John Rex's main mistake

Science progresses by the discovery and correction of mistakes in the interpretation of data. John Rex sought ‘to distinguish among the various studies made by sociologists those which are distinguishable as race relations studies’. He examined them from the standpoint of classical sociological theory. His main mistake was his continued but unsuccessful attempt to synthesize two quite different kinds of sociological knowledge. He underestimated the importance of differences in the criteria for the validation of causal explanation and for the projection of historical trends.     

Indian agency admits publishing "wrong" HIV figures

The National AIDS Control Organization, India's top government agency responsible for tracking HIV infection, admitted that it published inaccurate figures of new HIV cases detected in the country over the past 3 years. It is noted that the agency estimated that 3.5 million people were infected, based on a sentinel screening program aimed at determining the HIV prevalence rates among high-risk communities and the general population. However, the Joint Action Council, the nongovernmental association monitoring the government's HIV program has questioned these findings. The Council claimed that the agency downplayed several figures and that its reports do not reflect reality. This is because the agency's surveillance figures suggested that the states of Kerala, Punjab, and West Bengal detected no new cases of HIV over the past 2-4 years. Moreover, epidemiologists have long suspected that thousands of infected people may be dying of HIV-related illnesses but are being missed by India's poor death recording system.     

Shared and unique determinants of the erythropoietin (EPO) receptor are important for binding EPO and EPO mimetic peptide.

We have shown previously that Phe93 in the extracellular domain of the erythropoietin (EPO) receptor (EPOR) is crucial for binding EPO. Substitution of Phe93 with alanine resulted in a dramatic decrease in EPO binding to the Escherichia coli-expressed extracellular domain of the EPOR (EPO-binding protein or EBP) and no detectable binding to full-length mutant receptor expressed in COS cells. Remarkably, Phe93 forms extensive contacts with a peptide ligand in the crystal structure of the EBP bound to an EPO-mimetic peptide (EMP1), suggesting that Phe93 is also important for EMP1 binding. We used alanine substitution of EBP residues that contact EMP1 in the crystal structure to investigate the function of these residues in both EMP1 and EPO binding. The three largest hydrophobic contacts at Phe93, Met150, and Phe205 and a hydrogen bonding interaction at Thr151 were examined. Our results indicate that Phe93 and Phe205 are important for both EPO and EMP1 binding, Met150 is not important for EPO binding but is critical for EMP1 binding, and Thr151 is not important for binding either ligand. Thus, Phe93 and Phe205 are important binding determinants for both EPO and EMP1, even though these ligands share no sequence or structural homology, suggesting that these residues may represent a minimum epitope on the EPOR for productive ligand binding.     

Rabbit EPO gene and cDNA: expression of rabbit EPO after intramuscular injection of pDNA

Erythropoietin (EPO) cDNA was cloned from kidney total RNA of a NZW rabbit. The cDNA comprises a 588-bp open reading frame encoding a 195 amino acid protein with distinguishable regions of high of homology to other mammalian EPOs. Intramuscular injection of mice with a rabbit EPO expression plasmid resulted in a significant hematocrit increase. A rabbit genomic DNA fragment was also cloned using the rabbit EPO cDNA. This 4312-bp genomic DNA fragment contains sequences homologous to the mouse EPO promoter and hypoxia-responsive enhancer. In addition, the genomic DNA also presents a high degree of conservation to other regions involved in hypoxia response. Sequence divergence in the 3' UTR may indicate differences in regulation of mRNA stability or response to low oxygen tension.