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The ability of polymers displaying lower critical solution temperatures (LCSTs) to mediate bioadsorptive processes was assessed. Three carboxyl-terminated polymers P1−3 with LCSTs respectively of 20, 32, and 42 °C were prepared by free-radical polymerization of N-isopropylacrylamide with and without comonomers acrylamide and N-tert-butylacrylamide. The polymers were grafted to amine-functionalized glass substrates, and their surface properties were investigated by contact angle goniometry and atomic force microscopy. Increases in water contact angle of up to 24° were observed between 10 and 37 °C for polymers with LCSTs of 20 and 32 °C, whereas no change was apparent for control amine-functional and the LCST 42 °C polymer surfaces over this temperature range. Variations in topography in water were also apparent from atomic force microscopy (AFM) studies for all the polymer grafts but not the amine surfaces over these temperatures. Adsorption of ³H-labeled bovine serum albumin and cytochrome c also increased to polymer grafts above the LCST, with the greatest change in the amount of attached protein being exhibited by polymer P1 (1.13 pmol·cm^-2 cytochrome c at 10 °C, 3.95 pmol·cm^-2 at 37 °C):  adsorption to control surfaces varied by less than 10% in this assay. Incubation of the graft and control substrates with a gram negative and motile bacterium (Salmonella typhimurium) and gram positive, nonmotile species (Bacillus cereus) showed the same overall pattern of attachment as the protein adsorption experiments, with polymers P1 and P2 retaining more bacteria (increases of up to 1350%) at 37 °C than at temperatures below their LCST, while amine-functional and P3 polymer surfaces showed less than 20% changes in the number of attached microorganisms. Further incubations at temperatures below polymer LCST resulted in fewer adsorbed cells at the surfaces showing the reversibility of short-term attachment to these materials. The results show that protein adsorption and short-term bacterial attachment correlate well with observed changes in surface properties as determined by contact angle goniometry and indicate that control of bioadhesion is possible by grafting suitably functionalized polymers capable of temperature-mediated hydrophilic−hydrophobic switching.

Few studies have assessed risk factors for sporadic cryptosporidiosis in industrialized countries, even though it may be numerically more common than outbreaks of disease. We carried out case-control studies assessing risk factors for sporadic disease in Melbourne and Adelaide, which have water supplies from different ends of the raw water spectrum. In addition to examining drinking water, we assessed several other exposures. 201 cases and 795 controls were recruited for Melbourne and 134 cases and 536 controls were recruited for Adelaide. Risk factors were similar for the two cities, with swimming in public pools and contact with a person with diarrhoea being most important. The consumption of plain tap water was not found to be associated with disease. This study emphasizes the need for regular public health messages to the public and swimming pool managers in an attempt to prevent sporadic cryptosporidiosis, as well as outbreaks of disease.

Perineurioma is an uncommon, benign tumour of the peripheral nerve sheath that has two major clinicopathological forms - intraneural and extraneural. We present a case of extraneural perineurioma that occurred at an unusual site - the facial skin of a 70-year-old woman - which illustrates the wide, and potentially misleading, clinicopathological spectrum of this poorly recognized tumour.

Polyisobutylene (PIB) possessing alkene end groups was ozonized. NMR spectroscopy showed that trioxolanes and tetroxolanes were the main products and that these products were relatively stable. Thermolysis of the ozonolysis products generated radicals, which were shown by ESR spin-trapping experiments to be alkyl and oxyalkyl species. Thermolysis in butyl propionate solution also generated radicals with structures consistent with those expected of species arising from hydrogen abstraction from solvent. Thermolysis in the presence of methyl methacrylate (MMA) or styrene (S) led to polymerization of both. Size exclusion chromatography (SEC) and gradient polymer elution chromatography (GPEC) were used to investigate the possibility that the newly formed polymer might be attached to PIB. In the case of MMA polymerizations, the final product was a blend of the two homopolymers:  no evidence for block copolymers could be seen by SEC or GPEC. In contrast, both SEC and GPEC indicated that a large fraction of the newly formed polystyrene was attached to PIB, most probably in the form of P(IB-b-S) block copolymer.

Cryptosporidium parvum is now recognised as being responsible for around 2 of gastroenteritis cases in the immunocompetent population in developed nations, as well as being a significant cause of morbidity in immunocompromised hosts with depressed T-cell function. The resistance of Cryptosporidium oocysts to chlorine-based disinfectants creates particular concerns for drinking water supplies, and numerous outbreaks of cryptosporidiosis have been recorded from both drinking water and recreational water sources in parts of Europe and North America. In Australia, there have been a number of swimming pool-associated outbreaks of cryptosporidiosis, and only one drinking water outbreak from a small private water supply has been documented. Two genotypes of Cryptosporidium parvum have been identified as the major cause of infections in immunocompetent humans. Genotype 1 (or H), appears to infect humans specifically, whereas genotype 2 (or C) may infect humans and a range of other mammals (including cattle, sheep and goats). Species other than C. parvum have been reported to be responsible for up to 20 of infections in immunocompromised hosts, and there is emerging evidence that such species are also responsible for a minority of infections in the immunocompetent human population. We carried out case-control studies of cryptosporidiosis in Melbourne (with high quality source water treated by chlorination only) and Adelaide (with poor quality source water treated by conventional flocculation, sedimentation, filtration and chlorination). The results indicated that drinking tap water was not a significant risk factor for cryptosporidiosis in either city, but that person-to-person transmission and public swimming pools were the main sources of public health risk. Cryptosporidium isolates from participants in the Adelaide case-control study were characterised genetically using single strand conformation polymorphism analysis of the small subunit gene (pSSU; ~300bp) and second internal transcribed spacer (pITS-2; 230bp) of nuclear ribosomal DNA. Of 26 isolates characterised to date, 15 (58) were identified as C. parvum genotype 1, 9 (35) were C. parvum genotype 2 and 2 (7.5) were C. meleagridis. Neither of the people infected with C. meleagridis had reported any illness or condition affecting the immune system when interviewed for the case-control study. These results support observations from Europe that a small proportion of Cryptosporidium infections in immunocompetent people are caused by species other than C. parvum, in particular C. meleagridis. Acknowledgment: This work was funded by the CRC for Water Quality and Treatment, the Water Services Association of Australia, Melbourne Water Corporation, City West Water Ltd, South East Water Ltd and Yarra Valley Water Ltd.