Leo Valentín, MD

Médico. JD. Política pública.
Endovascular radiology @harvardmed
Por una salud accesible, libertad económica y un mejor futuro para Puerto Rico.

[Eric Topol @EricTopol]

The danger of e-scooters (ES). Injuries that are worse than motorcyclists (MC) and bicyclists (PC)
Excess vs MC: traumatic brain injury, vascular trauma, internal organ injury
Excess vs PC: Traumatic brain injury
https://t.co/3DCgGIuzLq

[Leo Valentín, MD @drleovalentin]

@EndWokeness insane 🔥

[NEJM @NEJM]

𝗜𝗺𝗺𝘂𝗻𝗼𝗽𝗮𝘁𝗵𝗼𝗴𝗲𝗻𝗲𝘀𝗶𝘀 𝗼𝗳 𝗛𝗲𝗽𝗮𝗿𝗶𝗻-𝗜𝗻𝗱𝘂𝗰𝗲𝗱 𝗧𝗵𝗿𝗼𝗺𝗯𝗼𝗰𝘆𝘁𝗼𝗽𝗲𝗻𝗶𝗮 (𝗛𝗜𝗧)

The pathogenesis of HIT is summarized in the figure. Platelet factor 4 (PF4) undergoes conformational changes when binding to polyanions, thereby expressing neoantigens. The rapid formation (approximately 5 days after an immunizing heparin exposure) of anti–PF4–heparin antibodies of IgG class to these neoantigens — even in a patient who has never previously received heparin — suggests presensitization, perhaps through exposure to PF4 bound to polyanions on bacteria. Many healthy persons have natural, polyreactive IgM antibodies that recognize PF4–heparin complexes and bind complement factor C3. The PF4–heparin–natural IgM–C3 complexes bind to nearly all B cells at their complement receptors. This action stimulates preexisting B cells bearing the cognate anti–PF4–polyanion receptor, which results in production of anti–PF4–polyanion antibodies of IgG, IgA, and IgM classes, in various combinations, but only a subset of IgG anti-PF4 antibodies induce the platelet activation that is responsible for development of clinically evident thrombocytopenia and thrombosis (iceberg model). Some of these pathogenic HIT antibodies are monoclonal.

Learn more about HIT and other anti–platelet factor 4 disorders in the Review Article “Platelet-Activating Anti–Platelet Factor 4 Disorders” by Theodore E. Warkentin, MD, and Andreas Greinacher, MD: https://t.co/5mnvrPal1Z

[Leo Valentín, MD @drleovalentin]

@phil_mcalister This analysis is excellent. This supposed project will soon be exposed as the blatant, large-scale demagoguery it truly is…and in the end, it will be a great educational example for generations to come.

[Leo Valentín, MD @drleovalentin]

Jefferson Health sues Independence Blue Cross over nearly $100M in disputed payments https://t.co/Of3vEpqE2t #

[Leo Valentín, MD @drleovalentin]

@elonmusk @Deancain best part of the interview

[Leo Valentín, MD @drleovalentin]

@muskonomy excellent! best part

[Leo Valentín, MD @drleovalentin]

@maguyar83 hermoso 🥹🫡💪🇦🇷

[Leo Valentín, MD @drleovalentin]

@Castro1021 what song was in this clip? it was the best one by far!

[Adam Friedland @AdamFriedland]

I just keep watching over and over

[Eric Topol @EricTopol]

We stress tested many frontier AI models for multimodal medical reasoning (including GPT-5, Claude 3.5, Gemini 2.5 Pro). They’re not ready. Faulty reasoning, use of inappropriate shortcuts, hallucinations. Published today @NatureMedicine https://t.co/P6eHZEmfbW

[Bambulu @Bqmbulu]

“If you haven't read hundreds of books, you are functionally illiterate, and you will be incompetent, because your personal experiences alone aren't broad enough to sustain you.”

— James N. Mattis

[DogeDesigner @cb_doge]

BREAKING: Starlink will help power emergency communications across all 78 Puerto Rico municipalities.

• Announced by Puerto Rico Governor Jenniffer González Colón

• Puerto Rico will equip emergency management offices with Starlink satellite internet.

• Starlink will donate satellite antennas to Puerto Rico’s emergency management bureau

• The deployment will cover all 78 municipalities

• Designed to keep communications online during hurricanes, disasters, and emergencies

• Provides backup internet when cellular and fiber networks fail

• Helps emergency responders coordinate rescue and recovery efforts during outages

This is why Starlink matters: internet when everything else goes down.

[Aaron Ng @localghost]

History forgets fast.

The creators of the MRI got rejected by the NIH for a grant. Then their paper got rejected by Nature. The company they worked for thought it was a waste of time to even draft the patent documents.

Took 15 years from there to become clinically useful.

[Matt Devitt @MattDevittWX]

SAHARAN DUST: Multiple plumes ahead over the next 10 days across the Caribbean and even into the United States. 'Tis the dusty season!

[Eric Topol @EricTopol]

If you want to know a lot about a person's brain health, it's embedded in a retina photo, deciphered by AI
https://t.co/3xN8k8R6CX @LancetDigitalH

[Leo Valentín, MD @drleovalentin]

De una fístula perforada a una reparación endovascular completa.

Este paciente en hemodiálisis presentó una ruptura tipo “blowout” en un sitio de punción de su fístula arteriovenosa.

Mediante una fistulografía detallada, identificamos las estructuras críticas que debíamos preservar y definimos con precisión el segmento que necesitábamos cubrir.

La selección y colocación de un stent cubierto permitió sellar la ruptura, preservar el flujo y mantener funcional este acceso vascular vital, todo mediante un abordaje endovascular.

Un agradecimiento especial a Carol Pedraza, representante de Bard, por su valiosa colaboración en la selección del tamaño adecuado del dispositivo para este paciente.

#AccesoVascular #FístulaArteriovenosa #Hemodiálisis #CirugíaVascular #TerapiaEndovascular #Endovascular #VascularSurgery

[OpenEvidence @EvidenceOpen]

Rigorous evaluation of medical AI is good for everyone, and we welcome it. Counter to a half-dozen independent studies from institutions such as the Mayo Clinic that were highly positive on OpenEvidence—a lone paper now purports to show that generalized AI beats specialized clinical AI (@UpToDate, @EvidenceOpen). The paper has a massive undisclosed conflict of interest and irredeemable methodological flaws.

Behind the scenes: The study authors run a competing in-house medical AI at their hospital, and asked OpenEvidence for an API to power it — including rights to build a "competing product" with OpenEvidence's own API. OpenEvidence declined. Then, this paper coincidentally appeared.

Point-by-point, looking closely at the datasets used in the study, the disingenuous and fatal flaws become immediately apparent 🧵.

[The Associated Press @AP]

BREAKING: A new outbreak of the highly contagious Ebola virus has been confirmed in Congo’s eastern Ituri province, Africa’s top public health body said. There have been 246 suspected cases and 65 deaths recorded so far. https://t.co/pfH5dhDyvK

[Leo Valentín, MD @drleovalentin]

Hospital demanda en foro federal a ASES por disparidad en reembolsos https://t.co/9iS7gRlSXv