重组pEGFP-N1-IGF-1体内转基因预处理对脊髓损伤后一氧化氮合酶活性的影响

目的:观察阳离子脂质体介导的重组pEGFP-N1-IGF-1体内转基因预处理对脊髓损伤后血清一氧化氮合酶及脊髓组织诱导型一氧化氮合酶影响,进一步探讨转基因治疗脊髓损伤的机制。方法:实验于2005-07/11在解放军第二军医大学动物实验中心完成。取54只雄性SD大鼠单纯随机分为3组:①生理盐水组(24只):采用脊髓内直接注射法,将2μL生理盐水 6μLTransfectamreagent共8μL注入T8～T10脊髓内,无下肢功能障碍者1周后按改良Nystr"m’s压迫法制作大鼠脊髓不完全损伤模型(压迫总质量35g,压迫时间5min)。②pEGFP-N1-IGF-1转基因组(24只):给药方法、部位、剂量以及造模方法与生理盐水组相同,但脊髓内注入6μLTransfectamreagent 2μg质粒pEGFP-N1-IGF-1。③正常组(6只):不损伤脊髓,不给药,作为正常对照。前2组损伤后1,4,8,24h、1,2周,取尾静脉血和损伤区域脊髓,测定血清一氧化氮合酶活性及局部脊髓组织诱导型一氧化氮合酶活性变化。结果:经补充后54只大鼠进入结果分析。①血清一氧化氮合酶活性:正常组为(305.4±52.0)μkat/L,其他2组在损伤后1～8h迅速升高,并于伤后24h达到高峰[pEGFP-N1-IGF-1转基因组:(522.6±60.3)μkat/L;生理盐水组:(757.0±83.7)μkat/L],其后逐渐降低,术后一两周仍维持在较高水平。pEGFP-N1-IGF-1转基因组各个时间点均低于生理盐水组(P<0.05,0.01)。②脊髓组织诱导型一氧化氮合酶活性:正常组为(72.5±17.3)μkat/g,其他2组在损伤后1～8h迅速升高,并于伤后24h达到高峰[pEGFP-N1-IGF-1转基因组:(140.2±24.2)μkat/g;生理盐水组:(207.2±36.8)μkat/g],其后逐渐降低,术后一两周仍维持在较高水平。pEGFP-N1-IGF-1转基因组各个时间点均低于生理盐水组(P<0.05,0.01)。结论:阳离子脂质体介导胰岛素样生长因子1基因转染预处理能够有效地下调大鼠一氧化氮合酶活性,特别是其可有效抑制诱导型一氧化氮合酶,从而减轻继发性损伤所致的神经组织的损害,侧面证明了胰岛素样生长因子1转基因治疗的可行性。     

Tenofovir induced acute kidney injury in a patient with unilateral renal agenesis despite initially non-impaired renal function

Nephrotoxicity is observed in 1.6 % of patients treated with tenofovir disoproxil fumarat (Fux 2007).     

Endosomal proteolysis regulates calcitonin gene-related peptide responses in mesenteric arteries

Background and Purpose

Calcitonin gene-related peptide (CGRP) is a potent vasodilator, implicated in the pathogenesis of migraine. CGRP activates a receptor complex comprising, calcitonin receptor-like receptor (CLR) and receptor activity-modifying protein 1 (RAMP1). In vitro studies indicate recycling of CLR•RAMP1 is regulated by degradation of CGRP in early endosomes by endothelin-converting enzyme-1 (ECE-1). However, it is not known if ECE-1 regulates the resensitization of CGRP-induced responses in functional arterial tissue.

Experimental Approach

CLR, ECE-1a-d and RAMP1 expression in rat mesenteric artery smooth muscle cells (RMA-SMCs) and mesenteric arteries was analysed by RT-PCR and by immunofluorescence and confocal microscopy. CGRP-induced signalling in cells was examined by measuring cAMP production and ERK activation. CGRP-induced relaxation of arteries was measured by isometric wire myography. ECE-1 was inhibited using the specific inhibitor, SM-19712.

Key Results

RMA-SMCs and arteries contained mRNA for CLR, ECE-1a-d and RAMP1. ECE-1 was present in early endosomes of RMA-SMCs and in the smooth muscle layer of arteries. CGRP induced endothelium-independent relaxation of arteries. ECE-1 inhibition had no effect on initial CGRP-induced responses but reduced cAMP generation in RMA-SMCs and vasodilation in mesenteric arteries responses to subsequent CGRP challenges.

Conclusions And Implications

ECE-1 regulated the resensitization of responses to CGRP in RMA-SMCs and mesenteric arteries. CGRP-induced relaxation did not involve endothelium-derived pathways. This is the first report of ECE-1 regulating CGRP responses in SMCs and arteries. ECE-1 inhibitors may attenuate an important vasodilatory pathway, implicated in primary headaches and may represent a new therapeutic approach for the treatment of migraine.     

hCG和LHRH-A对人早孕和孕终末期胎盘绒毛分泌孕酮作用的体外研究

在妊娠的不同时期,胎盘中黄体生成素释放激素(LHRH)的含量不同。离体培养的绒毛组织实验也发现,相同剂量的外源性LHRH对妊娠中期和终末期胎盘绒毛组织分泌hCG和孕酮作用强度也不同。本实验室曾发现,LHRH类似物(LHRH-A)对体外培养孕早期(10～12周)和孕终末期(38～40周)绒毛组织分泌hCG均有兴奋作用,但对分泌孕酮的作用不同,即LHRH-A对早孕绒毛分泌孕酮有抑制作用,而对终末期分泌孕酮     

Bilateral activation of fronto-parietal networks by incrementing demand in a working memory task

Working memory (WM) is known to activate the prefrontal cortex. In the present study we hypothesized that when additional contingencies are added to the instruction of a WM task, this would increase the WM load and result in the activation of additional prefrontal areas. With positron emission tomography we measured regional cerebral blood flow in nine subjects performing a control task and two delayed matching to sample tasks, in which the subjects were matching colours and patterns to a reference picture. The second of the two delayed matching tasks had a more complex instruction than the first, with additional contingencies of how to alternate between the matching of colours and patterns. This task thus required the subjects not only to remember a stimulus to match but also to perform this matching according to a specified plan. Both delayed matching tasks activated cortical fields in the middle frontal gyrus, the frontal operculum, upper cingulate gyrus, inferior parietal cortex and cortex lining the intraparietal sulcus, all in the left hemisphere. When alternated delayed matching was compared to simple delayed matching, increases were located in the right superior and middle frontal gyrus and the right anterior inferior parietal cortex. The increased demand during alternated matching thus resulted in bilateral activation of both dorsolateral prefrontal and inferior parietal cortex. The area in the inferior parietal cortex has previously been coactivated with the dorsolateral prefrontal cortex in several WM tasks, irrespective of the sensory modality of the stimuli, and during tasks involving planning.      

Oral Langerhans cell histiocytosis in Malaysian children: a 40-year experience

Background.  Oral Langerhans cell histiocytosis is generally seen in children.
Objective.  To determine the clinicopathological features of oral LCH in Malaysian paediatric patients.
Methods.  A retrospective study was carried out to determine the clinicopathological features of Langerhans cell histiocytosis (LCH), Letterer–Siwe disease, Hand–Schuller–Christian disease, eosinophilic granuloma, and histiocytosis X occurring in the oral cavity in children, diagnosed histologically in the main oral histopathology laboratory in Malaysia from 1967 to 2007.
Result.  There were 17 cases (eight girls and nine boys) with age ranging from 1 to 7 years. There were ten Malays, four Chinese, two Indians, and one of other ethnicity. Thirteen cases presented as gingival swellings with six of these cases accompanied with mobility of the teeth. Nine cases involved the mandible, two in the maxilla, and two cases in both the maxilla and mandible. The radiographic findings were mentioned only in nine cases with presence of bony erosion or destruction of the jaw bones. Four cases had punched-out radiolucencies of the skull. The patients also had other systemic signs and symptoms: skin lesions ( n  = 5), hepatosplenomegaly ( n  = 2), prolonged fever ( n  = 2), diabetes insipidus ( n  = 1), and exophthalmos ( n  = 1). Two cases were known cases of systemic LCH.
Conclusion.  The histopathologic features of LCH are easily recognized; however, with the development of immunostaining, the use of CD1a helps in confirming the diagnosis.