Joint Lubrication Aided by Flexing

Joint Cartilage Gets Slippery During Flex Time describes how the production of molecules, which lubricate and protect joints, is induced by shear forces on cartilage. The molecule is proteoglycan 4 and it is chondrocyte cells that produce it. Proteoglycan is a glycoprotein i.e. a protein with a carbohydrate attachment. It is found in connective tissue throughout the body. There are different forms of proteoglycan. Some provide rigidity to cartilage but proteoglycan-4 has a lubrication function. It is primarily secreted into joint fluid.

To quote the article "Sah’s team attached bovine stifle joints, which are similar to human knee joints, to a bio-reactor that provided continuous irrigation with sterile nutritional fluids under normal physiological conditions. Immobile joints were compared to joints that were flexed 24 hours in a way that mimicked walking motions. The flexing was provided by a specially designed continuous passive motion device."

Results showed a direct relationship between proteoglycan 4 production and the amount of shear forces created by opposing bones sliding against each other. Much sliding led to greater production. Immobility was linked to less production. An intermediate amount of sliding caused intermediate production levels.

It is hoped that researchers will be able to generate proteoglycan 4 in a lab by stimulating chondrocytes in cartilage tissue; smooth, well-lubricated cartilage surface being the goal.

The Birth of Christ According to a Physician

On this Christmas day tribute is paid to Luke who is one of the four Gospel writers and was a physician by trade. He authored this account of the birth of Christ:

(Second Chapter NASB)

4Joseph also went up from Galilee, from the city of Nazareth, to Judea, to the city of David which is called Bethlehem, because he was of the house and family of David,

5in order to register along with Mary, who was engaged to him, and was with child.

6While they were there, the days were completed for her to give birth.

7And she gave birth to her firstborn son; and she wrapped Him in cloths, and laid Him in a manger, because there was no room for them in the inn.

8In the same region there were some shepherds staying out in the fields and keeping watch over their flock by night.

9And an angel of the Lord suddenly stood before them, and the glory of the Lord shone around them; and they were terribly frightened.

10But the angel said to them, "Do not be afraid; for behold, I bring you good news of great joy which will be for all the people;

11for today in the city of David there has been born for you a Savior, who is Christ the Lord.

12"This will be a sign for you: you will find a baby wrapped in cloths and lying in a manger."

13And suddenly there appeared with the angel a multitude of the heavenly host praising God and saying,

14"Glory to God in the highest,
And on earth peace among men with whom He is pleased."

15When the angels had gone away from them into heaven, the shepherds began saying to one another, "Let us go straight to Bethlehem then, and see this thing that has happened which the Lord has made known to us."

16So they came in a hurry and found their way to Mary and Joseph, and the baby as He lay in the manger.

17When they had seen this, they made known the statement which had been told them about this Child.

18And all who heard it wondered at the things which were told them by the shepherds.

19But Mary treasured all these things, pondering them in her heart.

20The shepherds went back, glorifying and praising God for all that they had heard and seen, just as had been told them.


Henry Morris, Ph.D. authored an article entitled Doctor Luke which provides some details about this first century physician. From the article:

Only Luke is with me . . .--�? (II Timothy 4:11).

Luke—the author of the third Gospel and the book of Acts—is of special interest for several reasons. He was the only Gentile who wrote any of the books of the Bible. Furthermore, he was the only scientist among the writers.

He is also recognized as a great historian, with his excellent accounts of the key events of the most important era in the history of the world. He also was undoubtedly a devoted Christian, a truth especially demonstrated by his unselfish service and companionship to the apostle Paul. Finally, he was probably the first Christian apologist, zealously concerned to defend and establish the absolute truth of the gospel of Christ.

Luke As Scientist and Medical Doctor

We know nothing for certain about Luke's background or his medical training. He was called "the beloved physician" by Paul (Colossians 4:14), and undoubtedly one reason for his ongoing association with Paul was the latter's need for frequent medical care.

Paul spoke of his "thorn in the flesh," (II Corinthians 12:7), for example, and his "infirmities" (II Corinthians 12:9). We don't know what these were, although they affected him "in the flesh," and thus presumably needed a doctor's care from time to time. Paul had also suffered much actual physical persecution during his
ministry (see II Corinthians 11:23-27), and undoubtedly needed Luke's medical help on many occasions. We can assume that Dr. Luke could have built up a comfortable practice in such a city as Antioch (where he probably met Paul), but he chose instead to serve the Lord in this sacrificial and much-needed capacity of helping Paul. As a scientist, it is interesting to me that the only one of Paul's followers who stayed with him to the end was also a scientist (II Timothy 3:11).

Blood Clots and a Surprising Find

'SURPRISING FIND WITH BLOOD PLATELETS OPENS AVENUES FOR DEVELOPING ANTI-CLOT DRUGS' shows how an unexpected discovery can lead to the search for drugs that could remedy a serious medical problem.

An important finding related to blood clotting, alluded to in the linked article, may lead to the development of medications that prevent damaging blood clots and the strokes and heart attacks they can induce. This possibility results from knowledge acquired about the synthesis of tissue factor by human blood platelets as well as the regulatory activity of an enzyme known as Clk1. Tissue factor is essential to blood clotting so any drugs that disrupt its synthesis have potential medical benefits.

The Clk1 enzyme uses a splicing process to regulate tissue factor. Biochemical reactions involving the enzyme are referred to as the Clk1 pathway. Splicing involves this pathway and the transformation of pre-messenger RNA to its mature form. As the article states: "mature RNA is subsequently used to make biologically functional tissue factor protein that forms clots."

What goes wrong when blood clots form at the wrong times and in the wrong places? Clk1 is a prime suspect. If pre-messenger RNA is spliced at the wrong time the resultant synthesis of tissue factor can cause clots. If the clot has already formed it can be too late to reverse its effects but a drug that targets the Clk1 pathway offers the possibility of preventing harmful clots.

Scientific News

Here are some news items related to recent events in the world of science. Scientific advances tend to spillover into the medical world.

Team Detects 'Top Quark,' a Basic Constituent of Matter reports a finding of the top quark; the heaviest known elementary particle. The top quark is one of nature's fundamental building blocks but does not occur naturally. Instead it must be generated in a high energy particle accelerator. A group of 50 physicists led by Ann Heinson produced the top quark without also producing its antimatter counterpart. This was described as an extremely rare event. As the article explains: "The discovery of the single top quark could help scientists better explain how the universe works and how objects acquire their mass, thereby assisting human understanding of the fundamental nature of the universe."


Climate experts search for answers in the oceans refers to projects intended to gather data related to sea-surface temperatures and global ocean color in order to better understand their influence on climatic changes. The article explains the profound impact oceans have on climate by virtue of the fact that they absorb half the carbon dioxide emitted into the atmosphere. The absorption results from photosynthesis occuring in organisms known as phytoplankton which are described as sensitve to environmental changes.


The beauty of a rainbow can be more clinically viewed as evidence for the composite nature of electromagnetic waves. X-Ray Rainbow reveals how, like visible light, x-rays can yield rainbows of their own. This is apparent thanks to the efforts of physicists using the Advanced Photon Source at Argonne National Lab, in Illinois. While intrinsically interesting the x-ray rainbow also is expected to produce practical benefits in optics. Higher-resolution X-ray spectrometers, development of X-ray monochomators capable of producing X-rays of particular wavelegths or color and X-ray pulse compression are anticipated benefits.


Some like it hot as, Microbe fixes nitrogen at a blistering 92 C, reveals. The heat lover is an archaea organism able to fix nitrogen i.e. process nitrogen gas, which is unusable to life in its atmospheric form. Usable nitrogen compounds are obtained through a process involving a specific enzyme and its encoding gene.

Nitrogen is an element common to life forms. Indeed life as we know it would not exist without nitrogen compounds. Interestingly nitrogen is a key component of both enzymes and nucleic acids; both of which are essential to fix nitrogen. The article emphasizes the evolutionary significance of the nitrogen fixation function in high-temperature archaea by speculating that the capacity, which is also found in bacteria, was initially acquired by bacteria from archaea through common descent. This is an attempt at an answer that raises additional questions specifically, how would functions, involved in generating amino acids and nucleic acids, evolve prior to the point in time that a nitrogen fixation capacity existed?