Alpha 2- and beta-adrenergic receptors and adenosine A1 receptor of FRTL-5 rat thyroid cells in relation to fucosyl GM1 ganglioside

We have previously reported that anti-fucosyl GM1 ganglioside antibody partially suppresses cAMP production in FRTL-5 rat thyroid cells not via the TSH receptor but via guanine nucleotide-binding protein indirectly. In order to clarify further the mechanism of the antibody action, we studied the relationship with alpha 2- and beta-adrenergic and adenosine A1 receptors. FRTL-5 cells did not bind [3H]clonidine, suggesting the lack of alpha 2-adrenergic receptor or at least abnormality of its binding domain. On the other hand, the cells specifically bound [125I]iodocyanopindolol, but isoproterenol failed to affect the basal and TSH-stimulated cAMP production indicating the lack of coupling with adenylate cyclase. The inhibition of cAMP production induced by anti-fucosyl GM1 antibody was not altered by adrenergic agents. [125I]hydroxyphenylisopropyl adenosine binding was observed in FRTL-5 cells but was not displaced by the antibody. These results lead to conclusions that FRTL-5 cells lack alpha 2-adrenergic receptor but have beta-adrenergic receptor which lacks coupling with adenylate cyclase and have adenosine A1 receptor, and that the adrenergic receptors and adenosine A1 receptor are not the site of action of anti-fucosyl GM1 antibody.     

Acute promyelocytic leukemia accompanied by retinoic acid syndrome with complications of acute myocardial infarction and cerebral infarction during treatment with all-trans retinoic acid

A 71-year-old man visited our hospital complaining of fever and a bleeding tendency. The peripheral blood WBC count was 10,400/microliter with 90% promyelocytes. The bone marrow was hypercellular with 88% promyelocytes. Disseminated intravascular coagulation was recognized. The patient was diagnosed as having acute promyelocytic leukemia and was treated with daily oral administration of all-trans retionic acid (ATRA) (45 mg/m2/day) and cytarabine (160 mg/day, intravenous drip infusion for the initial five days). The ATRA treatment induced leukemic cells to undergo mature myeloid differentiation. On day 24 after the start of treatment, the WBC count rapidly increased and acute myocardial infarction appeared, with consciousness disturbance and bilateral Babinski reflex appearing three hours later. Magnetic resonance imaging showed a fresh lacunar infarction of the right lenticular nucleus, and serum levels of IL-6 and PAI-1 were found to be elevated at the onset of infarction. Since there was a possibility that the retinoic acid syndrome (RAS) might have helped bring about the infarctions, we stopped the ATRA treatment and started administration of methyl-prednisolone (500 mg/body/day for 3 days) and gabexate mesilate. The WBC count decreased immediately and the consciousness disturbance improved. In this case, ATRA treatment might have initiated the RAS and resulted in some endothelial damage, thus causing the infarctions.     

Circulating oxidized low density lipoprotein levels. A biochemical risk marker for coronary heart disease

Recent studies have established oxidative modification of low density lipoprotein (LDL) as an important atherogenic factor. We examined the clinical relevance of circulating oxidized LDL (OxLDL) levels in atherosclerotic disease by an enzyme immunoassay with use of specific antibodies against OxLDL (FOH1a/DLH3) and apolipoprotein B. Plasma OxLDL levels were significantly higher in patients with coronary heart disease (n=65) than in control subjects (n=181; 201. 3+/-11.2 versus 112.4+/-3.3 U/dL, respectively; P<0.01). OxLDL levels were not associated with age, sex, total cholesterol, or apolipoprotein B levels in normal control subjects. Our results suggest that circulating OxLDL may be a possible biochemical risk marker for coronary heart disease.     

Detection of latent subclones with abnormal karyotypes by long-term bone marrow cultures in cases of myelodysplastic syndrome

Cytogenetic studies on non-adherent cells from long-term bone marrow cultures (LTBMC) were done for 23 patients with myelodysplastic syndrome (MDS) and compared with the karyotypes detected during their clinical courses. Of 14 cases with normal karyotype before culture, abnormal karyotypes were detected first in LTBMC from seven. Novel abnormal karyotypes were observed after LTBMC in two of four cases which had had both normal and abnormal karyotypes before culture. Abnormal karyotypes were also newly detected in four of five cases with only abnormal karyotypes before culture. Among 13 cases in which abnormal karyotypes were observed during the cultures, three patients showed the same karyotypes 1-11 months later in their clinical courses. These findings suggest that our LTBMC might be useful for evaluating the prognosis and choice of treatment for MDS patients.     

Comparative genomic hybridization analysis in adult T-cell leukemia/lymphoma: correlation with clinical course

Sixty-four patients with adult T-cell leukemia/lymphoma (ATL; 18 patients with indolent subtype and 46 with aggressive subtype) associated with human T-lymphotropic virus type 1 (HTLV-1) were analyzed using comparative genomic hybridization (CGH). The most frequent observations were gains at chromosomes 14q, 7q, and 3p and losses at chromosomes 6q and 13q. Chromosome imbalances, losses, and gains were more frequently observed in aggressive ATL than in indolent ATL, with significant differences between the 2 ATL subtypes at gains of 1q and 4q. An increased number of chromosomal imbalances was associated with a significantly shorter survival in all patients. A high number of chromosomal losses was associated with a poor prognosis in indolent ATL, whereas the presence of 7q+ was marginally associated with a good prognosis in aggressive ATL. Paired samples (ie, samples obtained at different sites from 4 patients) and sequential samples from 13 patients (from 6 during both chronic disease and acute crisis and from 7 during both acute onset and relapse) were examined by CGH and Southern blotting for HTLV-1. All but 2 paired samples showed differences on CGH assessment. Two chronic/crisis samples showed distinct results regarding both CGH and HTLV-1 integration sites, indicating clonal changes in ATL at crisis. In 11 patients, the finding of identical HTLV-1 sites and clonally related CGH results suggested a common origin of sequential samples. In contrast to chronic/crisis samples, CGH results with all acute/relapse sample pairs showed the presence of clonally related but not evolutional subclones at relapse, thereby suggesting marked chromosomal instability. In summary, clonal diversity is common during progression of ATL, and CGH alterations are associated with clinical course. (Blood. 2001;97:3875-3881)