How does Oral Polio Vaccine work?
• Oral polio vaccine contains a live, attenuated (weakened) vaccine-virus.
• When a child is vaccinated, the weakened vaccine-virus replicates in the intestine and enters into the bloodstream,
• This triggers an immune response in the child, thus Child becomes immune to (wild) polio in future.
What is Vaccine-derived polio?
In rare cases, the live-weakened virus from Oral polio vaccine itself becomes mutated. Then child gets polio from the virus inside vaccine itself. This is known as Vaccine Derived Polio.
Why in News?
• In July 2013, an infant from Bead District Maharashtra was infected with ^this Vaccine-derived poliovirus (VDPVs) type 2 and got paralyzed.
• Our Heath ministry’s approach was “thik-hai this is just an isolated case”. But WHO is worried and rushed a team to the Maharashtra.
What do Experts say?
• That baby was not given sufficient number of polio doses (under vaccinated) so it seems baby infected by a vaccine-derived poliovirus from another person.
• Not every child who gets infected with VDPV will become paralysed but this baby was already undernourished, hence paralyzed.
Will this remove India’s polio free status?
• As per the WHO definition, only wild polio considered for deciding the polio-free status of a country.
• Therefore, this Maharashtra case will not alter India’s polio status. Because it was from Vaccine derived poliovirus and not from wild variety of polio virus.
• Although such technical juggling of definition will not bring that baby’s legs back, nor it will reduce the danger of polio among other India kids.
Then what should be done?
• The root cause of the problem is the use of live, weakened polio virus in the oral polio vaccine (OPV)
• But this virus are still alive and quite often undergoes genetic changes=> cause’s polio.
• Thus, the very vaccine that is supposed to protect children against polio causes the disease.
• Endgame / ultimate solution= introduce IPV (injectable polio-vaccine) instead of using oral polio vaccine. In just two injections of IPV, child becomes 100% immune to polio
Challenges in introducing IPV?
1. We don’t have enough trained doctors/nurses to give injections to all kids in rural areas. + The recent case in Uttar Pradesh, where a rickshaw puller gave injection to baby and the baby died.
2. IPV is more expensive to produce than OPV.
Mosquitoes are Crepuscular Ectothermic meaning They’re most active during dawn and dusk.
However, they are all not active at night.
• they seek warmth
• But are quite vulnerable to hot, dry conditions, hence hate direct sunlight.
Male vs Female Mosquitos
Male mosquito usually feed on nectar, juice and decaying matter, which serve as the energy source
Female mosquito need to ingest the blood meal that serves as the protein source for developing the eggs.
We experience more mosquito bites at night. Why?
1. Mosquitoes are known to be attracted UV light. They use UV light to find damp water sources.
2. But during daytime, Infra-red light is more intense during day time is known to curtail mosquito activity.
3. During evening and night, Mosquitoes’ thermal and odour receptors become more efficient at detecting blood source.
4. A Mosquito can detect victim more quickly if the person is big or, pregnant, exhaling more CO and has sweetish smell or had a pint of beer.
Malaria Vaccine: Haem Synthesis
• Haemoglobin inside human blood=helps in oxygen transport.
• When Malaria parasite consumes this Haemoglobin=> generates “haem”.
• Malaria Parasite needs Haem for its own energy production.
• So, if we can destroy parasite’s genes responsible for haem synthesis=> then we can make a genetically attenuated parasite that might serve as a vaccine candidate for malaria.
• IISc, Bangalore working on this logic.
• Cause: drinking water with excess fluoride content.
• water with moderate level=> dental enamel becomes defective.
• water with high level fluoride=>bones in skeletal system get affected. Stiffness and pain in the joints.
• Fluorosis is a crippling disorder. Its effects are permanent and irreversible in nature. Meaning there is no cure / treatment
• Permissible fluoride limit, as per BIS is 1 ppm in drinking water. But At least 19 States have been identified with fluoride in water level above the safe limit.
• Concerned at increasing cases of fluorosis, the Union government has asked the States to provide alternative source of drinking water to the people in areas with high concentration of fluorosis in groundwater.
National Programme for Prevention and Control of Fluorosis (NPPCF)
WHO? Ministry of Health and Family Welfare (AND NOT Ministry of Drinking water)
WHEN? 11th FYP
WHERE 100 districts in 17 affected states
WHAT? Support provided for: 1 district lab with staff, carry out water and urine samples, + awareness.
• Iodised salt=essential to prevent mental retardation and goitre.
• National Policy of Universal Salt Iodisation (1986) = recommends Iodine should be mixed in salt for 15 parts per million.
• But in Chhattisgarh alone 70 per cent public doesn’t get access to iodised salt.
Success in Madhya Pradesh
• Anjha Chula (community kitchen), a state-wide joint feeding programme
• It converges two existing national programmes, 1) Supplementary Nutrition Programme of the Integrated Child Development Services and 2) Midday Meal Scheme
• Meals served at anganwadi centres and schools are prepared in a common kitchen, by trained staff, and iodised salt is used.
Two Types of Headaches
More common among patients less
1. Migraine is the commonest cause of all primary headaches
2. Migraine is a chronic disease, meaning you’ve to deal with for years.
3. Migraines are genetically inherited.
4. Migraine attacks are often linked to a trigger (unavoidable external conditions such as heat, sunlight or sweat)
• Aspergillus= one type of Fungus
• Aspergillosis=disease caused by above Fungus
• Australian researchers found it to be deadly in cats, dogs and men. + Common antifungal drugs failed to kill this fungus, hence more dangerous.
• In 1951, Henrietta Lacks died at an American hospital due to cervical cancer.
• In that era, USA didn’t have any regulations for genetic research. So, the doctors used her biopsy sample to create HeLa Celine, without her knowledge or consent.
• Since then, these cells have been extensively used for a wide variety of biomedical research.
• They even played a part in several Nobel-Prize-winning scientific discoveries.
• Her family didn’t learn of the cells until 20 years after Lacks’ death, when scientists began using her children in research without their knowledge. Later even their medical records were released to the press and published without consent.
• But now researchers have made an agreement with her family for controlled access to the HeLa genome sequence.
• This year, H7N9 bird flu virus killed many people in China.
• Chinese authorities order the closure of poultry markets => outbreak under control.
• But Scientists fear infections may rise again in the winter. There is always a chance that virus will undergo mutation and become more dangerous.
• Hence they want to carry lab-experiment on H7N9 virus, increase its virulence in lab, and study its ability to spread between people.
1. The proposed experiments should give scientists early warning of the kinds of virus-mutations that could spark a pandemic.
2. The work will be done in high-security laboratories to minimise the risk of the modified viruses escaping and causing any damage.
3. This will help in advance research into drugs and vaccines before pandemic breakout of H7N9.
1. This could help terrorists create lethal viruses as bioweapons.
2. If virus escapes the lab because of some natural disaster (e.g. earthquake, tornado, tsunami) =massive damage to population.
2002 SARS (Severe Acute Respiratory Syndrome), appeared in China and next year exploded worldwide.
2012 Middle East Respiratory Syndrome (MERS) is viral respiratory illness first reported in Saudi Arabia in 2012. It is caused by a coronavirus called MERS-Cove
1. It is a corona virus just like SARS.
2. Like SARS, it causes severe respiratory disease.
3. Like the SARS virus, it appears to have originated in bats.
4. MERS virus has crossed from bats into an animal that humans frequently come into contact with. But which animal exactly? Was it bird/pig/goat…that is yet to be found?
5. MERS-CoV can spread through close contact with a sick person, and such transmission has occurred in families as well as in hospitals.
6. The SARS virus mutated over time and gained the ability to pass more easily from one human to another. The big worry is that the MER-CoV might do something similar.
• Scientists have succeeded in growing meat “in vitro” (=outside body, in a lab/petri-dish)
• using stem cells
• But Cost of such meat burger- 2, 50,000 euros.
Then why bother with artificially grown lab meat? Why not just eat normal meat from animals?
• Austrian scientists have grown tiny brain (called cerebral organic) in their lab
• using stem cells.
• This tiny brain has many key features of the brain in a nine-week-old human embryo.
• does not yet display all the brain regions organised in the fashion that would be found in a developing embryo.
• Since there are no blood vessels to bring oxygen and nutrients to cells deep inside=> tiny brain will not develop beyond about four millimetres in size.
1. Microcephaly= is a genetic disorder, leads to greatly reduced brain size and associated mental disabilities.
2. Earlier scientists tried to experiment on mice-brain to understand this disease but did not succeed.
3. But now with tiny brain, they can do more research on Microcephaly disorder.
4. Ultimately they’ll be able to research on more common disorders like schizophrenia or autism
• Japanese scientists has used ‘induced pluripotent stem cells’ (iPS cells) cells to produce a rudimentary human liver that could function in mice.
• iPS cells=created from normal cells, you don’t need stem cells. (Recall earlier article about Yamanaka’s stem cell research).
• Will help patients with life-threatening liver damage.
• Same principle can be used to make pancreas, kidneys and lungs in the lab.
• These lab-grown liver buds are too small in size, must be produced in vast numbers
• It’ll take yet another 10 years before such a method is ready for clinical trials in humans.
Some Canadian dentist has a tooth of late British Pop legend John Lennon- he wants to clone it.
What is Clone?
• A clone is a cell or an organism that is produced asexually from an ancestor. (=without sperm meeting egg)
• A Clone cell genetically identical to its ancestor.
• Thus the clone of Lennon, produced today, will be genetically the same John Lennon of the 70s.
Scientists chose three sheep: Molly, Polly and Polly
Polly (Black face): they removed genetic material from her egg-cell. Thus her egg remained only an empty reaction vessel.
Molly (White face): they took cells from her udder, extracted genetic material out of it, and planted in Dolly’s empty egg cell. Thus an embryo created.
Holly: they planted above embryo in Holly’s womb. Thus holly served as a surrogate mother.
Result: Dolly sheep was born. White faced, inherited the genes from Molly only. The only male DNA of Dolly came from Molly’s father’s DNA contained in her somatic cells.
• Whether Cloning of Humans should be allowed or not? => It’s a Group Discussion/Interview topic.
• But whether Cloned John Lennon will be equally good singer-musician like original John Lennon=> Answer is No.
• Because a Man does not live by body alone. What goes into the brain is interaction with the external world. Culture is not coded in our DNA. Experience, education, environment — all these matter.
Why Mitochondria important?
• Mitochondria crucial to the energy supply of cells.
• Defective Mitochondria= disrupted energy supply to muscles, heart, liver and brain.
• Mitochondrial diseases are incurable.
• In Britain alone, around one in 6,500 children is born annually with a severe mitochondrial disease like muscular dystrophy.
• Current methods can only reduce but not eliminate the risk; no treatment is available either.
Solution: mitochondrial transfer/ 3-Parent IVF
Mom: gives egg but her DNA material has defective genes for Mitochondria. So that part related to Mitochondria is removed.
Donor (female) gives DNA that has right ‘codes’ for healthy Mitochondria.
Thus, with help of genetic material from ^three people, an IVF baby is created. Embryo transferred to mother and baby is born without any disease related to mitochondria.
1. UK government is planning to allow doctors to use this technique. But some MPs are against this method citing this is also stem-cell research, you are ‘playing God’ and interfering with his creation and hence against the (Christianity) religion.
2. This research will lead to “Designer babies” for example, pick DNA of Sachin for Stamina, DNA of Bacchan for Height, Hrithik Roshan for white skin and thus assemble an embryo like assembling a mobile phone or computer.
3. Designer babies are bad because then society will be divided into two parts: those with superior looks-body thanks to genetically engineering vs. those normally born. Hitler was also trying similar thing: remove all the Jews, handicapped and gypsies and create the strong Aryan race with pure genes.
Pro Arguments for Mitochondria-Transfer:
1. Mitochondria from a healthy woman donor doesn’t affect the appearance of the baby. It merely prevents baby from getting defective mitochondria related diseases. Thus the donor-lady is not ‘third’ parent.
2. Mitochondria are the power producers of a cell and do not in any way contribute to the traits that make us humans. Hence, any fear that the latest development is a slippery slope that would lead to producing ‘designer babies’ is unfounded.
3. The inheritance of donated mitochondria, will stop with the succeeding generation if the baby is male.
• Naked mole rats live underground
• They can live for more than 30 years, almost seven times longer than normal rats.
• They are also the only mammals that do not regulate their body temperature.
• Unlike normal house rats, they’re immune to cancer.
Why in News?
• Scientists use rats to do cancer study and test various anti-cancer drugs.
• To induce cancer in a rat, the scientists expose them to gamma radiation, transplanting tumours or injecting cancer-causing agents.
• But when scientists tried these cancer-tools on naked mole rat=#epic fail, nothing happened. It didn’t develop cancer.
• Hyaluronan= a chemical found in all animals, helps to hold cells together, and controls when cells grow in number.
• Cancer= unregulated growth of cells. So hyaluronan was thought to be involved in the progression of malignant tumours.
• In Naked Mole rat, scientists found an unusually thick layer of ^this chemical.
• Thick hyaluronan might have helped increase the elasticity of the rat’s skin, allowing it to live in small tunnels underground. This trait might be helping in preventing cancer cell growth as well.
Why beneficial? This mechanism may help us find cure for cancer.
• Scientists are now interested in silver because Bacteria can’t develop resistance against silver.
• Silver – unlike most antibiotics – works in more than one way to kill bacteria.
• Now, silver is combined with conventional antibiotics to make a killer combo. First silver will weaken the bacterial cell membrane, then conventional antibiotics will attack the bacteria.
• Bacteria are broadly classified into two groups called Gram-negative and Gram-positive.
• Gram-negatives have an extra cell membrane that protects the bacteria; this means that it is much more difficult for some antibiotics, such as gentamicin and vancomycin, to penetrate the cell.
• But with added silver, even weak antibiotics can fight with such strong “gram negative” bacteria.
• It is generally believed that brain cells stop growing in adults=>as your age increases, your memory capacity decreases.
• But Sweden researchers measured the rate at which new neurons are added in the adult human brain, using Carbon dating method.
How does Carbon Dating work?
• Carbon dating makes use of an isotope, carbon-14.
• Carbon-14 is generated in the upper atmosphere when cosmic rays strike nitrogen atoms. It then finds its way into different substances.
• When scientists measure the amount of the isotope in them, they can calculate how much of it there was originally based on how quickly it is radioactively decaying.
• This number can reveal the age of the substance, too.
• Neuroplasticity = ability of the nervous system (brain) to modify its organisation in response to conditions imposed on it.
• Experiment on animals showed that increase physical exercise=increases grey matter in the brain, promotes the formation of new nerve cells, blood vessels and connections (synapses) between neurons
• Thus exercise helps improve your brain, apart from keeping obesity, type 2 diabetes, stroke and hypertension away from your body.
Mid-Day Meal Deaths and Monocrotophos
• In Chapra (Bihar) >20 kids died after eating Mid-day meal, contaminated with pesticide known as Monocrotophos.
• Monocrotophos is an organ phosphorus pesticide.
• Considered highly hazardous by FAO and World Health Organisation (WHO).
• Already banned in Australia, China, the European Union and the United States, and in many countries in Africa, Asia and Latin America.
• 2004: WHO says this pesticide must be banned. But our (bogus) government refused saying Monocrotophos pesticide = cheaper than its competitors and more effective in controlling pests.
• FAO+WHO+World Bank agree that Monocrotohpos and similar highly hazardous products should not sold in Developing countries because:
International Code of Conduct on Pesticide Management
• Adopted by FAO member- countries,
• It establishes voluntary standards of conduct for all public and private entities involved in pesticide management.
• Code states that a hazardous pesticide should be banned if risk-assessment says that given pesticide cannot be handled without unacceptable risk to humans and the environment.
• For monocrotophos, many governments have concluded that prohibition is the only effective option to prevent harm to people and environment.
• But India hasn’t done it so far.
Open Sale of TB Drugs
Total more than 8 million TB patients in the world, among them more than 2 million just living in India alone.
Through Government funded DOTs program 65% patients covered
Through private clinics remaining 35%
What is the problem?
Patients receiving treatment through private clinics= they take drugs irregularly. As a result, disease resurfaces and TB bacteria becomes more resistant to the drugs.
What is the solution?
• Gov. mulling ban on sale of TB drugs in open market
• Under the new initiative, patients going to private practitioners for treatment will get medicines free of cost from chemists but only after the doctor informs them through a dedicated call centre to be set up by the government.
Allied topic: DOTS therapy and MDR-TB.
Pioglitazone: Banned & unbanned
• Oral Antibiotic drug. Works as “insulin sensitizer”.
• Major players, such as Ranbaxy, Cipla and Sun Pharma, manufacture the drug. Market >700 crores.
• used by over 35 lakh diabetes patients across the country
• France bans this drug because it is believed to cause bladder cancer, anaemia and even heart failure.
• But drug continues to be used in the US, the UK and other countries, albeit with a warning label.
A doctor files petition to drug controller general of India (DGCI) to ban Pioglitazone after 8 cases related urinary bladder cancer were reported in the Chennai.
• Ministry bans the drugs, on advice of the Central Drugs Standard Control Organisation (CDSCO).
• But Ministry didn’t consult Drug Technical Advisory Board (DTAB).
• Indian doctors protest against the ban. Government refers the matter to Drugs Technical Advisory Board (DTAB).
• DTAB recommends lifting the ban with some conditions
Finally, ban is lifted, with following conditions
1. Drug will now be sold with a box warning (that the drug carries a significant risk of serious or even life-threatening adverse effects)
2. Doctors will also be told that pioglitazone should not be prescribed as the first line of treatment.
• Painkiller drug.
• Sold under the brand name Novalgin
• Adverse effect: decreases WBC (white blood cell count) =>fatal.
• Anlagen is banned in many countries including US, France, Nepal but the medicine continued to be sold in India as an over-the-counter drug for years.
• Anyways finally government woke up and banned It (along with diabetic drug Pioglitazone)
mild pain killer and local anaesthetic effects
Directorate of food and drugs administration
Under Drugs and Cosmetic Act, 1940.
• Because already banned in USA, the UK, the European Union, Australia, Canada, and Japan.
• This drug has potentially life-threatening effects convulsions, hypotension etc.
Is it safe to give Honey for babies?
• Honey contains spores from a certain bacteria, which find their way into honey comb from dust and soil.
• These bacterial spores have no effect on adults.
• But for children, honey can cause death/paralysis, since the immune system of infants has not matured.
• Therefore, Paediatricians around the world strictly advise against feeding honey to infants.
• But if your child is above one year, honey is perfectly safe and can even offer lasting relief from chronic cough.
What? Glycaemic index?
Food with Higher glycaemic index= bad because
• Foods with a higher glycaemic index lead to a higher rise in blood sugar levels= problem for diabetic patients.
• Even in normal person, such food causes the body to keep releasing insulin from the pancreas to process all that sugar. High insulin levels in the blood=> lead to obesity.
Honey and Healing property?
• Before the discovery of antibiotics, honey was widely used in healing
• Honey has Acidic PH=>prevents the growth of many bacteria
• Honey has hydrogen peroxide=>gives antiseptic value
• Honey has phytonutrients=> prevent colon and other cancers.
Honey and Weight loss?
• It is a myth that honey does not add fat to your body.
• Honey has just as much carbohydrates as sugar so it is best to restrict its use, especially if you’re trying to lose weight or are diabetic.
Raw vs Processed Honey?
• Raw honey (that which has been directly collected from the honey comb and has not been processed and packaged) => more effective anti-bacterial agent than the processed honey.
• When raw honey is subjected to excessive heat and preservatives during food-processing, many nutrients/compounds are lost.
• Honey is a mixture of glucose and fructose, both forms of simple sugar. And much like ordinary sugar, it is absorbed fairly quickly into your blood stream and has almost the same effect on your body.
Food additives are Poisonous
Not much relevant from exam point of view, but before you eat junk food, wafers next time, do check the labels to protect your own health:
Children like bright colour food. Therefore most baked goods (cupcakes, frosting) and fast foods (like pastas, cereals and some ready-to-mix sauces) come in eye-catching colours. Problem:
food colouring agent causes
Red#40 ADHD (attention deficit hyperactivity disorder) in children (which affects their ability to concentrate and focus).
Red#3 used as artificial colour to cherries. Causes thyroid tumours
Carmine/Cochineal extract derived from insect. Gives pinking blush to candies, fruit juices etc. While these are generally safe to consume, it can cause adverse reactions in some people.
• used as a sugar substitute in “diet” soda, ice-creams etc. but it is
• Neurotoxin (affects the brain)
• Carcinogen (has the potential to cause cancer).
used in gums and gelatine (used in jellies) .causes cancer
Monosodium glutamate (MSG) Ingredient in many a restaurant-style Chinese meal. Also found in most packaged foods, from potato chips to soups and canned meats Increases obesity, causes liver inflammation.
Sodium Nitrate/Sodium Nitrite (E 250)
used in canned pickles. Causes cancer.
• Potassium Bromide Used in baking breads. It gives a creamy white colour, and elasticity to bread. But potassium bromate is a known carcinogen, but in the US and in India, it is still legal.
• Therefore, it is better to use brown bread and ensure that you purchase a loaf that is freshly baked.
#1: Resilin, the rubber like protein
• Resilin is a rubber-like protein
• It helps dragonflies, grasshoppers and other insects to flap their wings, jump and chirp
• Resilin can stretch to three times its original length, then spring back to its initial shape without losing its elasticity.
• Scientists looking for its application in Nano springs, bio rubbers, biosensors etc.
• Scientists have modified resilin with gold nanoparticles for possible use in medical diagnostics.
#2: Animals do self-medication
Sparrows pick up used cigarette butts and place them in their nests to reduce the parasite infection affecting the eggs and baby birds in the nests!
Mongoose feeds on chota-chand plant, before fighting cobras. Thus Nepalese found out that Chota Chand is an antidote for snake bite.
Goat From observing the goats eating the coffee plant, Men found that coffee was a stimulant.
Caterpillars chew on some medicinal plants to survive longer and produce healthier eggs.
Fruit Flies lay their eggs on food with high ethanol, to ward off infection by parasites
Chimpanzees swallow whole leaves of some plants and defecate them in order to “flush” out intestinal parasites
It would thus appear that the practice of natural medicine, including Ayurveda, has its origin from the plant and animal kingdom.
• ‘Active travel’ means walking, cycling or use of public transport
• World Health Organisation (WHO) recommends active travel address the growing burden of non-communicable diseases.
• It is the biological process clearing dead cells.
• Apoptotic cells= Cells that are aging, damaged or infected and about to die,
• Immune cells (phagocytes) engulf and destroy the apoptotic cells.
• If a dying cell is not cleared it will go into a post-apoptotic stage called necrosis=> leads to inflammatory diseases like lupus in humans.
Pain Management Techniques
Steroid Injections effective for patients suffering from arthritis steroid injections greatly reduce inflammation (especially at the site of a nerve compression) and can offer great relief from tortuous knee paibut have side effects
Nerve Heating The heat is transmitted to the tip of a needle => applied directly to the paint transmitting nerves=>relieves pain and doesn’t hamper with any other body processes
• Procedure involves injecting a combo of anaesthetic + irritant, into the site of pain.
• It also stimulates natural healing processes.
• when your pain is an obvious outcome of psychological issues, anti-depressants are prescribed
• These pills will restore the chemical serotonin in your brain, a lack of which can lead to chronic pain.
• But they should be taken as a long-term course in order to be effective.
Elastic Energy and Human Shoulder
• Humans do not have any of the characteristics so essential for hunting — speed, strength, agility, claws or sharp canines to hunt down and kill a prey.
• Hence the ability to throw a spear or stone at high speed and great precision to kill/injure an animal =part of evolution.
• We can throw balls/stones/spears accurately because of the anatomical features that allow the storage of elastic energy at the shoulder.
• The human shoulder acts much like a slingshot during a throw. It stores and releases large amounts of elastic energy is stored in the stretched ligaments and tendons.
• Chimpanzees, on the other hand, do not have much mobility at the waist hence cannot throw objects at great speed.