Dear member,
Best wishes for a Merry Christmas and a Happy New Year from Council!
We are sorry to announce that Prof. Nick Lane of UCL is unable to come and give December's advertised talk – 'How Energy Flow Shapes the Evolution of Life' – due to an unavoidable clash with his professional duties.
However, our own Dr Kevin Devine has kindly stepped into the breach, and will talk about:
An Astronaut in Structure Space: Redesigning Nucleic Acids Using Synthetic Organic Chemistry
Modern terran life uses several essential biopolymers like nucleic acids, proteins and polysaccharides. The nucleic acids DNA and RNA are arguably life’s most important, acting as the stores and translators of genetic information contained in their base sequences, which ultimately manifest themselves in the amino acid sequences of proteins. But just exactly what is it about their structures that enables them to carry out these functions with such high fidelity? In the past three decades, leading chemists have created in their laboratories synthetic analogues of nucleic acids which differ from their natural counterparts by replacing three key components. The talk will examine in detail the physical and chemical properties of these synthetic nucleic acid analogues, in particular on their abilities to serve as conveyors of genetic information. And if life exists elsewhere in the universe, will it also use DNA?
Some of you will know that the Hampstead Scientific Society website has a 'Subscription service', where subscribers are notified by email whenever the website is updated. That means they have early notice of when there are, for instance, changes to the programme. Members are not automatically subscribed, as the service was developed some years ago when spam was prolific and filters were not as sophisticated as they are now, so some members were wary of yet more emails, even if from the Society. We try to distinguish them by prefixing the subject with HSS Web Update.
If you are interested, and are over 13, just send an email info@hampsteadscience.ac.uk with HSS Subscribe in the subject line and you will be added to the list. Non-members may subscribe as well.
As the cost of postage increases, so does the cost of sending out this newsletter. Council has suggested that some members may be willing or even prefer to receive the newsletter by email instead.
So, if any member would like to have the newsletter by email only, please send an email, this time to secretary@hampsteadscience.ac.uk with HSS Newsletter in the subject line, and we will arrange it.
Our web site has long hosted the programme of our sister scientific society in Richmond. They have now proudly launched their own at http://www,rssbtck.co.uk. Do have a look. We have redirected their pages on our site to their site, and will eventually just leave a link. In case you don't have internet access, their next talk will be at 8pm on Wednesday 19th December in the VESTRY HOUSE, 21 Paradise Rd TW9 1SA:
Scanning Probe Microscopy: measurements in the nanoscale Andrés Muñiz Piniella, C4AD CIC
Simon Lang
Thames Water re-covering the reservoir with a 'smart membrane' has caused us many a conundrum and some external works on the building were somewhat overdue as well. We got the keys back to re-enter the site in July '17 and could finally take stock of just how much the works had affected us.
As part of our obligations we had to remove the Met. Station and all the cables for our lighting and supply from the intake head by the front gate. This entailed gutting all the wiring to our split fuseboard in the dome building. During the year of works we removed the Cooke object glass for cleaning, all the other expensive equipment and stored everything else away in a sardine like manner.
On going back in, we first tackled the outside of the building, to make good a number of timbers which were subject to weathering with some damage caused by the works. The door to the dome had been forced open at some point and was already poorly, as well as its frame and so it's had to be repaired and with break-ins now more likely, it was decided to reinforce the door and its frame.
Another key draw back was they put the concrete path to the building back to 1910 specs and so we lost about 5sqm of viewing area that had been subsequently poured. I asked the contractor about paving some of the Met Station area, having checked with the Met. men that we wouldn't be upsetting their readings. I pointed out that our tripods could sink into the ground and potentially damage the new membrane (extremely unlikely but...) and paving would spread the load. He agreed and so I went and got 20sqm of paving. Oops. Should have checked with Thames Water. On seeing the slabs waiting to be laid they asked why we had them and we were told in no uncertain terms to leave them until permission was sought and granted. Well after chewing it over the engineers have agreed we can have it, so YAAAAY! We have to adhere to certain conditions on its installation but I've had experience of that, so it'll be no problem.
Our needing to get onto the top of the reservoir to do works now has to be passed and Thames Water need to install temporary barriers to demarcate any work zone, all to do with insurance I believe. We couldn't wait for them and our painters have had to put their arms through the railings to paint their far sides but of course you can't see what you're doing and so there was much walking around in between, to check the backs of them were covered. Julia Daniels came up with the great idea of Thames Water completely surrounding our building by extending the existing style railings, permanently, so that we could go all around, doing maintenance whenever we needed to, especially important if an urgent job were to come up and gaining permissions would hold it up. Again in principle this should meet approval, subject to the engineers being happy with it.
Volunteers ran in new armoured cables to replace the 45 year old pyro's which were past their use by date. Where we had bulkhead lights that rather dazzled one going up the steps and which needed replacing as they were now irreparable, it was decided they'd be replaced by a rope light that gives an even illumination along their whole length and at 9m long, would illuminate the steps right down to the gate where there had previously been a black hole which the bulkhead lights failed to show up and where the steps are at their most precarious.
They'd have to be housed such that light would be cast across the steps, not up into the eyes nor shining across to the Observatory either and so a bespoke housing to take them has been designed and made. The main electrical intake box, serving us and Thames Water's equipment needed repairing too. In all, 52 pieces of ply and pine have had to be cut to shape, sanded, resined for weatherproofing and then given 6 coats of paint to adequately seal them. All that remains is for them to be assembled & mounted in situ, along the railings, with gap filling and touching up.
It was realised that the railings they'd be attached to could do with painting first, as it would be much more difficult with them in place. Teams of volunteers and a heroic Trevor Law, who joined me for several afternoons each week for weeks on end, stripped the worst rust off and they sanded clean the sound paintwork. In some exposed metal areas, no fewer than 6 coats of paint were put on to ensure they'd be well protected.
Having got the dome door, railings, overall outside work done while we had good weather (and that dragged on which really helped!) it was time to now get on with the inside. This meant moving things around inside the annexe and at that point the dreaded dry rot was discovered. Soon it was realised the floor was no longer sound enough to walk across safely. It had to be replaced for new. So far I've lifted about a third of it but gently because the spores from it can cause illness so I've been spraying it with water to keep dust down. I've slowly bagged up the smaller sections and am making a pile of the bigger stuff. It'll all have to be burnt on site, once I've secured a brazier.
Sadly the rot is also in the wall timbers and their supports but that can be dealt with next spring. It requires jacking the building up, section by section and replacing the base timbers with treated hardwood. This has been done on the dome section already, some 10 years ago. Being a telescope maker and using a water level we got the building base sections to RMS 1mm, I kid you not! Most of summer '19 pencilled into my diary then.
We've a helper doing the electrical work but he's having to squeeze in odd half days between other pressing projects and so that is coming on bit by bit. We should have the electrics reconnected within 2 weeks.
The BBC are doing an 8 minute slot about the HSS and Amateur Telescope Makers of London and how we cross over, in a London Inside Out program, that's likely to be aired in January. So far they've filmed me ripping up flooring to emphasise our need for donations. The rest will be telescope making and an observing session where we'll attempt a live feed through the Cooke of Mars or the Moon. It's all happening!
Live long and paint it,
Simon Lang.
oOo
Julie Atkinson
My mother had a venous leg ulcer which wouldn't heal. Nasty open sores, painful dressing changes, vulnerable to infection. I'd heard about alternative treatments, such as use of maggots, though was more inclined to think of them as undesirable infestations, indicating neglect, and associated with rubbish and mess. Or, in the case of those omnipresent detective series on the telly, as indicators of the time of death of an infested corpse.
But Prof. Yamni Nigam from Swansea was so enthusiastic about the little larvae and their properties at the British Science Festival a couple of years ago that I decided to look more into the topic.
The traditional medicines in some cultures made use of maggots: Hill People in Northern Burma, the Ngema tribe in Australia, and in the past, the Maya, used maggots on wounds, applying them directly or attracting flies to blow. In the 1500's in the West, a French surgeon named Ambroise Paré observed the healing of a severe head wound in the presence of maggots, and thereafter allowed any infestations in patients to remain for a while in an attempt to aid recovery. I don't know if others followed the practice. A compatriot surgeon in the Napoleonic wars in Syria observed that blue fly larvae cleaned the dead flesh from a wound and had a beneficial effect on the living flesh. It was a Confederate surgeon during the American Civil War, John Zacharias, who actually applied maggots to gangrenous tissue, saying that, in a single day, they would clean a wound much better than any agents they had at their command, and he believed he saved many lives by their use.
However, it appears that 19th century experiments introducing maggots into wounds were not always so successful. If maggots were cultivated and applied to a wound, they might still themselves harbour pathogens, and so could bring infection to the site. Common bacteria in the soil or on raw meat could cause tetanus or gas gangrene in the patient. So considering maggots as dirty, revolting, to be removed rather than encouraged, was a quite logical response.
In the First World War, deaths from open wounds were increasing, as the cases overtook the means of treatment, even reaching 70%. So, when another American, William Baer noticed that two soldiers with battlefield injuries a week old had no pus, fever or infection and appeared to be healing, he was interested. What they did have were swarms of maggots. Back in the US, at the Baltimore Children's Hospital he experimented with applying maggots to wounds, with some success until two patients died of tetanus. But that drove Baer to attempt to sterilize the maggots. He found he could easily sterilize the outside, but the gut would remain contaminated, so eventually devised a method involving washing the fly eggs with a solution containing mercurous oxide and acidified alcohol.
The availability of sterile maggots led to a boom in maggot therapy in the 1930's. However, alternatives such as sulphonamides were also produced in the 1930's and antibiotics became available in the 1940's, soon gaining almost total supremacy. Probably helped by patients' natural aversion to creepy crawlies on their person.
Why is there recent renewed interest in maggot therapy? It may be due to the increase in antibiotic resistant infections. The treatment had been regularly used and promoted by Dr Ronald Sherman, University of California, Irvine, in the 1990's, claiming it led to more rapid removal of debris than other non-surgical methods, and faster healing.
Also in the early 1990's, a member of the Surgical Materials Testing Laboratory (SMTL) in Bridgend became aware of efforts to stimulate interest in maggot therapy in the UK. Steve Turner persuaded his NHS trust to fund work in the area, resulting in a method of sterilizing maggots and successful treatment of a number of patients. That in turn led to sales of the sterile larvae and the eventual spin-off to a commercial entity in 2005, the year after maggot therapy was made available on prescription on the NHS and also recognised as a prescription only treatment by the US FDA.
So, what type of maggot is suitable for the treatment? Flesh eating insects come in various guises. The screwfly larva, for instance, eats living flesh and so can be dangerous, particularly to livestock. Other fly larvae may restrict their diet to dead flesh but still be detrimental to the wounds. The larva of the greenbottle blowfly, Lucilia sericata, causes damaging lesions on sheep, but it is the preferred candidate for maggot therapy, where it feeds on decomposing human tissue.
The main use for maggots is for 'debriding' wounds, i.e. the medical removal of dead, damaged or infected tissue to give the remaining flesh a better chance of healing.
The maggots don't have teeth to chew the dead tissue. They secrete enzymes which selectively dissolve it, and then they can suck up the result. That means that the maggots don't actually need direct contact with the flesh. These days, they can be applied onto the wound in a little sealed sachet, rather like a tea-bag. Patients don't feel them, and there is no pain when applying or removing the bags.
The maggots need to grow from hatchlings 1-2mm in length to 8-10mm before pupating and emerging as flies, the rate of growth depending on temperature. A maggot therapy nurse from the SMTL, Mary Jones, recalled that the hatchlings were kept in a fridge to slow down metabolism until they were needed, and she would travel to the patient with maggot pots up her jumper to warm them for application. In order to grow rapidly, the grubs are voracious eaters, helping to clean up a wound quickly. The sachet will hold any excreta and their moultings as they grow. They are generally removed after 3 days.
But if maggots eat infected tissue, won't the bacteria just be excreted back into the wound? Maggot cleaning seems to include eradication of bacteria. A group in Oxford and Israel have found that the larva gut kills almost all Escherichia coli passing through.
Is this wound cleaning the only benefit of maggots? The earlier work implies that there are positive effect that are not just due to the clearing of dead matter.
Prof. Yamni Nigam has a background in medical entomology, and set up the Swansea University Maggot Research Group in 2001. The group has carried out numerous investigations into the composition of maggot 'spit', at the molecular level.
Fans of maggot therapy had long believed that the secretions contained an antibiotic. The research group has found that there are several antibiotic molecules present, the most interesting of which is Seraticin. This is a relatively small molecule, but with apparently powerful effect, attacking various pathogens, including several strains of MRSA. The group is now trying to purify the extract.
In long term wounds, bacteria may form a biofilm, a slime comprising layers of the micro-organisms sticking to proteins on the wound edges, and covered by a sugary layer that protects them from antibiotics. The research group has found that maggot secretions can destroy these biofilms, or even prevent their formation.
Bacteria are just one type of potential pathogen. Another are fungi. Some fungi could indeed attack the maggots themselves. The research group have also found that maggot secretions contain antifungal agents.
And finally, during her talk, Prof. Nigam speculated on whether the healing observed in maggot therapy may in part be due to growth factors contained in the maggot secretions, reasoning that the larvae are of course the young of the greenbottle fly, and are feeding in order to grow to maturity, so are likely to be producing such hormones. But, would they act on humans as well to promote cell growth and hence healing?
In investigating this, the group have found that there are particular components of maggot secretions that can stimulate proliferation of some blood vessel cells, and so are potentially positive healing factors. The research continues.
At the British Science Festival talk, Prof. Nigam showed some rather gruesome pictures of wounds which had been treated conventionally without success, and which as a last resort were cleaned and healed with the help of maggots. Now the use of maggots is becoming more routine. Mary Jones commented that they were particularly useful for diabetic foot ulcers, which could be cleaned by the larvae within days rather than months.
Given her revulsion at my mentioning maggots as a potential treatment, it is just as well that my mother's ulcer finally managed to heal over without their help!
I have consulted the following for this article:
oOo
Last updated 3-Mar-2019