The results of examinations of sera, blood and organs of different species of monkeys from some Asian and African countries for the presence of antibody to smallpox and viruses of the smallpox group. Significant titers of smallpox antibodies (antihemagglutinins virus-neutralizing and, in some cases, precipitating antibody) were found in a considerable number of monkeys shot near foci with human cases (Equatorial province of Zair Republic). In the same monkeys kidney tissues yielded 3 isolates of smallpox virus group two of which were indistinguishable in the laboratory tests from variola virus. On the basis of these data it is concluded that smallpox viruses circulate among wildlife monkeys in some areas of Equatorial Africa. Further studies along these lines are necessary.
Background: Imatinib mesylate, a tyrosine kinase inhibitor specifically targeting the BCR/ABL fusion protein, induces hematological remission in patients with chronic myeloid leukemia (CML). However, the majority of CML patients treated with imatinib develop resistance with prolonged therapy. Dendrophthoe pentandra (L.) Miq. is a Malaysian mistletoe species that has been used as a traditional treatment for several ailments such as smallpox, ulcers, and cancers. Methods: We developed a resistant cell line (designated as K562R) by long-term co-culture of a BCR/ ABL positive CML cell line, K562, with imatinib mesylate. We then investigated the anti-proliferative effects of D. pentandra methanol extract on parental K562 and resistant K562R cells. Trypan blue exclusion assays were performed to determine the IC50 concentration; apoptosis and cell cycle analysis were conducted by flow cytometry. Results: D. pentandra extract had greater anti-proliferative effects towards K562R (IC50= 192 μg/mL) compared to K562 (500 μg/ mL) cells. Upon treatment with D. pentandra extract at the IC50. concentration: K562 but not K562R demonstrated increase in apoptosis and cell cycle arrest in the G2/M phase. Conclusion: D. pentandra methanol extract exerts potent anti-proliferative effect on BCR/ABL positive K562 cells.