The effect of sampling on quantitative nuclear image features in histologic sections of lung carcinomas

A feasibility study showed that quantitative nuclear image (QNI) analysis, in which the morphology of the nucleus is described by a number of mathematical parameters, can be used to make the therapeutically and prognostically important distinction between small cell lung carcinoma (SCLC) and non-SCLC, which can be difficult to make with subjective histologic typing. In the present study, the effects of sample size and sample site on the QNI features were investigated. For all sample sites in a given tumor, comparison was made between the histologic classification, the ultrastructural findings and the classification based on the QNI features. Using a running mean, it was found that a sample size of 25 nuclei is sufficiently large. Histologic and quantitative classifications of samples from different sites of the same tumors were in agreement with regard to the separation of SCLC and non-SCLC in 19 of 20 sections. In the case in which disagreement occurred in one section, the ultrastructural findings supported the quantitative classification. These data indicate that sampling from different sites has no essential influence on the QNI classification of lung carcinomas.     

Morphometry in the differential diagnosis of granulosa-cell tumors of the ovary

Although the diagnosis of granulosa-cell tumors of the ovary is usually consistent and reproducible, in some cases the differentiation from poorly differentiated adenocarcinomas can be difficult. To investigate our subjective impression of the similarity of nuclei in both types of tumors, seven granulosa-cell tumors and eight poorly differentiated adenocarcinomas were studied with morphometry, with a variety of nuclear parameters measured in 100 nuclei per case. The findings showed that, in general, granulosa-cell tumors have a slightly higher mean nuclear contour index (NCI), which is a measure of the nuclear indentation or grooving, and a somewhat lower mean nuclear area than do adenocarcinomas. There is considerable overlap, however, with the nuclear patterns of the two types of tumors forming a morphologic continuum. Multivariate analysis gave a better discrimination but did not entirely eliminate the overlap. The maximum NCI was the best single discriminator. While only one of the granulosa-cell tumors had a maximum NCI less than 5.11, none of the adenocarcinomas exceeded this value. The only granulosa-cell tumor with a maximum NCI below the threshold was in a case with a much less favorable clinical course. The results of this study indicate that objective morphometric nuclear criteria are useful in the diagnosis of granulosa-cell tumors and possibly have some prognostic value.     

Study of permeation and blocker binding in TMEM16A calcium-activated chloride channels

We studied the effects of mutations of positively charged amino acid residues in the pore of X. tropicalis TMEM16A calcium-activated chloride channels: K613E, K628E, K630E; R646E and R761E. The activation and deactivation kinetics were not affected, and only K613E showed a lower current density. K628E and R761E affect anion selectivity without affecting Na⁺ permeation, whereas K613E, R646E and the double mutant K613E + R646E affect anion selectivity and permeability to Na⁺. Furthermore, altered blockade by the chloride channel blockers anthracene-9-carboxylic acid (A-9-C), 4, 4''-Diisothiocyano-2,2''-stilbenedisulfonic acid (DIDS) and T16inh-A01 was observed. These results suggest the existence of 2 binding sites for anions within the pore at electrical distances of 0.3 and 0.5. These sites are also relevant for anion permeation and blockade.