Weekly Roundup #3: Designer Babies & Cancer Towns


This week has been a big one for major healthcare discoveries. A new Anti-TB drug on the block and a new method of IVF that could allow parents to choose the sex of their babies! Here we talk about the science behind these stories, and the impact they will have on the masses. 


CANCER TOWN

This week Cancer Alley is making headlines as, yet another person has died in the region. Geraldine Mayho passed from pneumonia last week, having spent years fighting for better environmental conditions for her fellow residents. But what is Cancer Alley and why are people talking about it?
The region of Louisiana known locally as ‘Cancer Alley’ is the states ‘chemical corridor’, home to more than 100 industrial plants. Its less than affectionate alias comes from the clusters of recorded cancer cases that have popped up in towns throughout the eighty-five mile stretch along the Mississippi river. The high concentrations of oil refining in the local plants results in unusually high concentrations of carcinogenic compounds in the air.

This would suggest higher cancer incidence, however, there have been conflicting studies of the area. A 2004 analysis of 1970-1999 census data indicating that there is no difference in mortality between Cancer Alley and the rest of Louisiana, yet a 2015 statement from the EPA suggested that there may be a 700x increase in cancer risk for residents.1,2

Despite the presently conflicting healthy implications, the area has been a proven environmental hazard, the region hosting 7 of the 10 plants with the greatest amount of waste produced. Furthermore, this week Trump has been touring a Shell petrochemical plant opening in Pennsylvania – a suggestion that Cancer Alley is set to multiply and spread.
  1.  http://www.pollutionissues.com/Br-Co/Cancer-Alley-Louisiana.html
  2.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1740760/pdf/v061p00295.pdf

DESIGNER BABIES: X VS Y

A new method has been published this week that could lead to the selection of male or female offspring. 1

Human cells contain 23 pairs of chromosomes, structures that form the blueprints that produce all living beings. In mammalian species (plus many others), including humans, the 23rd pair of chromosomes determines biological sex. A pair of ‘X’ chromosomes produces female offspring, And one ‘X’ and one ‘Y’ chromosome produces male offspring. All cells in the body contain these 23 pairs of chromosomes, except for sex cells (eggs and sperm) which instead only contain 23 single, unpaired chromatids (half-chromosomes). This means when reproduction occurs the two half chromosomes from each parent will fuse with a random combination of the parent’s genes to form an embryo. As sex cells only contain half of the chromosome-pairs, this means each sperm cell will contain either an X or a Y chromosome, thus determining whether the offspring will be biologically male or female.

The Japanese study has identified functional differences between X cells and Y cells which could allow for selection techniques to arise, consequently allowing individuals undergoing IVF to choose the sex of their children. They have identified receptors (TLR7/8) present on 50% of sperm cells. Interacting with these receptors in a process called ‘ligand activation’ resulted in the suppressed motility of X-chromosome bearing sperms. Using this difference in motility the researchers were able to use IVF to breed litters of mice pups that were over 80% male, or over 80% female (depending on sperms used).

This technology could be used in the not too far future to pre-select a child’s sex when parents undergo IVF treatment

1. https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3000398

 
NEW ANTI-TB DRUG – FIGHTING THE RESISTANCE!

A new drug has been approved by the FDA this week that treats almost 90% of patients suffering from drug-resistant tuberculosis (TB).1

The drug, Pretomanid targets extensively drug-resistant TB (XDR-TB).2 When taken as a combination drug 85% of patients in the clinical trials were successfully cured. It has been developed by a non-profit organisation called the ‘TB Alliance’, an organisation dedicated to developing more effective and cheaper anti-TB drugs.3

At present the drug is only licensed for use in patients with XDR-TB and must be taken in combination with existing drugs; bedaquiline and linezolid (broad-spectrum and potent antibiotics).1 This is to minimise the risk of further drug resistance developing by ensuring the pathogen is completely eradicated from the body.1 This is ever more essential as last year WHO estimated that there were 558,000 new TB cases worldwide that were resistant to rifampicin, the most effective first-line drug.4

This is particularly exciting news as only two other tuberculosis drugs have been granted FDA approval in 40 years! The drug has been in development for over 14 years, with preclinical testing taking place in 2005.5

This drug is vital in treating those in poverty-stricken nations, where TB is rampant. The hope is that with the new drug, fewer people will remain infected with the disease, minimising the spread and bringing us one step closer to total eradication.

  1. https://www.fda.gov/news-events/press-announcements/fda-approves-new-drug-treatment-resistant-forms-tuberculosis-affects-lungs
  2. https://www.tballiance.org/portfolio/compound/pretomanid
  3. https://www.tballiance.org/news/pretomanid-enters-FDA-review
  4. https://www.who.int/news-room/fact-sheets/detail/tuberculosis
  5. https://aac.asm.org/content/49/6/2294

That's all for this week. Feel free to write in or leave a comment if there are any stories you want to see covered in the weekly roundup. See you back here next week for another instalment of the latest healthcare news. 

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