Segment 1 Opening credits. Dr Pegg explains that cryobiology is the study of the effects of cold in biology and that he will deal with the applications of cryobiology in transplantation in this lecture. First, he discusses fundamental research in cryobiology to explain the mechanisms of freezing injury and how cryoprotective agents work. A graph is seen, showing the effect of falling temperature on oxygen consumption. He explains what happens when cells are frozen, and uses the example of sodium chloride solution. Graphs are seen, showing the results of freezing, and Pegg explains the charts. Time start: 00:00:00:00 Time end: 00:04:29:12 Length: 00:04:29:12
Segment 2 Simple drawings show what happens to sodium chloride solution when it freezes. A graph shows the mass of cell water in red cells suspended in sodium chloride solutions of increasing strength. Pegg explains how shrinkage affects cells. A series of graphs shows what happens to cell potassium in red cells suspended in sodium chloride solutions of increasing strength. He discusses salt concentration increase during freezing and says there are additional factors contributing to freezing injury. One relates to the thawing of frozen cells and the other is re-dilution and temperature change. Pegg discusses Dr James Lovelock's research into the second factor. A series of graphs show the results of his experiments. Time start: 00:04:29:12 Time end: 00:10:23:20 Length: 00:05:54:08
Segment 3 Pegg discusses whether cooling rate has an effect on cell survival. A series of graphs show the survival of human red blood cells after cooling. Pegg discusses the data and what research has been done in this area. Different cell types have different survival rates, which is shown on a graph. Two electron micrographs of cooled cells are seen, one cooled rapidly and one slowly. Pegg explains the differences. Time start: 00:10:23:20 Time end: 00:15:28:00 Length: 00:05:04:05
Segment 4 Pegg explains the use of glycerol to protect against freezing injury, glycerol being a cryoprotective agent. A graph of the freezing point of glycerol solutions is seen, and he explains the difference between glycerol and sodium chloride. He then discusses freezing a solution of glycerol, water and sodium chloride, the results of which are seen in a graph. Time start: 00:15:28:00 Time end: 00:19:38:03 Length: 00:04:10:03
Segment 5 Footage of red blood cells on a freezing microscope operation is shown. The cells are shown both with and without glycerol. Pegg narrates over the film, explaining what is happening to the cells. Next, Pegg discusses another class of cryoprotective agent - polymers such as polyvinylpyrrolidone and dextran. A graph showing their freezing points is seen. Time start: 00:19:38:03 Time end: 00:24:48:00 Length: 00:05:09:22
Segment 6 Next, Pegg begins to talk about some of the practical applications of cryobiology. He discusses using it in cell and tissue preservation. Pegg is seen at a blood transfusion centre with Dr John Blagdon. Dr Blagdon explains the system in use at the centre and demonstrates how blood is stored and prepared. Time start: 00:24:48:00 Time end: 00:30:39:02 Length: 00:05:51:02
Segment 7 Back in the studio, Pegg says that red cell preservation is the most important use of cryopreservation. He then talks about its use in bone marrow transplantation. A graph shows the survival of haemopoietic cells of a mouse at different cooling rates and in differing concentrations of glycerol. Fresh and frozen cells are then used in irradiated mice, and a graph shows that there is no significant difference between the two groups. Pegg then talks about preservation of skin and cornea using cryopreservation. Time start: 00:30:39:02 Time end: 00:34:38:15 Length: 00:03:59:13
Segment 8 The next section of the lecture deals with organ preservation. Pegg says that the most important organ that is transplanted is the kidney and says it would be an advantage to be able to store kidneys for longer than a few hours. He talks about an experiment he did on dog kidneys to see how long they could be kept. He found that they could be stored for longer if the blood was washed out. The results of this are seen in a graph. He discusses the results of washing the kidneys out with a hyperosmolar solution, which produces better results. He displays the results of using different solutions. Time start: 00:34:38:15 Time end: 00:41:15:18 Length: 00:06:37:03
Segment 9 Pegg shows the actual composition of solution used to wash a kidney out. He then talks about how this research can be applied to human kidney transplants, and how other countries around the world are thinking about it. He talks about the equipment needed to wash the kidney out and store it. Time start: 00:41:15:18 Time end: 00:44:47:20 Length: 00:03:32:02
Segment 10 Pegg is seen at St Bartholomew's Hospital with a Gambro Perfusion Machine and Mr O'Donaghue from the Institute of Urology. Mr O'Donaghue demonstrates how the machine works. Then Pegg talks about how the right perfusate should be used. He says that a true kidney bank is not possible as a machine is needed per kidney, so the use of true cryopreservation techniques for kidney storage is being investigated. Two charts show the effect on vascular resistance and on weight gain of perfusion with glycerol. Time start: 00:44:47:20 Time end: 00:50:55:00 Length: 00:06:07:05
Segment 11 A series of graphs show the vascular resistance of kidneys using different perfusates. Pegg explains that scientists are currently investigating the viability of kidneys, glycerolised and deglycerolised both by an in vitro technique and by transplantation. Time start: 00:50:55:00 Time end: 00:53:49:10 Length: 00:02:55:10
Segment 12 In the final section of the film, Pegg is seen at his lab. He shows the equipment used for experimenting on rabbit kidneys. He fully explains the various pieces of equipment. There is an experiment being conducted at the lab, and Pegg explains that it is designed to determine the optimum rate of addition and rate of removal of glycerol from rabbit kidneys at a constant temperature. He ends the film by saying that this research is being done in order to develop a method of long-term storage of kidneys for transplantation. Time start: 00:53:49:10 Time end: 00:59:06:14 Length: 00:05:17:04