Expression of HIF-1alpha, VEGF and VEGF receptors in the carotid body of chronically hypoxic rat

We examined the protein expression and localization of HIF-1alpha, VEGF, VEGF receptors in the carotid body (CB) of rats breathing 10% inspired oxygen for up to 4 weeks. The immunoreactivity (IR) of HIF-1alpha was distributed numerously in the nuclei of glomus (type-I) and other cells since hypoxia for 1 day, but was faint and scattered in the normoxic CBs. Cytoplasmic staining of the VEGF was intense in glomus cells of the hypoxic but not the normoxic group. The IR levels of HIF-1alpha and VEGF reached plateau at 4 weeks, and the IRs of VEGFR-1 and VEGFR-2 were strongly positive in the hypoxic group. Yet, the expression of VEGFR-1-IR was mild, whereas the VEGFR-2-IR was intense in normoxic CBs, suggesting an upregulation of VEGFR-1 but not VEGFR-2 in hypoxia. Hence, HIF-1 may activate the expression of VEGF and VEGFR-1 in the CB and the expression of VEGF in the chemoreceptors may play a paracrine role in the vascular remodeling during chronic hypoxia.     

Techniques for rapid quantitative assessment of activity levels in small-group tutorials

Two techniques for the rapid quantitative analysis of student participation in small-group teaching were investigated. In the first approach an observer, who also acted as a `critical friend', recorded the length of individual contributions using a computer keyboard as a simple timing device. In the second approach, small-group sessions were recorded with a portable stereophonic audiotape recorder. The teacher was recorded on one channel, all students on the other. A computer program produced automated analysis of these small group interactions by computing relative amount of speech on each channel. Simple analysis produced automatically by the programs revealed the overall style of the tutorial – variably `mini-lectures' by teachers with very little participation by the student body, rapid `question and answer' sessions with about equal teacher/student body involvement or `mini-presentations' by students with the teacher offering sparse comments in the manner of a facilitator. By presenting results in a graphic format, teachers can be given rapid objective feedback on their teaching style. Coupled with short verbal/non-verbal quizzes at the end of tutorials and information from other assessments, the value of using levels of participation as a measure of the efficiency of such small-group sessions can itself be assessed.     

血清对神经嵴细胞向神经胶质细胞分化诱导的体外研究

目的：探讨神经嵴细胞在含血清培养基中向神经细胞的自发分化过程，方法：取妊娠第8．5天的BALB／c胎鼠的神经嵴细胞，分别在无血清和含血清培养基中培养，免疫组化和透射电镜鉴定和观察神经嵴细胞的分化情况.结果：在无血清的培养基中，NSE染色结果阳性，透射电镜下未见神经内分泌颗粒，神经嵴细胞保持其原有的特性，在有血清的培养基中，神经嵴细胞自发分化，胶质纤维酸性蛋白（GFAP），神经特性烯醇化酶（NSE）和S－100染色阳性，透射电镜下可见大量的神经内分泌颗粒。结论：血清可使神经嵴细胞自发的向神经胶质细胞分化。     

Combined acoustic radiation force impulse,aminotransferase to platelet ratio index and Forns index assessment for hepatic fibrosis grading in hepatitis B

AIM: To investigate the combined diagnostic accuracy of acoustic radiation force impulse(ARFI), aspartate aminotransferase to platelet ratio index(APRI) and Forns index for a non-invasive assessment of liver fibrosis in patients with chronic hepatitis B(CHB). METHODS: In this prospective study, 206 patients had CHB with liver fibrosis stages F0-F4 classified by METAVIR and 40 were healthy volunteers were measured by ARFI, APRI and Forns index separately or combined as indicated. RESULTS: ARFI, APRI or Forns index demonstrated a significant correlation with the histological stage(all P 0.001). According to the AUROC of ARFI and APRI for evaluating fibrotic stages more than F2, ARFI showed an enhanced diagnostic accuracy than APRI(P 0.05). The combined measurement of ARFI and APRI exhibited better accuracy than ARFI alone when evaluating ≥ F2 fibrotic stage(Z = 2.77, P = 0.006). Combination of ARFI, APRI and Forns index did not obviously improve the diagnostic accuracy compared to the combination of ARFI and APRI(Z = 0.958, P = 0.338). CONCLUSION: ARFI + APRI showed enhanced diagnostic accuracy than ARFI or APRI alone for significant liver fibrosis and ARFI + APRI + Forns index shows the same effect with ARFI + APRI.     

Up-regulation of circulating adhesion molecules in bronchiectasis.

Adhesion molecules are expressed on the surface of endothelial cells and leukocytes and are responsible for mediating the migration of intravascular leukocytes into inflamed tissue. Intensive recruitment of neutrophils into the airways occurs in bronchiectasis, although little is known about the role of adhesion molecules in this process. The authors, therefore, determined serum levels of E-selectin, intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 in stable bronchiectasis patients (n=37) and healthy control subjects (n=17), and evaluated their relationship with clinical markers of disease severity in bronchiectasis. Serum levels of E-selectin, ICAM-1 and VCAM-1 in bronchiectasis patients were significantly higher than those in control subjects (p=0.02, <0.0001 and 0.0002 respectively). Both E-selectin and ICAM-1 levels were inversely related to forced expiratory volume in one second (FEV1)% predicted (r=-0.57, p<0.001; and r=-0.53, p=0.001 respectively), and FVC% predicted (r=-0.52, p=0.002; and r=-0.46, p=0.005). This was not the case for VCAM-1 levels. There was a correlation between serum ICAM-1 levels and 24 h sputum volume (r=0.34, p= 0.04). Serum E-selectin and ICAM-1, but not VCAM-1, levels showed correlation with the number of lung lobes affected by bronchiectasis (r=0.35, p=0.04 and r=0.34, p=0.04 respectively). These original observations strongly suggest that E-selectin, intercellular adhesion molecule-1 and Vascular adhesion molecule-1 could play a significant role in the pathogenesis of bronchiectasis.     

CNTFR在面神经再生的表达变化及TGF-β、BMP-2的调控

目的 :　探讨睫状神经营养因子受体CNTFR在面神经切断后的蛋白表达及转化生长因子 (TGF - β)及重组骨形成蛋白 - 2 (rhBMP - 2 )对其的表达影响。方法 :将面神经切断后分别注入TGF - β、rhBMP - 2及生理盐水。取不同时期的面神经核组织切片标本 ,采用免疫组化染色和计算机图像分析仪对不同时期中面神经核CNTFR的表达进行定量分析。结果 :面神经切断后 ,CNTFR在术后一天开始表达 ,一周后面神经元中CNTFR的含量达到最大。术后二周出现下调。术后一个月又有所提高 ,从而出现第二个高峰。此后逐渐下降。TGF - β处理组在面神经损伤后期CNTFR的表达高于生理盐水组。结论 :面神经运动神经元损伤及再生过程中 ,内源性CNTFR的表达提高使神经元损伤后增加CNTF的摄入 ,减少了面神经元的死亡 ,为神经元的恢复及神经轴突的延伸具有促进作用。而TGF - β对CNTFR的表达具有一定的促进作用。对面神经核运动神经元起着间接的营养作用     

Melatonin ameliorates endothelial dysfunction,vascular inflammation,and systemic hypertension in rats with chronic intermittent hypoxia

The pathogenesis of hypertension in patients with obstructive sleep apnea (OSA) is associated with endothelial dysfunction induced by chronic intermittent hypoxia (IH). Studies have shown that administration of melatonin ameliorates oxidative injury and inflammation. This study examined the effect of melatonin on the oxidative stress, endothelial dysfunction, and inflammation during the pathogenesis of hypertension in chronic IH. Adult Sprague‐Dawley rats that had received a daily injection of melatonin or vehicle were exposed to IH treatment mimicking a severe OSA condition for 14–21 days. Systolic pressure was significantly higher in the vehicle‐treated (144 ± 2.7 mmHg) but not in the melatonin‐treated rats (123 ± 5.1 mmHg) by 21–day IH treatment when compared with the normoxic control. Levels of malondialdehyde and the expressions of NADPH oxidase, pro‐inflammatory mediators (TNF‐α, inducible NO synthase, COX‐2), and adhesion molecules (ICAM‐1, VCAM‐1, and E‐selectin) of the thoracic aorta were markedly increased by 14‐day IH treatment preceding the hypertensive response. Also, levels of nitric oxide (NO˙), endothelial‐dependent relaxation, and the expressions of endothelial NO synthase (eNOS) and antioxidant enzymes (GPx, CAT, and Cu/Zn SOD) were significantly lowered in the IH rats. Melatonin treatment significantly mitigated the increased expression of NADPH oxidase, pro‐inflammatory mediators, and adhesion molecules. Moreover, melatonin prevented the endothelial dysfunction with ameliorated levels of NO˙, endothelial‐dependent relaxation, and expressions of eNOS and antioxidant enzymes. These results suggest that melatonin is protective against IH‐induced hypertension and endothelial dysfunction via an antioxidant and anti‐inflammatory mechanism.     

睫状神经营养因子在面神经再生中的表达变化及TGF-β、rhBMP-2的调控

目的　探讨睫状神经营养因子(CNTF)在面神经切断后的免疫定位及转化生长因子β(TGF-β)及人重组骨形成蛋白2(rhBMP-2)对其的调控作用。方法　选取面神经切断后不同时期的面神经核组织切片,通过免疫组化染色和图像分析对比不同时期面神经核中CNTF的浓度变化。结果　面神经切断后,术后1 d CNTF就开始表达并逐渐增加,分别于术后1周和1月面神经核运动元中CNTF的含量达到最大。此后逐渐下降。rhBMP-2对CNTF的表达无明显作用,而TGF-β能促进神经再生过程中CNTF的表达。结论　内源性CNTF在神经再生过程中对神经轴突的延伸也具有一定的促进作用。TGF-β可通过促进CNTF的表达而对面神经运动神经元起着重要的保护作用。     

In vitro study of regulation of IL-6 production in bronchiectasis

Persistent airway inflammation is an important pathogenetic factor in bronchiectasis, and interleukin (IL)-6 is among the mediators implicated in regulation of inflammation in bronchiectatic airways. We postulated that airway secretion with its constituents of cytokines and enzymes would provide an environment for perpetuation of inflammation in vivo. We aimed to determine the action of sputum from patients with bronchiectasis on IL-6 production from cultured normal human bronchial epithelial (NHBE) cells and its modulation by anti-inflammatory drugs in vitro. Cultures of NHBE cells were tested with (i) sputum of bronchiectatic patients, (ii) anti-tumor necrosis factor-alpha (TNF-alpha) pre-treated sputum, or (iii) recombinant human (rh)-TNF-alpha. Alternatively, NHBE cells were incubated with one of the anti-inflammatory drugs before treatment with sputum or rh-TNF-alpha. IL-6 produced into the medium was assayed by ELISA. Sputum in bronchiectasis stimulated IL-6 production from NHBE cells by 1.9 times. This was largely attributable to TNF-alpha as pre-incubation of sputum sol with anti-TNF-alpha almost neutralized the sputum effect. Apart from dexamethasone, the other drugs exerted inhibitory effects on IL-6 production. Ibuprofen suppressed sputum-stimulated IL-6 production to levels above control and effect levelled off at 50-100 microg/mi, contrasting the dose-dependent suppression to control level with MK-663 (0.1-10 microg/ml) and to sub-control levels with triptolide (20-1000 ng/ml). Our results support that sputum in bronchiectasis can stimulate IL-6 production from NHBE cells, and TNF-alpha is an important cytokine mediating the process. The suppressive effects observed with ibuprofen, triptolide and MK-663 warrant further study.