Oncolytic virotherapy with an HSV amplicon vector expressing granulocyte-macrophage colony-stimulating factor using the replication-competent HSV type 1 mutant HF10 as a helper virus.

Direct viral infection of solid tumors can cause tumor cell death, but these techniques offer the opportunity to express exogenous factors to enhance the antitumor response. We investigated the antitumor effects of a herpes simplex virus (HSV) amplicon expressing mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) using the replication-competent HSV type 1 mutant HF10 as a helper virus. HF10-packaged mGM-CSF-expressing amplicon (mGM-CSF amplicon) was used to infect subcutaneously inoculated murine colorectal tumor cells (CT26 cells) and the antitumor effects were compared to tumors treated with only HF10. The mGM-CSF amplicon efficiently replicated in CT26 cells with similar oncolytic activity to HF10 in vitro. However, when mice subcutaneously inoculated with CT26 cells were intratumorally injected with HF10 or mGM-CSF amplicon, greater tumor regression was seen in mGM-CSF amplicon-treated animals. Furthermore, mGM-CSF amplicon treatment prolonged mouse survival. Immunohistochemical analysis revealed increased inflammatory cell infiltration in the solid tumor in the mGM-CSF amplicon-treated animals. These results suggest that expression of GM-CSF enhances the antitumor effects of HF10, and HF10-packaged GM-CSF-expressing amplicon is a promising agent for the treatment of subcutaneous tumors.

Cytogenetic studies of Hynobiidae (Urodela) XVI. Comparative C-banded karyotype analysis of Pseudohynobius flavomaculatus (Fei et Ye), Ranodon shihi (Liu) and Batrachuperus pinchonii (David).

Initial analysis of Pseudohynobius flavomaculatus chromosomes determined the chromosome number of this species to be 2n = 52. A re-examination of Ranodon shihi chromosomes detected 2n = 66 chromosomes, in contrast with a previous finding of 2n = 64. The C-banding patterns of these two species and that of Batrachuperus pinchonii were compared with each other. Regions of homoeology in the C-banding pattern among these three species represented 33.51-48.30% of the total length of their chromosomes. We also detected two types of chromosome rearrangement in hynobiid species based on the results of the present and previous cytogenetic studies.

Flumazenil but not FG7142 reverses the decrease in pentobarbital sleep caused by activation of central noradrenergic systems in mice.

Central noradrenergic systems have been shown to modulate the hypnotic activity of pentobarbital in mice. To determine whether the GABA(A)/benzodiazepine receptor system is involved in the decrease in pentobarbital sleep caused by activation of central noradrenergic systems, we examined in mice the effects of the benzodiazepine receptor ligands flumazenil and FG7142 on pentobarbital-induced sleep, and on adrenoceptor ligand modulation of pentobarbital sleep. The intracerebroventricular (i.c.v.) administration of methoxamine (8-200 nmol), an alpha1-adrenoceptor agonist, and yohimbine (1-30 nmol), an alpha2-adrenoceptor antagonist, produced a dose-dependent decrease in sleeping time induced by pentobarbital (50 mg/kg, intraperitoneally (i.p.)). The i.c.v. administration of flumazenil (16.5 and 33 nmol), a selective benzodiazepine receptor antagonist, had no effect on pentobarbital sleep, whereas an i.p. injection of FG7142, a selective benzodiazepine receptor inverse agonist, shortened pentobarbital sleep. Flumazenil (33 nmol, i.c.v.) caused the pentobarbital sleep time, shortened by methoxamine (200 nmol, i.c.v.) and yohimbine (30 nmol, i.c.v.), to return to the control level, while FG7142 (10 mg/kg, i.p.) had no effect on the methoxamine- and yohimbine-shortened pentobarbital sleep. These results suggest that putative endogenous benzodiazepine receptor ligands with an inverse agonist-like property are involved in the methoxamine- and yohimbine-induced decrease in pentobarbital sleep in mice.

Chromosomes and causation of human cancer and leukemia: XXXIX. Usual and unusual findings in Ph1-positive CML.

The chromosomal changes in the leukemic cells of 48 patients with Ph1-positive CML are reported. The karyotypic findings in the chronic phase (CP) and blastic phase (BP) were similar to those reported in the past, with +8, and extra Ph1, and an iso (17q) being the most common anomalies observed in BP. Unusual cytogenetic findings were observed in one patient whose cells (from lymph nodes, bone marrow, and blood) were characterized by very marked hypodiploidy and hypo-haploidy, with some of the cells having less than 20 chromosomes. In each of these very hypodiploid metaphases, conglomerations of darkly stained and condensed chromosomes were seen. These conglomerations consisted of a few to eight chromosomes. The role played by these chromosomes in the genesis of severe hypodiploidy is uncertain. The patient was thought to have "lymphoid" types of leukemic cells in BP, with an extramedullary origin of such cells, particularly in lymph nodes, playing a major role in the genesis of BP. The reported cases of near-haploidy with Ph1-positive CML and those with constitutional translocations with CML have been tabulated and the possible significance of the cytogenetic abnormalities discussed.

Chromosomes and causation of human cancer and leukemia. XXXIV. A case of "hypereosinophilic syndrome" with unusual cytogenetic findings in a chloroma, terminating in blastic transformation and CNS leukemia.

A 47-year-old white male developed massive hepatosplenomegaly, a pleural effusion, leucocytosis, and a left parasternal mass following a relatively symptom-free persistent hypereosinophilia for about 5 years. Bone marrow aspiration and biopsy and peripheral blood differential showed eosinophilia and a shift to the left with immature cells. A high serum B12 vitamin level and low LAP activity were found. Biopsy of the soft tissue mass revealed a granulocytic sarcoma (chloroma) with a hyperdiploid karyotype (49,XY, + 10, + 15, + 19,3q-), whereas the bone marrow cells had a normal male karyotype. The patient responded temporarily to chemotherapy but eventually developed CNS leukemia and went on to terminate in a frank blastic phase. This case illustrates hypereosinophilia and a myeloproliferative syndrome characterized by a somewhat indolent chronic course evolving into "eosinophilic leukemia" and granulocytic sarcoma, CNS involvement by leukemic cells and, finally, blastic transformation. It is possible that this case represents a variant of Ph1-negative CML to which the term "chronic eosinophilic leukemia" could be justifiably applied.

Radiation-induced aneusomic clones in bone marrow of rats.

Wistar rats 3 months old were given a single whole-body X-irradiation with 700 R. They were killed 9.3 months, on average, after irradiation. From the bone marrows of the 23 irradiated rats, 54 clones of cells with radiation-induced chromosome abnormalities, ranging from 3.3 to 78.3% in size, were obtained. Karyotype analysis at the banding level showed that 43 out of the 54 clones had balanced chromosome constitutions, and that the remaining 11 clones were unbalanced. The 43 balanced clones consisted of 33 clones with reciprocal translocations, 6 with inversions and 4 with both translocations and inversions. The 11 unbalanced clones were made up of 7 aneuploid clones and 4 pseudo-diploid clones. Of the 54 clones, 15 were large with frequencies of more than 25%. Contrary to general belief that cells with unbalanced chromosome constitutions have less capacity to proliferate than those with balanced ones, 8 of the 15 large clones, especially all, except 1, of the largest 6 clones were unbalanced, either aneuploid or pseudo-diploid.