Kasla External Factor

Castle Extrinsic factor is a term used in the field of hematology and physiology to describe the influence of external factors on the human body. It was proposed by American hematologist William Kasla in the 1920s.

Kasla developed the concept of extrinsic factor to explain how extrinsic factors can influence the human immune system. He believed that the immune system could respond to various external stimuli, such as infection, injury, or stress, and that these responses could be enhanced or weakened by external factors.

One example of an external factor is the food we eat. Some foods may contain substances that can enhance or weaken the body's immune response. For example, some vegetables and fruits contain antioxidants, which can help protect the body from free radicals, and some foods, such as red meat, can be high in fat and protein, which can increase blood cholesterol and increase the risk of heart disease.

Another example of an external factor is the environment in which we live. Various factors such as air, water or soil pollution can affect our body and cause various diseases. For example, air pollution can lead to the development of asthma or other respiratory diseases, and water pollution can cause digestive problems or even cancer.

Thus, extrinsic factor is an important concept in the field of hematology and physiology that helps explain how various extrinsic factors can affect the human body and its immune system.



William Walter Castle was an American physiologist who headed the department of biochemistry at Columbia University until his resignation in 1934. He is recognized for his research and discoveries in the field of enzymology, and his work continues to influence research in medicinal biochemistry.

Kasla, who received his PhD from Princeton University, is known for his research on enzyme activity, particularly as an alpha-amylase catalyst, and as the founder of the concept of extrinsic factors, as well as basic research into the physiological relationships between proteolysis and lecithinase action. As a result of these studies, Castle, together with his colleague Divoyce Solly, rediscovered pancreatic amidase, an enzyme present in pancreatic tissue and necessary for the conversion of inactive pancreatic trypsin into active peptidase, i.e., an important protein of the pancreatic duct.