In a placebo-controlled trial of the ef?cacy of a short course zidovudine regimen from 36 wk gestation in Thailand, pregnant women exposed to zidovudine had a significantly lower mean haematocrit than unexposed women, 31.9% versus 33.0%, p?0.03. In our study, the mean haematocrit level at delivery was higher��34.8% in women exposed to zidovudine from 35 wk. The absence of Pseudolaric-Acid-B difference in the mean haemoglob in level at delivery in two other placebo-controlled trials may be explained by their relatively limited sample size. From 26 wk of gestation to delivery, CD4 counts less than 200 cells/mm3, HIV RNA viral load higher than 50,000 copies/ ml, and an advanced HIV clinical stage were independently associated with a negative evolution of the haematological parameters. Similar ?ndings have already been reported, emphasising the need for systematic CD4 testing during pregnancy and access to highly active antiretroviral therapy for immunocompromised women. This result is consistent with the hypothesis that HIV, per se, may be associated with the development of anaemia, presumably because of direct effects of the virus on bone marrow suppression and reduction of erythropoietin production and response. Over the past several years, complete or nearly complete sets of clones representing the open reading frames of various species have been constructed and made available. These collections often employ recombinational cloning vectors, enabling the transfer of the ORFs into virtually any protein expression vector in a simple conservative transfer reaction. Once transferred, these expression clones can be employed in a wide variety of assays, including high-throughput cell-based and 2,6-Diaminopurine proteomic discovery assays. Clone collections have been used successfully to produce proteins using in vitro, bacterial or insect cell expression systems. Although several heterologous protein expression systems are capable of HT protein expression, simplicity and ease of handling have made the bacterial systems the best starting point to express large numbers of recombinant proteins. Among the most important properties that transferable clone collections should embody include comprehensive genomic representation of the ORFs and full length sequence validation, a combination of features that has thus far eluded the collections available today. In part, this is because sequence validation of clones is a tedious process that cannot be easily achieved without a well developed automated pipeline. Nevertheless, the major use of these collections will be to study protein function, emphasizing the critical importance of full length sequence validation. There is a pressing need to generate clone and protein resources for highly infectious organisms that could be used in bioterrorism.