Deadly effects of smoking

By Dhaneshi YATAWARA

Would you mind inhaling vapours of insecticides, coal tar, car exhaust, gas chamber poison, white ant poison, floor cleaner, mothballs and nuclear weapons in one puff? Surely NO, isn’t it? Then why smoke? This is all what a smoker breathes in a single tobacco puff.

The insecticide is nicotine, car exhaust is carbon monoxide, hydrogen cyanide is the gas chamber poison, white ant poison is arsenic, chemical in floor cleaner is ammonia, substance in mothballs is naphthalene and nuclear weapons have radioactive compounds. This is not the end of the horrific story. Chewing tobacco contains, apart from nicotine, arecoline - a chemical producing cancer cells, lime what you find in cement, menthol that is used for local anaesthesia, cadmium which you find in car batteries, formaldehyde used to embalm dead bodies and lead found in paint.

Tobacco is the deadliest consumer product that causes an estimated 4.2 million premature deaths a year. “This is a product where death comes close to the consumer by using it according to the manufacturer’s instructions,” said Professor Carlo Fonseka, Chairman of the National Authority on Tobacco and Alcohol (NATA).

The most alarming factor is that about a third of all adults in the world use tobacco and almost one billion of these are found to be men.Luckily women are rarely included in this lot due to many reasons such as social taboo and limited finances. “In Sri Lanka we are lucky to have a minimal percentage among women in smoking,” Prof. Fonseka said.

Cigarettes kill half of all lifetime users and each cigarette you smoke cuts life expectancy by seven minutes! If you smoke to enjoy life this is a factor you should never forget. Smoking causes 90% of all lung cancers, 75% of chronic bronchitis and emphysema and 25% of blood related heart diseases. One on a suicide mission can use this as the slogan but unfortunately it is not only the smoker that gets affected but others around him too. This is in fact a human rights violation of healthy living beings. Passive smokers have a 20 - 30% increased risk of lung cancer and a 23% greater risk of heart disease.

Humans falling sick as a result of smoking becomes a great burden to the country’s health system causing the Government to spend a large amount of money on these preventable illnesses.

Nicotine is the principal constituent of tobacco responsible for its addictive character. Addicted smokers regulate their nicotine intake and blood vessels by adjusting the frequency and intensity of their tobacco use both to obtain the desired psychoactive effects and avoid withdrawal. Unburned cured tobacco contains nicotine, carcinogens and a list of other deadly toxins. The smoke when a tobacco is burned contains 4000 other toxic compounds other than nicotine.

According to medical information the blends of tobacco utilised for pipes and cigars allows sufficient absorption of nicotine across the oral mucosa to satisfy the smoker’s need. Thus in the case of pipes and cigars the toxics are confined largely to the upper airway causing diseases in those areas. The acidic condition of smoke generated in cigarettes dramatically reduces the absorption of nicotine in the mouth making it compulsorily absorbed in the lungs.

“One cannot limit the number of diseases caused by cigarette smoke to few parts of the body,” Prof. Fonseka explained.

Accordingly the cigarette chemicals cause a gigantic change in the body biochemical balance causing degeneration of cells and triggering cancer cells. The list of diseases cover the entire body from head to toe.

It compulsorily includes coronary heart diseases, cerebovascular diseases, aortic aneurysm, chronic airway obstructions, cancers in lungs, larynx, oral cavity, esophagus, bladder and other urinary organs, kidney and the list continues. And do you still consider smoking as your favourite past time? Completely ending smoking will reduce the risk of a second coronary event within 6 - 12 months. Rates of first myocardial infarction or death from coronary heart disease also decline within the first few years following cessation. After 15 years in the present living environments the risk of a new myocardial infarction or death from coronary heart disease in former smokers will be similar to that for those who have never smoked.

In the case of cancers the cessation of cigarette smoking reduces the risk of developing cancer relative to continuing smoking but even 20 years after cessation there is a modest persistent increased risk of developing lung cancer.

According to medical findings within 1 - 2 years of beginning to smoke regularly, many young smokers will develop inflammatory changes in their small airways.

After several years of smoking tissues in the lung also face severe damages. Changes in the small airways in the early stages of smoking will reverse probably after 1 - 2 years of cessation. This is only if you are young but as you grow older the return to normality is highly unpredictable.

This information is enough to break a weak heart like your kids waiting to be with you today.

The father, brother, the man of the house is responsible not to break hearts but to mend them when broken and protect them from breaking.

So please use the ash tray only as a flower vase ; don’t allow it to be littered with cigarettes. Don’t smoke to protect the future generation and above all to protect humanity. It’s your responsibility.

Caffeine as food source for bacteria

A new bacterium that uses caffeine for food has been discovered by a doctoral student at the University of Iowa. The bacterium uses newly discovered digestive enzymes to break down the caffeine, which allows it to live and grow.

“We have isolated a new caffeine-degrading bacterium, Pseudomonas putida CBB5, which breaks caffeine down into carbon dioxide and ammonia,” says Ryan Summers, who presented his research at the 111th General Meeting of the American Society for Microbiology in New Orleans.

Caffeine itself is composed of carbon, nitrogen, hydrogen and oxygen, all of which are necessary for bacterial cell growth. Within the caffeine molecule are three structures, known as methyl groups, composed of 1 carbon and 3 hydrogen atoms. This bacterium is able to effectively remove these methyl groups (a process known as N-demethylization) and essentially live on caffeine.

Summers and his colleagues have identified the three enzymes responsible for the N-demethylization and the genes that code for these enzymes. Further testing showed that the compounds formed during break down of caffeine are natural building blocks for drugs used to treat asthma, improve blood flow and stabilize heart arrhythmias.Currently these pharmaceuticals are difficult to synthesize chemically. Using CBB5 enzymes would allow for easier pharmaceutical production, thus lowering their cost. Another potential application is the decaffeination of coffee and tea as an alternative to harsh chemicals currently used.

“This work, for the first time, demonstrates the enzymes and genes utilized by bacteria to live on caffeine,” says Summers.

Source: Jim Sliwa American Society for Microbiology

Wound healing and the power of hydrogen peroxide

New information has come to light explaining how injured skin cells and touch-sensing nerve fibres coordinate their regeneration during wound healing. UCLA researchers Sandra Rieger and Alvaro Sagasti found that a chemical signal released by wounded skin cells promotes the regeneration of sensory fibres, thus helping to ensure that touch sensation is restored to healing skin. They discovered that the reactive oxygen species hydrogen peroxide, which is found at high concentrations at wounds, is a key component of this signal.

The study was conducted in zebrafish larvae - an experimental model widely used to investigate development and regeneration. The optical transparency of these larvae make it possible to image sensory fibres in live animals and measure their regeneration.

Detection of touch stimuli, such as pressure, temperature, and noxious chemicals, is achieved by peripheral sensory axons, which form highly branched networks in the skin. Following injury, skin cells proliferate and migrate to seal the wound, and peripheral sensory axons innervating the skin must also regenerate to restore sensory function. Experiments in amphibians and chickens have suggested that wounded skin promotes peripheral axon regeneration, but molecular mediators of this effect had not been identified. Hydrogen peroxide has long been known to be a toxic byproduct of cellular damage, but only recently has it been appreciated that low concentrations of it can activate certain molecular pathways that regulate cellular development. Whether hydrogen peroxide also plays a role in peripheral axon regeneration had not been explored.

To test whether injured skin can promote axon regeneration, Rieger and Sagasti amputated the tip of a larval zebrafish tail and used time-lapse fluorescent microscopy to monitor the behaviour of nearby peripheral sensory axons. Amputating the tail boosted axon growth and allowed axons to penetrate regions of the skin that normally repel them.

They also found that damaging skin cells anywhere in the body promoted the regeneration of nearby sensory axons, demonstrating that injured skin cells are the source of the signal. Adding hydrogen peroxide to the media of uninjured larvae mimicked the axon growth-promoting effect of damaging skin cells. Conversely, preventing the production of hydrogen peroxide blocked the ability of damaged skin to promote axon regeneration. Together these results demonstrate that hydrogen peroxide released by damaged skin cells is a key component of a signal that promotes axon regeneration.

(Source: Bryan Ghosh Public Library of Science)

A new understanding of the way enzymes work

Thanks to a detailed study of the binding of a compound with therapeutic properties to its biological target, a research team from the Institut des Sciences du Vegetal (ISV, CNRS) has demonstrated the dynamic operation of enzymes.

One of the fundamental principles of the living world is its ability to undergo chemical reactions of great complexity, in an extremely rapid and precise manner, and to sequence them together. It is in this way that cells survive and divide. Specific macromolecules, enzymes in infinitesimal quantities compared to the reactants, catalyze these biochemical reactions and can be reused countless times. But can these proteins essential to life accelerate reactions so efficiently? In fact, the substrate firstly needs to be recognized by the enzyme, come into contact with certain chemical groups specific to it, then undergo a transformation, favoured by the chemical environment thereby created and associated with deformations of molecular groups physically close to each other in space.

The macromelecular assembly thus attains a highly reactive ephemeral state known as a “transition state”, which increases the rapidity of the biochemical reaction by a factor of several hundred billion.

This fundamental knowledge has inspired researchers to identify and improve small compounds that mimic the substrates, without undergoing modifications, but which remain nevertheless fixed for a long time to the enzyme. This persistence in fact makes the macromolecule inactive and incapable of exercising its activity on its natural substrate.

Drugs work on exactly the same principle; they usually correspond to inhibitors that mimic the transition state and literally “bond” to the target enzyme, preventing it from operating and inducing associated pathologies. However, the bases of the recognition between the enzyme and its substrate (or inhibitor) remained for a long time poorly understood.

According to the work of the chemist Emil Ficher in 1894 (1), the enzyme recognizes its substrate via a “key-lock” mechanism. It then remained to be understood when and how the so-called “conformational” morphological modifications of the enzyme take place and what processes are involved in these modifications.

In 1958, Daniel Koshland proposed a first model (2), which assumes that the small compound firstly interacts with the enzyme and that it is this interaction that induces the conformational change of the macromolecule, thereby making it capable of transforming the substrate. According to this “induced adjustment” model, the substrate thus plays a very active role in the modification of the form of the enzyme. In the alternative “conformational equilibrium” model, formalized in the 1990s (3,4), it is suggested that the enzyme can exist as several - at least two - conformational isoforms and that the substrate attaches itself preferentially to one of the minor forms, which is the only one suited for catalysis. In this mechanism, the change of conformation takes place before the reaction and the substrate does not contribute directly to it, unlike the first model.

Over the past few years, numerous data has accumulated in favour of this second mechanism, whereas the first has remained hypothetical, without any tangible experimental proof of its existence.

However, the recent work of the team supported the existence of the model proposed by Koshland over 50 years ago.

By using a therapeutic target enzyme, the researchers took advantage of the detailed study of a small compound mimicking the substrate, capable of binding very strongly to the enzyme, blocking its activity and thus exhibiting antibiotic, antineoplastic and herbicidal properties. The efficient binding of this compound to the target enzyme, as revealed by a series of structural biological, enzymological and biophysical analyses and computer modelling, requires an “induced adjustment” stage. In other words, it is the small compound which, once bonded to the enzyme, induces its conformational modification.

Thanks to the resolution of the fine structure of this enzyme derived from the chloroplast of the plant Arabidopsis thaliana in several sequential conformational states, the scientists have succeeded in precisely describing the interactions and conformations of each of the partners, enzyme and substrate, at each stage of the reaction.

In this respect, the modification of a “pocket”, in which one of the groups of the substrate inserts itself, allows the formation of a hydrogen bond, thereby stabilizing the enzyme-substrate complex in the transition state and making it highly reactive to perform the enzymatic hydrolysis reaction efficiently.

This study enabled researchers to gather a series of proofs that this model applies to all forms of the enzyme, in particular those found in bacteria, the targets of powerful antibiotics. They have also helped explain the mechanism by which a therapeutic molecule can bind to its target so that it no longer manages to “unbind” from it, which makes it possible to prolong the effect of the drug beyond the actual treatment.

Consequently, this research work is based on the detailed understanding of a therapeutic mechanism in order to answer a fundamental question and, conversely, this conceptual understanding could, in return, have repercussions in applied biology and in therapeutics. However, as this work demonstrates, the strategies adopted by these extraordinary biological catalyst enzymes are both multiple and plastic, and may also be completed by a conformational selection.

These are important factors to take into consideration when designing ab initio or improving the pharmacological properties of drug candidates.

Sources: CNRS (Delegation Paris Michel-Ange), AlphaGalileo Foundation.

Cancer in women is more curable than in men

Dr. Vijay Anand P. Reddy

The Hand that Rocks the Cradle Rules the World. It’s a different matter altogether that more and more men are participating in the rocking of the cradle these days! Nevertheless, the statement justifies the role that women play in society.

Love, care, compassion and selfless service are synonymous with women, and valid through all the varied roles that they play - right from the sweet little girl to a bubbly teenager, loving and supporting wife to caring mother, and the praying and blessing grandmother.

It was Mahatma Gandhi who once said, “Man can never be a woman’s equal in the spirit of selfless service”.

Besides being the more admirable part of creation, nature has also been partial to women in one more way. Compared to men most cancers in women are curable. Cancer of the breast, cervix, uterus, ovary and Gestational Trophoblastic Neoplasia (GTN) are the common cancers in women, and are very often cured.

Nature has probably showered this gift on women because he knows women are indispensable!

Also, cancers in women cause early symptoms and signs, and hence are prone to be detectable and diagnosed early. The diagnostic procedures are very simple, minimally invasive, easily accessible and affordable.

Early symptoms of cancer (Ca)

1. Ca. Cervix - White or red discharge, inter-menstrual spotting / bleeding, post coital bleeding.

2. Ca. Uterus - Post menopausal bleeding or spotting, inter menstrual bleeding or spotting.

3. Ca. Breast - Lump in the breast, bleeding from the nipple, change in colour of the breast, retraction of nipple etc.

4. Ca. Ovary - Lower abdominal distention, persistent pain in the abdomen.

5. G.T.N. - Post abortion persistent bleeding, post delivery persistent bleeding, grape-like bleeding in young women.

Early diagnosis

1. Breast self examination - Look for change in shape, colour, bleeding from nipple, lump in breast or armpit.

2. Bilateral Mammogram.

3. Ultrasonography - of the abdomen for uterus, cervix and ovary.

4. Pap smear - a five min outpatient non-invasive procedure to detect early Cervical Cancer.

Treatment in early stage cancer is almost always curable

1. Ca. Cervix - either removal of uterus and cervix or radiotherapy.

2. Ca. Uterus - Removal of uterus (Hysterectomy) followed by +/- radiotherapy.

3. Ca. Breast - Removal of the lump and axillary nodes followed by +/- chemo or hormonal therapy, or radiotherapy.

4. Ca. Ovary - Removal of the ovaries and uterus followed by +/- chemotherapy.

5. G.T.N. - Dilatation and Curettage followed by +/- chemotherapy.

Tips for cancer prevention in women

* Regular physical exercise.

* Avoid fatty food, alcohol and tobacco.

* Avoid obesity.

* Breastfeeding

* Avoid long term use of hormones

* Limit the number of children to 2 or 3

* Avoid multiple sexual partners

* Maintain good vaginal hygiene

* Get vaccinated - HPV vaccine prevents cancer of cervix up to 90%.