the N-terminal fragments were unaffected. The four transferrin variants therefore appear to be made up from three electrophoretically distinguishable N-terminal halves and two C-terminal halves. The feature responsible for the electrophoretic double banding of homozygous bovine asialotransferrins is consistently associated with the C-terminal half of the molecule.     

An autonomously replicating plasmid transforms Botrytis cinerea to phleomycin resistance

Abstract A transformation system has been developed for the pathogen fungus Botrytis cinerea , based on the utilization of the wide host plasmid pUT737 that contains the Sh ble gene, conferring resistance to phleomycin. Transformed protoplasts were regenerated at 10–25 μg ml⁻¹ of phleomycin, at a frequency of 25–40 transformants per μg of DNA, and they were resistant up to 50 μg ml⁻¹. Southern hybridization using undigested and digested total DNA showed the presence of circular autonomously replicating plasmid pUT737 in the transformants. Reisolated plasmid from transformed fungus transformed E. coli and rescued plasmid was identified as pUT737. Transformants were grown for four generations under non-selective conditions and replicative plasmids were still detected. Plasmids present in all transformants at this stage had been modified from native pUT737 and showed the same size and configuration indicating that selection through stabilizing plasmid forms has happened.     

Sex chromosomal abnormalities associated with equine infertility: validation of a simple molecular screening tool in the Purebred Spanish Horse

Chromosomal abnormalities in the sex chromosome pair (ECAX and ECAY) are widely associated with reproductive problems in horses. However, a large proportion of these abnormalities remains undiagnosed due to the lack of an affordable diagnostic tool that allows for avoiding karyotyping tests. Hereby, we developed an STR (single‐tandem‐repeat)‐based molecular method to determine the presence of the main sex chromosomal abnormalities in horses in a fast, cheap and reliable way. The frequency of five ECAX‐linked (LEX026, LEX003, TKY38, TKY270 and UCDEQ502) and two ECAY‐linked (EcaYH12 and SRY) markers was characterized in 261 Purebred Spanish Horses to determine the efficiency of the methodology developed to be used as a chromosomal diagnostic tool. All the microsatellites analyzed were highly polymorphic, with a sizeable number of alleles (polymorphic information content > 0.5). Based on this variability, the methodology showed 100% sensitivity and 99.82% specificity to detect the most important sex chromosomal abnormalities reported in horses (chimerism, Turner's syndrome and sex reversal syndromes). The method was also validated with 100% efficiency in 10 individuals previously diagnosed as chromosomally aberrant. This STR screening panel is an efficient and reliable molecular–cytogenetic tool for the early detection of sex chromosomal abnormalities in equines that could be included in breeding programs to save money, effort and time of veterinary practitioners and breeders.