Research fellows from Science and Research Centre of Physical and Chemical Medicine (Federal Agency for Public Health and Human Services) and Yaroslavl regional cancer detection centre have developed unique devices – biological sensors for detecting stomach cancer on its earliest stages. The heart of said biological sensor has natural origin, it is a microorganism – bacteria Helicobacter pylori, which has been genetically modified. Scientists have invented an unusual technique for diagnostics – they use the ability of these bacteria to fluoresce, moreover, fluorescence of said microorganisms depends on pH of human digestive juice – changes are significant. The flavour of the described technique is that pH of digestive juice of healthy people is different from that of human beings who have stomach cancer. Cancer cells are unable to produce hydrochloric acid, thus sites, where such cells appear, show local alkalization (pH growth) of environment.

However, the question appears – why have scientists paid so much attention to Helicobacter pylori, not any other microorganism? Let us remind you that several years ago, in 2005, Australian medics Barry Marshall and Robin Warren have been awarded the Nobel Prize in physiology and medicine for discovering bacterial origin of gastric ulcer – the stunning fact is that Helicobacter pylori bacteria appeared to be blamed for causing this disease. Today medical experts have no doubt that said microorganisms have some indirect effect on stomach cancer development. Mechanisms of their participation in disease development still remain obscure – do not forget that Helicobacter pylori inhabit the major part of Earth’s human population, however, only some people tend to fall ill.

First stage of the research of think-tank from Science and Research Centre of Physical and Chemical Medicine in developing biological sensors was following – scientists have performed studies on finding and confirming associative relation between Helicobacter pylori and stomach cancer. Fellows have succeeded in detecting sensor genes, which show abrupt changes in expression (more than two-fold) under change of environmental pH from 3.0 to 7.4, as well as in early stage of tumor growth in gastric mucosa. Activity of genes discovered depends on the stage of cell growth. Next stages of said breaking research involved creating a library of pH-sensitive constructions of Helicobacter pylori by means of genetic engineering, immobilizing said structures on a micro-fluid chip (micro-fluid chip is a chip, pierced with micro-channels for liquid circulation) and performing tests of obtained biological sensors. All this much ado resulted in a pilot lot of samples of biological sensors – developers claim that said sensors show high accuracy and specificity in detecting stomach cancer on its early stages without any gross interference into an organism.

Source:
    http://www.nkj.ru/
    http://tvoidoktor.ru/a>

Kizilova Anna