David F. Dexter

Establishment of a human large cell lung tumor line (QU‐DB) with metastatic properties in athymic mice

A continuous human cell line was established from a patient with large cell anaplastic lung carcinoma. This cell line, designated QU‐DB, has been in culture for over 36 months and grows as an adherent monolayer with a doubling time of 10–12 hours. Its morphology, ultrastructure, karyotype, ability to grow in soft agar and heterotransplantability, indicate it is a large‐cell lung tumor cell line of human origin. Three cell lines were established from metastatic tumors in nude mice receiving subcutaneous injections of QU‐DB cells. The morphology and growth characteristics exhibited by these cell lines were similar to the primary cell line. Karyotypic analysis of cell lines derived from the primary tumor and a metastasis to the diaphragm were similar, but cells from a liver metastasis culture showed additional karyotypic changes. This large cell lung tumor cell line may prove useful as a model system for studies of human tumor progression and metastasis.

A practical method to rapidly dissolve metallic stents

Metallic stents are commonly used in many clinical applications including peripheral vascular disease intervention, biliary obstruction, endovascular repair of aneurysms, and percutaneous coronary interventions. In the examination of vascular stent placement, it is important to determine if the stent is open or has become obstructed. This is increasingly important in the era of drug-eluting stent usage in coronary arteries. We describe a practical, rapid and cost-effective method to dissolve most metallic stents leaving the vascular and luminal tissues intact. This practical method may replace the laborious and expensive plastic embedding methods currently utilized.

EVIDENCE FOR IN VIVO NK REACTIVITY AGAINST PRIMARY TUMORS

Publisher Summary This chapter presents evidence for in vivo natural killer (NK) reactivity against primary tumors. There is strong evidence that NK cells play a role in protection against the growth and metastasis of transplantable tumors. There is, however, little evidence that NK cells play a protective role against the development of primary tumors. One of the important evidences on this topic is that aging mice (> 6 months) have diminished NK function and also exhibit an increased incidence of spontaneous tumors. In one study described in the chapter, raised in vitro NK activity against YAC or syngeneic, MCA-induced fibrosarcomas in mice deprived of B cells by chronic anti-μ treatment correlated well with an increased resistance to induction of primary tumors by MCA. An important control in these studies was the observation that the incidence and growth-rate of progressing tumors induced by Moloney sarcoma virus (MSV) did not differ in anti-μ-suppressed or normal control mice that were untreated with normal gammaglobulin. Because host defense in the MSV system is clearly Tcell-dependent, this indicates that B cell-deprived mice have normal T function and augmented NK activity does not influence a T-cell-dependent rejection system.

Mediastinal thymolipoma : A rare occurrence with striated myoid cells

We describe a 49-year-old man who presented to hospital with unstable angina and who underwent emergency coronary artery bypass grafting. During the surgical procedure, an incidental anterior mediastinal mass was discovered. Histological examination of this mediastinal mass revealed a thymolipoma containing numerous polygonal, striated myoid cells that were immunoreactive for desmin, muscle-specific actin and myoglobin. Electron microscopy demonstrated numerous Z band structures confirming myoid differentiation. Even though the appearance of myoid cells in thymolipoma may be alarming, this tumor should be recognized as a benign entity. Thymolipomas containing striated myoid cells should be differentiated from more ominous thymic neoplasms, including teratomas and thymic liposarcomas. To our knowledge, this is only the third reported case of thymolipoma containing striated myoid cells.