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Using the Internet for electronic business has become an area of action for the Australian government. This paper presents research results from two regional areas, which indicate that while most manufacturing SMEs use e-mail, very few are involved in electronic commerce activities. Major barriers are concern about security and privacy of transactions, cost of consultants, and lack of IT expertise of staff. Employing people with appropriate knowledge has been added to current training methods such as onthe-job training. Results from the two regional areas are found to be consistent. Comparisons between small and medium organisations highlight some differences.

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1 Cyclic AMP generation by adenosine analogues was examined in human embryonic kidney (HEK 293) cells by use of a [ 3 H]-adenine pre-labelling methodology. 2 Adenosine analogues showed the following rank order of potency (pD 2 value): 5'-N-ethylcarboxamidoadenosine (NECA, 5.24)42-chloroadenosine (4.41) 5 adenosine (4.19)=N 6 -(2-(4-aminophenyl)-ethylamino)adenosine (APNEA, 4.11). The A 2A -selective agonist CGS21680 failed to elicit a signi®cant stimulation of cyclic AMP generation at concentrations below 30 mM. 3 Of these agents, NECA was observed to exhibit the greatest intrinsic activity, while in comparison maximal responses to adenosine (76+8% NECA response), 2-chloroadenosine (70+6%) and APNEA (40+3%) were signi®cantly reduced. 4 Antagonists of the NECA-evoked cyclic AMP generation showed the rank order of apparent a nity (apparent pA 2 value): CGS 15943 (7.79)=XAC (7.74)4DPCPX (7.01)=PD115199 (6.93)=8FB-PTP (6.80)4KF 17837 (5.98)43-propylxanthine (5.13). 5 Agarose gel electrophoresis of the products of the polymerase chain reaction, with cDNA generated from HEK 293 cell total RNA showed virtually identical patterns and nucleotide sizes in comparison with the vector for the full length human brain A 2B adenosine receptor. 6 We concluded that HEK 293 cells express an endogenous adenosine receptor coupled to cyclic AMP generation which is of the A 2B subtype.

1 An [3H]-adenine pre-labelling methodology was employed to assay cyclic AMP generation by adenosine analogues in Chinese hamster ovary (CHO.A2B4) cells, transfected with cDNA which has been proposed to code for the human brain A2B adenosine receptor, and in guinea-pig cerebral cortical slices. 3 Of these agents, NECA was observed to exhibit the greatest intrinsic activity in CHO.A2B4 cells (ca. 10 fold stimulation of cyclic AMP), while, in comparison, maximal responses to adenosine (32% NECA response), 2-chloroadenosine (61%), and APNEA (73%) were reduced. 4 Antagonists of NECA-evoked cyclic AMP generation showed the rank order of apparent affinity (apparent pA2 value in CHO.A2B4 cells: guinea-pig cerebral cortex): XAC (7.89: 7.46)> CGS 15943 (7.75: 7.33)>DPCPX (7.16: 6.91)>PD 115,199 (6.95: 6.39)>8FB-PTP (6.52: 6.55)>3-propylxanthine (4.63: 4.59).5 We conclude that, using the agents tested, the A2B adenosine receptor cloned from human brain expressed in Chinese hamster ovary cells exhibits an identical pharmacological profile to native A2B receptors in guinea-pig brain.