In order to find out a valuable control measure for soil-transmitted parasties, the infectivity in mice of Ascaris eggs irradiated with Cobalt(60) were examined. The results were summarised as follows. In vitro, Ascaris eggs irradiated with larger doses of Cobalt(60) developed poorly, and no difference was found between fresh eggs and those cultured for a few days. Ascaris eggs irradiated with doses of 200,000 rad. developed at the rate of 90 percent after 4 weeks, whereas those irradiated with 1,000,000 rad. developed 28 percent. Ascaris eggs irradiated with Cobalt(60) after 2 weeks of culture were poor in development compared with those of 4 week culture. Eggs cultured for 5 weeks showed weaker infectivity in mice than those cultured for 8 weeks. In the control groups, the infectivity in mice of Ascaris eggs was remained the same between 5 and 8 weeks. The minimum dose of Cobalt(60) irradiation effective for preventing infectivity in mice was estimated to be 200,000 rad.
parasiotology ; radiology ; prevention ; Ascaris suum ; nematode ; Cobalt(60) ; irradiation

This study was carried out in order to find out the valuable measure to kill the parasite eggs in night soil. The fresh eggs of Ascaris put into human stool were irradiated with Cobalt 60 of 200,000 to 1,000,000 rad and cultured in test tubes at 25-30 C, washing with 2 percent formalin solution every 24 hours. The continuous development of those eggs were observed under microscope and the proprotions of developed eggs were compared with those of control groups. The major result can be summarized as follows: In general, The eggs in stool developed poorly than the eggs in saline. If the eggs were irradiated with the larger dose of Cobalt 60, the proportion of developed eggs were reduced subsequently. The eggs irradiated with the dose of 1,000,000 rad in saline developed in the proportion of 15.5 percent, whereas irradiated with 200,000 rad 94 percent developed in 4 weeks. The 44.5 percent of eggs in stool irradiated with 200,000 rad developed after 4 weeks, 30.5 percent with 300,000 rad, 25 percent with 500,000 rad and 3.5 percent with 1,000,000 rad respectively. The effective minimum dose of Cobalt 60 irradiation to kill the Ascaris eggs in stool was estimated 1,000,000 rad. Further examination will be required to observe the infectivity of irradiated Ascaris eggs to animals and to evaluate the effect from the standpoint of sanitary engineerings.
parasitology-nematode-Ascaris lumbricoides ; Cobalt 60 ; radiology ; prevention ; egg ; infectivity

OBJECTIVETo explore the effects of hypoxia on the proliferation of human leukemia HL-60 cells and the cellular expression of hypoxia inducible factor-1α (HIF-1α).

METHODSHuman acute myeloid leukemia HL-60 cells with exponential growth in routine culture were exposed to 50, 200, 400, 800 µmol/L CoCl(2) to mimic hypoxic conditions. At 24, 48, and 72 h, the cells were collected for morphological observation, MTT assay, and real-time quantitative PCR for HIF-1α mRNA expression.

RESULTSCompared with the cells without CoCl(2) treatment, the cells with CoCl(2) exposure exhibited obvious morphological changes and a significant growth inhibition which increased with CoCl(2)concentration and exposure time. At low concentrations (50-200 µmol/L), CoCl(2) treatment caused a dose- and time-dependent enhancement of HIF-1α expression in HL-60 cells.

CONCLUSIONHypoxia mimicked by CoCl(2) exposure significantly inhibits the proliferation of HL-60 cells, and at the non-toxic doses, CoCl(2) dose- and time-dependently increases the expression of HIF-1α. The mimicked hypoxic conditions do not cause differentiation of HL-60 cells.

Cell Hypoxia ; Cell Proliferation ; Cobalt ; pharmacology ; HL-60 Cells ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism

BACKGROUND: Leukemic cells originate from hypoxic bone marrow, which protects them from anti-cancer drugs. Although many factors that cause drug resistance in leukemic cells have been studied, the effect of hypoxia on drug-induced apoptosis is still poorly understood. METHODS: In this study, we examined the effect of hypoxia on anti-leukemic drug resistance in leukemic cell lines treated with cobalt chloride (CoCl2), a hypoxia-mimetic agent. Cellular proliferation was evaluated using the methyl thiazolyl tetrazolium (MTT) assay. Flow cytometry analysis and western blots were performed to investigate apoptosis-related proteins. RESULTS: Unlike its previously known apoptotic effect, the expression of HIF-1alpha increased the survival rate of human promyelocytic leukemia HL-60 cells when these cells were exposed to anti-leukemic drugs; these effects were mediated by heat-shock protein HSP70 and the pro-apoptotic protein Bax. CONCLUSION: These findings may provide new insights for understanding the mechanisms underlying hypoxia and for designing new therapeutic strategies for acute myeloid leukemia.
Anoxia ; Apoptosis ; Arsenicals ; Blotting, Western ; Bone Marrow ; Cell Line ; Cell Proliferation ; Cobalt ; Drug Resistance ; Flow Cytometry ; Heat-Shock Proteins ; HL-60 Cells ; Humans ; Leukemia ; Leukemia, Myeloid, Acute ; Oxides ; Proteins ; Survival Rate

AIMTo find a new PDT sensitizer.

METHODSThere were four complexes (Cu, Zn, Co, Ni) synthesized through reaction of metal and deprivating-Mg bacteriochlorophyll in the organic solvent. Their antitumor action was detected by MTT.

RESULTSThe ultraviolet-visual spectrum and the fluorescence spectrum of these complexes showed that synthesis of these four complexes was succeeded. And these metal complexes have potent antitumor action on two kinds of leukaemic cells.

CONCLUSIONMetal bacteriochlorophylls as PDT sensitizers have very good properties and this is a way to develop new PDT sensitizers.

Antineoplastic Agents ; chemical synthesis ; chemistry ; pharmacology ; Bacteriochlorophylls ; chemistry ; Cell Proliferation ; drug effects ; Cobalt ; chemistry ; Copper ; chemistry ; HL-60 Cells ; cytology ; Humans ; K562 Cells ; cytology ; Metals, Heavy ; chemistry ; Nickel ; chemistry ; Organometallic Compounds ; chemical synthesis ; chemistry ; pharmacology ; Photosensitizing Agents ; chemical synthesis ; chemistry ; pharmacology ; Zinc ; chemistry