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Laser microbeam microdissection (LMM) is an increasingly important method for obtaining pure cell samples for genetic and proteomic analysis. Immunohistochemistry (IHC) and in situhybridization (ISH) are useful techniques for targeting specific cell populations for microdissection but are difficult to apply with the tissue support membranes often used during LMM. Using detection of cytokeratins and Epstein-Barr virus gene products in head and neck carcinoma as a model, we describe optimized protocols for membrane and section preparation and for low temperature antigen retrieval that allow IHC and ISH to be used reliably on membrane mounted paraffin tissue sections. Visualization of cellular targets was markedly improved by staining and this could be further improved using a variety of optical media before microdissection. Tissue fragments thus stained were suitable for subsequent polymerase chain reaction analysis of extracted DNA using standard techniques. These IHC and ISH procedures are generally applicable and will be useful for detecting a wide range of antigens and nucleic acids in paraffin sections in conjunction with LMM.

We used the molecular cytogenetic in situ techniques chromosome painting and PRimed IN Situ labeling (PRINS) to elaborate the cytogenetic observations in two cases of the rare aberration der(16)6(1;16), which occurs in a wide variation of hematologic and nonhematologic malignancies [1–13]. Review of the literature showed that, in contrast to the chromosome 1 breakpoint, the breakpoint on chromosome 16 is associated with diagnosis as well as patient age.

Trisomy 8 is a frequently acquired cytogenetic abnormality in myeloid malignancies, but may also represent a constitutional chromosome abnormality with a wide phenotypic variation. We report a case of myelodysplastic syndrome (MDS) that developed in a child with trisomy 8 mosaicism and normal phenotype. Bone marrow (BM) cells all showed trisomy 8 with additional clonal abnormalities in most cells. Based on the present case and a review of previously published cases of myeloid malignancies in patients with trisomy 8 mosaicism, it appears likely that the malignant cells developed from the trisomic cell population, suggesting that constitutional trisomy 8 may be a predisposing condition to myeloid malignancies. Trisomy 8 in malignant cells is usually considered an acquired abnormality, but this implies a risk of ignoring a constitutional trisomy 8 mosaicism. Examination for constitutional trisomy 8, despite a normal phenotype, may therefore be warranted in hematologic malignancies with trisomy 8 of BM cells to evaluate further the possible association and to preclude erroneous use of trisomy 8 as a tumor marker.

Thirty-four patients with myelodysplastic syndrome (MDS) subtypes refractory anemia (RA) and RA with ringed sideroblasts (RA-S) (26 and eight patients, respectively) were investigated for clinical and morphologic significance of the most frequently occurring minor chromosome deletions [del(17)(p12), del(8)(p22), del(2)(p24), and del(9)(p22)]. The occurrence of 17p- was statistically significantly related to a low initial bone marrow cellularity (p = 0.01) and severe granulocytopenia (p = 0.05). A diagnosis of RA was seen more frequently among patients with 17p-, also. 17p- alone was not related to progression to RA with an excess of blasts (RAEB). The occurrence of 8p- was statistically significantly related to a higher initial frequency of bone marrow myeloblasts (p = 0.05), but not to bone marrow cellularity or initial granulocytopenia. 8p- alone was not related to initial diagnosis, but a statistically significant relation to progression to RAEB was found (p = 0.05). 2p- was related to progression to RAEB, also (p = 0.02), but not to any of the other investigated parameters. No significant relations between the occurrence of 9p- and other parameters were demonstrated. The simultaneous occurrence of 17p- and 8p- was also statistically significantly related to progression to RAEB (p = 0.02). These relationships suggest that 17p- is involved in the development of bone marrow and peripheral blood granulocytopenia and that 8p-, and possibly 2p-, interferes with differentiation of primitive granulocyte precursors and, thus, play a part in the process leading to RAEB and acute myeloid leukemia.

The mechanical strength was determined for the cicatrices resulting from eight corneal cataract incisions and six corneoscleral incisions. The healing periods of the corneal incisions ranged from 4 days to 521 years. The healing periods of the corneoscleral incisions were between 8 and 12 years. Wound specimens and controls were deformed until failure at a constant speed in a materials testing machine while recording load and deformation. Load-deformation curves were transformed to load-strain curves. Mechanical strength was expressed by the maximum load values and the relative failure energy values derived from the load-strain curves. The strength of corneal cicatrices increased gradually up to the fourth post-operative year; after 4 years the strength of the cicatrix equalled that of uninjured specimens, which failed at the corneoscleral transitions. The average strength of specimens with corneoscleral incisions was 64% of that of uninjured specimens.

Of eight patients with primary myelodysplastic syndrome (MDS) treated with Roacutane (13-cis retinoic acid, Roche, Basel, (13-RA)) 20 mg/m2 for 6 weeks and an additional 100 mg/m2 for 4 weeks (3 patients), 4 responded either with a slight increase in peripheral blood neutrophil count or a decrease in myeloperoxidase deficient neutrophils. In agar cultures 2 patients showed a concurrent increase in growth of day 11 colonies and clusters. In 2 of the patients a decrease in the number of immature bone marrow cells positive for the myeloid antibody anti-My7 was observed. Only minor alterations were seen in natural killer cell activity. In 4 patients showing clonal chromosomal abnormalities before treatment a disappearance of minor clonal abnormalities during treatment was observed, and in 3 chromosomal abnormalities reappeared after cessation of therapy. Even though the overall impact of 13-RA on the hematopoietic system was minor, the increase in myeloperoxidase normal granulocytes in the blood and the decrease in My7 positive cells and in clonal chromosomal abnormalities warrants further interest in this agent as a treatment modality in MDS. The side effects, especially experienced by the patients receiving 100 mg/m2, were, in spite of symptomatic treatment, of such a degree that only low dose treatment (10-20 mg/m2) administered for prolonged periods of time (3-6 months) would seem recommendable.