Mode of action of the IgG inhibitor of erythropoiesis in transient erythroblastopenia of children

Twelve cases of transient erythroblastopenia of childhood (TEC) have been studied to evaluate their marrow cell erythropoiesis in vitro and the effect on it of their serum or IgG. The number of colony-forming units-erythroid (CFU-E) and burst-forming units-erythroid (BFU-E) in the bone marrow of nine cases was extremely variable and did not allow any conclusion regarding the pathogenesis of this anemia. An IgG inhibitor of growth of erythroid colonies or bursts was detected in 8/12 cases. This IgG inhibitor had no effect on the growth of granulocyte-macrophage colonies. Further studies on its mode of action indicated that the IgG did not have antierythropoietin antibody properties and did not affect the mature erythroblasts, as shown by a lack of inhibition of their responses to erythropoietin and by the lack of a cytotoxic effect on 59Fe-labeled erythroblasts. In four cases, preincubation studies demonstrated a direct effect of the IgG on the CFU-E, which was complement-mediated in three cases and complement- independent in one case. In two other cases, the IgG suppressed the growth of normal BFU-E only without affecting the growth of CFU-E. The IgG inhibitor was no longer present after the erythroblastopenia had remitted. These studies demonstrate that in the majority of cases of TEC, an IgG suppressor of erythropoiesis in vitro is present. Its mode of action is heterogeneous regarding its requirement for complement. Its target cells are the earlier or later erythroid progenitors, BFU-E or CFU-E, but not the differentiated erythroblasts.     

Misonidazole neurotoxicity in rats: Part I

Summary The effects of misonidazole (MISO) on brain stem evoked potentials (BAEPs) and cortical evoked potentials (CEPs) were evaluated in 16 Sprague-Dawley rats treated with the agent. As found in previous studies, serial BAEP'values were diagnostic of the onset of MISO toxicity before clinical signs and symptoms appeared. However, MISO had no effects on CEPs, which remained essentially unchanged through the course of the experiment. At histologic examination, significant changes were found in the area of the brain stem, but there was no histologic evidence of damage to cortical or subcortical structures caused by MISO administration. The results of this study suggest that the neurotoxic effects of MISO are species-specific, and that while the rat model may be useful for comparison of the relative toxic effects of nitroimidazole radiosensitizers, it is not a model suited for measurement of neurotoxicity caused by MISO in humans and nonhuman primates.     

商品黄芪的地区用药及其易混品的形态与显微鉴别

黄芪的地区用药及易混品共5种,即:梭果黄芪Astragalus ernesti Comb.,淡紫花膜荚黄芪A.membranaceus (Fisch.) Bunge f.purpurinus (Y.C.Ho)Y.C.Ho,乌拉特黄芪A.hoantchy Franch.,甘青黄芪A.tanguticus Batalin和马衔山黄芪A.mahoschanicus Hand.-Mazz.等,对其生药形态和组织特征进行了比较研究,并编写了生药性状和组织特征检索表。     

The significance of splenomegaly in 101 adults with acute lymphoblastic leukemia (ALL) at presentation and during remission

One-hundred-one adult patients with ALL were analyzed to determine the prognostic implications of splenomegaly occurring at any time during the course of their illness. The clinical status of the spleen at presentation was not found to be of major prognostic significance. Complete response rates, remission durations, and survivals did not differ between patients with and without splenomegaly at presentation. An enlarged spleen accompanied relapse in four patients. In six additional patients, splenomegaly was present during complete remission, and splenectomies performed in five of these patients revealed no evidence of leukemia to account for the splenomegaly. Splenectomy does not appear to be detrimental, as all five patients are currently in complete remission from 20 to 63 mo after splenectomy. Evidence implicating the spleen as a source of an antibody directed against autologous leukemia cells in one patient is reviewed.     

Loxoribine induces chronic lymphocytic leukemia B cells to traverse the cell cycle

Leukemic B cells from a majority of patients with chronic lymphocytic leukemia (CLL) enter the cell cycle upon stimulation in vitro with loxoribine, a potent 7,8-disubstituted guanine ribonucleoside immunostimulant. In the absence of added costimulants, a proportion of these cells become activated and undergo DNA synthesis and mitosis accompanied by a marked increase in expression of an array of cell surface activation antigens. The resultant activated B-CLL cells exhibit greatly enhanced sensitivity to cycle-active cytotoxic drugs. This approach may be of potential value in the therapy of CLL.     

Monovalent cation composition and ATP and lipid content of irreversibly sickled cells

Discontinuous Stractan gradients were used to separate heterogeneous populations of sickle cells into discrete subpopulations containing varying proportions of reticulocytes, mature discoid cells, and irreversibly sickled cells (ISC). The improved homogeneity of these preparations, together with an enhanced yield of ISC, allowed us to distinguish effects of cell maturation from those of irreversible sickling. With these cell preparations we have begun to define physical properties of ISC. We confirmed the marked abnormalities in cation composition of native ISC. Measurements of ATP in ISC did not substantiate prior reports of ATP deficits. Finally, no evidence for substantial loss of membrane lipids during the process of ISC formation could be demonstrated.