To understand the mechanisms of starfish regeneration, the arms of adult starfish Asterias rollestoni Bell were amputated and their regeneration patterns and cellular mechanisms were studied.It was found that cells in...To understand the mechanisms of starfish regeneration, the arms of adult starfish Asterias rollestoni Bell were amputated and their regeneration patterns and cellular mechanisms were studied.It was found that cells in the outer epidermis and inner parietal peritoneum near the end of the stump began to dedifferentiate 4 d after amputation. The dedifferentiated cells in the outer epidermis proliferated,migrated to the wound site and formed a thickened pre-epidermis which would then re-differentiate gradually into ma-ture epidermis.The new parietal peritoneum formed on the coelomic side of wound might be from the curvely elongated parietal peritoneum, resulting from the dedifferentiated and proliferated cells by extension. Afterwards, the proliferated cells made the outer epidermis and inner parietal peritoneum invaginate into the interior dermis and formed blastema-like structures together with induced dedifferentiated dermal cells. Most interestingly, the arm regeneration in A. rollestoni was achieved synchronously by de novo arm-bud formation and growth, and arm-stump elongation. The crucial aspects of arm-bud formation included cell dedifferentiation, proliferation and migration, while those of arm-stump elongation included cell dedifferentiation, proliferation, invagination, and arm-wall-across blastema-like structure formation. The unique pattern and cellular mechanisms of amputated arm regeneration make it easier to understand the rapid regeneration process of adult starfish. This study may lay solid foundations for the research into mo-lecular mechanisms of echinoderm regeneration.展开更多
Senile Dementia is the illness with a symptom of ongoing cognitive obstacle and loss of memory function. With our population aging, dementia and depression in old age is increasing rapidly. It is estimated that by 202...Senile Dementia is the illness with a symptom of ongoing cognitive obstacle and loss of memory function. With our population aging, dementia and depression in old age is increasing rapidly. It is estimated that by 2020, depressive disorder will become the second largest human disease leading to crippling. By 2040, globally the number of people with dementia will reach 81.1 million while the number of dementia patients in China will be the sum of that in all developed countries. Its incidence increases exponentially with age and the incidence of the elderly over 85 reach up to 8% -10%. Among all dementia patients, people with Alzheimer＇ s disease （Alzheimer＇ s disease, AD） accounted for 50 % -70%, the rest is vascular dementia （vascular dementia, VD） and mixed dementia. In the United States, Alzheimer＇ s disease has become the fourth leading cause of death followed after cardiovascular disease, cancer and stroke. Through comprehensive control strategy, we can improve the mental health level of old people, so as to protect the physical and mental health, improving the life quality of old people.展开更多
基金supported by the funds for Natural Science Research from the Bureau of Science and Technology of Qingdao(04-2-JZ-8)
文摘To understand the mechanisms of starfish regeneration, the arms of adult starfish Asterias rollestoni Bell were amputated and their regeneration patterns and cellular mechanisms were studied.It was found that cells in the outer epidermis and inner parietal peritoneum near the end of the stump began to dedifferentiate 4 d after amputation. The dedifferentiated cells in the outer epidermis proliferated,migrated to the wound site and formed a thickened pre-epidermis which would then re-differentiate gradually into ma-ture epidermis.The new parietal peritoneum formed on the coelomic side of wound might be from the curvely elongated parietal peritoneum, resulting from the dedifferentiated and proliferated cells by extension. Afterwards, the proliferated cells made the outer epidermis and inner parietal peritoneum invaginate into the interior dermis and formed blastema-like structures together with induced dedifferentiated dermal cells. Most interestingly, the arm regeneration in A. rollestoni was achieved synchronously by de novo arm-bud formation and growth, and arm-stump elongation. The crucial aspects of arm-bud formation included cell dedifferentiation, proliferation and migration, while those of arm-stump elongation included cell dedifferentiation, proliferation, invagination, and arm-wall-across blastema-like structure formation. The unique pattern and cellular mechanisms of amputated arm regeneration make it easier to understand the rapid regeneration process of adult starfish. This study may lay solid foundations for the research into mo-lecular mechanisms of echinoderm regeneration.
文摘Senile Dementia is the illness with a symptom of ongoing cognitive obstacle and loss of memory function. With our population aging, dementia and depression in old age is increasing rapidly. It is estimated that by 2020, depressive disorder will become the second largest human disease leading to crippling. By 2040, globally the number of people with dementia will reach 81.1 million while the number of dementia patients in China will be the sum of that in all developed countries. Its incidence increases exponentially with age and the incidence of the elderly over 85 reach up to 8% -10%. Among all dementia patients, people with Alzheimer＇ s disease （Alzheimer＇ s disease, AD） accounted for 50 % -70%, the rest is vascular dementia （vascular dementia, VD） and mixed dementia. In the United States, Alzheimer＇ s disease has become the fourth leading cause of death followed after cardiovascular disease, cancer and stroke. Through comprehensive control strategy, we can improve the mental health level of old people, so as to protect the physical and mental health, improving the life quality of old people.
