Interesting Science This Week. Week 6

Originally posted on July 30, 2016 at my blogger site.

The basic idea of of immunization is to inject inactivated pathogens or their parts which then activates and prepares the body’s immune system to fight infection by live pathogen in future. Development of innate immunity in the body involves production of specific proteins called antibodies which will identify the pathogen during an infection. After antibody binding to the pathogen, a group of proteins called the Complement system assists in further processing and eventual clearance of the pathogen from the body.
Malaria is one of the deadliest diseases in the world inflicting greatest damage in the developing and under-developed countries. As per WHO, there were 214 million cases of malaria in 2015 resulting in 438,000 deaths. In India itself there were more than 1 million malaria cases and 287 deaths, according to the data available with National Vector Borne Disease Control Programme. In keeping with the seriousness of this disease, efforts have been going on for several years now to develop a vaccine against malaria. The efforts till now have been without much success because prospective vaccines that worked in blocking the parasite in laboratory conditions were not effective when tested in humans. But in recently published research, scientists seem to have identified the reason behind the failure of these vaccines in animal trials. It appears that the malaria pathogen, Plasmodium falciparum, exploits the immune response generated in response to the vaccine to further its infection. The pathogen uses the components of the complement system to enhance its ability to enter the red blood cells (RBC) inside which it replicates. The presence of antibodies in the blood only further enhances the exploitation of complement system by P.falciparum. It was further shown that complement deficiency in mice resulted in decreased efficacy of infection by the pathogen. These results are a very important observation that could inform the future design of strategies towards a successful development of anti-malaria vaccine.

Most people know regular exercise is required for good physical health. What is less well known is that exercise also helps with mental health. Regular exercise helps keep the brain active, improve memory and learning and helps in dealing with conditions such as depression. One of the many factors which contributes to this effect of exercise on mental health is the increased production of a protein in brain called Brain Derived Neurotrophic Factor (BDNF) after exercise. BDNF is a growth factor required for growth, maturation and upkeep of nerve cells. This protein also actively participates in the formation and maintenance of connections between nerve cells (called Synapses) which are required for learning and long-term memory. How exercise contributes to increasing the synthesis of this protein was, however, not known. A group of American researchers have addressed this missing link between exercise and mental health in a recently published report. They found that in mice exercise resulted in increased production of beta-hydroxybutyrate, a metabolite produced in the liver when fatty acids are used as energy source instead of glucose. The beta-hydroxybutyrate that reaches brain through blood activates the DNA in brain cells that codes for BDNF to be translated into protein molecules which then help with improved brain function.

The cells in our body can be divided into two types based on the number of sets of chromosomes they contain – diploid and haploid cells. Diploid cells contain two sets of chromosomes (each set contains 23 chromosomes) each derived from one of the parent. Most of the cells in our body are diploid. Only haploid cells in the body are the gametes (or the sex cells, sperm in males and egg or ova in females) that are involved in reproduction. These cells contain only one set of chromosomes. Scientists have been trying to grow these gametes in laboratories for a while now in order to better understand their biological development process. Sperms have already been cultured successfully in petridishes before. In a report published in the journal PNAS, scientists have now reported successfully growing a mature, functional ovum (egg) from mice in laboratory conditions. These lab cultured eggs, fertilized with sperm and implanted into surrogate mothers, lead to the birth of healthy mice. Apart from serving as a critical tool in studies to understand the development of ova, the technique reported in this publication can also be useful in future for treatment of female infertility.

There is a new map of brain. After more than 100 years since the publication of the first map in 1907 identifying different regions of brain to various functions, scientists have now published the new map where they have identified 97 new areas in addition to the 83 previously known using the data available from the Human Connectome Project. New York Times has published a report on this development (which you can find here). For the technically inclined, you can find the original paper published in the journal Nature here.

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