Science topic
Heart - Science topic
The hollow, muscular organ that maintains the circulation of the blood.
Questions related to Heart
Deep learning is at the heart of many technological advancements, yet it is often perceived as a "black box." The inability to explain how a model arrives at a decision poses ethical and technical challenges, especially in critical fields such as healthcare, finance, and automation.
What strategies can be adopted to make models more understandable and interpretable without compromising their performance? What tools exist to audit the decisions made by these systems?
Hello,
I have a basic question. I work with mouse hearts and I want to collect them to do bulk RNA-seq in the future. What is the best way to store them?
Right now it was recommended to collect them, rinse in RNA-free dH20 and store them in RNA Later in -80ºC until ready for extraction.
Should I mince them before freezing or can I just freeze them as a whole?
I want to start making sections of the SAN of the heart of mice. Anyone having experience with this? Thanks in advance!
Every organ causes disease. The diaphragm is a vital pump just as important as the heart, yet little is known about it. So, the question is why (and how) did modern medicine miss this? Sadly, this is why the SIDS mystery was a mystery. I am qualified to state this based on over 15 years' experience as a ER doctor as well as holding a Pathology Master's degree and two years of SIDS research (with three co-authored, peer-reviewed articles published). Sudden unexpected respiratory arrest from acute diaphragm failure appears to be a cause of SIDS. It is precipitated by a ventilatory workload surge on a critically fatigued diaphragm, typically from a roll to prone sleeping position or REM sleep onset (CNS inhibition of accessory respiratory muscles).


Is anyone familiar with an article in which heart is described as an organ on crossroads of sympathetic and parasympathetic innervation? It is probably a sentence from the introduction of the article. And the article has been published most probably recently. I lost that article and cannot find it nether in my folders or on web.
I am trying to extract protein from a 3mg tissue. I used 85ul ripa and used a bead homogenizer. It’s a nervous tissue. The protein concentration were satisfactory (using bca) and I proceeded with western but when I did Ponceau staining it looks less protein. Each well is having 50 ug protein.
Top blot:Well 1 next to protein ladder is my concerning tissue and well 5 too! other lanes are heart tissue.
bottom blot: the well next to protein ladder is the nervous ti other labs are heart.
The heart and nervous tissue all had same protein amounts. But I had more tissue weight wise for heart so I added ripa accordingly In those samples when I homogenized.
1- How can I improve protein extraction?
2- what ripa to tissue ratio I shall be using for small tissues?
3- Can fat contamination give me false protein concentrations using bca assay?

Hi,
I found more monocytes in the heart in treated group accoring to the FACS data. And I did qpcr to validate this result.
First I checked CCL2 (or MCP-1) and other cytokines/chemokines because CCL2 plays an important role in monocytes recruitment in many research papers. But there's no significance among different groups.
Then I found the TGFb1 gene expression level significantly increased in treated group. But I couldn't find too much information about TGFb1 inducing the infiltrating of monocytes to the heart.
Does anyone have any ideas about TGFb1 and monocytes? And what else for monocytes recruitment?
Many thanks.
Hello everyone!
I have a question about the air pollutant PM2.5 (fine particulate matter).
The question is what actually reaches the heart, for example, the elements that make up PM2.5 that may have been diluted in the blood, may have an affinity for adipose tissue and may even be excreted from the body, what actually reaches it?/????
In the identified case of familial desminopathy (T341P DES mutation in heterozygous state), the son has bradycardia, but the father did not have bradycardia. How can this fact be explained?
Hi,
I'm working on heart flow cytometry, and I use anti-mouse CCR2-BV785 (biolegend, cat150621) for staining, 20 minutes, 4 degree. But I couldn't see any CCR2+ cells. So I'm not sure if it's actually right or it's because of antibody not working. I just checked some literature and it's supposed to have more CCR2+ cells in heart failure.
Do you have any ideas?
Thank you so much.
Best,
What would be the effect of distance from CNC cum Heart on the structure and function of a particular part of the human body? Do short people have evolutionary advantages to control body parts in a better and more precise way? Explicit research can be done on this theory by comparative analysis such as the functionality of body parts concerning coordinates of origin as CNS, and short people control-coordination precision compared to tall people. (Does the evolution endorse the better footwork of Messi than Ronaldo? This could be answered too.)
As with most changes in life, there will be positive and negative impacts on society as artificial intelligence continues to transform the world we live in. How that will balance out is anyone’s guess and up for much debate and for many people to contemplate. As an optimist at heart, I believe the changes will mostly be good but could be challenging for some. Here are some of the challenges that might be faced (and we should be thinking about how to address them now) as well as several of the positive impacts artificial intelligence will have on society.
As part of my medical doctoral thesis, I am trying to improve the cryopreservation process in our laboratory. To do this, I would like to compare different glycol-based freezing media. These are used for the cryopreservation of heart tissue at -80°C and should provide good results in cryosectioning and microscopy. The following four are on the shortlist:
“Tissue-Tek O.C.T. Compound” (Sakura Finetek)
“Cryomatrix” (Thermo Fisher Scientific)
“Neg-50 Frozen Section Medium” (Richard-Allan Scientific)
“Cryo-Gel” (Electron Microscopy Sciense)
Since the possibilities for research are mostly limited to the manufacturer's specifications, I would be very pleased to receive assessments, experience reports and further information.
We've developed a concise survey focusing on atrial fibrillation management, targeting physicians directly involved in care. It adheres to ethical standards and aims to inform clinical practices and patient care strategies.
Thank you for considering our proposal. I look forward to your response.
Best regards,
Dr. Habib Khan
London Heart Rhythm Program

African literature has potential. My hero, Chinua Achebe, blessed us when he learnt the novel format from the Europeans. We should follow in his footsteps.
Hello I am researching this topic to obtain resources to write a paper at our facility to reinforce the need to have involvement with the local schools for a topic close to my heart nursing. Reaching out for resources and research others may have. Thank you, Barbara Jean
We can each look at this novel from a different angle. I think the vividness was not specific toward Africans. We all know how novelists write to bring out readers' emotions, etc.
What are the latest advancements in minimally invasive heart surgery techniques, and how do they compare in terms of patient outcomes and recovery times to traditional open-heart surgery?
As compared to male it is observed that female have lower incidence of ischemic heart disease.Is there any difference in pathophysiology of IHD in male and female.
Dear Community,
I'm currently completing my bachelor's thesis, which focuses on a topic close to my heart: Factors influencing women's career success in leadership roles.
To gather diverse insights and build a comprehensive understanding, I'm seeking the participation of female and male professionals currently employed in leadership roles. Your experiences and perspectives are invaluable to this study and can significantly contribute to enriching our understanding of this important topic.
📊 Survey Details:
- Target Audience: Female and male professionals in leadership roles
- Time Commitment: Approximately 5–7 minutes
- Language options: German and English
- Confidentiality: All responses will be anonymized and used solely for academic purposes.
👉 Link to the survey: https://www.soscisurvey.de/test402333/
Your support is immensely appreciated. Kindly consider participating and sharing this survey within your network. Together, let's shed light on the pathways to success for women in leadership roles.
Thank you so much for your time and contribution! 🙏
Dear All,
Could you tell me how to run MD simulation by any software. I have DS, VMD in hand. But I try to run 30 nsec in DS that spent 6 days, is that right? The reviewer asked me to perform this procedure in 100 nsec, however, my computer can not complete this process. Could you let me know how set up all parameters and settings to finish them. Many thanks for your help with my deep heart.
I'm searching for the right rodent model to study diabetic neuropathy in T2D, to investigate the neuropathy complications on the heart
I want to conduct haemolyis assay on mouse blood (I need 0,5 - 1 ml of blood), I know that it is generally hard to collect good sample without inducing haemolysis. As a anticoagulant do you prefer EDTA or heparin? Syrgine must be coated with anitcoagulant? And need I special tubes that are coated with anticoagulant or can I just prepare solution of anticoagulant in a tube? As I understand blood should be collected from heart or junglar vein? Do you have any recommendations?
Does anybody know how many endothelial cells are present in the heart of an adult mouse?
Can you please share one heart-touching picture ever taken or any picture that touched your heart deeply ?
Dear colleagues,
I'm genuinely excited to share with you all a teaching approach for ESP and EFL that I've been developing, which weaves together adaptive AI technology with real-world, immersive learning experiences. This approach is something close to my heart, crafted to resonate with each student's unique learning journey and professional ambitions.
At its core, it's about understanding and adapting to each learner's patterns through AI, creating a learning path that feels personal and relevant. More than just theory, this method brings language to life by simulating scenarios our students might actually encounter in their fields, making the learning process not just educational but truly practical and engaging.
Although my new approach is still at its early stages, I've incorporated interactive elements, such as virtual reality, to enrich the experience. It's not just about learning a language; it's about experiencing it in a way that sticks. The early feedback has been heartening, showing marked improvements in language proficiency and application skills.
I'm eager to embark on discussions and collaborations with any of you who are intrigued by this approach. Let's explore together how we can make language learning more effective and joyful!
Warm regards to colleagues the world over and to everyone,
Michael
Thanks to "In Vitro Culture of Epicardial Cells From Mouse Embryonic Heart", I have cultured primary epicardial cells, but after continuing to culture and passage, I found that the proliferation rate of the cells was slow. Does the cell have a requirement for growth density, or is it due to other reasons? Has anyone encountered this problem?
Thanks
What's the longest time recommended for perfusing a heart on the Langendorff?
Dear colleagues;
I hope that you're in good health. Due to the fact that we represent a main category in the world, I'd like to discuss with you an important humanitarian issue called "Palestine", The discussion is summarised in just this question:
Why are so many children being killed in Gaza and the whole world in silence?
I know that we have the biggest feature, which is humanity, because researchers without this feature will become monstrous, not human. Therefore, I'd like to ask every researcher in which world place they share with me this issue, which concerns all of humanity as a whole, and everyone who has a compassionate heart for the children who were buried in large numbers under the land of Gaza. Everyone who has a clear mind should think about why we remain silent, and at the moment when we are trying to publish a scientific article, there are laboratories, hospitals, and peaceful places being destroyed without pity or mercy.
I am waiting for your discussion to support this cause based on the spirit of humanity.
Thanks

Hello,
Can someone please provide me with some assistance? I am currently extracting RNA from human heart tissue using Omega Bio-Tek RNA kit I.
Here is a picture of some samples I did recently. Does anyone have any idea why samples C & D look like this and why I have no RIN ^e? Would anyone be willing to share the successful protocols they use also it is worth noting that the samples are already in a powder form that I achieved using liquid nitrogen to grind the tissue. Thank you!
Dear all,
I'm experiencing the presence of tiny spots on transmission electron microscopy pictures of muscles. Attached you will see 3 pictures of heart tissue in which all the structures (fibers, mitochondria, ER, ecc.) are covered with these very tiny spots. What could be?
For may years I'm always followed the same fixation/embedding protocols without any issue, but sometimes on muscle tissue I have this problem.
I will really appreciate if someone could give some advices.
Thanks!!!
Francesco



Heart disease has been the leading cause of death globally over the past 20 years. However, the number of people it kills today is greater than ever before. The number of deaths from heart disease has risen by more than 2 million since 2000, reaching nearly 9 million deaths in 2019. Heart disease now represents 16 percent of all deaths from all causes. More than half of the additional two million deaths resulting from it were concentrated in the Western Pacific region. In contrast, the European region witnessed a relative decline in heart disease, with deaths resulting from it decreasing by 15%.
Adrenal stress is the modern misunderstood syndrome that affects most of us to varying degrees. Stress, whether physical, emotional or environmental, can stimulate a cascade of hormone production by the adrenals which includes adrenaline, noradrenaline and cortisol.
Adrenaline is the most famous of the three stress hormones and acts like an ‘upper’ helping to enhance the function of all our body’s systems in order to meet the demands of stress such as circulation. Noradrenaline is the body’s modulating hormone working to keep us revved up without causing stress to our body’s systems including the heart. Cortisol is the body’s ‘downer’ working to bring the body back into its normal healthy state when it has been revved up for too long or once the stressor has gone away.
area of infarct in percentage of total ventricle area. excluding the background
Hi, I want to make a medium called BYGT. According to the paper, it consists of 1.9% Brain heart infusion, 0.5% Yeast Extract, 0.2% Glucose, and 0.1 volume of 1.0M Tris at pH8. If I want to make 500ml of this medium, where should I start? Thank you for your help in advance.
Dear researchers, I am performing heart staining with TTC. after staining, the tissue becomes hard, rough and shrinks and i am unable to take photographs. How I can avoid it?
Does anyone know the diameter (size) of mouse heart endothelial cell?
Zebrafish heart is very small, Like a pinhead. We are trying to make histology of zebrafish hearts but facing problems. organ fixation is going well but after block prep tissue is becoming fragile. Kindly help me out in paraffin embedding of zebrafish heart.
I have been following the HeartMath Institute, reading about their teachings on heart coherence, Lately, I have been reading ''Science of the Heart,'' and I am trying to find a counter-argument, to the scientific discovery that the heart communicates with the brain; But have not yet found anything questioning this discovery. Is anyone aware of an author or peer-reviewed article, etc. that I can look at to learn the opposite point of view? Such as flaws in this notion of 'heart coherence' or 'heart-mind communication.'
Thank you,
Dear all,
I'd like to know your opinion about an issue I'm facing during the isolation of adult rat cardiomyocytes (CMs).
The protocol I've been following is as follows:
- Rats are anhestetized and heparinized before heart extraction
- Langendorff perfusion of isolated heart with Krebs solution (119 mM NaCl, 4.7 mM KCl, 0.94 mM MgS04, 1.2 mM KH2PO4, 25 mM NaHCO3, 11.5 mM glucose, 1 mM CaCl2 and equilibrated to ph 7.4) until the flow is clear from blood
- Low calcium buffer perfusion of 5 minutes step (120 mM NaCl, 5.4 mM KCl, 5 mM MgSO4, 5 mM pyruvate, 20 mM glucose, 20 mM taurine, 10 mM HEPES, 12-14 mM of CaCl2, 5 mM NTA pH-balanced to 7.4)
- A solution similar to the previous one but without NTA and 200 uM CaCl2 addition and with 1 mg/mL of collagenase type II (210 units/mg) and 0.6 mg/mL hyaluronidase, perfused for about 10 minutes
The flow rate is set to 1 drop/second.
- The heart is then removed from the Langendorff system, the ventricles are separated from the atria and minced to get single cells suspension.
- The digestion is completed under the fume hood and after getting the cell pellet, the CMs are resuspended in RPMI, complemented with additional Ca2+ to reach 1.2 mM concentration, BSA (0.2 %), ascorbate (100 mM), creatine (5 mM), carnitine (2 mM), taurine (5 mM), insulin (0.1 uM) and antibiotics.
The issue I've been experiencing is that my cells look pretty good and viable but I can't detect spontaneous contraction or even when paced via field stimulation (range of 8 V).
Could someone help me or suggest some improvements in the protocol?
I'm searching for a more gentle digestion that could improve my cells contraction and I'm doubfull about the Ca2+ gradient throughtout the protocol.
Thank you in advance for the help!
Phonocardiography is an old and efficient technique for assesing the condition of the heart during cardiac cycles. Through auscultation, doctors can determine various abnormalities of the heart by listening. Is there any resources addressing the acoustic propagation of these mechanical waves through the human tissue towards the boundaries of the skin?
Hi everyone!
We isolated and sequenced our nuclei, and performed hashing prior to sequencing by combining four samples in a single batch, with each sample being stained with a different TotalSeq B hashtag antibody. I am curious whether the 10X Cloud Analysis tool can support the demultiplex Cellranger pipeline for our specific case.
Thank you for your help.
Hi all,
I need to test strains of L. monocytogenes for their potential lactic acid resistance. The idea is to introduce lactic acid at different concentrations of its undissociated form in a culture medium (e.g. Brain heart infusion), keeping the pH around 6-7, and test my strains for growth. Any suggestions on how to calculate it or how to measure it?
Thanks in advance
This week's blog post is on a subject near to my heart: psychotherapy research. In it I take a look at the "common factors" argument for why therapy works, from a two-minds perspective. https://sites.google.com/view/two-minds/blog
Hey everyone..
Would like to get your views on certain questions relating to Blood Pressure & cardiovascular physiology...
How is vascular pressure generated in the body? Is it because of the heart or the vessels?
What happens to pulse pressure when central artery stiffness rises?
Looking for a cell surface marker to identify adult mouse cardiomyocytes (from the heart, not cultures) by flow cytometry???
Hello everyone,
After the lysis step of cardiomyocyte isolation, we observed a lot of white dots (attached pic/circled) in the suspension when checking under a bright-field microscope. We wonder are those nuclei? If not, can you please help us to clarify what that is?
Thanks a lot!

I am looking for a way to digitize scanned clinical ECGs so that I can analyze time intervals. I say several MATLAB-based methods published but without the script itself. The method should be reliable of course, published, and be open source.
Can anyone give advice?
To date, there is an extensive and quite evidence-based literature on the negative impact of rock music (primarily hard rock) on the natural biorhythms of the human heart, brain and other organs. it's easy to get a list of hundreds of papers on the subject by googling keywords like rock-music and heart arrhythmia or similar.
An analysis of these publications shows that the harm of hard rock to people's health, in any case, is no less than the harm of smoking. So isn't it time to extend to heavy rock the same bans that apply to smoking in public places?
FFPE tissue sections of various murine tissues including the heart and liver, when stained using Polysciences' PSR kit (Cat# 24901), display 'blotches' or regions where there is a clear difference in the background (non-collagen) stain. Typically, PSR staining gives a straw or golden-colored background in the cytoplasm (sometimes pale pink), while collagen is very intense pink/red. I've attached an example low magnification image of a liver section we stained displaying the phenomenon I describe - non-uniformity in the background. I would love to hear if anyone else has experienced such an issue and what can be done to eliminate it. Although the collagen is stained well regardless of the background, it is visually unappealing. Thanks!

Hello everyone,
We're working on the cardiomyocyte nuclei isolation from the snap-frozen heart, and we are still facing some problems when it comes to determining if they're good/bad nuclei under brightfield microscope. Does any of you have pictures of how good nuclei should look like after isolation? And do nuclei always have to be in good round shape to be considered good? We take a look at 10x genomics pictures about good nuclei (https://kb.10xgenomics.com/hc/en-us/articles/360020348651-How-can-I-assess-the-quality-of-my-nuclei-for-Single-Cell-ATAC-or-Single-Cell-Multiome-ATAC-GEX-Sequencing-) but we see it differently every time we lyse the tissue, so we are not sure what are the real nuclei and how to evaluate whether they're good or not.
Attached is the picture we have the other day when we check the suspension under a 40x microscope, but we are not sure if the round white dot is the nuclei. Can someone please help me to verify this?
Thanks a lot!

Hello everyone,
We are planning to use this protocol for our cardiomyocyte isolation: https://www.jove.com/pdf-materials/4205/isolation-of-cardiomyocyte-nuclei-from-postmortem-tissue
I am just curious about the functions of some reagents they have in the lysis buffer. Can you please help me to clarify the function of DTT and EGTA added in the buffer?
Thank you so much!
Hello everyone,
I have heart frozen sections that I need to use for measuring necrotic core area,
Mostly I stained for Oil-red O but I found it very confusing when it comes to calculate the necrotic core area. Does anyone have any suggesting or software that can be used?
Many many thanks.
Hello everyone,
We are currently working on cardiomyocyte isolation. We follow the protocol from the previous study and their lysis buffer consisting of 0.5 mg/ml Liberase TL, DNase1 (Worthington, LK003172), and 10 mM HEPES, dissolved in 1.305 ml DMEM (Dulbecco’s Modified Eagle Medium, high glucose, GlutaMAX Supplement, pyruvate. I am curious if DMEM will suppress Liberase activity by any chance, which makes the lysis buffer not strong enough to lyse the cell and isolate the nuclei.
Thank you so much for your help!
- Concrete is the heart of civil engineers, as it plays a crucial role in binding materials properly. Nowadays construction costs are very high due to the scarcity or unavailability of natural resources. This problem can be resolved by the replacement of concrete with a different material that is not conventional in terms of required properties. From previous scientists' research, cement, sand, and metal are replaced by using different artificial materials.
- I wonder what other new materials can as binding to reduce cement or concrete?
I have taken confocal images using Second Harmonic Generation of infarcted heart samples. I would like to analyze the collagen organization using image-j. What macros are best for this?
is there anyone who have completed his research on heart beat evoked potential. can we discuss it on the base of literature? thanks,
Has anyone heard the concept "heart failure is depression of the heart"? As TMS (transcranial magnetic stimulation) gains further FDA approvals for treating depression, is anyone looking at what it can do for the heart?
If possible, through which technique and/or use which model
Hello everyone, we are working on isolating the cardiomyocyte nuclei from mouse hearts for single-cell sequencing and still facing some problems with high debris and blebbing nuclei. If anyone has experience with that, can you please help us to know which protocol you are using, I'd greatly appreciate that!
I have been doing IR model (30min- ischemia, 120min-reperfusion) and than I reocclude the LAD(at 120min) , injection of 0.5-0.8 ml of Evans blue to the jugular vain than harvesting the heart rapping it with Plastic wrap and freezing at -20 for 15min, than cutting the heart using matrix to 1-2mm slices and incubating in 1% TTC in 37 degrees for 15min with shacking. than 10% PFA for about 90 min. What am I doing wrong??? why don't I get the blue/red/white staining that people show in their papers???
Hi, is hyperammonemia associated with worse outcomes of acute myocaridal infarction yet decreased risks of coronary and/or cerebrovascular events?
Hello,
Could someone recommend me an antibody to label macrophages and M1 macrophages for an immunofluorescence on frozen heart sections ?
Thank you in advance
What are some known weaknesses in non-traditional connected devices, like internet connected IVs, pacemakers, heart monitors, etc. and how they can be exploited to the detriment of the patient?
I'm wondering if mouse heart samples need to be submerged in 15% sucrose after fixation, then 30%, or if I can put them straight into 30% overnight at 4°C. What is the reason for using a gradient and not just 30% straight away?
Note these aren't full mouse heart organs, but roughly 1/6th chunks of heart tissue.
Hi!
I am looking to establish a zebrafish model that only expresses a transgene in skin / epidermis. Not in neurons and muscles and heart cells.
Maybe someone would you be able to recommend a good promoter?
Thank you very much!
The below is a link to my thesis. I have been asked at interviews about either my philosophical or theoritical background underpinning my study but I realized my answers were never satisfactory to them. I will be very grateful if any experienced researcher(s) can help me get it once and for all so I can give a befitting answer whenever I encounter such a question. I count on your generous heart for answers. Thank you
What is the prevalence of an ischemic CVA following an ERCP to remove a gallstone from the common bile duct by endoscope, and is there an effect on the heart.
I mean where is the boundary between being alive and being dead ?
Hello All,
I need to identify the heart region and thorax region in an automated manner in an ultrasound scan image of the heart. Could anyone tell me the step by step guide to identify the regions once an input image is given. Any assistance regarding this would a great help.
Hi :D Im Juan Ignacio and this is the first time ive worked with animal cells.
Im currently establishing two cell cultures of two different types of tissue that i extracted from the same mice. One of them is a heart tissue culture that I made using the ventricles of a 14 week old mice and the other is a mesenchymal cell culture extracted from the inguinal fat of the same specimen the same day.
Heart tissue extraction protocol: https://www.jove.com/es/t/54012/isolation-culture-and-transduction-of-adult-mouse-cardiomyocytes
Mesenchymal fat tissue extraction protocol: https://www.scielo.sa.cr/scielo.php?pid=S0379-39822019000400069&script=sci_arttext
I have linked 2 pictures taken from an inverted microscope of both cultures and in both of them i can see small round bodies that are much smaller than my cells of interest. The first image is of the mesenchymal cells (red circle) at 40x and the second one is of cardiac tissue at 20X.
My concern is that these white bodies may be evidence of a yeast contamination but ive never had this sort of contamination before so im not sure if those white bodies are merely a by-product of the fact that its a primary culture. Both cultures are 1 week old and ive changed the media of both of them twice. Any sort of feedback is greatly appreciated, a big thank you beforehand.
-Juan Ignacio Garro Rodriguez
I studied the gene expression (PCR test) and the protein level (ELISA) of collagen type I in heart tissues. In PCR, I found a difference between the study groups in the expression of collagen gene but in ELISA, no difference has been detected. What is the justification of this difference between the findings for the same marker ?