A novel translocation t(1;7)(p36;q34) in three patients with acute myeloid leukaemia.

Studies of large numbers of patients have enabled the identification of relatively infrequent chromosome changes, such as inv(3)(q21;q26), t(6;9)(p23;q34) and t(8;16)(p11;p11), whose clinico-biological significance is gradually becoming clearer. Translocations involving chromosomes 1 and 7 are relatively rare in myeloid neoplasias, being found in far less than 1% of cases; the rearrangement that occurs most frequently consists of an unbalanced translocation [t(1;7)(p11; p11)], resulting in complete loss of 7q, associated with therapy-related or environmentally-induced high-risk myelodysplasia. We recently observed three cases of acute myeloid leukaemia (AML) with a previously unreported balanced translocation t(1;7) (p36;q34). Case 1 underwent autologous bone marrow transplantation and remains alive in CR; cases 2 and 3 relapsed after 10 and 4 months, respectively. The response to chemotherapy observed in our cases suggests that variable clinical features might be present in the broad cytogenetic category usually referred to as '7q abnormalities' and contributes to an interesting previous observation of prolonged disease-free survival in a subset of AMLs with 7q- as the isolated chromosome change.

Mast cell populations in the chick embryo lung and their response to compound 48/80 and dexamethasone.

Two mast cell populations, connective tissue mast cells (CTMCs) and mucosal mast cells, (MMCs) containing different proteoglycans in their granules, can be distinguished in several animal species by means of histochemical methods. In this study we documented the presence of these two types of mast cell in the chick embryo lung, from the 15th incubation day for the MMCs, and from the 18th incubation day for the CTMCs. Lungs of embryos treated with compound 48/80, which produces degranulation of the CTMCs, showed a decrease in the number of this type of mast cell and an unchanged number of MMCs. In the lungs of embryos treated with dexamethasone, which degranulates MMCs, a reduction in the number of these cells and an unchanged number of the CTMs were found.

Effect of tray space on the accuracy of monophasic polyvinylsiloxane impressions.

The effect of tray space on the dimensional accuracy and stability of impressions made from four brands of monophasic polyvinyl siloxane material was assessed on the recovered stone casts by quantitative and qualitative methods. In general, both evaluation methods agreed that tray space and repeat pour did not affect the accuracy of the dies for individual castings. But disagreement was observed in the findings for fixed partial dentures (FPDs). Quantitative measurement of the interpreparation (IP) dimensions did suggest the possibility of a potential problem when a FPD is cast in one piece because of a significantly reduced distance between the two abutments. However, from the findings of this study it can be concluded that a rigid stock tray can be used with a monophasic polyvinyl siloxane impression material.

Do mast cells intervene in the vasoproliferative process of the rheumatoid synovitis?

On the basis of these evidences: a) the role played by heparin in the promotion of angiogenetic processes; b) the isolation of an angiogenetic factor in the synovial fluid from patients with rheumatoid arthritis; c) the significant increase of mast cells in the synovial membrane of the same patients, we suggest the possibility that the vasoproliferative processes in the course of rheumatoid arthritis may be mediated by heparin contained in the secretory granules of mast cells and released during the inflammatory process in response to numerous and heterogeneous stimuli.

Possible role of mast cells in the mechanism of action of intrauterine contraceptive devices.

The presence and number of mast cells and their relationship to other inflammatory cells were investigated in smears from intrauterine contraceptive devices. The results obtained suggest a possible role of mast cells in the mechanism of action of intrauterine contraceptive devices, on the basis of the peculiar known functions of mast cells.

PIP: The presence and number of mast cells and their relationships to other inflammatory cells were investigated in smears from IUDs. Triplicate slide smears were obtained from IUDs removed from 5-25 months after insertion in 100 healthy women (age range 24-40 years). Normal endometrial smears were obtained from 30 women (age range 28-41 years). The slides were stained by Papanicolaou, toluidine blue, and Giemsa methods, and cellular populations were identified and counted, with particular attention being given to the mast cells. 22 samples were studied by electron microscopy. The cellular layers adherent to the IUDs were fixed in glutaraldehyde for 20 minutes, washed, postfixed in 1% osmium tetroxide solution for 1 hour, dehydrated, and embedded in Araldite. Neutrophils, lymphocytes, endometrial cells, and macrophages were observed. The latter cells predominated, and they had hyperchromatic nuclei with distinct nucleoli, and vacuolated cytoplasm with or without phagocytosed material. No giant cells were seen, but red blood cells, degenerated spermatozoa, and cellular debris were present. Mast cells were observed in all smears examined, with a range of from 120-180 cells/10 microscopic fields at 100x for each slide, as compared with smears of endometrium obtained from 30 normal women, which had only 10-50 cells. Pelvic pain, spotting, and other manifestations of pathologic conditions due to use of IUDs were observed in most cases with highly increased numbers of mast cells, whereas no clinical manifestations were present in a few cases, although the number of mast cells was similarly elevated. Endometrial cells were present, free or in clumps, and did not show dysplastic or neoplastic alterations. A conspicuous number of mast cells was intermingled with the other inflammatory cells and endometrial cells, thus confirming the aspects observed with light microscopy. Most mast cells presented with semilunar features of granules characteristic of a slow but progressive degranulation in response to low level but constant stimulation. Mast cells were in close physical contact with the other inflammatory cells. Some mast cells had peculiar morphologic aspects. The exact roles of mast cells in inflammatory and immunologic phenomena, other than the classic reaginic primary type reaction, are largely unknown, but there is reason to believe, on both biochemical and morphologic grounds, that these roles are complex.

Intracoronal pressure during crown cementation.

A model system was developed which recorded the intracoronal pressure during crown cementation at three locations simultaneously. Peak pressures and residual pressures were greatest with zinc phosphate cement. The zinc oxide-eugenol cement generated the smallest amount of peak and residual pressures. The polycarboxylate cement exhibited an intermediate pressure intensity. The uneven intracoronal pressure in the cement suggests a complex flow pattern capable of developing the separation of phases that earlier work reported. However, the small residual pressure indicates that these internal back pressures appear to play a limited role in preventing a complete seating of a crown.