A single microbubble formulation carrying 5-fluorouridine, Irinotecan and oxaliplatin to enable FOLFIRINOX treatment of pancreatic and colon cancer using ultrasound targeted microbubble destruction

FOLFIRINOX and FOLFOXIRI are combination chemotherapy treatments that incorporate the same drug cocktail (folinic acid, 5-fluorouracil, oxaliplatin and irinotecan) but exploit an altered dosing regimen when used in the management of pancreatic and colorectal cancer, respectively. Both have proven effective in extending life when used to treat patients with metastatic disease but are accompanied by significant adverse effects. To facilitate improved tumour-targeting of this drug combination, an ultrasound responsive microbubble formulation loaded with 5-fluorouridine, irinotecan and oxaliplatin (FIRINOX MB) was developed and its efficacy tested, together with the non-toxic folinic acid, in preclinical murine models of pancreatic and colorectal cancer. A significant improvement in tumour growth delay was observed in both models following ultrasound targeted microbubble destruction (UTMD) mediated FIRINOX treatment with pancreatic tumours 189% and colorectal tumours 82% smaller at the conclusion of the study when compared to animals treated with a standard dose of FOLFIRINOX. Survival prospects were also improved for animals in the UTMD mediated FIRINOX treatment group with an average survival of 22.17 ± 12.19 days (pancreatic) and 44.40 ± 3.85 days (colorectal) compared to standard FOLFIRINOX treatment (15.83 ± 4.17 days(pancreatic) and 37.50 ± 7.72 days (colon)). Notably, this improved efficacy was achieved using FIRINOX MB that contained 5-fluorouricil, irinotecan and oxaliplatin loadings that were 13.44-fold, 9.19-fold and 1.53-fold lower than used for the standard FOLFIRINOX treatment. These results suggest that UTMD enhances delivery of FIRINOX chemotherapy, making it significantly more effective at a substantially lower dose. In addition, the reduced systemic levels of 5-fluorouracil, irinotecan and oxaliplatin should also make the treatment more tolerable and reduce the adverse effects often associated with this treatment.

A simple, two-component buffer enhances use of chromatofocusing for processing of therapeutic proteins

To extend the feasibility of chromatofocusing to industrial use, we have developed a simple chromatofocusing buffer system capable of generating a smooth pH gradient without the use of an external gradient maker. Using two cationic buffering components, an internal pH gradient is produced on appropriate chromatography media over a broad pH range (9.5 to 5.0). The utility of this buffer system is demonstrated with PBE94 and DEAE Sepharose fast flow ion-exchangers, as well as with experimental fast flow chromatofocusing gels. Using a rapid flow rate, we evaluated this buffer system for recovery of a therapeutic protein from a bacterial cell extract. The simplicity of the buffer system requiring no external gradient maker, coupled with the use of fast flow chromatographic media to produce broad-range pH gradients, improves the scalability of chromatofocusing for processing of therapeutic proteins.

Titration of human immunodeficiency virus type 1 (HIV-1) and quantitative analysis of virus expression in vitro using liquid RNA-RNA hybridization

An assay is described for titration of human immunodeficiency virus type 1 (HIV-1) and for quantitative analysis of virus expression in vitro. The assay utilizes a liquid RNA-RNA hybridization method coupled with reversible target capture (RTC) on oligo(dT) derivatized magnetic particles. The assay provides a rapid, specific, and sensitive method for quantitation of HIV-1 RNA molecules present either in cells or in viral particles from cell-free culture media. Chronically infected monocytoid U1.1 cells were found to carry 52 pg HIV-1 RNA per 200,000 cells (160 HIV-1 RNA molecules per cell). In contrast, acutely infected CEM and H9 cells carried 3010 and 4370 pg HIV-1 RNA per 200,000 cells (9040 and 13,110 HIV-1 RNA molecules per cell, respectively). No hybridization was observed with uninfected cells or cells infected with HIV-2, HTLV-I, HTLV-II, or EBV. Use of liquid HIV-1 RNA hybridization in association with HIV-1 protein detection methods permits more complete characterization of HIV-1 expression in host cells than either method alone, and also provides a method for standardizing preparations of virus.

Histones H1(0) and H5 share common epitopes with RNA polymerase II

We report here the cross-reaction of RNA polymerase II antiserum with histones H1(0) and H5 and the complementary cross-reactions of antisera to the globular domain of histone H1(0) (GH1(0)) and histone H5 (GH5) with RNA polymerase II. Immunoblotting of RNA polymerase II antiserum with fragments of histone H1(0) localized the cross-reaction at the junction of the globular and C-terminal domains of histone H1(0). The structural homology implied by these cross-reactions is interesting in light of reports that suggest H1(0) may play a role in differentiation and development.

Identification of histone H1(0) in Physarum polycephalum. Its high level in the plasmodial stage increases in amount and phosphorylation in the sclerotial stage

An antiserum specific for the globular domain of the bovine very lysine-rich histone subfraction H1(0) cross-reacted with a single protein band in the chromosomal proteins isolated from microplasmodia of the true slime mold Physarum polycephalum. Its amino acid composition was characteristic of a very lysine-rich histone which supported its identification as Physarum H1(0). Unlike Physarum H1(0), which is 50% larger than mammalian H1, Physarum H1(0) migrated very close to bovine H1(0) on sodium dodecyl sulfate gels. In microplasmodia, the ratio of H1(0) to H1 was 0.66, whereas in sclerotia H1(0)/H1 was 1.33. Furthermore, both H1 and H1(0) in sclerotia were highly phosphorylated. The high level of H1(0) in the mitotically active microplasmodia argues against the proposed role of H1(0) just as an inhibitor of DNA replication. More probable is an association of H1(0) with quiescent but transcriptionally competent chromatin which could also include cell cycle genes. Hyperphosphorylation of H1 and H1(0) in sclerotia is probably required to maintain an inactive condensed state which can be reversed by dephosphorylation to allow transcriptionally competent chromatin to become available for expression.

Immobilizing wild mountain lions (Felis concolor) with ketamine hydrochloride and xylazine hydrochloride

A mixture of 120 mg ketamine hydrochloride (KHCL)/20 mg xylazine hydrochloride (XHCL)/ml was used to immobilize 37 wild mountain lions (Felis concolor) 46 times. Observations were recorded during 37 trials that included kittens, adult females, and adult males. Dosages were based on 11 mg KHCL and 1.8 mg XHCL/kg estimated body weight. Actual doses for 24 lions requiring a single injection for immobilization ranged from 4.7-15.8 mg KHCL/kg and 0.8-2.6 mg XHCL/kg. Induction, duration, and recovery times did not differ (P greater than 0.05) between the sex and age classes. Two kittens were overdosed with the drug combination, but the effects were not life threatening. Eleven other lions, nine of which were initially underdosed, required additional injections of the drug combination for safe handling. Immobilization was characterized initially by semi-consciousness, open eyelids, pupillary dilation, and muscle rigidity. Later, most lions appeared unconscious, muscles relaxed, and breathing slowed considerably. No convulsions or hypersalivation occurred. The KHCL/XHCL mixture given at approximately 11 mg KHCL and 1.8 mg XHCL/kg body weight proved useful for immobilizing wild mountain lions for research purposes. Suggestions for case of immobilized cats are included.

Antibody against globular domain of H10 histone

Antibodies against the globular domain of histones H10 and H5 were developed in rabbit. The antibody against the globular domain of H5 cross-reacted with H10 but not with H1; the antibody against the globular domain of H10 did not cross-react with H5, H1 or with HMG proteins. The globular domain of H10 therefore appears to have an immunological determinant(s) which does not exist in H1 and H5. By use of these antibodies, we show that nucleated erythrocytes of bullfrog contain an H10-like protein (not an H5-like protein). This observation coincided with the report of Shimada, T. et al. [J. Biol. Chem. 256 (1981) 10577-10582]. These antibodies have application in detecting H10-like proteins in eukaryotic cells.