This was a shocking discovery. Sun Lien was stunned for a long time without saying anything. All he could think about was Liu Tangchun's original words, "It's just a bag of mannitol..."

That’s it? If there was a time machine, Sun Lien would definitely travel back two days and slap himself hard on the face. Mannitol is your illegitimate son? Why do you always feel that you owe it? You have to use it

?

To be fair, Sun Lien certainly could not foresee that mannitol would have any adverse effects on Tang Min's condition. It would be impossible for any doctor to foresee this. But... if he could be more cautious in handling the condition, maybe

He would not use mannitol on Tang Min.

Sun Lien was busy reprimanding himself for not being cautious enough in his heart, while Zhou Ce frowned and asked Yuan Pingan, "You mean, the inhibition of the aqp4 protein led to the progression of her disease?"

"This is a possible inference." Yuan Pingan was very cautious on this issue, "But... I have never heard that inhibition of aqp4 protein can cause disease..."

"Then according to this 'possible inference'..." Zhou Ce emphasized the pronunciation of the five words "possible inference", "Can we think that the many low-signal areas in her brain are due to aqp4 being blocked?

Caused by inhibition?”

Yuan Pingan thought about it again and again, and finally shook his head, "I can't say for sure."

The aqp4 protein is a highly sensitive aquaporin. Its role is not only to pump water molecules into glial cells. It can also pump out water molecules inside glial cells. From the analysis of this mechanism, the paper itself

The conclusion seems to be somewhat contradictory to reality - after mannitol crosses the brain-blood barrier, it creates an osmotic gradient in the brain, thereby prompting water molecules in neurons and glial cells to enter the blood vessels.

But if mannitol inhibits the expression of aqp4 protein...then what is the reason for the expanded low-signal shadow? After using the osmotic gradient to pump water molecules from the cells and inhibiting aquaporin, it actually expands the scope of edema?

"The aqp4 protein not only pumps water molecules into the interstitial cells during the acute phase of cerebral edema, but also slowly pumps out water molecules after the acute phase - you can understand this process as when a heavy rain comes, many reservoirs peak and store water.

Water." Yuan Pingan explained Zhou Ce's question in the simplest way and said, "aqp4 is the gate that quickly stores water in the reservoir, while interstitial cells are the reservoir itself - mannitol acts more like a reservoir.

The water itself evaporates, but its rate is many times stronger than that of simple solar radiation."

This metaphor is easier to understand. Sun Lien frowned and said, "So... after the reservoir evaporated rapidly, the water level actually rose?"

"It is not in line with intuitive logic, but it is consistent with the current situation." Yuan Pingan nodded, "If we only consider the reservoir, then after excluding all other possibilities, the change can only occur in the upstream water."

Sun Lien was about to continue discussing this issue, but... it seemed that because of Zhou Ce's words against Bruen, a strange idea suddenly came to his mind.

"How can you be sure that we have listed all the possibilities?" He asked in a arrogant manner, "It can't be other problems?"

"Other questions cannot explain the reason for the rising water level." Yuan Pingan glanced at Sun Lien strangely, as if the person asking the question was not the deputy leader of his diagnostic team, but a poor child with congenital dementia. "Other factors

You can’t create water molecules out of thin air, right?”

"There is an idiom called 'increase revenue and reduce expenditure'." Sun Lien shook his head and said, "Water coming from upstream is considered to increase revenue. So what if there is a problem in reducing expenditure?"

"What do you mean..." Yuan Pingan said hesitantly, while Sun Lien rushed in front of him and added, "What if this reservoir... didn't have a gate from the beginning?"

"She did not have any problem after the aqp4 protein was inhibited. She was born with insufficient expression of aqp4 protein!" At this point, Sun Lien finally made his own diagnosis for the first time. Although there was not enough evidence, he

Intuitively, I think this possibility is very high, "That's why mannitol can cause such obvious changes!"

·

·

·

Tang Min's condition can be said to be very complicated, but if the concept of insufficient aqp4 protein expression is introduced, all problems suddenly have a common solution.

Why was her first symptom a decrease in vision? Because the aqp4 protein is most distributed in the optic nerve, and the optic nerve is also the most sensitive to the interstitium and synapses. The expression of aqp4 protein is insufficient, and the water content in the optic nerve rises rapidly, so it appears.

symptom.

Why did she later develop hydrocephalus that was difficult to correct? Because the expression of aqp4 protein was insufficient, it was difficult for the interstitial cells in the brain to regulate water content. However, due to the large number of members of the aqp protein family, other aqp proteins compensated for the loss of aqp4 protein to a certain extent.

Effect. Therefore, only refractory hydrocephalus and mild microscopic interstitial cell edema occurred.

Why were her other neurological functions not affected much after hydrocephalus appeared? Because the low expression of aqp4 protein inhibited the occurrence of cytotoxic edema - the interstitial cells could not play the role of water storage, and other nerves could not

In order to absorb excess water, she suffered a brain herniation, but did not damage much neurological function. But at the same time, she also developed unexplained and stubborn increase in intracranial pressure.

At the same time, insufficient expression of aqp4 protein may even explain the current "exacerbation of symptoms after using mannitol".

Before using mannitol, the cerebrospinal fluid and plasma osmotic pressures in the human body are completely consistent. After using mannitol, the plasma osmotic pressure in the human body will rise rapidly, resulting in the physical phenomenon of water transfer from cerebrospinal fluid (brain tissue) to plasma.

This phenomenon often rebounds quickly after stopping the use of mannitol - the plasma osmotic pressure quickly returns to its original value after stopping the use of mannitol, while the cerebrospinal fluid osmotic pressure will inevitably increase due to water loss. Sometimes the cerebrospinal fluid osmotic pressure will even occur

The reverse osmotic pressure gradient is greater than the plasma osmotic pressure.

Because mannitol inhibits aqp4 protein expression, and Tang Min herself is in a state of insufficient aqp4 protein expression, her body cannot balance the pressure difference between cerebrospinal fluid and plasma through this specific water channel system. This leads to

The current situation of "After using mannitol, the area of ​​intracranial edema expands".

"So...these low-signal areas are indeed edema. And Tang Min's problem is not a tumor or an autoimmune disease. There is something wrong with her genes." Sun Lien concluded, "She is not completely unable to produce aqp4 protein, but
Chapter completed!