Sammy

My pinned thread of threads, primarily containing citations and explanations about neurological/ psychological sex differences, sexuality, gender dysphoria, and other academic research interests of mine:

@bwaydiva1 @ChuckIsLucky @bionicIsfuture @datadriven_tdoc Two factors contribute to the sex reversal in transgender individuals; 1) Co-occurring homosexuality, and/or 2) cross sex hormones.

@ChuckIsLucky @bionicIsfuture @datadriven_tdoc Wrongo.

HRT doesn’t make a natal male biologically female But it does give natal males more “femaleness” through biologic means. And people respond to femaleness more than they do to effeminacy.

Fun fact: On average, homosexual individuals show sex reversal in the brain. Another fun fact: Homosexual transsexuals show sex reversal in the brain. Can you see the common feature? 🤔🤔 Correlation is NOT causation…

Does anyone have access to this new paper? 😊 pubmed.ncbi.nlm.nih.gov/41832672/

Officially another year older today! 😬 There’s no way I’m 30 already Goodbye my 20s 😭😭😭

@NeuroSGS The balloons suggest it's likely to be a special day - if so, I'd like to wish you a very Happy Birthday! 🥂🍾🎉🎂💐

@LouiseGrace12 Yes, you are correct hahaha 30 today 😬 Thank you very much Louise, very nice of you 😊😊

Head-to-head comparison of brain-derived pTau217 and total pTau217 for brain amyloid and tau pathology classification pnas.org/doi/abs/10.107…

iPad reading before bed (vs printed books) caused: 1) 55% melatonin suppression 2) 1.5-hour circadian delay 3) 10 minutes longer to fall asleep 4) Less REM sleep 5) Groggier next morning

We have anti-amyloid therapies (which will get better with time). The general idea is to identify who’s at risk, and give these interventions to stop the amyloid-induced tau pathology (the main driver of cortical atrophy and cognitive decline). 25 years may be excessive for that specifically haha, but you get the idea.

@NeuroSGS @EricTopol Lifestyle changes, yes. Interventions? Do you mean medical interventions? Doesn't seem that we have those just yet.

Predicting Alzheimer's disease up to 25 years in advance of any symptoms with the p-tau217 biomarker blood test, among 2,766 women mean age 70 jamanetwork.com/journals/jaman…

@bikesalsa @EricTopol Early detection, so interventions/lifestyle changes can be applied.

@EricTopol For what purpose? I really mean this question.

@louisanicola_ Is it due to her circumference though? Women have smaller brains, on average (9-13% difference), and women experience higher rates of Alzheimer’s. Did the paper control for sex differences in dementia risk? (Apologies, I didn’t read the full paper, just curious).

New research caught my attention today. In a population study of 649 older adults, researchers found that a smaller head circumference was linked to higher odds of Alzheimer’s disease. People in the smallest head size group had about 2–3× greater risk of Alzheimer’s compared with others. Why it matters: head circumference reflects early brain development and overall brain reserve. A larger brain may provide more resilience against the damage caused by Alzheimer’s. This supports the brain reserve hypothesis: what happens early in life may influence dementia risk decades later.

Excited to share our new study using engineered immune proteins to quench inflammation in aged brains!! Congratulations to @Paloma_Negredo and team! Fantastic collaboration with several labs - Chris Garcia's lab, @rsaxton_, @theRafLab, @wysscoray, and @VilledaLab!

Using knock-in mouse models of Alzheimer’s disease, Liu et al. show that Aβ-induced loss of parenchymal border macrophages disrupts glymphatic function even before amyloid plaques form. Plaque-reducing immunotherapy fails to restore glymphatic clearance. shorturl.at/zfDg6

The breakthrough blood test p-tau 217 for risk and diagnosis of Alzheimer's disease is more accurate than total p-tau 217, in a head-to-head comparison using PET imaging pnas.org/doi/full/10.10…

@Psychgirl211 @DingsdaleJ95299 @MPSLewisham @metpoliceuk Happy to read (if I have time)

@DingsdaleJ95299 @MPSLewisham @metpoliceuk @NeuroSGS Ah, thanks xx

Hi X Are there any neuropsychologists amongst the Terven who can read over my article on Trans-Type Brain Damage (TTBD) before I post? Thanks Dr P. (Ps. I'm still waiting for my promised call back from the new OIC of my case @MPSLewisham @metpoliceuk).

New article: Authors "investigated the transcriptomic profile of the hypothalamic paraventricular nucleus in hypertensive strains and across sexes, aiming to identify novel sex-specific molecular pathways involved in the regulation of blood pressure": link.springer.com/article/10.118…

I do Alzheimer’s biofluid lab research too. GFAP and NfL are biomarkers of non-specific processes. BD-tau is more AD-specific and is still amyloid-associated and tracks N. Yes, other things can affect p-tau217, such as BMI or even time of day (diurnal variation), but it’s still the most specific biomarker we have. While it may be increased in other diseases like ALS, the new BD-ptau217 assays get rid of this confound. I don’t disagree other markers aren’t important, I’m just saying they are limited in their specificity.

I know … I had done Alzheimer’s research in labs academically and clinically …there are sub groups that still does not detect even though ptau could run side by side with the amyloid at early stages … there is a low tau group and the N group is a highly debatable group. This is why we always used GFAP and NFL

Patu 217 is an amazing Alzheimer's disease blood biomarker. But most forget the ATN network. A = amyloid pathology T = tau pathology N = neurodegeneration Some people show 1. Amyloid alone, 2. some tau alone, 3. Some both amyloid and tau, and 4. There are also cases of neurodegeneration without classic amyloid/tau patterns. That tells us from the start this isn’t a single-pathway disease. Focusing only on patu217 means you miss amyloid alone or N-type Alzheimer's pathologies. The best is a mixture of biomarkers 1. amyloid 2. ptau217 3. ptau 181 4. Gfap 5. Nfl

@Neuroscope_mp Depends what you are investigating. p-tau217 is an amyloid-associated marker, and has specificity for AD other other dementias and tauopathies. We now have even better brain-specificity with BD-ptau217

@NeuroSGS But the point is that for a complete analysis and prediction for predisposition, we need more than just one biomarker.