Kinetics of accumulation and depletion of soluble newly synthesized histone in the reciprocal regulation of histone and DNA synthesis.

Procedures are presented which permit the identification and analysis of cellular histone that is not bound to chromatin. This histone, called soluble histone, could be distinguished from that bound to chromatin by the state of H4 modification and the lack of H2A ubiquitination. Changes in the levels of newly synthesized soluble histone were analyzed with respect to the balance between histone and DNA synthesis in hamster ovary cells.

Differential silver staining in lymphocytes and lymphoblastoid cell cultures.

An analysis of the patterns of silver-stained nucleolar organizer regions (AgNORs), an indication of rDNA transcriptional activity, was carried out in metaphases from peripheral lymphocytes and young lymphoblastoid cell cultures (LCL) transformed by Epstein-Barr virus. Four individuals previously shown to carry a double NOR (dNOR) were studied. The dNOR varied in staining frequency and showed intra-individual variation in appearance in both cell types.

Experimental chemotherapy (L1210) with 5-aza-2'-deoxycytidine in combination with pyran copolymer (MVE-4), an immune adjuvant.

The life-span of CDF1 (BALB/c X DBA/2)F1 mice that received intraperitoneal implants with 10(5) L1210 tumor cells was prolonged to 23 days (compared to 8 days in L1210 tumor-implanted, untreated mice) when 5-aza-2'-deoxycytidine (DAC) was given to the mice after the tumor cells were allowed to metastasize (3 days after implant); DAC, however, resulted in no cures (survival beyond 48 days). When the pyran copolymer MVE-4, an immune adjuvant, was given the day after DAC, 25% of the mice treated were cured and the life-span of dying mice was increased by 7 days. When MVE-4 was repeated weekly for 4 weeks, 79% of treated mice were cured.