Abdominal zygomycotic thromboangiitis in a patient with AML and t(1;13;14)

 The case report of a 61 year-old man with AML M2 FAB, t(1; 13; 14) and zygomycotic mesenterial thromboangiitis is presented. Two induction cycles of chemotherapy were administered due to primary drug resistance. They were complicated by pneumonia, colonic pseudo-obstruction and perforation with peritonitis. The patient died on the 40th day of therapy, 4 days after undergoing palliative surgery. Zygomycotic thromboangiitis, which very probably contributed to the intestinal perforation, was confirmed morphologically at necropsy. The novel complex chromosomal translocation t(1; 13; 14) (q31; q32; q24) and the problems connected with the diagnosis of invasive fungal infections are discussed. Received: 26 January 1996 / Accepted: 12 June 1996     

Follow-up of outpatients with essential hypertension. A comparison of three methods of blood pressure measurement.

Compared with conventional, routine blood pressure measurement in the outpatient department of a hospital, 24-hour blood pressure monitoring provides more comprehensive information about blood pressure values in day-to-day life of the hypertensive patient. The hospital setting with all its stimuli affects the hypertensive patients so that their values will be statistically significantly higher compared with normal ones. Recent years have seen the introduction into clinical practice of self-monitoring by the patients themselves. Comparison of these three methods for blood pressure measurements revealed that self-monitoring may provide fairly accurate values comparable with those obtained by the "standard method", i.e., 24-hour monitoring. In view of the low variability of the mean value of blood pressure over a period of several days, self-monitoring can be employed in groups of selected outpatients on long-term follow-up.     

Fusion-induced malignancy? A preliminary study. (a challenge to today's common wisdom).

Five fusions between mouse embryonic cells and syngeneic adult peritoneal macrophages were performed. The resulting hybrids as well as both parental cells (6 cultures of embryonal cells and 6 cultures of adult macrophages) were grown in vitro under the same culture conditions. All populations of explanted macrophages died during the second month in primary culture and five populations of cultured embryonic cells were lost within six months under in vitro conditions as well. One embryonic cell line survived and acquired transformed and/or malignant phenotype: When inoculated into either newborn or adult syngeneic mice, progressive growth of tumors with 100% take (6/6), histologically classified as poorly differentiated fibrosarcoma with areas of metaplastic bone and osteoid, was observed. Two out of five wild hybrid strains died within six months of cell culture. The resulting three hybrid cultures adapted themselves to in vitro conditions and finally permanent lines were established with all features of transformed phenotype in vitro and with the capacity to grow as undifferentiated fibrosarcomas with 100% take (6/6) when inoculated into syngeneic mice either s.c. or i.p. Cytogenetic studies were performed and phenotypic characteristics of these lines were explored as well. Biological assays performed for the presence of oncogenic viruses were negative and none of the malignant cell lines showed positive staining with the monoclonal antibody specific for large T-antigen. It is suggested that cell fusion of two normal partners may switch on the cascade of abnormal processes which may culminate in neoplastic conversion. Cell fusion might play also a significant role in the so called "spontaneous" transformation.     

Neurotoxicity and dermatotoxicity of cyanomorpholinyl adriamycin

Summary The highly lipophilic cyanomorpholinyl adriamycin (CMA) is the most potent antineoplastic anthracycline yet described. CNS distribution and toxicity were examined after i.v. administration of CMA to mice. At doses 0.1 mg/kg, a neurotoxic syndrome including ataxia, hypokinesia, and tremors appeared. At doses of 0.05 mg/kg, which have been reported to be antineoplastic, no neurotoxicity was observed. On histopathologic examination, no changes were observed in the brain, spinal cord, or dorsal root ganglia. Unlike adriamycin (ADR), which rapidly appears in the nuclei of several tissues, CMA showed no fluorescence, suggesting a different cellular microcompartmentalization. The i.d. injection of CMA disclosed a 200-fold increase in toxicity compared with that of adriamycin. In comparisons of CMA and ADR, neurotoxicity and cardiotoxicity occurred equally only at higher doses; however, the dermatotoxicity and antineoplastic activity of CMA were increased several hundred-fold.     

DNA synthesis of human XYY cells

The autoradiographic YY labelling pattern of the DNA replication in 47, XYY cells of two patients has been studied. Both Y chromosomes began DNA replication simultaneously but later than the rest of the chromosomes. During later stages the YY labelling pattern in both patients was correlated to the position of the cells in S, as indicated by the cell grain count: in cells with more than approximately 500 grains the synchronous labelling of the Y chromosomes was the rule; whereas during later stages in cells with approximately 100–400 grains, synchronous as well as asynchronous labelling in the same patient was found. In cells with less than about 100 grains, both Y chromosomes usually had completed replication. No obvious difference between the labelling pattern of the two Y chromosomes was found when cells from the 2 patients were compared at the same stage of S. Our results demonstrate the importance of analysing cells of comparable developmental stages of S when comparing DNA labelling patterns of different XYY individuals in search of a possible correlation between labelling pattern and phenotypic expression of the syndrome.
In one of the patients the QM fluorescence pattern as well as the autoradiographic pattern of the same cells was studied. The characteristic intense fluorescence pattern of both Y chromosomes was found even in cells where the autoradiographic labelling pattern indicated distinct asynchrony between the two Y chromosomes. The significance of these findings is discussed.     

Multiple effects of caffeine on calcium current in rat ventricular myocytes

Caffeine exerts a number of different effects on L-type calcium current in rat ventricular myocytes. These include: (1) a slowing of inactivation that is comparable to, but not additive to, that produced by prior treatment of the cells with ryanodine (a selective sarcoplasmic reticulum Ca²⁺ releaser) or high concentrations of intracellular 1,2-bis[2-aminophenoxy]ethane-N,N,N,N-tetraacetic acid (BAPTA) (a fast Ca²⁺ chelator), (2) a stimulation of peak I _Ca that is comparable to, but not additive to that produced by prior treatment with isobutylmethylxanthine (a selective phosphodiesterase inhibitor), and (3) a dose-dependent decrease of peak I _Ca that is not prevented by pretreatment with any of these agents. None of the caffeine actions could be mimicked or prevented by administration of 8-phenyltheophylline, a specific adenosine receptor antagonist. We conclude that only the slowing of I _Ca inactivation is due to caffeine's ability to deplete the sarcoplasmic reticulum of calcium. The stimulatory effect of caffeine on peak I _Ca is probably due to phosphodiesterase inhibition, while caffeine's inhibitory effect on I _Ca is independent of these processes and could be a direct effect on the channel. The multiplicity of caffeine actions independent of its effects on the sarcoplasmic reticulum lead to the conclusion that ryanodine, though slower acting and essentially irreversible, is a more selective agent than caffeine for probing sarcoplasmic reticulum function and its effects on other processes.The experimental part of this work was published during the postdoctoral stay of I. Zahradník in the Department of Physiology and Biophysics, The University of Texas Medical Branch, Galveston, TX 77555, USA     

Multiple unit activity study of brain stem and limbic structures during environmental habituation and circadian rhythm

Multiple unit activity (MUA) of brain stem, hypothalamic and limbic structures was studied during habituation to a novel environment and circadian rhythm in chronically implanted freely moving rats. MUA was analysed in the mesencephalic reticular formation (MRF), area hypothalami posterior (PH), basal nuclear group of amygdala (AMY), area septalis (SEPT), dorsal hippocampus (HIPP) and area hypothalami anterior (AH). It was found that in the novel environment MUA of all subcortical structures increased to a high level. During habituation MUA in each phase of wakefulness--sleep cycle decreased to stable low level both in brain stem and forebrain structures. Gradual decrease in MUA was characteristic to MRF, and a sharp decrease occured in AH and AMY. The environmental habituation proved to be a long lasting process in rat. During all phases of wakefulness--sleep cycle activity was significantly higher in the light period than in the dark, and MUA base level showed circadian variation both in brainstem and limbic structures. Close correlation was found between the actual MUA level and responsiveness to various sensory modalities both during habituation and circadian rhythm. The higher the MUA level, the higher the responsiveness, and a fall in activity was accompanied by decreased neuronal responsiveness.