Dr James George Beaney (1828-1891): A pioneer Australian paediatrician and paediatric surgeon

Dr James George Beaney (1828-1891) was a flamboyant and controversial Melbourne surgeon and paediatrician. He was the first in Australia, in 1859, to publish a medical textbook; and the first, in 1873, to publish a paediatric text, Children: their treatment in health and disease. An analysis of four of his published works relating to paediatrics and paediatric surgery establishes his place as a true pioneer in the chronology of children's medicine and welfare in his adopted land. He undertook heroic yet conservative surgery on children, was the first to write in detail about paediatric anaesthesia, and was the pioneer of family planning in Australia. In Children: their treatment in health and disease, he described in detail the supreme importance of breastfeeding, detailed clear practical concepts for the weaning of infants and discussed the diagnosis and management of diseases of the mouth, ears, eyes and teeth of infants. Beaney was shunned by much of the established medical profession because of his self-promoting flamboyance and his egotism. However, an audit of surviving archives and of his published works affords him a place as another, hitherto unacknowledged true pioneer of Australian paediatrics.

Transient production of recombinant proteins by chinese hamster ovary cells using polyethyleneimine/DNA complexes in combination with microtubule disrupting anti-mitotic agents

We have developed a simple and robust transient expression system utilizing the 25 kDa branched cationic polymer polyethylenimine (PEI) as a vehicle to deliver plasmid DNA into suspension-adapted Chinese hamster ovary cells synchronized in G2/M phase of the cell cycle by anti-mitotic microtubule disrupting agents. The PEI-mediated transfection process was optimized with respect to PEI nitrogen to DNA phosphate molar ratio and the plasmid DNA mass to cell ratio using a reporter construct encoding firefly luciferase. Optimal production of luciferase was observed at a PEI N to DNA P ratio of 10:1 and 5 mug DNA 10(6) cells(-1). To manipulate transgene expression at mitosis, we arrested cells in G2/M phase of the cell cycle using the microtubule depolymerizing agent nocodazole. Using secreted human alkaline phosphatase (SEAP) and enhanced green fluorescent protein (eGFP) as reporters we showed that continued inclusion of nocodazole in cell culture medium significantly increased both transfection efficiency and reporter protein production. In the presence of nocodazole, greater than 90% of cells were eGFP positive 24 h post-transfection and qSEAP was increased almost fivefold, doubling total SEAP production. Under optimal conditions for PEI-mediated transfection, transient production of a recombinant chimeric IgG(4) encoded on a single vector was enhanced twofold by nocodazole, a final yield of approximately 5 mug mL(-1) achieved at an initial viable cell density of 1 x 10(6) cells mL(-1). The glycosylation of the recombinant antibody at Asn(297) was not significantly affected by nocodazole during transient production by this method. (C) 2004 Wiley Periodicals, Inc.

On the optimal ratio of heavy to light chain genes for efficient recombinant antibody production by CHO cells

Monoclonal antibodies (Mab) are heterotetramers consisting of an equimolar ratio of heavy chain (HC) and light chain (LC) polypeptides. Accordingly, most recombinant Mab expression systems utilize an equimolar ratio of heavy chain (he) to light chain (lc) genes encoded on either one or two plasmids. However, there is no evidence to suggest that this gene ratio is optimal for stable or transient production of recombinant Mab. In this study we have determined the optimal ratio of hc:lc genes for production of a recombinant IgG(4) Mab, cB72.3, by Chinese hamster ovary (CHO) cells using both empirical and mathematical modeling approaches. Polyethyleneimine-mediated transient expression of cB72.3 at varying ratios of hc:lc genes encoded on separate plasmids yielded an optimal Mab titer at a hc:lc gene ratio of 3:2; a conclusion confirmed by separate mathematical modeling of the Mab folding and assembly process using transient expression data. On the basis of this information, we hypothesized that utilization of he genes at low hc:lc gene ratios is more efficient. To confirm this, cB72.3 Mab was transiently produced by CHO cells at constant he and varying lc gene dose. Under these conditions, Mab yield was increased with a concomitant increase in lc gene dose. To determine if the above findings also apply to stably transfected CHO cells producing recombinant Mab, we compared the intra- and extracellular ratios of HC and LC polypeptides for three GS-CHO cells lines transfected with a 1:1 ratio of hc:lc genes and selected for stable expression of the same recombinant Mab, cB72.3. Intra- and extracellular HC:LC polypeptide ratios ranged from 1:2 to 1:5, less than that observed on transient expression of the same Mab in parental CHO cells using the same vector. In conclusion, our data suggest that the optimal ratio of hc:lc genes used for transient and stable expression of Mab differ. In the case of the latter, we infer that optimal Mab production by stably transfected cells represents a compromise between HC abundance limiting productivity and the requirement for excess LC to render Mab folding and assembly more efficient.

Participation in the RACS sentinel node biopsy versus axillary clearance trial

Background: The Royal Australasian College of Surgeons (RACS) SNAC trial is a randomized controlled trial of sentinel node biopsy (SNB) versus axillary clearance (AC). It opened in May 2001 and is recruiting rapidly with good acceptance by consumers. Methods: A study of eligibility and treatment choices was conducted between November 2001 and September 2002 for women presenting with early breast cancer to 10 centres participating in the trial. Results: More than half of the 622 women (54%) were ineligible for trial entry because they had large (> 3 cm) or multicentric cancers. Participation was offered to 92% of eligible women and was taken up by 63%. The commonest reason for not participating was the desire to choose treatment rather than have it randomly allocated. Despite this there is a great acceptance of clinical trials because very few women (4% of those eligible) gave 'lack of interest in clinical trials' as the reason for non-participation. Few women who declined trial participation chose to have SNB alone (4.5% of those eligible). Conclusion: Sentinel node biopsy may become the standard of care for managing small breast cancers, but a significant number of patients will still require or choose axillary dissection. Results from large randomized trials are needed to determine the relative benefits and harms of SNB compared with AC. Surgeons must carefully discuss options for management with their patients.