Clonal chromosomal abnormalities in hemangiopericytoma

We report the cytogenetic findings in nine hemangiopericytomas studied after short-term culture. Clonal chromosome abnormalities were present in four cases. One case had a simple translocation (12;19)(q13;q13.3) as the sole abnormality whereas complex and multiple chromosomal abnormalities involving almost all chromosomes in the complement characterized tumors from the three other cases.     

Chromosome changes in bladder cancer: clinical and other correlations

The chromosome changes in bladder cancer are reviewed with particular emphasis on the application of recent advances in techniques for cytogenetic analyses of bladder cancer and the establishment of nonrandom (specific) karyotypic changes characterizing a significant number of bladder cancers. At present, these groups are characterized by one of the following cytogenetic changes: i(5p), +7, or -9. The results are discussed in relation to the significance of these changes and possible involvement of some oncogenes and other gene loci.     

Studies on thymocyte subpopulations in guinea pigs: in vivo differentiation of bromodeoxyuridine labelled cells, with special reference to rosette-forming ability

Cycling thymocytes were labelled by an intracardial injection of bromodeoxyuridine (BrdUrd) in a total of 32 guinea pigs and the incorporation into DNA studied in subpopulations of cells defined by buoyant density and rosette-forming ability. The labelling pattern was compared at different times after injection (0.5 h to 120 h). A marked shift of labelled cells from large, low density cells (population 1a) to small, high density cells (population 2) was observed. During the first 48 h, the ratio between labelling indices of cell populations 1a and 2 decreased from 10 to 0.5. The number of labelled cells forming rosettes with rabbit erythrocytes (RFC+) increased while the number of labelled non-rosetting cells (RFC-) decreased from 0.5 h to 48 h, probably representing transformation of RFC- to RFC+. Then, after a decreased labelling in all cell populations at 72 h, an increase in both RFC+ and RFC- populations occurred at 96 h. The labelling in RFC- cells at 96 h was nearly as high as immediately after labelling. This second labelling of RFC- cells could represent immigration of precursor cells, a wave of proliferation in initially labelled precursors, and/or the formation of mature cells from the initially labelled precursors. The results indicate that a great majority of proliferating cells differentiate into small, high density cells within 48 h and that rosetting ability is acquired in many cells during this period. A model of intrathymic differentiation which fits the observations is presented.     

Chromosomes and causation of human cancer and leukemia. LIV. Near-tetraploidy in acute leukemia

Near-tetraploid cell populations were observed in a case of T-cell acute lymphoblastic leukemia (T-ALL) and in one of acute myeloblastic leukemia (AML). In the ALL case, hyperdiploid chromosomal changes, characterized by an isochromosome 17q [i(17q)], as well as other changes, were seen at the onset of the disease. At the first relapse, hypertetraploid cells appeared in about 10% of the mitoses in the bone marrow (BM), and by the second and third relapses, the hypertetraploidy was present in more than 90% of the mitoses in the BM. Even though karyotypic instability was evident, all abnormal karyotypes contained one or two i(17q) at every sampling. In spite of karyotypic instability at each relapse, karyotypic evolution was observed whenever relapse occurred. A normal female karyotype was confirmed in the BM of each period. Immunologic examinations performed at each sampling revealed no recognizable changes before and after the appearance of tetraploidy. In the AML case, which was classified as FAB M2, cytogenetic examination was performed at diagnosis and relapse. In both, hypotetraploid cells were observed in over 60% of the BM cells; the modal chromosome number was 90. Banding analysis was successful at relapse, and a pseudodiploid clone characterized by t(8;21) and a hypotetraploid clone with two t(8;21) and a loss of two Y chromosomes were observed in the same BM sample. A normal male karyotype was also observed in BM cells. In both cases, giant and bizarre blasts were seen in the BM. A close correlation between near-tetraploid mitoses and giant and bizarre blast cells in BM smears of the same samples was observed. Previously published tetraploid acute leukemia cases analyzed with banding methods were accumulated and compared with our two cases.     

Antihypertensive mechanism of action of ketanserin and some ketanserin analogues in the spontaneously hypertensive rat

Summary Ketanserin is a new antihypertensive agent with affinity to serotonin (5-HT)₂ receptors and at higher concentrations also to ₁-adrenoceptors. The present study was designed to evaluate the relative functional importance of the antagonism of ₁-adrenoreceptors and 5-HT₂-receptors in the antihypertensive mechanism of action of ketanserin and analogues after acute administration. In the spontaneously hypertensive rat, ketanserin and the two ketanserin analogues, R56413 and R55667 (which have relatively weaker -adrenolytic properties) were studied with regard to their ability to reduce the blood pressure after acute administration in the conscious rat and their ability to shift the dose response curves for 5-HT and phenylephrine in the pithed rat. The agents tested reduced the blood pressure only in a dose range where they blocked ₁-adrenoceptors and there was a striking correlation between the degree of hypotension and the degree of inhibition of the phenylephrine induced pressor responses. 5-HT₂-receptor blockade alone did not influence basal blood pressure. However, following pretreatment with R55667 in a low dose the blood pressure reduction to prazosin was enhanced.It is concluded that following acute administration in the rat the major portion of the antihypertensive response to ketanserin is due to an ₁-adrenoceptor blockade but that the 5-HT₂-receptor blockade contributes.Abbreviations 5-HT 5-hydroxytryptamine - SHR spontaneously hypertensive rat - SNS sympathetic nervous stimulation     

"Panic disorder" in schizophrenia

A patient is described with operationally diagnosed chronic schizophrenia who simultaneously experienced repeated "attacks" during which times he had intense apprehension and autonomic hyperactivity entirely similar to that usually described under the rubric of "panic attacks" in nonschizophrenic patients. Delusional and hallucinatory symptoms were also transiently exacerbated during these episodes. Alprazolam, as an adjunct to fluphenazine decanoate, was effective in ameliorating these symptoms. Diagnostic and treatment implications are discussed.     

Self-excited mono-ion oscillator

We propose self-excitation as a potentially more sensitive technique for studying a mono-ion oscillator of frequency v_z ≈ 0.1-100 MHz. This technique also makes only low demands on the harmonicity of the ion oscillation. It should therefore work with inexpensive, easily constructed rf traps. In our analysis, the bound ion between the trap electrodes is represented by an effective circuit resembling that of a piezoelectric quartz crystal. The feedback circuit developed, when operated below self-excitation threshold, may also make efficient electronic cooling of the ion possible, particularly in conjunction with a heterodyne feedback scheme. In the super-regenerative mode, the apparatus might function as a powerful atomic amplifier of the ion oscillation for an energy as low as a fraction of hv_z. These techniques may prove especially useful in conjunction with attempts to synthesize in an rf trap a loosely bound anti-hydrogen atom from a positron and antiproton.