Measurement of annexin V uptake and lactadherin labeling for the quantification of apoptosis in adherent Tca8113 and ACC-2 cells

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90 percent of lactadherin but only about 75 and 70 percent of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.

Phase II trial in China of a new, rapidly-acting and effective oral antimalarial, CGP 56697, for the treatment of Plasmodium falciparum malaria.

One hundred and two Chinese out-patients with naturally acquired, previously untreated, falciparum malaria were selected to evaluate the efficacy of a new combination anti-malaria therapy, CGP 56697 (artemether plus benflumetol). In this open non-comparative trial each patient received a combination of 80 mg artemether and 480 mg benflumetol given orally at 0, 8, 24 and 48 hours (total: 320 mg artemether, 1,920 mg benflumetol). Patients were kept for 28 days in a transmission-free hospital in an area with chloroquine resistant falciparum malaria to prevent reinfection and to aid diagnosis of recrudescence. Progress and possible adverse effects were monitored by blood film parasitology, blood biochemistry assays, urinalysis, ECG and X-ray. Ninety-eight of the 102 patients were shown to be free of infection at 28 days, a 96.1% cure rate. Parasite reduction at 24 hours was 99.4%. Time to effect complete parasite clearance ranged from 24 to 54 hours (median 30 hours). Time for fever clearance ranged from 6 to 78 hours (median 18 hours). Recrudescence was low (3.9%). No significant adverse side-effects were encountered. It is concluded that CGP 56697, a combination anti-malaria therapy of artemether with benflumetol, offered a rapid and highly effective treatment for acute uncomplicated falciparum malaria in an area of chloroquine-resistant malaria in China.