Marrow transplantation for children with acute lymphoblastic leukemia in second remission

Fifty-seven children between the ages of 3 and 17 years with acute lymphoblastic leukemia (ALL) in chemotherapy-induced second bone marrow remission were given cyclophosphamide, total body irradiation, and bone marrow transplants from HLA-matched donors. Sixteen died of transplant- related complications. Eighteen relapsed between 56 and 833 days after transplantation, and 16 died of leukemia. Two survive in remission off treatment following chemotherapy. Twenty-three survive in continuous remission from 1.4 to 10.4 years after transplantation and the actuarial analysis shows disease-free survival of 40% with a plateau extending from 2.5 to 10.4 years.     

Cytogenetic and molecular delineation of a region of chromosome 7 commonly deleted in malignant myeloid diseases

Loss of a whole chromosome 7 or a deletion of the long arm, del(7q), are recurring abnormalities in malignant myeloid diseases. To determine the location of genes on 7q that are likely to play a role in leukemogenesis, we examined the deleted chromosome 7 homologs in a series of 81 patients with therapy-related or de novo myelodysplastic syndrome or acute myeloid leukemia. Our analysis showed that the deletions were interstitial and that there were two distinct deleted segments of 7q. The majority of patients (65 of 81 [80%]) had proximal breakpoints in bands q11-22 and distal breakpoints in q31-36; the smallest overlapping deleted segment was within q22. The remaining 16 patients had deletions involving the distal q arm with a commonly deleted segment of q32-33. To define the proximal deleted segment at 7q22 at a molecular level, we used fluorescence in situ hybridization with a panel of mapped yeast artificial chromosome (YAC) clones from 7q to examine 15 patients with deletion breakpoints in 7q22. We determined that the smallest overlapping deleted segment is contained in a well- defined YAC contig that spans 2 to 3 Mb. These studies delineate the region of 7q that must be searched to isolate a putative myeloid leukemia suppressor gene, and provide the necessary cloned DNA for more detailed physical mapping and gene isolation.     

Dynamic Recrystallization and Its Effect on Superior Plasticity of Cold-Rolled Bioabsorbable Zinc-Copper Alloys

High plasticity of bioabsorbable stents, either cardiac or ureteral, is of great importance in terms of implants’ fabrication and positioning. Zn-Cu constitutes a promising group of materials in terms of feasible deformation since the superplastic effect has been observed in them, yet its origin remains poorly understood. Therefore, it is crucial to inspect the microstructural evolution of processed material to gain an insight into the mechanisms leading to such an extraordinary property. Within the present study, cold-rolled Zn-Cu alloys, i.e., Zn with addition of 1 wt.% and 5 wt.% of Cu, have been extensively investigated using scanning electron microscopy as well as transmission electron microscopy, so as to find out the possible explanation of superior plasticity of the Zn-Cu alloys. It has been stated that the continuous dynamic recrystallization has a tremendous impact on superior plasticity reported for Zn-1Cu alloy processed by rolling to 90% of reduction rate. The effect might be supported by static recrystallization, provoking grain growth and thereby yielding non-homogeneous microstructures. Such heterogeneous microstructure enables better formability since it increases the mean free path for dislocation movement.     

Modulation of the Functions of Dengue Virus-Specific Human CD8+ Cytotoxic T Cell Clone by IL-2, IL-7 and IFNγ

Lymphokines play an important role in immune responses to viruses by modulating functions of T lymphocytes. In the present study, we examined the effects of interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interleukin-7 (IL-7), and interferon gamma (IFNγ) on proliferation, cytotoxic activity and lymphokine production of a dengue virus-specific CD8⁺ human cytotoxic T lymphocyte (CTL) clone. IL-2 and IL-7 induced proliferation of the CD8+ CTL clone in the presence or absence of specific antigen, while IFNγ suppressed proliferation of the clone. IL-7 and IFNγ augmented dengue virus-specific cytotoxic activity without inducing non-specific cytotoxic activity, and IL-2 induced non-specific cytotoxic activity. IL-2 induced IFNγ production by the CD8+ CTL clone. IL-4 and IL-6 did not modulate the functions of the CD8+ CTL clone in these experimental conditions.

These results suggest that functions of dengue virus-specific CD8+ CTL are modulated by IL-2, IL-7 and IFNγ, and that IL-7 is a lymphokine useful to induce growth and to maintain specific cytotoxic activity of CD8+ CTL clones in vitro.     

A neural model of binocular integration and rivalry based on the coordination of action-potential timing in primary visual cortex

In normal vision, the inputs from the two eyes are integrated into a single percept. When dissimilar images are presented to the two eyes, however, they compete for perceptual dominance, so that one eye's view suppresses that of the other. Recent evidence suggests that this phenomenon, known as binocular rivalry, arises through competition between alternative stimulus interpretations in extrastriate cortex. Because eye-specific information appears to be lost at this stage, it remains unclear how the stimulus conditions that yield binocular rivalry are distinguished from those that produce stable single vision. Using a neural network that models the mammalian early visual system, I investigate here the hypothesis that congruent and conflicting stimuli are distinguished by their different effects on the relative timing of action potentials in primary visual cortex (V1), where monocular inputs are first combined. In the model, congruent stimulation of both eyes results in synchronization of discharges among binocular neurons in V1. By contrast, conflicting stimulation of the two eyes results in neuronal asynchrony in this area. This asynchrony then produces rivalrous response suppression at later stages in the visual pathway. Synchronization of firing in V1, however, prevents such competition, thereby ensuring non-rivalrous responses. These novel effects of spike timing on competition emerge naturally from the network dynamics. The results suggest that input-related differences in relative spike timing at an early stage of visual processing may play an important part in the phenomena both of binocular integration and rivalry; furthermore, they indicate that the temporal patterning of cortical activity may be a fundamental mechanism of selection among competing stimulus representations.      

Use of special mammographic views to maximize radiographic information

Additional x-ray views can offer helpful information in both symptomatic patients (better evaluating the area of clinical abnormality) and screening patients (often preventing unnecessary biopsies). A wide variety of views have been devised to help solve specific problems raised by either suspected clinical or mammographic abnormalities. We have found those views described above to be most useful.     

Suicide in Northern Ireland: a comparison of two quinquennia (1982–1986 and 1987–1991)

This study compares government records of death by suicide, in Northern Ireland, during two quinquennia in the decade 1982–1991. Specifically these quinquennia are 1982–1986 l 1987–1991. During the latter quinquennium there was an increse m rate for males in most age groups, except the 45–54 and the over 65 years age groups. However, females had an increased rate in the 15–24 and 35–54 years age groups, but have a decreased rate in the other age groups. There has been a decrease in the rate of suicides by poisoning with solids and liquids for both sexes. However, male suicide rates by more violent methods have increased substantially during the latter quinquennium. Three cohorts of males, those in the 15–24, 25–34, and 55–64 age groups, have shown substantial increases during the latter quinquennium. Suggestions for psychiatric intervention strategies are made.