The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major componen...The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major component of the renin-angiotensin system (RAS). It mediates the classical biological actions of Ang II. Among the structures required for regulation and activation of the receptor, its carboxyl- terminal region plays crucial roles in receptor internalization, desensitization and phosphorylation. The mechanisms involved in heterotrimeric G-protein coupling to the receptor, activation of the downstream signaling pathway by G proteins and the Ang II signal transduction pathways leading to specific cellular responses are discussed. In addition, recent work on the identification and characterization of novel proteins associated with carboxy1-terminus of the AT1 receptor is presented. These novel proteins will advance our understanding of how the receptor is internalized and recycled as they provide molecular mechanisms for the activation and regulation of G-protein-coupled receptors.展开更多
AIM： To evaluate a series of patients with hepatocellular carcinoma （HCC） treated with several different protocols and devices. METHODS： We treated 138 patients [chronic hepatitis/ liver cirrhosis （Child-Pugh A/...AIM： To evaluate a series of patients with hepatocellular carcinoma （HCC） treated with several different protocols and devices. METHODS： We treated 138 patients [chronic hepatitis/ liver cirrhosis （Child-Pugh A/B/C）, 3/135 （107/25/3）] with two different devices and protocols： cool-tip needle [initial ablation at 60 W （standard method） （n = 37） or at 40 W （modified method） （n = 28）] or; ablation with a LeVeen needle using a standard single-step, full expansion （single-step） method （n = 39） or a multi-step, incremental expansion （multi-step） method. RESULTS： Eleven patients experienced rapid and scattered recurrences 1 to 7 mo after the ablation. Nine patients were treated by the cool-tip original protocol （60 W） （9/37 = 24%） and the other two by the LeVeen single-step method （2/39 = 5%）. The location of the recurrence was surrounding and limited to the site of ablation segment in three cases, and spread over one Iobule or both Iobules in the other eight cases. There was no recurrence in the patients treated with the modified cool-tip modified method （40 W） or the LeVeen multi-step method. CONCLUSION： There is a risk of rapid and scattered recurrence after RFA, especially when the standard cool- tip procedure is used. Because such recurrence would worsen the prognosis, we recommend that modified protocols for the cool-tip and LeVeen needle methods should be used in clinical practice.展开更多
Traumatic brain injury （TBI） is a major cause of mortality and morbidity in the world. Recent clinical investigations and basic researches suggest that strategies to improve angiogenesis following TBI may provide pr...Traumatic brain injury （TBI） is a major cause of mortality and morbidity in the world. Recent clinical investigations and basic researches suggest that strategies to improve angiogenesis following TBI may provide promising opportunities to improve clinical outcomes and brain functional recovery. More and more evidences show that circulating endothelial progenitor cells （EPCs）, which have been identified in the peripheral blood, may play an important role in the pathologic and physiological anglo-genesis in adults. Moreover, impressive data demonstrate that EPCs are mobilized from bone marrow to blood circula- tion in response to traumatic or inflammatory stimulations. In this review, we discussed the role of EPCs in the repair of brain injury and the possible therapeutic implication for func- tional recovery of TBI in the future.展开更多
文摘The mechanisms of regulation, activation and signal transduction of the angiotensin II (Ang II) type 1 (AT1) receptor have been studied extensively in the decade after its cloning. The AT1 receptor is a major component of the renin-angiotensin system (RAS). It mediates the classical biological actions of Ang II. Among the structures required for regulation and activation of the receptor, its carboxyl- terminal region plays crucial roles in receptor internalization, desensitization and phosphorylation. The mechanisms involved in heterotrimeric G-protein coupling to the receptor, activation of the downstream signaling pathway by G proteins and the Ang II signal transduction pathways leading to specific cellular responses are discussed. In addition, recent work on the identification and characterization of novel proteins associated with carboxy1-terminus of the AT1 receptor is presented. These novel proteins will advance our understanding of how the receptor is internalized and recycled as they provide molecular mechanisms for the activation and regulation of G-protein-coupled receptors.
文摘AIM： To evaluate a series of patients with hepatocellular carcinoma （HCC） treated with several different protocols and devices. METHODS： We treated 138 patients [chronic hepatitis/ liver cirrhosis （Child-Pugh A/B/C）, 3/135 （107/25/3）] with two different devices and protocols： cool-tip needle [initial ablation at 60 W （standard method） （n = 37） or at 40 W （modified method） （n = 28）] or; ablation with a LeVeen needle using a standard single-step, full expansion （single-step） method （n = 39） or a multi-step, incremental expansion （multi-step） method. RESULTS： Eleven patients experienced rapid and scattered recurrences 1 to 7 mo after the ablation. Nine patients were treated by the cool-tip original protocol （60 W） （9/37 = 24%） and the other two by the LeVeen single-step method （2/39 = 5%）. The location of the recurrence was surrounding and limited to the site of ablation segment in three cases, and spread over one Iobule or both Iobules in the other eight cases. There was no recurrence in the patients treated with the modified cool-tip modified method （40 W） or the LeVeen multi-step method. CONCLUSION： There is a risk of rapid and scattered recurrence after RFA, especially when the standard cool- tip procedure is used. Because such recurrence would worsen the prognosis, we recommend that modified protocols for the cool-tip and LeVeen needle methods should be used in clinical practice.
基金This work was partially supported by grants from the National Natural Science Foundation of China （No. 30772229） and the Research Fund for the Doctoral Program of Higher Education in China （No. 20070062008）.
文摘Traumatic brain injury （TBI） is a major cause of mortality and morbidity in the world. Recent clinical investigations and basic researches suggest that strategies to improve angiogenesis following TBI may provide promising opportunities to improve clinical outcomes and brain functional recovery. More and more evidences show that circulating endothelial progenitor cells （EPCs）, which have been identified in the peripheral blood, may play an important role in the pathologic and physiological anglo-genesis in adults. Moreover, impressive data demonstrate that EPCs are mobilized from bone marrow to blood circula- tion in response to traumatic or inflammatory stimulations. In this review, we discussed the role of EPCs in the repair of brain injury and the possible therapeutic implication for func- tional recovery of TBI in the future.
