Talk:Collaboration:Shriner

Reviewers' comments from the 1st stage of selection were:

1. How does this extend beyond what you have already done?

2. Please discuss how this study will affect human health.

These are quite important questions.

1. More shot-term, direct impact on clinical setting;

I will list up a few example, out of so many.

In the field of cardiac surgery, there are two famous operations; Maze Operation for atrial fibrillation, and Batista Operation for dilated myopathy. Both operations are about dissecting out some unnecessary/harmful portion of the heart either to improve the cardiac output, or to treat arrhythmia. Both operations are, however, extremely difficult and requires skill, especially when we try to evaluate where to dissect. Clearly, no one wants to remove too much of the healthy part of the heart. So, question has always been, how one can distinguish the normal portion and abnormal portion?

If one can somehow "see" the focus of arrhythmia, it becomes so much easier to determine which portion to cut out by Maze Operation, based on such information. If one can visualize which part of the left ventricle has poor contractility, has more fibrosis than other parts, or has poor shedding of blood vessels due to such fibrotic changes, it becomes easier for one to decide the dissection area.

In the experimental setting, we are already at the stage we are, on the regular basis, observing calcium waves in detail, measuring practically all the different parameters of microcirculation, movement of the myofibers, detailed morphology, cell death, autophagy, extent of NO production, ROS production, etc, all in the muscles of live mice.

Why not imagine these techniques all combined, might serve to improve those difficult cardiac surgery?

2. Impact in the long-term

In my idea, this grant proposal is about a completely new technology, and the potential application in the human health is virtually infinite.

The impact on the study of pathophysiology in the cardiac diseases with this new technology is enormous. This space is too small to list up all such diseases or potential experiments. However, the study of pathophysiology is more about basic science, though it is difficult not to imagine that such finding from basic pathophysiology impacting heavily on clinical science.

Very important things one have to remember are, MACRO-scopic blood flow measurement and analysis of MICRO-circulation represent completely different circulatory state. These two are, sometimes, discrepant. There will be many disease mechanisms or physiological regulation that can be very well overlooked, if one is only studying macroscopic blood flow. In vivo microscopy is thus indispensable. Secondly, we might, under the current medical technology, prefer to take biopsy from the tissue of the patients or animals and study the histology of those tissues. However, once we take the tissue out, all that is left there is structure, but not function. If functions of, let's say, microcirculation, calcium signaling, NO production, etc, were essential in the pathogenesis of some disease, histological analysis will not be covering such mechanisms no matter how beautiful slide staining one can make. Medical science will, soon in the future, will come to the stage where those "functions" play important roles in the explanation of many diseases. Such discussion goes on and on and on. The interaction between the tissue and the blood vessels, the interaction between the nerves and the blood vessels, the intercommunication between myocyte and the blood vessels, etc, etc. Those can only be studies by in vivo methodologies in the live animals. Cardiac diseases will be no exception. In vivo microscopy is one of such research tools that might fulfill these purposes.

From the second stage:

Is the technology developed for too small size of motion correction for the mouse heart, and thus unsuitable for application for big-sized heart in the human setting?

The simple correct answer after good amount of deliberation is, NO. This technology can very well cover the range of movement of the human heart beat, at least in the x-y dimension.

Well, very often, when some body for the first time hears about our motion control, he/she might, by mistake, think we are trying to motion-correct by moving the objective lens of the microscope. The truth is, we are not moving the lens, but we are moving the mirrors that send the illumination beam to the objective lens. Therefore, it is the angle of the beam, but not the lens that moves. If one can remember the basic optics, the angle at the oblective lens represents the position of the focal plane.

So, this will lead to the equation, the dynamic range of the motion-correction is a function of angle x focus distance.

We are using long-focal distance, sometimes, like >3cm. The moving range thus can be as large as >3cm. It can probably become much larger, if we design such optical light path.

Even under the current setting, this range of motion will be big enough to cover that of human heart beat.

Can't the heart movement be oblique? We seem to be only discussing the image caption in the xy plane, and thus our technology might be useless for the actual volumetric observation of the human heart?

We are already aware of such potential problem, and have been discussing this issue intensely. To overcome this problem, we are already trying to install multiple PMTs (detectors) in order to attain multi-focus confocal microscope. This new setting will be capturing multiple slices simultaneously. Once the image is captured, the computer will reconstitute the image into 3D. Thus, by using this technique, we will be able to capture obliquely aligned cells or structures in the heart.