Increased sequence diversity coverage improves detection of HIV-specific T cell responses

The accurate identification of HIV-specific T cell responses is important for determining the relationship between immune response, viral control, and disease progression. HIV-specific immune responses are usually measured using peptide sets based on consensus sequences, which frequently miss responses to regions where test set and infecting virus differ. In this study, we report the design of a peptide test set with significantly increased coverage of HIV sequence diversity by including alternative amino acids at variable positions during the peptide synthesis step. In an IFN-gamma ELISpot assay, these "toggled" peptides detected HIV-specific CD4(+) and CD8(+) T cell responses of significantly higher breadth and magnitude than matched consensus peptides. The observed increases were explained by a closer match of the toggled peptides to the autologous viral sequence. Toggled peptides therefore afford a cost-effective and significantly more complete view of the host immune response to HIV and are directly applicable to other variable pathogens.     

Transesterification of farnesol mediated by a lipase from Andrographis tissue cultures

A cell-free system from Andrographis paniculata tissue cultures catalysed the transesterification of administered cis, trans-farnesol-[1-³H₂] with (glyceryl) oleate and palmitate present in the coconut water that forms part of the culture medium.     

Some physiological responses of cotton leaves to foliar applications of potassium 3,4-dichloroisothiazole-5-carboxylate and S,S,S-tributyl phosphorotrithioate

The effects of foliar application of potassium 3,4-dichloroisothiazole-5-carboxylate (TD-1123) and S,S,S-tributyl phosphorotrithioate (DEF) on some physiological events that occur in cotton ( Gossypium hirsutum L.) leaves are reported. Transport of ¹⁴C from cotton leaves was significantly reduced as soon as 1 day after treatment with DEF. In addition the DEF-treated leaves exhibited reductions in water potential recovery values (predawn measurements), stomatal conductance, specific weights, soluble N content, and an alteration in free amino acid distribution. Little change in any of these parameters was noted in leaves treated with TD-1123 alone. A sequential treatment of TD-1123 followed in 10 days with DEF had an apparent synergistic effect in that the effect on most parameters measured was more pronounced and occurred earlier in such leaves than in those treated with either chemical alone.     

Environmental and social influences on emerging infectious diseases: past, present and future

During the processes of human population dispersal around the world over the past 50 000-100 000 years, along with associated cultural evolution and inter-population contact and conflict, there have been several major transitions in the relationships of Homo sapiens with the natural world, animate and inanimate. Each of these transitions has resulted in the emergence of new or unfamiliar infectious diseases.The three great historical transitions since the initial advent of agriculture and livestock herding, from ca. 10 000 years ago, occurred when: (i) early agrarian-based settlements enabled sylvatic enzootic microbes to make contact with Homo sapiens; (ii) early Eurasian civilizations (such as the Greek and Roman empires, China and south Asia) came into military and commercial contact, ca. 3000-2000 years ago, swapping their dominant infections; and (iii) European expansionism, over the past five centuries, caused the transoceanic spread of often lethal infectious diseases. This latter transition is best known in relation to the conquest of the Americas by Spanish conquistadores, when the inadvertent spread of measles, smallpox and influenza devastated the Amerindian populations.Today, we are living through the fourth of these great transitional periods. The contemporary spread and increased lability of various infectious diseases, new and old, reflect the combined and increasingly widespread impacts of demographic, environmental, behavioural, technological and other rapid changes in human ecology. Modern clinical medicine has, via blood transfusion, organ transplantation, and the use of hypodermic syringes, created new opportunities for microbes. These have contributed to the rising iatrogenic problems of hepatitis C, HIV/AIDS and several other viral infections. Meanwhile, the injudicious use of antibiotics has been a rare instance of human action actually increasing 'biodiversity'.Another aspect of this fourth transition is that modern hyper-hygienic living restricts microbial exposure in early life. This, in the 1950s, may have contributed to an epidemic of more serious, disabling, poliomyelitis, affecting older children than those affected in earlier, more endemic decades. As with previous human-microbe transitions, a new equilibrial state may lie ahead. However, it certainly will not entail a world free of infectious diseases. Any mature, sustainable, human ecology must come to terms with both the need for, and the needs of, the microbial species that help to make up the interdependent system of life on Earth. Humans and microbes are not "at war"; rather, both parties are engaged in amoral, self-interested, coevolutionary struggle. We need to understand better, and therefore anticipate, the dynamics of that process.