Category Archives: Health and Technology

The Uncalled Guests

The environment that surrounds us consists of numerous chemical substances which, in one way or the other, come in contact with us. Many a times these compounds are a potent threat to our health. When these foreign entities enter our body, they interrupt with normal physiological activities of the cells and organs, creating a ruckus inside us, ultimately, leaving behind some grave consequences for us to bear. These uncalled guests of our body are together known as Xenobiotics.

Xenobiotics are omnipresent and pervasive. They may be present in the food or fresh water (mycotoxins, flavonoids, nitrates, nitrites, nitrosamines, PCBs, PAHs, arsenic, cadmium, chlorination of water), in air that we breathe in (organic metals, particulate matter of automobile smoke, cigarette smoke) and in the household (construction material that contains formaldehyde, styrene, acrylates, vinyl chlorides, pesticides, some cosmetic products).

To define, xenobiotics are substances that are pharmacologically, endocrinologically and toxicologically active, not produced endogenously and are thus, foreign to an organism. The term has been derived from a Greek word xenos that means foreigner or a stranger and bios that means life. It was coined by Mason, et al.

Majorly exogenous in nature, these compounds like food additives, chemical entities, insecticides, pollutants, carcinogens, enter the living body via edible food stuffs, drugs or inhaled from the environment. At times, these substances may be produced endogenously as metabolites of various processes in the body and have effects similar to those of exogenous xenobiotics. E.g. Bilirubin, bile acids, steroids, eicanosides and certain fatty acids.

Their Metabolism

Xenobiotics enter our body via numerous ways as mentioned above. There is a general tendency of the body to eliminate any substance that is foreign to its environment via immunological reactions or metabolise them to be able to get them excreted from the body. Xenobiotics, too, meet the same fate once inside the living body. As soon as they enter the body plentiful of biochemical reactions start to convert them into less toxic form and ultimately to remove them from the body. Such biochemical reactions are known as Detoxification or Biotransformation reactions.

Chemically these xenobiotic compounds are water insoluble. The main purpose of the detoxification reaction is to transform them from lipophilic hydrophobic substances to lipophobic hydrophilic ones. This biotransformation makes it easier for the body to get rid of them.

The major site for detoxification is the liver wherein the hepatocytes contain myriad of enzymes to process xenobiotic entities, altering their solubility characteristics, helping in their detoxification and metabolic activation. At times the above situation may turn around and instead increase the noxiousness of the foreign substance. Such reactions are known as entoxification reactions.

The biotransformation reactions can be divided into two phases.

The phase 1 reactions work towards making the compound hydrophilic for their easy elimination by the kidneys and to limit the toxicity of these substances. Major reactions involved are oxidation, reduction and hydrolysis wherein a functional group is either exposed or introduced, like a hydroxyl or amine or sulfhydryl group that increases their solubility in polar medium and at times generate some rective intermediates act as an acting point for phase 2 reactions. The basic reaction goes as below where a hydroxyl group has been introduced into a xenobiotic compound (RH).

                               RH +O2 + NADPH + H+     →   R-OH +NADP+ H2O

The reactions are majorly catalysed by the enzyme Cytochrome P450 accompanied by other enzymes like aldehyde and alcohol dehydrogenase, deaminases, esterase, amidases, epoxide hydrolases.

The phase 2 reactions occur if phase 1 reactions are insufficient to get rid of these foreign substances or if a reactive metabolite has been generated. The metabolism involves conjugation of larger polar groups like glucuronide to further increase the solubility of the compound. The reactions are catalysed by the class of enzyme Transferases like uridine diphosphoglucuronosyl transferase (UGT), N-acetyl transferase (NAT), glutathione S-transferase (GST) and sulphotransferase (ST).

Xenobiotic_metabolism
Image source: http://www.commons.wikimedia.org

The combined action of these two phases renders a lipophobic hydrophilic substance from lipophilic hydrophobic ones that can be easily removed from the body.

How do they affect our body?

While inside the body these foreign substances when undergo metabolism produce some reactive intermediates that have a negative influence on the physiological processes ongoing in the cells. The toxicity of these metabolites can adversely affect a cell, tamper an immunological reaction or can even be carcinogenic leading to deadly cancers.

Some chemicals like polychlorinated biphenyls, styrene, butadiene, vinyl chloride, food stains based on acridine, combustion products of cigarette smoke, chemicals in car exhaust etc are potent mutagenic xenobiotic substances. These mutagens may either cause somatic mutations (changes in the DNA of somatic cells) leading to rapid cell aging or risk development of cancer; or gametic mutation (mutation in the DNA of egg or sperm) that may result in abortions Congenital disorder, sterility, cancer, and other adverse consequences.

Certain chemicals in food and tobacco like heterocyclic amines, N-nitrosamines, olefins, aflatoxin B1, etc. are potent carcinogens. The reactive intermediates alter the DNA that may lead to incessant cell division, tumour growth and eventually taking the body to mestastic stage.

Nitrosamines, chlorinated hydrocarbons, Toxoplasma gondii, Treponema pallidum, ionizing radiations have been known to have teratogenic effects (Teratogenicity is the ability of an exogenous factor to induce congenital malformations by unpleasantly affecting the embryogenic development). At times, the metabolism of xenobiotics into reactive and antigenic metabolite may have some dire consequences as these tend to alter the antigenicity that may cause certain allergic reactions or produce antibodies that can damage the cells by producing a heightened immunological response.

Their Biomonitoring

Xenobiotics are ubiquitous in nature. They are found everywhere. It is, thus, imperative to map out a strategy that would help us to monitor their presence and effect on human health. To cater the requirement biomarkers have played a role of highest importance. Biomarkers are naturally occurring molecules, gene or characteristics that help in the identification of a pathological or physiological process, disease etc.

Based on the exposure of xenobiotics, their effect on the organism and the intensity of the exposure the biomarkers can be classified into three categories. Biomarkers of exposure yields information whether the organism has been exposed to xenobiotics and their extent of exposure by measuring the DNA and protein adducts in body fluids and cells. It is followed by biomarkers of effect which help to determine the consequence of the exposure to xenobiotics on the organism by studying cytogenetic analyses and lastly, the biomarkers of susceptibility that let us measure the intensity of the effect (or response) by reviewing genetic polymorphisms.

On a concluding note

The presence of xenobiotics in nature has been marked since the embarkment of life on earth. With the establishment of the civilizations and development of society their number has only increased. Till date more than 20,000 chemical compounds have been classified as dangerous to human health. The above article has enabled to have an insight into the world of these foreign entities, their types, metabolism, effects on health and their biomonitoring. The presence and effect of these uncalled guests cannot be negated but we can be a little more careful to limit their entry into our bodily houses.

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A Cat’s Poop Coffee is the most expensive beverage across the globe.

Image result for kopi luwak

Image source: http://www.google.co.in

A cup of coffee from Coffea cherries eaten, digested and defecated by Civet Cat- is, in fact, the world’s most expensive coffee!

                                                                        AMAZED!!!

Image result
Kopi Luwak

An energizing cup of coffee from feces of this feline-like creature is the costliest one because of its unique taste, aroma , high demand and the unusual production methods. This exotic coffee has its roots from Indonesia, where these cats are known as luwaks and kopi is an Indonesian word that means coffee, hence, the name  kopi luwak.

Image result for luwak
http://www.google.co.in

 

These frugarious creatures are known to feed on the best and the ripest coffee cherries. During digestion the coffee cherries and the pulp are assimilated but not the coffee beans. The beans , that are actually coffee seeds, during the process are uniquely fermented that gives this brew its distinctive savor.

 

The exemplary and apetizing aroma of Kopi Luwak has increased its demand across the globe to an extent that a kilogram of the coffee costs a whopping Rs 20,000-25,000. To maintain the demand supply ratio the farmers have retorted to slaving practices of the civet cats in cages where they are force fed coffee beans. This farming drill has only lowered the original quality of the product alongside putting the innocent creatures to cruelty. Thus, much precautions have to be followed while landing up with this coffee cup on ones’s table.

Recently, India has also started the production of Civet Coffee. The project has been undertaken by Coorg Consolidated Commodities, in Coorg town of coffee growing state Karnataka. The luxury coffee is being sold locally under the brand name “Ainmane”.

An insight into this sumptuous coffee and its production methods have made me even more curious to sip the palatable drink and sunk into its aroma. I have already started to save money, have you?

Hike in hypertensive patients in U.S. as per new guidelines from American Heart Association and American Academy of Cardiology Task Force.

downloadBlood pressure is defined as the pressure  which the blood applies against the artery walls while flowing. It is measured using sphymomanometer or blood pressure meter in simple words.  It measures both the systolic pressure ( blood pressure when the heart beats) and the diastolic pressure (blood pressure between two heart beats i.e. when the heart is at rest). It is described as systolic pressure/diastolic pressure in millimeters of Mercury (mmHg)

For a healthy individual the normal blood pressure is 120/80 mmHg . A person is said to be suffering from hypertension  when the pressure against the walls increases i.e. both the systolic and diastolic value increases. There can several reasons behind this like smoking, drinking, obesity, high salt intake, genetic factors, etc. High blood pressure thickens and weakens the heart muscles, eventually leading to strokes, heart attacks, heart failure and other cardiac complexities. On the other hand, a person is said to be suffering from hypotension if the pressure against the walls is less than the normal i.e. both systolic and diastolic value decreases. Common causes are reduced blood volume, hemorrhage, sepsis, certain medications, abnormal hormone levels, etc. The condition leads to strokes, cardiac arrest and vital organ failures.

Recently the American Heart Association and American Academy of Cardiology Task Force have revised the high blood pressure values. Earlier, as per the guidelines released in 2003 the threshold value of  blood pressure of an individual was considered to be 130/80 mmHg. But as per the revised guidelines the threshold value has been increased to 140/90 mmHg. It has also been emphasized to measure both the white-coat hypertension (elevated blood pressure at medical settings and not at home) and the masked-hypertension ( elevated blood pressure not at medical setting but  at home).The new guidelines have also eliminated the prehypertension value ( blood pressure ranging between 120-139/80-89 mmHg).Instead, patients will now be categorized as having either Elevated (120-29 and less than 80) and Stage I Hypertension (130-39 or 80-89). Patients with blood pressure 140/90 mmHg are now being classified as Stage II Hypertension.

The new guidelines have resulted in hike in the number of  patients suffering from hypertension in the United States, with earlier statistics reading 32% people suffering from  high blood pressure as against to 46% people with similar conditions as per the latest guidelines released.

For more details click Here.

 

The Daunting Pandemic

swine-fluIn recent years several disease outbreaks like Ebola virus, Avian Influenza A virus, Middle East Respiratory Syndrome coronavirus (MERS-CoV) have paralyzed the lives of millions across the globe. The current outburst of Influenza virus A, Swine Flu has claimed and is still claiming thousands of lives along with a high morbidity rate. In the year 2009, the virus was first detected in Mexico and started intruding to other parts of the United States and gradually to the entire world. HIN1 upsurge claimed nearly 50,000 lives worldwide. Looking at the gravity of the situation the World Health Organization (WHO) has declared it a ‘pandemic. ’

In India, the situation is no better. This year the flu virus has claimed as many as 1000 lives so far. Till now a total of 22,186 cases have been registered, and the figure increases with each passing day! The situation is getting worse with each passing year as well. In current year approximately 1094 deaths and 22,196 cases have been observed as compared to 265 deaths and 1786 swine flu cases in the year 2016. The highest number of people succumbing to the deadly viral infection have been reported in Maharashtra (467), followed by Gujarat (269), Kerala (73) and Rajasthan (69). The disease is slowly gripping its roots to other parts of the nation as well.

What is Swine flu?

Swine Flu is a contagious respiratory infection caused by one of the several strains of the Influenza Virus. The virus belongs to the family Orthomyxoviridae.

These RNA viruses have a genome that is approximately 13.5 kbps in size and is segmented into 8 coding regions that code for 11 different proteins:

  1. Envelope proteins: Hemagglutinin (HA) and Neuraminidase (NA).
  2. RNA Basic Polymerase: PA, PB-1, PB1-F2, and PB-2.
  3. Matrix Proteins: M1 and M2.
  4. Non-structural Proteins: NS-1 and NS-2.

HA and NA are the major surface glycoproteins that are responsible for viral attachment, replication, and pathogenesis and thus, are the main targets for antiviral drugs. These pathogens fast mutate into new strains by re-assorting the HA and NA genes and this is the main roadblock in the treatment of flu virush1n1 virus str.jpg

Image source: www.dreamstime.com

The RNA viruses are classified into three genera based on their antigenic differences1 in their nucleoprotein and matrix protein- Influenza virus A, Influenza virus B and Influenza virus C.

Influenza virus A cause severe flu outbreaks in domestic poultry and are the most virulent human pathogens that are mainly responsible for giving rise to human influenza pandemics. They are further subdivided into different serotypes2 based on the antibody response to these viruses- H1N1 (Swine flu pandemic 2009), H1N2, H2N2, H3N2, H5N1, H7N7, H7N2, H7N3, H10N7, and H7N9.

Influenza virus B mainly infects humans but is less pathogenic than Type A. They do not result in pandemics.

Influenza virus C targets humans, dogs, and pigs but they are less common than the other types and cause mild disease.

How the virus does attacks and invades the host body?

When the virus enters the host body it attaches to the sialyl moiety3 of the target cell surface. This binding is highly specific in nature. The whole invasion process can be summarised below:

Viral particles attach to the sialyl moiety of the host cell

Viral particles then enter the host cell via the process of endocytosis4

Transcription of the viral RNA genome by RNA polymerase

m-RNA produced

m-RNA is processed into ss-RNA using host cell machinery

Assembly, maturation, production, and release of new viral progenies.

As the viral progenies are released they target other cells and this marks the onset of infection. The incubation period5 of the flu is 2-4 days.

Once the incubation period is over the symptoms begin to appear. The common signs of the diseased state are chills, fever, running nose, sore throat, body aches, nausea, vomiting, diarrhea, and fatigue.

Pigs are the main reservoir of the virus and act as an intermediate host for interspecies transmission and genetic variation. The virus strains that infect humans are different from the strains that attack the swine population. It spreads through saliva and mucus particles that are released when an infected person or pig coughs, sneezes or touching the germ-covered surface or eyes. SWINE FLU IS NOT CAUSED BY EATING PORK MEAT.

What are the possible treatments available?

The treatment regimen includes drugs that precisely inhibit progeny virion production. These drugs are Zanamivir (Relenza), Peramivir (Rapivab), Favipiravir Oseltamivir (Tamiflu). The first three drugs are administered intravenously while Tamiflu is given orally. Many times combination drug therapy is also administered for effective treatments. E.g. Favipiravir is given in addition to Oseltamivir and Zanamivir. This drug amalgam efficiently inhibits the RNA polymerase of viral particles, thus, checks viral replication.

Apart from drugs Flu vaccination is the most preferred choice for reducing the risk of contracting the disease. Flu vaccines are composed of either live attenuated6 or killed viruses. When given to the body it triggers the immune system to produce antibodies against the virus and thus, protects the host.

The traditional flu vaccines that are made are protective against two influenza virus A strains namely H1N1&H3N2 and an Influenza virus B. This is trivalent vaccine5 (Vaccine that has three different antigenic sites). The other is quadrivalent that protects against the above three vaccines and an additional Influenza virus B strain. The Flu vaccine can be administered using either a needle or a nasal spray. The flu vaccine given using a needle (Flu Shot) are made in two ways: either using viruses that are inactivated or recombinant flu vaccine. The nasal spray flu vaccine contains live attenuated viruses. Both Flu Shot and Nasal spray flu vaccine are associated with some mild and short-lasting side effects-running nose, headaches, muscle aches, soreness, swelling at the place where vaccine is given, mild fever, to name a few. But in case if the flu vaccine causes some severe problems post vaccination then it is strongly recommended to consult the doctor.

Apart from the above vaccinations and treatments, it is of utmost importance to maintain personal hygiene and always use a hand sanitizer after coughing, sneezing or touching any of the diseased animal or person.

Footnotes:

  1. Antigenic Variations is the mechanism with the help of which the pathogen alters its surface proteins to evade host immune system.
  2. Serotype is a distinct variation among different bacterial, viral species or immune cells of different individuals based on their difference in cell surface antigens.
  3. Sialyl moieties are sialic acid entities present at the terminus of the glycosylated oligosaccharide of the host cell surface.
  4. The process of taking in any matter by the living cell through membrane invagination.
  5. A period between exposure to the infection and appearance of the first symptom.
  6. Vaccines that are created by greatly reducing the virulence of the pathogen, keeping it alive.

Urinary Tract Infections and Antibiotics: Some points to seriously ponder on.

Treat-a-Urinary-Tract-Infection-Step-19

Image source :www.google.co.in/images

I would like all the women folk and young girls on the other side of the screen to read this article published in the magazine Popular Science.

UTIs are one of the common problems that we all have come across. Also, we know that in recent times the antibiotic resistance of the microbial community has dreaded the medical fraternity in some or the other way.  Research has been done that claims that antibiotics have made UTIs to treat a bit difficult. Bacteria being resistant to antibiotics do not flush out completely leading to re-occurrence of the infection, that is, the recurrent UTIs (RUTI). But anti biotic use is not only the sole reason behind RUTIs. There are other reasons too that are cited in the article. Follow the link below.

http://www.popsci.com/uti-recurrent-antibiotic-resistance#page-2

 

The Band-Aid of the Future!

band aids

Image source: MIT gallery

The Twenty First century has witnessed the so-called ‘Technology Revolution’ and that too at an enormous scale. The revolution still continues. From smart phones to smart computers to smart television sets we have now the Smart Band-Aid. The stretchy hydrogel band aid designed by the MIT engineers are the band-aids of the future.These tiny stretch can incorporate temperature sensors, LED lights, other electronics along with drug delivery channels. For more details click below.

http://www.sciencedaily.com/releases/2015/12/151207113854.htm