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#51
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CatNipped wrote: I am flabergasted! I have to admit, I was taken in hook, line, and sinker! If she is doing this, then she deserves all the get well cards that were sent because someone who does that just to garner attention is indeed sick! Oh my. What a very odd thing to do. Well, purrs to her anyway, that whatever it is that's wrong in her life can be put right. ------ Krista |
#52
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In article . net,
Tanada wrote: Howard Berkowitz wrote: When I first read the description of the condition, my initial reaction was that it sounded like something with very little chance of survival. Then, I thought about some specific recent advances in brain cancer treatment, that have greatly improved the odds. People are now symptom-free from things that would have been a prompt death sentence 3-5 years ago. I was surprised that they got the results from the biopsy so quickly, but assumed that they might have been closer to the pathologist than Rob was. Perhaps it would be useful to mention a bit about how pathological exams are done, since I've had to sit on my hands waiting for cat pathology. In Clifford (RB)'s case, the specimens had to be sent to Boston for a subspecialist, but definitive tissue examination just takes time to prepare the specimen. It's a lot faster today, with various automated equipment, when I first did a manual preparation 40-some years ago, when it took a week to get the specimen to the microscope, but even with the latest methods, it still takes the better part of a day, and often 24-48 hours. The fundamental problem is that to examine a tissue sample, it has to be sliced so thinly that it's a layer of only a few cells, through which light can transmit in a microscope. From the body, tissue is too soft to be sliced with that precision, so it has to be made rigid in some way. (You don't have this problem with blood smears, Pap smears, and the like, since the specimen is essentially liquid and spread onto a slide). One method that is used to get a preliminary diagnosis, while surgery is in progress, is to fast-freeze the tissue with liquid nitrogen or dry ice, and then slice the frozen block. There is likely to be chemical processing before and after this step -- the "after" is especially important, because to make sense under the microscope, usually two or more dyes are applied, which stain different parts of the cell different colors. The problem with "frozen sections" is that the freezing can deform the shape of the cells. The good news is that it can get a sample under the microscope in minutes, and the surgeon can get an answer on what to do while the patient is still on the table. The more definitive method, which has gotten faster with automated equipment, is based on getting wax into and around the cells. Since wax won't mix with the normal water in cells, you have to replace the water with alcohol, and then the alcohol with a solvent that dissolves wax (usually xylene). With the old manual methods, you had to go slowly from 10% to 20% to 30%, etc., dilutions of alcohol, to avoid distorting the cells. New methods use a specialized microwave oven to help the replacement. After you get the xylene or other solvent into the cells, you now put it into liquid wax. Preservatives have to have been applied so the wax doesn't cook the tissue. When the wax hardens, the tissue is sliced -- the blades used are often glass or diamond, because steel is hard to make sharp enough. Now you have waxy slices that need to be stained. The stains are water soluble, so you reverse the process -- use a wax solvent to get out the wax, replace the wax solvent with alcohol, replace the alcohol with water, stain the tissue, attach it to the slide, and then put it under the microscope. So, even with the pathologist right there, it takes a fair bit of time to get the specimen ready. A good hospital has the schedule worked out so the samples get to the pathologist just when they are ready to read them. |
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