Regenerative medicine some research has been done in other areas. Any such potential beyond blood and immunological uses is limited by the fact that cord cells are hematopoietic stem cells (which can differentiate only into blood cells), and not pluripotent stem cells (such as embryonic stem cells, which can differentiate into any type of tissue). Cord blood has been studied as a treatment for diabetes. However, apart from blood disorders, the use of cord blood for other diseases is not a routine clinical modality and remains a major challenge for the stem cell community. Along with cord blood, Wharton's jelly and the
Classification of sleep disorders occurred a slow confluence of the three systems of classification. Diagnoses of sleep disorders are based on self-assessment questionnaires, clinical interview, physical examination and laboratory procedures. The validity and reliability of various sleep disorders are yet to be proved and need further research within the ever-changing field of "Sleep Medicine". Admittedly, the development of sleep disorder classification remains as much an art as it is a science. The first book on sleep was published in 1830 by Robert MacNish; it described sleeplessness, nightmares, sleepwalking and sleep-talking. Narcolepsy, hypnogogic hallucination, wakefulness and somnolence were mentioned by other authors of the nineteenth