Human cytochromes P450: problems and prospects.

Cytochromes P450 are a superfamily of haem-containing monooxygenases. In mammals, two general classes of P450s exist: six families involved in steroid and bile acid biosynthetic pathways of metabolism; four families containing numerous individual P450s, mainly responsible for metabolism of foreign compounds. Many of the latter P450s, particularly those in the CYP2 family, exhibit a large degree of inter- and intra-species variability in regulation and catalytic activities. From a practical standpoint, these variabilities suggest the need for careful characterization of P450 catalytic activities and determination of P450 expression levels in humans. Human P450-based in vitro systems are being developed to evaluate drug and carcinogen metabolism.     

Pharmaceuticals and developing countries: problems and prospects

For many decades there was little consensus on the nature and type of pharmaceutical policies best suited for developing countries. In the aftermath of the Nairobi Conference on the Rational Use of Drugs and the formulation of criteria by expert groups convened by the World Health Organization a consensus has emerged on many aspects. Infrastructure development and the deployment of trained manpower are now perceived as two of the essential requisites for the implementation of national pharmaceutical policies. The article reviews selected problem areas in the pharmaceuticals sector and proposes strategies to overcome them.     

Carcinogenic effects of low-level ionizing radiation: problems and prospects

For public health purposes, the overall risks of cancer are assumed to increase in proportion to the dose of ionizing radiation, without a threshold. Assessment of the risks that may be attributable to doses below the range in which empirical data are available, however, entails the use of models, the credibility of which depends on the extent to which the models are consistent with what is known about the occurrence and mechanisms of the effects in question. Although the weight of existing evidence is consistent with the hypothesis that the risks of genetic and carcinogenic effects of ionizing radiation increase as linear-nonthreshold functions of the dose, this concept is challenged by some observers in view of growing evidence that low doses of radiation may elicit adaptive responses that enhance the repair of DNA damage and protect in other ways as well. Further research is needed to resolve the issue.     

The microbial postgenomic era: promises, problems and prospects

The inevitable emergence and spread of resistance to new antibiotics entering the market necessitates a new approach in drug discovery. Novel classes of antimicrobial compounds are required that are not enfeebled by widespread resistance mechanisms. The favoured approach is to gain a better understanding of the essential pathways and cellular functions and then to select new unexploited targets. This strategy has coincided with the deposition of fully assembled genomic sequences of several bacteria in the public databases. Various technologies have been reported that, when optimised, will enable the analysis of global cellular processes at the molecular level thus greatly contributing to our understanding of cellular physiology. In this article, some of the major advances in technology, which are expected in the future to be essential for the optimal use of the information contained within the genomic sequences, will be outlined.     

Drinking among teenagers in Australia: Research findings, problems and prospects

Studies of Australian teenagers' drinking patterns, beliefs and attitudes toward the use of beverage alcohol are reviewed and discussed. In a culture where alcohol use is widespread and acceptable, young Australians are exposed to drinking as a normative behaviour early in their lives. Most learn to drink without associated problems. There are, however, increasing numbers of young people still at school who report drinking on a daily basis and who regularly become intoxicated. In attempting to promote responsible drinking behaviour, researchers and educators must be aware of strong sociocultural supports for heavy drinking. Greater understanding of cultural norms and expectations about drinking is considered essential for the design and implementation of programs aimed at preventing teenage alcohol abuse.     

Harm reduction and the global drug control regime: contemporary problems and future prospects

Countries committed to a harm-reduction approach to drugs have exploited the latitude which exists within the UN global drug control regime to implement strategies which deviate from the strict prohibition ethos of the conventions. These nations risk pressure being brought to bear through the UN drug control regime, principally by the United States, determined to prevent what it sees as foreign challenges to its domestic 'zero tolerance' approach and its internationalisation. In this paper, based on his presentation to the International Conference on the Reduction of Drug Related Harm in Melbourne this year, David Bewley-Taylor, describes the conventions and the 'wiggle room' which exists, but also imagines ways like-minded states might together challenge and reform the conventions so that harm reduction can be accepted and hard wired into the UN drug control system itself. Simon Lenton Editor, Harm Reduction Digest     

创新发展的中国药大制药

中国药科大学制药有限公司始建于1938年，现已成为具有研制和生产化学原料药、生物工程产品和多种剂型能力的综合性制药企业。目前拥有片剂、胶囊剂、颗粒剂、膜剂、凝胶剂、栓剂、滴眼剂等7种制剂，共40多个品种。     

创新发展的中国药大制药

中国药科大学制药有限公司始建于1938年，现已成为具有研制和生产化学原料药、生物工程产品和多种剂型能力的综合性制药企业。目前拥有片剂、胶囊剂、颗粒剂、膜剂、凝胶剂、栓剂、滴眼剂等7种制剂，共40多个品种。     

创新发展的中国药大制药

中国药科大学制药有限公司始建于1938年，现忆成为具有研制和生产化学原料药，生物工程产品和多种剂型能力的综合性制药企业。     

Disease induction by human microbial pathogens in plant-model systems: potential, problems and prospects

Relatively simple eukaryotic model organisms such as the genetic model weed plant Arabidopsis thaliana possess an innate immune system that shares important similarities with its mammalian counterpart. In fact, some human pathogens infect Arabidopsis and cause overt disease with human symptomology. In such cases, decisive elements of the plant's immune system are likely to be targeted by the same microbial factors that are necessary for causing disease in humans. These similarities can be exploited to identify elementary microbial pathogenicity factors and their corresponding targets in a green host. This circumvents important cost aspects that often frustrate studies in humans or animal models and, in addition, results in facile ethical clearance.     

Pharmaceutical suspensions: micro electrophoretic properties.

The microelectrophoretic properties of the drugs griseofulvin, betamethasone, nalidixic acid and thiabendazole in aqueous dispersion have been examined and the zeta potentials calculated from the measured mobilities. Variation in magnitude of particle charge with pH of dispersion is reported and related to the chemical structure and the surface characteristics. The effect of adding anionic (sodium dodecyl sulphate) cationic (dodecyl trimethyl bromide) and non-ionic (polyoxyethylene glycol monoethers of hexadecanol) surface-active agents, and mixtures of these ionic and non-ionic species, on the electrophoretic properties of the drug dispersions has been measured. The results reported agree with those found previously for a model polystyrene latex suspension system under the same conditions.