This year the Nobel Prize in Medicine goes to a
Japanese scientist Yoshinori Ohsumi for his work on the process of
autophagy in the cell. Autophagy – meaning eating one self – is a
process developed in cells to recycle degraded proteins and organelles.
It may be an evolutionary tool to deal with starvation to conserve
nutrients, but is now considered a method to maintain cellular health,
resist infection and fight cancer. The organelle which degrades cellular
constituents had been discovered in the 1950’s. However, further
research into this mysterious organelle remained at a standstill when in
1990’s, Ohsumi decided to further study how exactly this happens because
"nobody else was studying it."
He conducted a series of experiments in yeast cells
which elegantly delineated the process of autophagy. First, he induced
autophagy by exposing the yeast to starvation. He then carried out a
series of experiments to disrupt the process. On studying it
microscopically, he observed that the yeast cell was full of small
vacuoles that had not been degraded. Ohsumi exposed the yeast cells to a
chemical that randomly introduced mutations in many genes, and then he
induced autophagy. Within a year, he had identified several of the genes
that played a role in autophagy. The results showed that autophagy is
controlled by a cascade of proteins and protein complexes, each
regulating a distinct stage of autophagosome initiation and formation.
Autophagy is the cells’ rapid response to provide
fuel for energy and aminoacids for renewal of cellular components.
Autophagy can eliminate invading intracellular organisms, and is vital
for embryo development and the negative consequences of aging. Disrupted
autophagy has been linked to Parkinson’s disease, type 2 diabetes,
cancer and other disorders of aging. An attempt is now being made to
develop drugs that can target autophagy in various diseases. (https://www.nobelprize.org/nobel_prizes/medicine/laureates/2016/press.html)
Nobel Prize for Chemistry 2016
This year’s Nobel Prize for Chemistry goes to three
men who have smashed open our window of imagination at nano level. Jean
Pierre Sauvage from the University of Strasboug, France developed the
first molecular machine. He linked two ring-shaped molecules to form a
chain called a catenane. What was simply marvelous was that one ring of
the molecule could freely move around the other.
In 1991, Sir J Fraser Stoddart from Northwestern
University, USA studied this phenomenon further. He threaded the
molecular ring onto a thin molecular axle. The ring remained around this
axle because the two components had complementary electron groups that
kept them together yet loose enough to move. When Stoddart added heat –
exciting the electrons on various segments of the axle – the ring slid
up and down. This type of control set the stage for devices, including a
molecular elevator, going up and down, and a molecular muscle that can
expand and contract.
Bernard Ferringa, from the Netherlands, added energy
to create spinning motions, essential for a true motor. In 1999, he got
a molecular rotor blade to spin in one direction, overcoming the basic
random movements of molecules. By 2014 he had this motor spinning at
12,000 revolutions per second. He also has used motors to spin a glass
cylinder that is 10,000 times bigger than the motor itself. And his team
has linked several motors and axles to create a four-wheel-drive "nanocar."
The molecular motors are being compared to the
electric motors of the 1830’s. Scientists then were happily
experimenting with spinning cranks and wheels little imagining that
these would evolve into the washing machines and sophisticated vehicles
of the future. (https://www.nobelprize.org/nobel_prizes/chemistry/laureates/2016/press.html)
The Delhi Neonatal Infection Study
The data from Delhi Neonatal Infection Study (DeNIS)
collaboration published in The Lancet this October has brought the
spotlight onto one of the major scourges haunting pediatricians in
India. Neonates born in one of three tertiary care centers in Delhi,
India, and subsequently admitted to the intensive care unit, were
followed up daily until discharge or death. Of 88 636 livebirths
enrolled between July 18, 2011 and Feb 28, 2014, the incidence of total
sepsis was 14·3%. Nearly two-thirds of total episodes occurred at or
before 72 h of life. Acinetobacter, Klebsiella and E
Coli accounted for 64% of the isolates. Multidrug resistance was
observed in 82% isolates of Acinetobacter. Nearly a quarter of
the deaths were attributable to sepsis. The high rate of early onset
sepsis and the apparent dominance of so-called nosocomial-type pathogens
in early-onset sepsis could possibly be due to ultra-early horizontal
transmission from delivery rooms and NICUs or vertical transmission from
the maternal genital tract colonized with these pathogens after
unhygienic personal and obstetric practices.
We are pushing institutional deliveries without considering the
significant risks of nosocomial infections. The problem is complex and
needs urgent attention. (Lancet Glob Health. 2016;4:e752–60)