RBCT Chapter 1456 Room temperature
Chapter 1456 Room temperature
Chapter 1456 Room temperature
Weber sat in the lab for the entire afternoon.
He spread his lab notebook on the table, next to three different brands of temperature recorders, a pH meter, a cell counting chamber, and a stack of freshly printed documents. Sunlight streamed in through the window, casting a bright spot on the table, within which tiny dust particles floated, like countless particles undergoing Brownian motion.
"Incubator temperature fluctuation record," he muttered to himself, writing the title on the first page.
For the past three hours, he recorded the incubator's actual temperature every ten minutes. The set value was 37 degrees Celsius, but the actual readings fluctuated between 36.8 and 37.3 degrees Celsius. Each time the door was opened to remove or place cells, the temperature would drop sharply to around 35 degrees Celsius, and it would take 15 minutes to return to the set value. This 15-minute exposure to low temperatures is insignificant for most cells, but for some sensitive stem cell differentiation systems, it can be a fatal disruption.
“But the temperature fluctuations were the same when we did the experiment last week.” Weber frowned and drew a curve on the paper. “If temperature is a variable, then last week’s data should also fail.”
He put down his pen, walked to the cell culture room, and opened the incubator door. Inside were petri dishes, like transparent flying saucers, neatly arranged on metal shelves. He took out his batch of stem cells and observed them under an inverted microscope.
The cells were morphologically normal, adhered well, and showed no obvious signs of contamination. However, he noticed a detail: the cell density at the edge of the culture dish appeared to be slightly higher than in the center. This indicated that the cell suspension was not sufficiently mixed during inoculation, resulting in uneven distribution.
“Cell density…” Weber muttered to himself, then suddenly remembered something, strode back to his desk, and opened his lab notebook.
上周那个“漂亮数据”的实验记录上，细胞计数那一栏写的是“1.2×10^6/ml”。而这三次失败的记录，细胞计数同样是“1.2×10^6/ml”。数字相同，但实际操作中，计数误差通常在百分之十到二十之间。如果上周的实际密度是1.0×10^6/ml，而这三次的实际密度是1.4×10^6/ml，那么细胞在接种时的状态就可能完全不同。
“No, that’s not right.” Weber shook his head. “Density differences will affect the rate of proliferation, but they won’t change the direction of differentiation. The differences between the conditioned medium group and the control group should still exist, just at different magnitudes.”
He leaned back in his chair, closed his eyes, and mentally reviewed the entire experimental procedure. From cell resuscitation to inoculation, from culture medium preparation to conditioned medium addition, from staining to flow cytometry... every step flashed through his mind like scenes from a movie.
Suddenly, a scene froze.
On the morning of the experiment last week, while he was preparing the conditioned medium, the lab's air conditioning was under repair, and the room temperature was about three degrees higher than usual. He remembers complaining about the heat and taking off his lab coat. All three repeated experiments were conducted with the air conditioning running normally, maintaining a room temperature of 23 degrees Celsius.
"Room temperature?" Weber's eyes snapped open. "Room temperature affects the temperature of the culture medium, which in turn affects the cell's stress response during the procedure?"
He immediately turned on his computer and searched for literature. A dozen minutes later, he found a paper published in *Cell Reports*, titled "Unintended Effects of Ambient Temperature on Stem Cell Fate Determination." The paper pointed out that if the culture medium temperature is below 35 degrees Celsius in the first two hours after cell seeding, a stress-related signaling pathway is activated. This pathway inhibits certain differentiation processes while enhancing the cell's self-renewal capacity.
“The first two hours…” Weber’s heart raced. Last week, the air conditioner was being repaired, and the room temperature was 26 degrees Celsius. When he was inoculating the cells, the culture medium was exposed to room temperature for a few minutes longer than usual after being taken out of the incubator. This temperature difference may have triggered the stress pathway, causing the cells to respond differently to the factors in the conditioned medium.
“But this is just a hypothesis,” Weber forced himself to calm down. In scientific research, a beautiful hypothesis is just a story if it isn’t experimentally verified. He needed to design a controlled experiment specifically to verify the variable of temperature exposure time.
He checked the time: 5:40 PM. There wasn't enough time for the validation experiment today; the cells needed to be thawed beforehand, and the culture medium needed to be prepared in advance. He saved the protocol, ready to begin early tomorrow morning.
As Weber left the laboratory, he ran into Tang Shun in the corridor.
"How's it going? Any progress?" Tang Shun asked.
“There is an assumption,” Weber explained his idea about temperature exposure time.
After listening, Tang Shun pondered for a moment: "Even if temperature exposure time is a variable, it may not be the only variable. The complexity of biological systems lies in the fact that multiple variables may interact. Temperature exposure time may interact with cell generation, serum batch, or the location of the incubator. Just because you've found one doesn't mean you've found the whole picture."
Weber nodded: "I understand, but that's how scientific research is—eliminating one by one, confirming one by one. At least now we have a direction, and we're no longer like the blind men and the elephant."
"Where is Professor Yang?" Tang Shun asked.
Weber said, "I went to the neurosurgery department this afternoon for Professor Gong's post-operative check-up. He said he'd go home for dinner tonight and come back tomorrow morning to discuss the unknown protein."
Tang Shun patted Weber on the shoulder: "If this experiment can uncover the hidden variables, your experience will be of great help to them."
Weber smiled, revealing a set of white teeth: "Thank you, I'll head back now, see you tomorrow."
When Yang Ping arrived at the neurosurgical ICU, Xu Zhiliang was making his rounds.
Teacher Gong lay on the hospital bed, his head wrapped in gauze, and connected to various monitoring lines. His eyes were open, and when he saw Yang Ping enter, his lips twitched as if he wanted to smile, but he lacked the strength and could only manage a small expression.
"Teacher Gong, how are you feeling?" Yang Ping walked to the bedside, leaned down and asked.
"It's alright..." Teacher Gong's voice was soft but clear, "It's just... I feel dizzy... and I want to sleep..."
“Dizziness is normal; there’s still some edema in the brain tissue after surgery.” Yang Ping checked his pupils; both were equal in size and round, and reacted briskly to light. He then asked him to stick out his tongue; it was centered and not deviated. “How about swallowing? Do you choke when you drink water?”
"It didn't choke me... I just... drank... a small sip..."
Yang Ping nodded and turned to Xu Zhiliang: "I've seen the postoperative CT scan, and it's very good. However, the peak period for edema after medullary surgery is 48 to 72 hours postoperatively. This is only the first day, so we can't let our guard down. The dehydration, hormone, and nerve nutrition regimens must be strictly followed, and any abnormalities must be dealt with immediately."
Xu Zhiliang nodded: "I have arranged for someone to monitor him and record his vital signs every hour. The respiratory rhythm monitoring is also on. If any abnormality occurs, the system will automatically alarm."
"Okay." Yang Ping looked at Teacher Gong again. "Teacher Gong, you should rest well and cooperate with the treatment. Your surgery was very successful, and the lesion was completely removed. You will feel better and better as the swelling subsides."
Teacher Gong blinked, indicating that she understood.
Yang Ping walked out of the ICU and stood in the corridor for a while.
"Professor!" Xu Zhiliang chased after him. "There's something... I'd like to discuss with you."
"Go on," Xu Zhiliang paused, then said, "Our neurosurgery department... recently admitted a difficult case and would like to ask you to consult on it..."
"What case?"
“A…twelve-year-old…girl, with a diffuse brainstem glioma, DIPG is being considered.” Xu Zhiliang’s voice lowered. “The family…doesn’t…want to give up, they’ve traveled all over the country, and finally came to us…here…here….”
"What is the family's attitude?" Yang Ping asked.
Xu Zhiliang said, "Shall we chat on WeChat?"
"Okay." Yang Ping nodded, then returned to the research institute.
Xu Zhiliang edited the WeChat post.
"The patient's family was very determined! They said that even if there was only a one percent chance, they would give it a try. I checked the literature and found a new experimental therapy called ONC201, which is a small molecule drug that targets the dopamine receptor D2 and has shown some effectiveness in some DIPG patients. However, it is not yet available in China and requires compassionate use procedures."
Yang Ping pondered for a moment. He knew ONC201 was a drug in clinical trials; its mechanism of action was not fully understood, but there was some early positive data. However, the compassionate use procedure was complex, the ethical review was rigorous, and the drug's efficacy was far from proven.
"Send me the medical records, I'll take a look. Also, inform the family that we'll discuss it together tomorrow afternoon, and everyone can make an assessment," Yang Ping replied.
"Okay, I'll arrange it."
Yang Ping checked the time; it was already 6:30. He hurried off work and went home.
Xiao Su's braised pork ribs are ready.
When Yang Ping pushed open the door, the kitchen was filled with a rich aroma of soy sauce, mixed with the sweet scents of star anise, cinnamon, and rock sugar. Xiao Su, wearing an apron, was stir-frying the last dish of greens, her spatula flying as the greens crackled and popped in the pan.
"You're back?" Xiao Su didn't even turn her head. "Wash your hands, dinner's ready in a minute."
Yang Ping changed his shoes, walked to the kitchen door, and gently wrapped his arms around her waist from behind. Xiao Su's belly was already quite noticeable; he could feel its rounded curve even through her apron. He placed his palm on it and felt a slight throbbing, like a small fish swimming inside her.
"I was quite active today," Yang Ping said with a smile.
"That's right, he was doing somersaults in there while I was cooking." Xiao Su nudged him gently with her elbow.
Yang Ping let go of his hand and went to the bathroom to wash his hands. He saw stubble growing on his face in the mirror; it was hard and a little prickly.
"I'll shave it tomorrow. It won't matter if I don't shave it for a few days." He muttered to himself.
The food was already set on the table.
"I went to see a post-operative patient in neurosurgery. I also came across a DIPG case and discussed it with Xu Zhiliang for a while." Yang Ping picked up a piece of pork rib; the meat was tender and the sauce was rich and flavorful. "Delicious."
Xiao Su watched him wolf down his food, her eyes smiling, but her brows furrowed slightly: "DIPG? Is that the childhood brain cancer we saw in the news last time?"
“Yes.” Yang Ping nodded. “That disease is very troublesome, but the family won’t give up. All we can do is give it our all.”
Xiao Su was silent for a while, then said, "You should also take care of yourself. There's so much going on lately, don't overwork yourself."
"Definitely." Yang Ping smiled.
After dinner, Yang Ping helped with the housework, then sat on the sofa watching TV and chatting with Xiao Su. A medical news report was on, saying that a certain country had approved a new gene therapy for treating rare diseases. Yang Ping watched for a while, found it uninteresting, turned off the TV, and went into his study.
He turned on his computer and logged into his email. Professor Green's reply had arrived, saying he fully understood his caution and agreed to hold a video conference first, with the co-corresponding authorship issue to be discussed later. The meeting was scheduled for next Thursday evening at 9 PM, which, considering the time difference, was Thursday morning in Boston.
Yang Ping replied with "OK" and then opened the DIPG medical record sent by Xu Zhiliang.
The girl, Lin Xiaoyu, is twelve years old and a second-year junior high school student at a prestigious middle school in Beijing. Three months ago, she developed symptoms of unsteady gait and facial asymmetry. An MRI at a local hospital revealed a mass in the pons. She was transferred to a top-tier hospital where a biopsy confirmed a DIPG tumor. She subsequently received standard radiotherapy, but the tumor continued to progress. Her family refused to give up and eventually came to Sanbo Hospital.
Yang Ping looked through the imaging data one by one. The latest MRI showed that the pons was significantly enlarged, with the tumor showing diffuse infiltration, indistinct borders, and almost occupying the entire cross-section of the pons. The fourth ventricle was compressed and deformed, cerebrospinal fluid circulation was obstructed, and mild hydrocephalus had already occurred.
"A typical DIPG," Yang Ping judged in his mind. He had seen this kind of imaging too many times.
He meticulously studied every detail: the tumor's signal characteristics, enhancement patterns, extent of diffusion restriction, spectral analysis...
Suddenly, his gaze fell upon a spectral analysis image. The choline peak (Cho) was significantly elevated, while the N-acetylaspartate peak (NAA) was decreased—typical signs of a malignant tumor. However, the lactate peak (Lac) was also significantly elevated, usually indicating hypoxia and necrosis within the tumor.
“Hypoxia…” Yang Ping murmured to himself. The hypoxic tumor microenvironment activates a series of adaptive signaling pathways, including the HIF-1α pathway. The activation of HIF-1α, in turn, affects tumor metabolism, angiogenesis, invasiveness, and treatment resistance.
K therapy is worth trying; theoretically, it should be very suitable for this type of tumor.
Yang Ping picked up his phone and called Lu Xiaolu. Currently, the K-therapy laboratory is one of the laboratories under Lu Xiaolu's supervision.
It would be a shame not to use ketamine in this case. Ketoconazole (K-therapy) has accumulated many cases, including diffuse brainstem gliomas. Although there are not many such cases yet, and they are all clinical trial cases, it has already proven to be effective against this type of tumor.