Evaluation of programmed cell death ligand 1 expression in a contemporary cohort of penile squamous cell carcinoma and its correlation with clinicopathologic and survival parameters: A study of 134 patients.

Objectives: Penile squamous cell carcinomas (PCs) are rare malignancies with a dismal prognosis in a metastatic setting; therefore, novel immunotherapeutic modalities are an unmet need. One such modality is the immune checkpoint molecule programmed cell death ligand 1 (PD-L1). We sought to analyze PD-L1 expression and its correlation with various clinicopathologic parameters in a contemporary cohort of 134 patients with PC.

Differentiation of positional isomers of hybrid peptides containing repeats of β-nucleoside derived amino acid (β-Nda-) and L-amino acids by positive and negative ion electrospray ionization tandem mass spectrometry (ESI-MSn).

A new class of positional isomeric pairs of -Boc protected oligopeptides comprised of alternating nucleoside derived β-amino acid (β-Nda-) and L-amino acid residues (alanine, valine, and phenylalanine) have been differentiated by both positive and negative ion electrospray ionization ion-trap tandem mass spectrometry (ESI-MS(n)). The protonated dipeptide positional isomers with β-Nda- at the N-terminus lose CH(3)OH, NH(3), and C(2)H(4)O(2), whereas these processes are absent for the peptides with L-amino acids at the N-terminus. Instead, the presence of L-amino acids at the N-terminus results in characteristic retro-Mannich reaction involving elimination of imine.

Novel helical foldamers: organized heterogeneous backbone folding in 1 : 1 alpha/nucleoside-derived-beta-amino acid sequences.

Secondary structural conformation of hybrid oligo-peptides comprised of 1 : 1 alternating Nucleoside Derived beta-Amino acid (NDA) and l-amino acid residues has been reported. The studies reveal that the NDA residues organize the heterogeneous backbone featuring the surface properties of both nucleic acids and peptides, to adopt a novel 11/8-helical fold.