The Met Office Hadley Centre climate modelling capability: the competing requirements for improved resolution, complexity and dealing with uncertainty.

Predictions of future climate change require complex computer models of the climate system to represent the full range of processes and interactions that influence climate. The Met Office Hadley Centre uses 'families' of models as part of the Met Office Unified Model Framework to address different classes of problems. The HadGEM family is a suite of state-of-the-art global environment models that are used to reduce uncertainty and represent and predict complex feedbacks. The HadCM3 family is a suite of well established but cheaper models that are used for multiple simulations, for example, to quantify uncertainty or to test the impact of multiple emissions scenarios.

Improving patient care and quality of life after laryngectomy/glossectomy.

Patients undergoing total laryngectomy/glossectomy are left without a voice at least temporarily in the early postoperative stage, since their larynx and/or tongue has been removed. Those patients rendered permanently speechless usually acquire a form of mechanical speech through electronic devices. However, the life-changing nature of this surgery should not be underrated as effectively these people have lost their normal voice. It can be argued that this patient group is also without a voice in a political sense - theirs seems to be a forgotten cancer, as other forms of cancer appear to attract greater attention for research priorities and funding. In some ways this research attempts to redress the balance through exploring the patient experience postoperatively, in particular the issues related to communication for this patient group. The results also highlight the emotional trauma experienced by patients and the mechanisms healthcare staff employ to support these patients. This research is multidisciplinary, involving patients and all those health workers that come into contact with them on the ward. The patient experience forms a major part of this article, allowing their stories to form much of the content. The results draw attention to deficiencies in service delivery that, as a direct result of this research, have been and are being addressed so that patients' care is improved and their quality of life is restored. Such change has been driven by patient comment such as: 'But then when you wake up after that operation that's the pits when you are laying there and you think "I'm dead". And then when you wake up properly that's the bit I always say you wish you were dead. That's when you wish you had died.'

Performance of small-scale CHO perfusion cultures using an acoustic cell filtration device for cell retention: characterization of separation efficiency and impact of perfusion on product quality.

Several small-scale Chinese hamster ovary (CHO) suspension cultures were grown in perfusion mode using a new acoustic filtration system. The separation performance was evaluated at different cell concentrations and perfusion rates for two different CHO cell lines. It was found that the separation performance depends inversely on the cell concentration and perfusion rate. High media flow rates as well as high cell concentrations resulted in a significant drop in the separation performance, which limited the maximal cell concentration achievable. However, packed cell volumes of 10% to 16% (corresponding to 3 to 6. 10(7) cells/mL) could be reached and were maintained without additional bleeding after shifting the temperature to 33 degrees C. Perfusion, up to 50 days, did not harm the cells and did not result in a loss of performance of the acoustic filter as often seen with other perfusion systems. Volumetric productivities in perfusion mode were 2- to 12-fold higher for two cell lines producing two different glycoproteins when compared to fed-batch or batch processes using the same cell lines. Product concentrations were in the range of 20% to 80% of batch or fed-batch culture, respectively. In addition, using the protease-sensitive product rhesus thrombopoietin, we could show that cultivation in perfusion mode drastically reduced proteolysis when compared to a batch culture without addition of protease inhibitors such as leupeptin.

Aberrant metabolic sialylation of recombinant proteins expressed in Chinese hamster ovary cells in high productivity cultures.

The incorporation of sialic acid into therapeutic recombinant glycoprotein expressed in Chinese hamster ovary (CHO) cells during growth in large bioreactors (10 l) has been monitored under high productivity conditions induced by the presence of sodium butyrate. Samples of the bioreactor culture (approximately 4 x 10(6) cells) were labeled with 3H-N-acetylmannosamine, a metabolic precursor of sialic acid. After 24 h, the recombinant glycoprotein, an immunoadhesion chimeric molecule, was purified and the amount of sialic acid incorporated was determined as radioactive counts. The labeling profile of the protein over the course of the culture was compared with the sialic acid content of the molecule as determined by direct chemical analysis. Early in the culture, the two methods of analysis gave a similar sialylation profile. However, after sodium butyrate was included in the culture, the metabolically incorporated sialic acid rapidly and dramatically decreased to near undetectable levels. In contrast, sialic acid content of the protein, as determined by chemical analysis, decreased only moderately and gradually over the culture period, from a maximum of 6.1 to about 5. 0 mol sialic acid/mole of protein after 10 days in culture. These results suggest that butyrate may enhance reutilization of existing glycoproteins in the culture, generating sialic acid for biosynthesis through lysosomal degradation and thereby bypassing de novo biosynthesis.

Chinese hamster ovary cells with constitutively expressed sialidase antisense RNA produce recombinant DNase in batch culture with increased sialic acid.

Under some cell culture conditions, recombinant glycoprotein therapeutics expressed in Chinese hamster ovary (CHO) cells lose sialic acid during the course of the culture (Sliwkowski et al., 1992; Munzert et al., 1996). A soluble sialidase of CHO cell origin degrades the expressed recombinant protein and has been shown to be released into the culture fluid as the viability of the cells decreases. To reduce the levels of the sialidase and to prevent desialylation of recombinant protein, a CHO cell line has been developed that constitutively expresses sialidase antisense RNA. Several antisense expression vectors were prepared using different regions of the sialidase gene. Co-transfection of the antisense constructs with a vector conferring puromycin resistance gave rise to over 40 puromycin resistant clones that were screened for sialidase activity. A 5' 474 bp coding segment of the sialidase cDNA, in the inverted orientation in an SV 40-based expression vector, gave maximal reduction of the sialidase activity to about 40% wild-type values. To test if this level of sialidase would lead to increased sialic acid content of an expressed recombinant protein, the 474 antisense clone was employed as a host for expression of human DNase as a model glycoprotein. The sialic acid content of the DNase produced in the antisense cultures was compared with material made in the wild-type parental cell line. About 20-37% increase in sialic acid content, or 0.6-1.1 mole of additional sialic acid out of a total of 3.0 mole on the product, was found on the DNase made in the antisense cell lines.

Population reduction as a factor in the control of skunk rabies in Alberta.

Population reduction is being used currently to combat skunk rabies in Alberta. A total of 2,398 striped skunks (Mephitis mephitis) were removed from three counties of southern Alberta during 1980-1983 in an effort to combat rabies outbreaks in those areas. The methods employed included trapping, poisoning, and shooting. Skunks in Forty Mile County have been rabies-free for 4 yr and the outbreaks in Newell and Warner counties appear to be under control. The data suggest that population reduction has been effective in controlling rabies in those areas.

Presence of neutralizing antibodies to rabies virus in striped skunks from areas free of skunk rabies in Alberta.

Nine percent of 198 serum samples from striped skunks, Mephitis mephitis (Schreber) from five areas of Alberta were positive for rabies neutralizing antibody. Positive samples were minimal (2%) from specimens sampled in an area enzootic for rabies and occurred at greater rates in areas negative for skunk rabies. Transmission of rabies virus to skunks may have been from a source other than skunks in those areas, most probably from bats.

A serological survey of Leptospira interrogans serotype pomona in Alberta and Saskatchewan striped skunks and possible transmission between cattle and skunks.

The range of known occurrence of Leptospira interrogans serotype pomona is extended to Alberta in striped skunks (Mephitis mephitis); no evidence of L. sejroe was found. Reacting sera from skunks were confined to the southern portion of Alberta and adjacent Saskatchewan, although a number of reactors were found sufficiently further north in Saskatchewan suggesting that a different mode of infection may be functioning there. Of 95 skunk sera from near a dairy farm infected with serotype pomona 40% were reactors. Of 438 skunk sera from other areas only 5.7% were reactors; that difference was suggestive of transmission from cattle to skunks on the dairy farm. Of 22 skunk sera collected near the dairy farm in summer none were reactors, whereas 52% of skunk sera taken the previous and following winters were. That seasonal difference was not evident among sera from other locations.

Sylvatic trichinosis in Alberta.

Results of surveys for Trichinella sp. in several species of wildlife in Alberta suggest that infection is limited to wolves (Canis lupus) in northern areas of the province and maintained by a wolf/wolf transmission.

Prevalence of antibodies to Toxoplasma gondii in striped skunks from Saskatchewan and Alberta.

Fifteen percent (81 of 542) of striped skunks, Mephitis mephitis, collected in the prairie of Alberta and Saskatchewan during 1974 to 1978, were positive for antibodies against Toxoplasma gondii. The seropositive rates varied from 8% (6 of 78) for skunks less than six months of age to 47% (9 of 19) in animals three or more years old. Spring and summer transmission was indicated by a preponderance of high titres (greater than or equal to 1:1024) in seropositive skunks collected April through September (22 of 40, 55%) compared to seropositives collected October through MFarch (10 of 38, 26%) (P = < 0.05). Prevalence was significantly greater among skunks collected in the relatively humid parkland (63 of 286, 22%) than in the arid prairie grassland biome (20 of 225, 8%) (P = < 0.01). The results indicate that T. gondii is focally enzootic in Alberta and Saskatchewan.

Oral papillomatosis in coyotes (Canis latrans) and wolves (Canis lupus) of Alberta.

Twelve cases of oral papillomatosis were detected in wild carnivores of Alberta, ten in coyotes (Canis latrans) and two in wolves (Canis lupus). Lesions ranged from mild with a few small papillomas to severe with much of the surface of the lips, tongue and buccal cavity covered with papillomas. Three of five coyotes with severe papillomatosis were in obvious poor health. The gross and histologic lesions are described and the significance of this disease in wild carnivores is discussed.