The deadliest enemies are invisible. Pollution is the
elephant in the room, we choose to ignore. An Air Quality Index (AQI)
upto 50 is considered healthy and upto 100 is satisfactory. As of 11th
November 2017, AQI in New Delhi was touching 600, Lucknow 300, Mumbai
224 and Bangalore 191.
The Lancet Commission on Pollution and Health,
published recently, has developed the concept of the ‘Pollutome’ to
classify pollutants that affect health. This is a pyramid with the tip
(Zone I) housing pollutants with well-established associations. Zone 2
has emerging but unquantified pollutants associated with common
disorders like diabetes, prematurity, autism and dementia. Zone 3 has
pollutants with still unknown health hazards such as neuro-toxicants,
endocrine disruptors, new pesticides and nano-particles. The report
quantifies disease burden, economic impacts and possible solutions to
this deeply pervasive predicament. Pollution was responsible for 9
million deaths worldwide in 2015. Pollution is thus responsible for more
deaths than a high-sodium diet (4·1 million), obesity (4·0 million),
alcohol (2·3 million), road accidents (1·4 million), or child and
maternal malnutrition (1·4 million). Pollution was also responsible for
three times as many deaths as AIDS, tuberculosis, and malaria combined,
and for nearly 15 times as many deaths due to war and all forms of
violence. The bulk of global deaths due to pollution were in India and
China. Deaths show a peak in children less than 5 years and elderly
above 60 years.
In 1952, a combination of windless conditions,
airborne pollutants and cold weather caused a severe fog to envelope the
city of London. The Great Fog resulted in more than 4000 deaths and
100,000 became seriously ill. But since then strict legislation has seen
much improvement in the air quality over London. Delhi and all large
cities in India need to learn how to clean up India’s air. (Lancet 19
October 2017)
Transgenic Stem Cells to Cure Epidermolysis Bullosa
A 7-year-old Syrian refugee suffering from severe
junctional epidermolysis bullosa is now cured of his disease – thanks to
German doctors and Italian researchers. Eighty percent of the boy’s skin
was involved in the blisters and his situation was critical. German
doctors contacted Michele De Luca, an Italian researcher who had once
used gene therapy in a single patient with the same illness. His work
had been side-railed due to bureaucratic hiccups for several years. The
German physicians sent a small sample of healthy skin to Italy. De
Luca’s team cultured the cells and using a phage inserted the normal
copy of the LAMB3 gene into the cell. They then grew sheets of
the cells in the laboratory. This was then transplanted onto his skin in
Germany. There was complete regeneration of the boy’s epidermis. The
experiment has proved that relatively few stem cells are adequate to
regenerate the entire epidermis. The child will be monitored for any
skin cancer, which is one of the major risks of gene therapy. (www.nature.com/articles/nature24487;
Scientific American 8 November 2017)
CFTR Modulators for Cystic Fibrosis
Cystic fibrosis is due to mutations in a gene which
results in dysfunctional or inadequate production of a protein – cystic
fibrosis transmenbrane conductance regulator (CFTR). This results in
abnormal chloride secretion, thick mucus, progressive lung disease and
pancreatic insufficiency. CFTR modulators are a new class of drugs. They
include potentiators, which increase function of the CFTR channels;
correctors, which improve the processing and delivery of the functional
CFTR protein to the cell surface; and production correctors, which
promote the read through of premature stop codons in the mRNA.
The NEJM has recently published two studies
evaluating the efficacy and safety of the oral CFTR modulators,
tezacaftor–ivacaftor. The studies have shown statistically lower
pulmonary exacerbations and significant improvements in lung functions
in patients on therapy. (NEJM November 10 2017)
Gene Therapy for Spinal Muscular Atrophy
In Spinal Muscular atrophy, mutations of the SMN
gene results in defective protein synthesis resulting in progressive
motor regression and finally death in early childhood. Fifteen patients
with Spinal Muscular Atrophy type 1 were infused with the adeno-associated
virus, which had been modified to carry the DNA for the SMN protein. All
patients were alive at 20 months compared to a historical control of 8%.
Two were walking and 11 were sitting unassisted, which is remarkable for
children with SMA type I.
The study opens new doors for a group of children whose outcome has
been largely bleak. (N Engl J Med. 2017;377:1713-22)