Futures - the way forward: Science

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Def-Eating tumours (date 01/12/01) An ongoing problem in the treatment of cancers has been the fact that "necrotic" regions build up in the centres of tumours. Usually a tumour supplies itself with food and oxygen by developing a system of blood vessels. Some tumours grow so rapidly that their interiors become starved of these essential nutrients and hence become necrotic. This makes them harder to destroy because drugs can't reach them at lethal doses due to the poor blood supply. In addition radiation treatments need an oxygen supply to trigger cell death. Once treatment has stopped the cancerous cells from the necrotic region, that have remained untouched, simply start dividing again. A solution may involve harnessing anaerobic bacteria that thrive in oxygen-poor environments. The theory goes that such bacteria could be used to attack the tumour in the necrotic regions, but once they reach the healthy oxygen-rich tissue they would stop growing. Bert Vogelstein at the John Hopkins School of Medicine in Maryland tested 26 strains of anaerobic bacteria on mice with tumours. He found that one strain of a soil bacterium, Clostridium novyi spread throughout the necrotic region of the tumours, consuming living tissue as well as dead cells. The microbes died near to the edge of the tumours. The researchers therefore combined this with radiation treatment and found that the tumours disappeared or shrank dramatically in 7 out of 8 animals. Unfortunately three of the eight mice died, which could have been due to the release of toxic bacterial waste products into the bloodstream. However, such a combined approach might work in larger animals whose bloodstreams could handle the sudden influx of such toxins. Source: New Scientist (01/12/01)
Lemurs (date 25/10/01) Up until now zoologists have expected to find lemurs in Africa, mainly in Madagascar. The primate ancestors of these animals were believed to have originated in continental Africa and somehow hitched a ride on rafts of vegetation to colonise the island of Madagascar and give rise to present day species. However, the first fossil find of lemur bones has posed a conundrum because 30 million year-old fossilised lemur teeth turned up in the Butgi Hills in Pakistan. A team of scientists from Montpellier University concluded that the animal, named Butgilemur mathesoni was closely related to the modern day dwarf lemur. However, Madagascar broke off from the Indian subcontinent about 88 million years ago, which is some 26 million years before previous molecular genetic studies showed that lemurs appeared as a separate species. One possible explanation is that a series of islands existed in the past which linked Madagascar to India so that the journey would not be as inconceivable as it is today. Source: New Scientist (25/10/01)
Sweet corn (date 5/10/01) What do you get when you mix a plant with an antibody? A "plantibody", of course. This is the term that researchers at Epicyte, a biotech company in San Diego, have given to their technique of introducing antibody genes into plant genomes so that antibodies can be produced easily and cheaply. Researchers at Epicyte introduced genes for an antibody that sticks to herpes viruses thus preventing the viruses from infecting target cells. Condoms provide some protection against sexually-transmitted herpes virus, but they are not 100% reliable! The new plantibody, called HX8, can provide protection for the vagina for 24 hours. The company is also working on antibodies that work against HIV transmission and genital warts. Clinical trials are due to start in 2002, with the ultimate aim being that the cheaply produced antibodies will be available as over-the-counter therapy. Source: New Scientist (6/10/01)
Training fish! (date 5/10/01) Fish bred in hatcheries are frequently released into rivers to boost stocks of fish for anglers and trawlers or to re-establish populations in the wild. However, a major drawback of this is the low levels of survival, approximately 5% for salmon, to adulthood. It appears that the hatchery-reared fish do not have the necessary predator-avoidance skills that would otherwise prevent them from being gobbled up. A team of scientists at Cambridge University have discovered that the key to survival is the ability to copy your nearest neighbours. Possible tactics for training include placing an experienced "demonstrator fish" in with the naive fish before they are released and showing video nasties of predators killing other fish. No other incentives required for paying attention to teacher then! Source: New Scientist (6/10/01)
Bitter pill (date 15/09/01) A team of scientists at the company, Globeimmune in Denver have produced an effective immune response to HIV proteins incorporated into a yeast genome. The HIV genes were inserted into the host brewer's yeast genome, and the resulting vaccine injected into mice. The mice mounted a strong killer T cell immune response which suggested that this might be a good form of treatment. Such a vaccine could be brewed easily to produce vast quantities in a short period of time. However, it remains to be seen whether the vaccine would prove as effective in primates and, eventually, humans. Source: New Scientist
Sweating it out (date 15/09/01) Have you ever been camping in mid-summer and found that whilst your partner is completely unaffected by insect bites, you are covered in them? Well, a team of scientists from the University of Edinburgh's Centre for Tropical Veterinary Medicine have discovered that the Highland biting midge is particularly attracted to certain types of sweat. Experiments carried out on willing volunteers on the Isle of Skye in Scotland demonstrated that there were notable differences between the "bite rates" of different individuals. The sweat of one individual, when placed in a midge trap overnight, attracted four times as many midges as a control trap containing no sweat. Two chemicals that mosquitoes are attracted to have already been isolated, and the researchers now aim to find out what exactly makes some of us so enticing! Source: New Scientist
Ageing (date 11/09/01) Humans have a constant battle with the march of time. Some try to beat the clock by choosing cosmetic surgery. Scientists at the Howard Hughes Medical Institute in Boston have investigated the possibility that longevity runs in families. Using genetic linkage analysis, which enables geneticists to home in on a region of the genome connected with a specific trait, they were able to show that a particular region of chromosome 4 is associated with long life. The next step is to isolate the genes located on this region of the chromosome. This may enable scientists to understand better the mechanisms of ageing in humans though the likelihood of this producing a miracle answer to advancing years is still a long way off. Source: New Scientist
Think again (date 11/09/01) It seems that a possible reason why humans have the ability to process complex concepts and develop language may be due to a movement of neurons in the brain during development. Neurobiologists at the Yale University Medical School in Connecticut have demonstrated that neurons migrate from the ganglionic eminence, where they arise, to the dorsal thalamus, which is itself a key gateway for information destined for the cortex. The cortex is the central area involved in attributes such as language recognition and speech. They showed that in mice this migration is blocked thus preventing the same increase in size of the dorsal thalamus that occurs in humans. However, it is not known whether this behaviour of the neurons is unique to humans or whether it also happens in other primates as well. Source: New Scientist

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Copyright by David Incoll 2001