David Sinclair, PhD Profile picture
Harvard professor, father, researcher, entrepreneur. Author of Lifespan. Tweets not medical advice or endorsement. Got questions? Email on website not DMs 🙏 ✌️
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15 May
One third of homes have a cat. There are 600M globally. A study @NEJM confirms cats spread #coronavirus to each other & may spread it between family members. I’m concerned it could mix with a fatal cat coronavirus... 1/n
Some say “Well, the virus has not been proven to spread from cat to human.” As @StevenAustad has pointed out, this hasn’t been tested or disproven either. It is like saying in December 2019 that a virus in China hasn’t been proven to spread to the US. 2/n
Is no one but me concerned about viral genetic mixing & a new strain emerging from cats? Cats have their own #coronaviruses. They can cause one of the most fatal cat diseases known by destroying white blood cells (HIV-like). 3/n
Read 10 tweets
14 May
1/ Let me start by saying that this was a fantastic piece on vaccine development by @stuartathompson at @NYTimes.
2/ Having started a now public company that makes vaccines (thanks to my cofounder Darren Higgins and to @gatesfoundation), I can tell you many people don't appreciate just how long it takes to develop a drug.
3/ Vaccines often take longer. Of every drug that is picked to go into humans, less than 5% will ultimately be approved. Luckily, the outbreaks of SARS and MERS in 2004 and 2012 have given us a head start (SARS and SARS-CoV-2 are ~80 percent identical).
Read 7 tweets
14 May
Outlook for this decade: POOR
1. 85% of economic impact is caused by fear of the virus not by stay-at-home. 2. WHO says the virus may never leave, like HIV. If true, we are in serious trouble. 1/n
Let’s not ignore the likelihood that survivors “will be left with chronic kidney & heart problems”, something the pro-herd immunity folks don’t consider. If you think spending 17% of US GDP on healthcare is bad now...2/n
We have also seen that leadership matters. NZ & Australia stopped movement, enforced it & tested and traced asymptomatics. They couldn’t even buy a coffee & are now essentially covid-free. US & Britain waited, let people travel & didn’t test & trace. We see the consequences. 3/n
Read 6 tweets
11 May
Finally had time to carefully read the new preprint that claims to reverse the age of rats by 54%. I spoke to the first author & in this thread ask whether the results are believable and what if it is true? tinyurl.com/yapwdy87 1/n
The result is so literally incredible that even the first author, Prof. Steve Horvath, didn't believe it at first. I suggested he check if the rats were mixed up, but he assured me he checked their genomes. The rats weren't mixed up and the data is the data. 2/n
Being from a commercial operation called Nugenics (sounds like eugenics?) and calling the blood plasma fraction "Elixir" doesn't inspire confidence. But let's dig in...3/n
Read 24 tweets
10 May
The Festival of Dangerous Ideas live streaming now. Dr. @normanswan and I chat live at 10EST tonight, midday AEST. Free to all. festivalofdangerousideas.com ✌️ #fodi #aging #health
Will check if it’s recorded and report back.
Yep, I’ve confirmed it’s recorded and will be uploaded to YouTube. I will provide the links. Get some sleep 😴
Read 5 tweets
9 May
Important! Largest study yet on #Covid_19 fatality shows top risks:
1. Age, BY FAR the highest
2. Cancers of the blood
3. Male
4. Obesity
5. Diabetes
I will say it again: Aging is a disease & it is treatable. Yes, treatable. 1/n #healthcare tinyurl.com/yahsd3vq @bengoldacre
Striking finding: smoking makes little difference to #Covid_19 fatality, so it can’t explain bias in male deaths (What can? Hint: males age faster). 2/n
For smoking, error bar on the hazard ratio chart is close to zero, so smoking is probably not protective either, as some have speculated. tinyurl.com/y8l2qpom 3/n
Read 6 tweets
8 May
1/ There's no disagreement between scientists and doctors that vitamin D is important for the immune system, especially for people who are unable to go outside (even for a five-minute social distancing stroll), like the elderly, or during the winter for those in higher latitudes
2/ Our immune cells depend on vitamin D to function properly. When we have inadequate levels of the sunshine vitamin, our immune systems can take quite a hit. SARS-Cov-2 virus enters cells via ACE2 receptors.
3/ Viral replication downregulates ACE2 dysregulating the ​renin-angiotensin system​ and leads to a cytokine storm in the host, causing Acute Respiratory Distress Syndrome (ARDS).
Read 8 tweets
2 May
What really is remdesivir? It’s chemical delivery vehicle for the active form: a variant of the letter A in the RNA code. Remdesivir interferes with the viral RNA copying enzyme, like a bit of plastic caught in a zipper. 1/n
Here’s a scientific paper on remdesivir if you’re curious m.jbc.org/content/early/… 2/n
The mechanism of action is called “delayed RNA chain termination”. Here’s what the natural A in the RNA code normally looks like. Remdesivir’s extra arm sticking out of the hip with the nitrogen atom at its end (N) is what gums up the zipper. 3/n
Read 5 tweets
25 Apr
Not sure which is more surprising:
1. Finally a breakthrough in treating pancreatic cancer, or
2. The treatment is chloroquine.
Chloroquine is an inhibitor of autophagy, the mechanism a celll uses to clear proteins it doesn’t want. What’s novel here is what happens when you combine it with immune checkpoint inhibitors, but I couldn’t resist 😉
Autophagy is the means by which pancreatic cancer cells limit the amount of MHC class I molecules on their surface, so they can hide from the immune system. Inhibiting autophagy exposes the the cancer cells, like lifting an invisibility cloak 👍
Read 4 tweets
21 Apr
There are currently 300+ different genetic versions of #coronavirus. Here's my take on a new study that investigates if they multiply at different rates, at a way to help explain regional & individual differences in #COVID19 ... tinyurl.com/y7bgzvse
Summary: scientists from Zhejiang University studies 11 strains of SARS-CoV-2, from early in the pandemic. They identified mutations, mapped them to protein structures, tested how the #coronavirus multiplied in & killed cells, & compared to patient outcomes... 2/ #COVID19
19 of the 31 identified mutations were novel, despite the relatively early sampling dates, indicating that the true diversity of the viral strains is still largely underappreciated. That's an interesting finding right there... 3/ #COVID2019
Read 8 tweets
18 Apr
Some scientists and reporters are saying smoking might protect because you'd expect more smokers in the hospital. Come now. 17 - 46% of smokers lie to their doctors about smoking...
#COVID_19 #FactsMatter #CoronaVirusUpdate tinyurl.com/y7waua22
tinyurl.com/y9mcv9uc ...1/3
Statistics lie and so do patients. Other classic lies include:
* 43% about exercising
* 38% about not drinking alcohol
* 29% about the number of sexual partners
Studies based on questionnaires are flawed...2/3
...@US_FDA warns that smoking makes #Covid_19 symptoms worse. This isn't rocket science. If you can't breathe from #COVID and your lungs are dirty and fibrotic, what do you expect? tinyurl.com/y87p3g2w ...3/3
Read 6 tweets
18 Apr
Here’s how PCR tests work, why they are flawed, and why people are retesting positive...
First: how #Covid_19 PCR tests work. It’s 1980s tech, a kid could run one, but if you don’t care, skip down to the flaws...
1. Get a nose or lung mucus/cell sample, deeper the better.
Read 25 tweets
16 Apr
The #coronavirus is part bat & part human virus. A new study says the Frankenstein event happened well before its transmission to humans. Wait, what? Humans first infected bats?... 🦠🧍🦇🧍🐈 #COVID19 #CoronavirusPandemic
The intermediate Frankenstein #coronavirus has part human/part bat versions of the spike protein (the knobs on the outside of the virus & what #COVID19 vaccines target). Coronafrankenstein is formally called RaTG13, the name, rank & serial # of a horseshoe bat 💩 sample...
...If we gave bats #coronavirus first, then people, including scientists, should stay away from bats especially if they don't feel well. That's why, as much as I like #cats, I don't like how they can catch it from us. It's a potential vicious cycle... tinyurl.com/tsnj65g
Read 4 tweets
16 Apr
Dino prints are sometimes seen on cave roofs. How did these 4-foot wide dinosaur footprints form?

1. The dino’s walked on mud that hardened over coral debris?

2. A volcanic eruption lowered sea-level and ash covered a shallow ocean?

3. Evolution is a lie...

#Science #puzzles
1500 feet down in a French cave, the #dinosaur footprints are some of the largest known, made by titanosauriforms 167M years ago. Tracks show impressions of digits, digital pads, and claws - from a new species they name Occitanopodus gandi. #ScienceFromHome...
Dino prints have been found in cave roofs before. Here’s a famous set from Fireclay caves in Queensland, Australia. You can read @NatureNews story here tinyurl.com/yavkonc5 #facts
Read 4 tweets
15 Apr
States that didn’t lock down have low death rates. This doesn’t mean #stayathome is wrong, healthwise. AR, UT, ND, SD & WY are relatively unpopulated & behind in their time-courses. Besides, the goal is to reduce total deaths, not just the rate. Ask anyone who’s lost a loved one.
Not saying the #stayathome hasn’t been painful, especially to those who’ve lost their jobs. We need to open up ASASAP - as safely and as soon as possible! I’ve been suggesting ways to do that...
But here I’m compelled to point out flaws in reasoning, agenda- and emotion-free, which is what we scientists are trained to do...
Read 5 tweets
15 Apr
Brazilian Formula E champ @LucasdiGrassi is building much safer far-UVC sterilizers & donating them to local hospitals. On a robot they could disinfect public bathrooms, schools, shops & airports... 👏 @roborace @elonmusk @iRobot @BostonDynamics
The study @scientific reports conducted by @Columbia Medical Center showed far-UVC light destroys aerosolized H1N1 influenza particles 🦠...
Scientists have known for decades that UV light is highly effective at destroying viruses by destroying their DNA & RNA 🧬. However, its widespread use is limited because conventional UVC can cause skin cancer & cataracts...
Read 7 tweets
13 Apr
Lucretius, the first century BC Roman philosopher, said humanity’s fear of death drives irrational beliefs & actions that harm society. And as COVID-19 sweeps across the globe, his key predictions are coming true...
1. Some imagine an eternal afterlife, or an immortal soul that is more important than the body and the material world...
2. When people are afraid of dying they might think that withdrawing from others will help keep danger, disease and death away. Witness divorces up 60%...
Read 4 tweets
11 Apr
@NEJM Advisory: Blood clotting in small blood vessels is a symptom of severe #COVID_19. It can be detected by a rise in D-dimer, a protein fragment not normally in blood, but is released from degrading clots... 1/6 Blood clot
Physician guidance: Upon presentation of #Covid_19, measurements advised, in order of importance, are of D-dimer, prothrombin time, and platelet counts.@NEJM @JWatch tinyurl.com/wqzjh59 2/6
Nonsurvivors have developed disseminated intravascular coagulation (clots in small blood vessels) around day 4. Significant worsening at days 10 & 14 also reported. 3/6
Read 7 tweets
9 Apr
How does the #pandemic end & how do we prevent a deadly resurgence of #Covid_19 later in the year? Release young people back into society first, a new paper says...
Bad situations occur if there is too little #socialdistancing (upper panel) or too much, causing a second wave of deaths (lower, an extreme case). Total mortality = TM; Green curves = #infections; blue = #ICU cases...
Here’s what happens if you release under 39 year-olds first. Here, either 2/3rds are released (assuming 1/3 live with older relatives; upper panels) or ALL of them are let out (lower panels). Total deaths drop from 1.5M to 900K to 390K...
Read 7 tweets
7 Apr
/1 I received many questions from my most recent newsletter. I will do my best to answer them in this thread:

Question from Lennart:

Is it possible that statins would impact lung recovery if infected with COVID-19?
A: There is evidence the anti‐inflammatory properties of statins in the lung could help with respiratory diseases. /2.1
ncbi.nlm.nih.gov/pmc/articles/P…
A: Results from preclinical studies and observations in relevant patient populations support the protective potential of statins in ALI, paving the way now for definitive clinical trials. /2.2
ncbi.nlm.nih.gov/pmc/articles/P…
Read 44 tweets
5 Apr
Getting back to normal life will require knowing who is immune to #coronavirus and who isn't. Here's a thread on how #COVID19 tests work, how long after a #Covid_19 infection are they still valid, how to get one & what government can do to help get us back to work... 1/8
There are 2 tests for the actual #coronavirus:

1. Viral genetic material (RNA) is amplified by RT-PCR (real-time polymerase-chain-reaction). More virus, more fluorescence

2. Genetic material is read by a DNA sequencer to detect its abundance & genotype (~10 clades/types) 2/8
There's a 3rd type of RNA test being developed @mason_lab called RT-LAMP (Reverse Transcription Loop-mediated Isothermal Amplification). Advantages are simplicity, low cost, and insensitivity to contaminants from blood🩸or sputum 👄 tinyurl.com/tdsza5n 3/8
Read 8 tweets