Monoclonal antibodies to different sites on human transcobalamin II

Two IgG1K monoclonal antibodies to human transcobalamin II (TC II) were generated. These antibodies, 16.1 and 16.6, did not cross-react with the other two types of human cobalamin-binding proteins, intrinsic factor and R binder (TC I). Both antibodies cross-reacted with orangutan and simiang TC II but not with TC II from cynomolgus and howler monkeys, who are less closely related to humans. This finding suggests close structural similarity of human to ape TC II. The antibodies also did not react with TC II of lower mammals which included the horse, dog, guinea pig, and mouse; in particular, reaction did not occur with rabbit TC II, which has been considered structurally close to human TC II. Neither of the two antibodies was directed at the cobalamin-binding site of TC II. However, antibody 16.6 hindered TC II binding to cell receptor. This reactivity with the receptor-binding site should prove particularly useful in studies of that region of the TC II molecule.     

The weighted reversal potential-a tool to study refractoriness and regenerativity in nerves

A weighted reversal potential, E, was defined as:

$\text{E}\text{=}\text{(g}{}_{\mathrm{Na}}\text{E}{}_{\mathrm{Na}}\text{+ g}{}_{\mathrm{K}}\text{E}{}_{\mathrm{K}}\text{+ g}{}_{\mathrm{L}}\text{E}{}_{\mathrm{L}}\text{)}\text{g}{}_{\mathrm{Na}}\text{+ g}{}_{\mathrm{K}}\text{+ g}{}_{\mathrm{L}}\text{)}$

. The concept was shown to be useful in describing threshold phenomena for single and multiple responses by providing explicit criteria which made possible the classification of responses into regenerative or non-regenerative. Within this framework E was also used to analyse the anodic break response and abolishment experiments. Using zero-duration (8-impulse) stimuli, the end of the absolutely refractory period was determined, according to the developed criteria, to be 3·17 t 0·01 ms after the peak of the spike, in the Hodgkin-Huxley model.     

Quantitative determination of ferritin by electroimmunoassay

A method for the quantitative determination of tissue ferritin protein is described. It is based on the electroimmunoassay of Laurell [Laurell, C. B. (1966) Anal. Biochem.15, 45–52] and uses the iron content of ferritin for its identification. It measures as little as 0.1 μg of ferritin protein, requires only a few milligrams of tissue, and is rapidly performed.     

PD-L1 and Tumor Infiltrating Lymphocytes as Prognostic Markers in Resected NSCLC

IntroductionImmune checkpoint inhibition has shifted treatment paradigms in non-small cell lung cancer (NSCLC). Conflicting results have been reported regarding the immune infiltrate and programmed death-ligand 1 (PD-L1) as a prognostic marker. We correlated the immune infiltrate and PD-L1 expression with clinicopathologic characteristics in a cohort of resected NSCLC.MethodsA tissue microarray was constructed using triplicate cores from consecutive resected NSCLC. Immunohistochemistry was performed for CD8, FOXP3 and PD-L1. Strong PD-L1 expression was predefined as greater than 50% tumor cell positivity. Matched nodal samples were assessed for concordance of PD-L1 expression.ResultsOf 522 patients, 346 were node-negative (N0), 72 N1 and 109 N2; 265 were adenocarcinomas (AC), 182 squamous cell cancers (SCC) and 75 other. Strong PD-L1 expression was found in 24% cases. In the overall cohort, PD-L1 expression was not associated with survival. In patients with N2 disease, strong PD-L1 expression was associated with significantly improved disease-free (DFS) and overall survival (OS) in multivariate analysis (HR 0.49, 95%CI 0.36–0.94, p = 0.031; HR 0.46, 95%CI 0.26–0.80, p = 0.006). In this resected cohort only 5% harboured EGFR mutations, whereas 19% harboured KRAS and 23% other. KRAS mutated tumors were more likely to highly express PD-L1 compared to EGFR (22% vs 3%). A stromal CD8 infiltrate was associated with significantly improved DFS in SCC (HR 0.70, 95%CI 0.50–0.97, p = 0.034), but not AC, whereas FOXP3 was not prognostic. Matched nodal specimens (N = 53) were highly concordant for PD-L1 expression (89%).ConclusionPD-L1 expression was not prognostic in the overall cohort. PD-L1 expression in primary tumor and matched nodal specimens were highly concordant. The observed survival benefit in N2 disease requires confirmation.     

Hedgehog signal transduction: from flies to vertebrates

The patterning and morphogenesis of multicellular organisms require a complex interplay of inductive signals which control proliferation, growth arrest, and differentiation of different cell types. A number of such signaling molecules have been identified in vertebrates and invertebrates. The molecular dissection of these pathways demonstrated that in vertebrates, mutations or abnormals function of these signaling pathways were often associated with developmental disorders and cancer formation. The Hedgehog (Hh) family of secreted proteins provides a perfect example of such signaling proteins. In the following review, we will not discuss in detail the role of Hh as a morphogen, but rather focus on its signal transduction pathway and its role in various human disorders.