Ablin could not detect his antigen in semen or prostatic fluid where PSA should be easily detected. In , they purified and characterized PSA, demonstrated its presence in normal, benign, and malignant prostate tissue, and showed that it was virtually prostate specific. Later they developed an immunoassay that could be used for blood testing and performed early studies exploring its potential clinical uses in prostatic diseases. Stamey of Stanford University was that PSA is quite useful for monitoring the course of patients already known to have prostate cancer.
In , I published the first results of a study showing that the PSA test was the most accurate method of detecting prostate cancer. Moreover, PSA could detect many cancers that were missed by both the rectal exam and ultrasonography. Thus, I was the first to suggest that PSA could be used as a first-line screening test for prostate cancer. I still believe that PSA is the best cancer blood test in medicine, and certainly the best we currently have for early prostate cancer detection.
I believe that if it were used intelligently and were combined with high-quality, effective treatment, it could reduce the prostate cancer death rate by more than half.
It is situated in front of the rectum, below the bladder, and surrounds the urethra, which is the tube through which urine flows out of the body.
The main function of the chestnut-sized prostate is to secrete part of the seminal fluid that combines with sperm to form semen. A healthy adult prostate weighs around 20 to 25 grams and is approximately 4 cm wide, 3 cm high and 2 cm thick. Prostate size remains the same until half of his life around 40 years. However, urologists use volume rather than weight to characterize it. Ultrasound are used to measure this data. Shaped as a chestnut, its common size is 3 cm high and 4 cm wide.
Its common volume is 20 cm3 for around 20 grams. These data may change from one person to another. What is the normal prostate size? A small prostate has a volume of 30 ml to 40 ml and a weight of 20 g to 70 g. A medium prostate has a volume of 40 ml to 80 ml and a weight of 20 g to g. A large prostate has a volume of 40ml to ml and a weight of 40 g to g.
Around age 40, prostate gland begins to grow. This method of analysis allows scientists to identify which genes are turned on in many individual cells in a tissue at once. From these data, they were able to completely map out the cell types found in a normal mouse prostate.
With the information, they could then determine which cell types remained in the prostate after the mice received androgen-deprivation therapy, and which divided to regrow the gland when androgen was restored. From these analyses, it was clear that nearly all the luminal cells in the prostate were dividing, rather than just a subset — as would be expected if a stem cell population were mainly responsible for regenerating the gland. In addition to the mouse work, the investigators performed scRNA seq on prostate tissue taken from men who had been treated for prostate cancer.
They found a similar pattern of luminal prostate cells that had acquired the attributes of stem cells. This implies that what is true of mice may also be true of men. By that way of thinking, stem cells are a rare and special type of cell that can give rise to many cell types yet retain a proliferative capacity. But recent studies — including, now, this one — have questioned how broadly this model applies across different organs.
At least in the prostate, fully differentiated cells can become stem cells under the right conditions, this study suggests. Prior work from the Sawyers lab showed that some prostate cancer cells possess an ability to change their identity.
This is called lineage plasticity.
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